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Sample records for alveolar ridge augmentation

  1. Alveolar ridge augmentation by osteoinduction in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1990-01-01

    The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were...

  2. Alveolar ridge augmentation by osteoinduction in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1990-01-01

    The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were perf...

  3. Alveolar ridge augmentation by osteoinductive materials in goats

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Roervik, M

    1992-01-01

    The purpose of the present study was to determine whether alveolar ridge augmentation could be induced in goats. In 12 male goats allogenic, demineralized, and lyophilized dentin or bone was implanted subperiosteally on the buccal sides of the natural edentulous regions of the alveolar process...

  4. Alveolar ridge augmentation by osteoinductive materials in goats

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Roervik, M

    1992-01-01

    The purpose of the present study was to determine whether alveolar ridge augmentation could be induced in goats. In 12 male goats allogenic, demineralized, and lyophilized dentin or bone was implanted subperiosteally on the buccal sides of the natural edentulous regions of the alveolar process of...... of the mandible. Light microscopic evaluation revealed fibrous encapsulation, a few multinuclear giant cells, little inflammatory reaction, and no osteoinduction. It was concluded that no osteoinduction took place in goats....

  5. Alveolar ridge augmentation in rats by Bio-Oss

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1991-01-01

    The purpose of the study was to examine if Bio-Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio-Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal...

  6. Alveolar ridge augmentation in rats by Bio-Oss

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1991-01-01

    The purpose of the study was to examine if Bio-Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio-Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal...... muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio-Oss. A foreign body reaction was observed around both forms....

  7. Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation

    DEFF Research Database (Denmark)

    Pinholt, E M; Ruyter, I E; Haanaes, H R

    1992-01-01

    The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material character......The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material...

  8. Titanium implant insertion into dog alveolar ridges augmented by allogenic material

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Donath, K

    1994-01-01

    The purpose of this investigation was to evaluate whether titanium endosseous implants would osseointegrate in dog alveolar ridges augmented by allogenic material. In 8 dogs en bloc resection, including 2 pre-molars, was performed bilaterally in the maxilla and the mandible. After a healing period...

  9. The effect of therapeutic radiation on canine alveolar ridges augmented with hydroxylapatite

    DEFF Research Database (Denmark)

    Pinholt, E M; Kwon, P H

    1992-01-01

    on the alveolar ridge. Following 4 months of healing, 12 dogs (experimental group) underwent therapeutic radiation therapy (Co60, 4,000 rad [40 Gy]) to the head and neck region. Four dogs were not irradiated and served as controls. Four animals (three experimental and one control) were killed at 5,6,7, and 8......The purpose of this investigation was to evaluate the effect of radiation on hydroxylapatite (HA) implanted subperiosteally for alveolar ridge augmentation in dogs. All bicuspids and molars were extracted from 16 dogs. After 6 weeks, nonporous HA granules were implanted subperiosteally...

  10. Titanium implant insertion into dog alveolar ridges augmented by allogenic material

    DEFF Research Database (Denmark)

    Pinholt, E M; Haanaes, H R; Donath, K

    1994-01-01

    The purpose of this investigation was to evaluate whether titanium endosseous implants would osseointegrate in dog alveolar ridges augmented by allogenic material. In 8 dogs en bloc resection, including 2 pre-molars, was performed bilaterally in the maxilla and the mandible. After a healing period...... and only minimal osteoconduction, few multinuclear giant cells and a sparse inflammatory reaction. The titanium implants healed mainly by fibrous encapsulation....

  11. Volumetric Changes in Edentulous Alveolar Ridge Sites Utilizing Guided Bone Regeneration and a Custom Titanium Ridge Augmentation Matrix (CTRAM)

    Science.gov (United States)

    2016-06-01

    resorbable collagen membrane. In this prospective observational study, up to 14 patients treatment planned to receive one or more dental implants will be...referred to Naval Postgraduate Dental School, Department of Periodontics for alveolar ridge augmentation and subsequent implant therapy. 2. A treatment ...placement. 3. Patients for whom CTRAM with GBR is treatment planned will be asked by their provider if they would like to read a one page brief

  12. The effect of therapeutic radiation on canine alveolar ridges augmented with hydroxylapatite

    DEFF Research Database (Denmark)

    Pinholt, E M; Kwon, P H

    1992-01-01

    The purpose of this investigation was to evaluate the effect of radiation on hydroxylapatite (HA) implanted subperiosteally for alveolar ridge augmentation in dogs. All bicuspids and molars were extracted from 16 dogs. After 6 weeks, nonporous HA granules were implanted subperiosteally...... on the alveolar ridge. Following 4 months of healing, 12 dogs (experimental group) underwent therapeutic radiation therapy (Co60, 4,000 rad [40 Gy]) to the head and neck region. Four dogs were not irradiated and served as controls. Four animals (three experimental and one control) were killed at 5,6,7, and 8...... reaction. This reaction decreased significantly as time elapsed after implantation. Osteoclastic activity was seen at the junction of HA and periosteum and as part of bone remodeling. Dissolution of the HA granules and the granulomatous inflammatory reaction were not significantly increased by therapeutic...

  13. Complications related to bone augmentation procedures of localized defects in the alveolar ridge. A retrospective clinical study

    DEFF Research Database (Denmark)

    Jensen, Anders Torp; Jensen, Simon Storgård; Worsaae, Nils

    2016-01-01

    PURPOSE: This retrospective clinical study aims to evaluate complications after augmentation of localized bone defects of the alveolar ridge. METHODS: From standardized registrations, the following complications related to bone augmentation procedures were recorded: soft tissue dehiscence......, infection, sensory disturbance, additional augmentation procedures needed, and early implant failure. RESULTS: A total of 223 patients (132 women, 91 men; mean age 23.5 years; range 17-65 years) with 331 bone defects had bone augmentation performed into which 350 implants were placed. Soft tissue dehiscence.......7 %), four after GBR procedures (1.6 %), and two (12 %) after staged vertical ridge augmentation. CONCLUSIONS: Predictable methods exist to augment localized defects in the alveolar ridge, as documented by low complication rates and high early implant survival rates....

  14. Alveolar Ridge Dimension 6 Months After Implant Placement with Simultaneous Hard Tissue Augmentation.

    Science.gov (United States)

    Heckmann, Siegfried Martin; Mörtlbauer, Barbara; Rieder, Dominik; Wichmann, Manfred; Krafft, Tim; Moralis, Antonios

    When failing front teeth are replaced by implants, vestibular bone deficiencies frequently require augmentation, even though the amount of missing alveolar volume may vary. The objective of this study was to analyze the horizontal alveolar ridge dimension after implant placement and simultaneous augmentation, and to compare it to the condition at the contralateral natural site. Forty-eight patients with a failing maxillary incisor received an immediate or early implant (Straumann Bone Level), according to a randomized study protocol. The vestibular wall of the implant site was reconstructed and moderately overcontoured with bovine hydroxyapatite and a collagen membrane (BioOss, BioGide, Geistlich). Provisional restoration followed either immediately, or after a 6-week healing period. To investigate the vestibular volume 6 months after surgery, a plaster model of the maxilla was scanned with cone beam computed tomography (CBCT; Morita 3D) and evaluated using coDiagnostiX software (Dental Wings). Statistical analysis comprised one- and two-sample t tests. The ridge volume was not significantly influenced by the treatment schedule. The vestibular segments had a mean ± SD volume of 207.9 ± 102.5 mm³ for the implant sites, and 202.1 ± 101.5 mm³ for the corresponding natural sites (P = .28). The difference in vestibular volume between implant sites and natural tooth sites was 10.4 ± 36.2 mm³ for immediate implantation, and 0.00 ± 31.1 mm³ for early implantation (P = .32). Comparing immediate and early restoration, a difference of 0.4 mm³ and 12.5 mm³ between the implant and contralateral site was found (P = .23). Six months after treatment, no significant differences between the alveolar volumes at augmented implant sites and natural sites were found. Moderate buccal overcontouring may have been beneficial to achieve a symmetrical contour. Long-term follow-up investigation will document if the restored volume remains stable over time.

  15. Alveolar ridge augmentation by connective tissue grafting using a pouch method and modified connective tissue technique: A prospective study

    Directory of Open Access Journals (Sweden)

    Ashish Agarwal

    2015-01-01

    Full Text Available Background: Localized alveolar ridge defect may create physiological and pathological problems. Developments in surgical techniques have made it simpler to change the configuration of a ridge to create a more aesthetic and more easily cleansable shape. The purpose of this study was to compare the efficacy of alveolar ridge augmentation using a subepithelial connective tissue graft in pouch and modified connective tissue graft technique. Materials and Methods: In this randomized, double blind, parallel and prospective study, 40 non-smoker individuals with 40 class III alveolar ridge defects in maxillary anterior were randomly divided in two groups. Group I received modified connective tissue graft, while group II were treated with subepithelial connective tissue graft in pouch technique. The defect size was measured in its horizontal and vertical dimension by utilizing a periodontal probe in a stone cast at base line, after 3 months, and 6 months post surgically. Analysis of variance and Bonferroni post-hoc test were used for statistical analysis. A two-tailed P < 0.05 was considered to be statistically significant. Results: Mean values in horizontal width after 6 months were 4.70 ± 0.87 mm, and 4.05 ± 0.89 mm for group I and II, respectively. Regarding vertical heights, obtained mean values were 4.75 ± 0.97 mm and 3.70 ± 0.92 mm for group I and group II, respectively. Conclusion: Within the limitations of this study, connective tissue graft proposed significantly more improvement as compare to connective tissue graft in pouch.

  16. Horizontal alveolar ridge augmentation using autologous press fit bone cylinders and micro-lag-screw fixation: technical note and initial experience.

    Science.gov (United States)

    Streckbein, Philipp; Kähling, Christopher; Wilbrand, Jan-Falco; Malik, Christoph-Yves; Schaaf, Heidrun; Howaldt, Hans-Peter; Streckbein, Roland

    2014-07-01

    The use of autologous block bone grafts for horizontal alveolar ridge augmentation in dental implantology is a common surgical procedure. Typically, bone grafts are individually moulded. The aim of this paper is to introduce an innovative procedure in lateral bone augmentation, where the recipient side is adjusted to the graft, not vice versa as in common procedures. Our initial clinical experience of twenty-five consecutive cases is presented. Adjusted trephine drills were used to harvest partly cylindrical grafts from the retromolar region of the mandible. After preparing the recipient site with accurately fitting grinding drills, the bone grafts were transplanted. The horizontally compromised alveolar ridges were successfully augmented and treated with dental implants. No major complication occurred during transplantation, the healing period, and subsequent implant therapy in our experimental setting with 25 patients and 38 augmentation procedures. One out of twenty-five patients presented with temporary dysaesthesia of the inferior alveolar nerve. The new method presented is an effective treatment option for horizontal alveolar ridge augmentation prior to single implant installation. Further studies should evaluate the donor site morbidity and long-term outcome on a larger population. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  17. Regeneración ósea guiada para el aumento vertical del reborde alveolar Guided osseous regeneration for the vertical augmentation of the alveolar ridge

    Directory of Open Access Journals (Sweden)

    CE Nappe

    2013-04-01

    Full Text Available Se considera como aumento óseo vertical, cualquier técnica que apunte a crear una mayor altura del reborde alveolar. A inicios de la década de los 90’s se empezó a utilizar la regeneración ósea guiada (ROG en mandíbulas atróficas, con el fin de permitir la instalación de implantes óseointegrados. Con el fin de evaluar y exponer parte de la evidencia disponible en la actualidad, con respecto a la ROG para aumento óseo vertical, se realizó la siguiente revisión bibliográfica.Any technique aimed to improve the alveolar ridge height is considered as a vertical bone augmentation procedure. In the early 90’s guided bone regeneration (GBR procedures began to be used in atrophic mandibles to allow the installation of osseointegrated dental implants. The following bibliographic review was made with the purpose of evaluating and exposing part of the available evidence at present in this field.

  18. Clinical outcome of alveolar ridge augmentation with individualized CAD-CAM-produced titanium mesh

    OpenAIRE

    Sagheb, K.; Schiegnitz, E.; Moergel, M.; Walter, C.; Al-Nawas, B.; Wagner, W.

    2017-01-01

    Background The augmentation of the jaw has been and continues to be a sophisticated therapy in implantology. Modern CAD-CAM technologies lead to revival of old and established augmentation techniques such as the use of titanium mesh (TM) for bone augmentation. The aim of this retrospective study was to evaluate the clinical outcome of an individualized CAD-CAM-produced TM based on the CT/DVT-DICOM data of the patients for the first time. Methods In 17 patients, 21 different regions were augme...

  19. Clinical outcome of alveolar ridge augmentation with individualized CAD-CAM-produced titanium mesh.

    Science.gov (United States)

    Sagheb, K; Schiegnitz, E; Moergel, M; Walter, C; Al-Nawas, B; Wagner, W

    2017-12-01

    The augmentation of the jaw has been and continues to be a sophisticated therapy in implantology. Modern CAD-CAM technologies lead to revival of old and established augmentation techniques such as the use of titanium mesh (TM) for bone augmentation. The aim of this retrospective study was to evaluate the clinical outcome of an individualized CAD-CAM-produced TM based on the CT/DVT-DICOM data of the patients for the first time. In 17 patients, 21 different regions were augmented with an individualized CAD-CAM-produced TM (Yxoss CBR®, Filderstadt, Germany). For the augmentation, a mixture of autologous bone and deproteinized bovine bone mineral (DBBM) or autologous bone alone was used. Reentry with explantation of the TM and simultaneous implantation of 44 implants were performed after 6 months. Preoperative and 6-month postoperative cone beam computed tomographies (CBCT) were performed to measure the gained bone height. The success rate for the bone grafting procedure was 100%. Thirty-three percent of cases presented an exposure of the TM during the healing period. However, premature removal of these exposed meshes was not necessary. Exposure rate in augmentations performed with mid-crestal incisions was higher than in augmentations performed with a modified poncho incision (45.5 vs. 20%, p = 0.221). In addition, exposure rates in the maxilla were significantly higher than in the mandible (66.7 vs. 8.3%, p = 0.009). Gender, smoking, periodontal disease, gingiva type, used augmentation material, and used membrane had no significant influence on the exposure rate (p > 0.05). The mean vertical augmentation was 6.5 ± 1.7 mm, and the mean horizontal augmentation was 5.5 ± 1.9 mm. Implant survival rate after a mean follow-up of 12 ± 6 months after reentry was 100%. Within the limits of the retrospective character of this study, this study shows for the first time that individualized CAD-CAM TM provide a sufficient and safe augmentation technique

  20. Ridge Splitting Technique for Horizontal Augmentation and Immediate Implant Placement

    Directory of Open Access Journals (Sweden)

    Papathanasiou Ioannis

    2014-03-01

    Full Text Available Insufficient width of the alveolar ridge often prevents ideal implant placement. Guided bone regeneration, bone grafting, alveolar ridge splitting and combinations of these techniques are used for the lateral augmentation of the alveolar ridge. Ridge splitting is a minimally invasive technique indicated for alveolar ridges with adequate height, which enables immediate implant placement and eliminates morbidity and overall treatment time. The classical approach of the technique involves splitting the alveolar ridge into 2 parts with use of ostetomes and chisels. Modifications of this technique include the use of rotating instrument, screw spreaders, horizontal spreaders and ultrasonic device.

  1. Bone augmentation procedures in localized defects in the alveolar ridge: clinical results with different bone grafts and bone-substitute materials

    DEFF Research Database (Denmark)

    Jensen, Simon Storgård; Terheyden, Hendrik

    2009-01-01

    PURPOSE: The objective of this review was to evaluate the efficacy of different grafting protocols for the augmentation of localized alveolar ridge defects. MATERIALS AND METHODS: A MEDLINE search and an additional hand search of selected journals were performed to identify all levels of clinical...... in the augmented bone. RESULTS AND CONCLUSION: Based on 2,006 abstracts, 424 full-text articles were evaluated, of which 108 were included. Eleven studies were randomized controlled clinical trials. The majority were prospective or retrospective studies including a limited number of patients and short observation...... of evidence (level A to B) to support that survival rates of implants placed in augmented bone are comparable to rates of implants placed in pristine bone....

  2. Ridge split and implant placement in deficient alveolar ridge: Case report and an update

    Directory of Open Access Journals (Sweden)

    Reenesh Mechery

    2015-01-01

    Full Text Available Dr. Hilt Tatum 1970s introduced a method of ridge splitting or bone spreading, which over a period have been used in implant dentistry for esthetic rehabilitation and implant site preparation in cases of deficient alveolar ridges to satisfy the basic ideal need of hard tissue augmentation for functional and esthetic outcome of implant. In this case report, we describe a case of horizontal ridge augmentation using ridge split and simultaneous implant placement in esthetic maxillary premolar zone.

  3. The influence of initial alveolar ridge defect morphology on the outcome of implants in augmented atrophic posterior mandible: an exploratory retrospective study.

    Science.gov (United States)

    Khojasteh, Arash; Motamedian, Saeed Reza; Sharifzadeh, Navid; Zadeh, Homayoun H

    2017-10-01

    Clinicians commonly consider atrophic site topography as an important determinant in deciding the augmentation technique to utilize, as well as forecasting the likelihood of success. The purpose of this retrospective study was to examine the influence of initial atrophic posterior mandible morphology on the outcome of implants placed following augmentation. A total of 52 patients contributed 71 edentulous sites, and 185 implants were placed with mean follow-up of 37.97 months. The initial defect morphology was classified according to ABC classification (Journal of Oral Implantology, 37, 2013a and 361). Ridge augmentation was performed by "cortical autogenous tenting" (CAT) followed by either simultaneous or delayed implant placement after 4-6 months of healing. The European Academy of Osseointegration success criteria were used to evaluate implant outcomes. The overall survival and success rates of dental implants were 98.91% and 80%, respectively. Cumulative success and survival rates in CAT group were 95% and 100% after 2 years of follow-up. The highest marginal bone loss (MBL) was observed (1.26 mm ± 0.99) around implants placed in augmented edentulous sites with initially narrow and flat alveolar crest (defect class CII). Conversely, least MBL (0.48 mm ± 0.78) was detected around implants placed into edentulous sites with two sloped boney walls (defect class AII). Differences between MBL observed around implants placed into initial defect class C, initial defect type and class A (I, II), as well as class BII, were statistically significant (P implants, 148 were considered as successful, 26 exhibited satisfactory survival, nine with compromised survival, and two implants failed. The present data confirmed the effect of initial ridge morphology on the outcome of implants placed into augmented bone. Specifically, class A and class B atrophic ridge defects, with one and two vertical boney walls, respectively, may be considered as more favorable

  4. Regeneración ósea guiada para el aumento vertical del reborde alveolar Guided osseous regeneration for the vertical augmentation of the alveolar ridge

    OpenAIRE

    CE Nappe; CE Baltodano

    2013-01-01

    Se considera como aumento óseo vertical, cualquier técnica que apunte a crear una mayor altura del reborde alveolar. A inicios de la década de los 90’s se empezó a utilizar la regeneración ósea guiada (ROG) en mandíbulas atróficas, con el fin de permitir la instalación de implantes óseointegrados. Con el fin de evaluar y exponer parte de la evidencia disponible en la actualidad, con respecto a la ROG para aumento óseo vertical, se realizó la siguiente revisión bibliográfica.Any techniqu...

  5. Hard tissue augmentation for alveolar defects before implant placement

    Directory of Open Access Journals (Sweden)

    Mutia Rochmawati

    2017-08-01

    Full Text Available Background. Often when planning implant therapy, there is a need to augment or  replace  bone  that  has  been  lost. The alveolar defects may occur as a result of tooth loss due to extraction, advanced periodontal diseases or trauma, long term use of removable appliances, dehiscence and fenestration defects, developmental defects/clefts, congenitally missing teeth and odontogenic cysts and tumors. Insufficient bone volume can be brought about by hard tissue augmentation. This techniques have led to increased predictability in reconstruction of alveolar ridge defects and functional implant placement. Purpose. To describe the methods of hard tissue augmentation which can be done with block grafts (autografts and allografts, particulate grafts (cortical and cancellous, xenografts, or synthetic materials. Review. The reconstruction of a normal alveolar housing, in height and width, is imperative to achieve a harmonious balance between biology, function, and aesthetics. Depending on the size and morphology of the defect, horizontal or vertical, various augmentation procedures can be used. Soft tissue management is a critical aspect of hard tissue augmentation procedures. Incisions, reflection, and manipulation should be designed to optimize blood supply and wound closure. The design and management of mucoperiosteal flaps must consider the increased dimensions of the ridge after augmentation as well as esthetics and approximation of the wound margins. The surgical procedure needs to be executed with utmost care to preserve the maximum vascularity to the flap and minimize tissue injury. Conclusion. Alveolar ridge defects can be classified by using Seibert’s classification or HVC System. The treatment of alveolar ridge defect before implant placement can be done with hard tissue augmentation.

  6. Alveolar Ridge Split Technique Using Piezosurgery with Specially Designed Tips

    Directory of Open Access Journals (Sweden)

    Alessandro Moro

    2017-01-01

    Full Text Available The treatment of patients with atrophic ridge who need prosthetic rehabilitation is a common problem in oral and maxillofacial surgery. Among the various techniques introduced for the expansion of alveolar ridges with a horizontal bone deficit is the alveolar ridge split technique. The aim of this article is to give a description of some new tips that have been specifically designed for the treatment of atrophic ridges with transversal bone deficit. A two-step piezosurgical split technique is also described, based on specific osteotomies of the vestibular cortex and the use of a mandibular ramus graft as interpositional graft. A total of 15 patients were treated with the proposed new tips by our department. All the expanded areas were successful in providing an adequate width and height to insert implants according to the prosthetic plan and the proposed tips allowed obtaining the most from the alveolar ridge split technique and piezosurgery. These tips have made alveolar ridge split technique simple, safe, and effective for the treatment of horizontal and vertical bone defects. Furthermore the proposed piezosurgical split technique allows obtaining horizontal and vertical bone augmentation.

  7. Bone morphogenetic protein-2 loaded poly(D,L-lactide-co-glycolide microspheres enhance osteogenic potential of gelatin/hydroxyapatite/β-tricalcium phosphate cryogel composite for alveolar ridge augmentation

    Directory of Open Access Journals (Sweden)

    Hao-Chieh Chang

    2017-12-01

    Full Text Available Background/Purpose: Sufficient bony support is essential to ensure the success of dental implant osseointegration. However, the reconstruction of vertical ridge deficiencies is still a major challenge for dental implants. This study introduced a novel treatment strategy by infusing poly(D,L-lactide-co-glycolide (PLGA microspheres encapsulating bone morphogenetic protein-2 (BMP-2 within a gelatin/hydroxyapatite/β-tricalcium phosphate (gelatin/HA/β-TCP cryogel composite to facilitate supra-alveolar ridge augmentation. Methods: The gelatin scaffold was crosslinked using cryogel technique, and HA/β-TCP particles were mechanically entrapped to form the gelatin/HA/β-TCP composite. Co-axial electrohydrodynamic atomization technology was used to fabricate PLGA microspheres encapsulating BMP-2. The composites of gelatin/HA/β-TCP alone, with infusion of BMP-2 solution (BMPi or microspheres (BMPm, were fixed on rat mandibles using a titanium mini-implant for 4 weeks, and the therapeutic efficiency was evaluated by micro-computed tomography, bone fluorochrome, and histology. Results: The gelatin/HA/β-TCP composite was homogenously porous, and BMP-2 was sustained release from the microspheres without initial burst release. Ridge augmentation was noted in all specimens treated with the gelatin/HA/β-TCP composite, and greater bone deposition ratio were noted in Groups BMPi and BMPm. Compared with Group BMPi, specimens in Group BMPm showed significantly greater early osteogenesis and evident osseointegration in the supra-alveolar level. Conclusion: BMP-2 loaded PLGA microspheres effectively promoted osteogenic potential of the gelatin/HA/β-TCP composite and facilitated supra-alveolar ridge augmentation in vivo. Keywords: bone morphogenetic protein-2, bone regeneration, dental implant, tissue engineering, tissue scaffolds

  8. Alveolar ridge sockets preservation with bone grafting--review.

    Science.gov (United States)

    Allegrini, Sergio; Koening, Bruno; Allegrini, Marcia Rivellino Facci; Yoshimoto, Marcelo; Gedrange, Tomasz; Fanghaenel, Jochen; Lipski, Mariusz

    2008-01-01

    Alveolar bone seems to play a key role in providing support to the teeth, which are anchored to the bone by desmodontal fibers. The progressive alveolar bone resorption process occurs due to a loss of anatomic, biologic and mechanical factors. Mechanical stimulation of alveolar bone during mastication is crucial in keeping the teeth and underlying bone healthy. Tooth extraction leads to typical bone deficiency of ridge width and height of alveolar crest and reduces the possibility of placing screw titanium implants. When tooth extraction is necessary, trauma should be minimized during the procedure and bone preservation should receive careful attention. The literature has shown that early bone loss can be significantly reduced by socket grafting. The process of socket grafting requires an understanding of wound healing and an appreciation of the biological properties of the products available for socket grafting. Augmentative measures may, thus, be required to guarantee optimal prosthetic replacement of the lost tissue. Success or failure of augmentation procedures is dependent on revascularization and remodelling of the grafted bone into a vital, load bearing bone. In contrast to a visible three-dimensional change, the concept of remodelling refers to the internal turnover of bone, which is a coupled process where osteoclastic resorption and osteoblastic formation are more or less balanced. To restore alveolar bone loss and support efficient placement of dental implants, many different bone substitute such as autografts, allografts, xenografts, synthetic biomaterials and osteoactive agents have been proposed. In order to avoid harvesting an autograft, and thereby eliminating additional surgical procedures and risks, bone grafting materials and substitutes are alternative filler materials to be used for ridge augmentation. To present a literature review about biomaterials applicable in alveolar ridge sockets preservation to future implants insertion. The

  9. Strategies for alveolar ridge reconstruction and preservation for implant therapy.

    Science.gov (United States)

    Masaki, Chihiro; Nakamoto, Tetsuji; Mukaibo, Taro; Kondo, Yusuke; Hosokawa, Ryuji

    2015-10-01

    In dental implant treatment, ridge preservation and immediate or early implant placement are recommended to minimize bone resorption after tooth extraction and achieve esthetic outcomes. However, there is no consensus concerning the efficacy of this surgical method. There is also no consensus on the efficacy of bone and soft tissue grafts and surgical methods for alveolar ridge reconstruction. This paper reports ridge alteration in the anterior maxilla after tooth extraction, and summarizes the efficacy of various ridge preservation methods and immediate or early implant placement as alveolar ridge preservation methods to minimize bone resorption after tooth extraction. The advantages and complications of alveolar ridge reconstruction methods, and the efficacy and surgical method of soft tissue graft are reviewed. The anterior maxilla is in the esthetic zone, and the thickness of the bone on the labial side around the natural tooth is less than 1mm in many cases. Therefore, it is impossible to prevent bone resorption completely, even if ridge preservation and immediate or early implant placement are performed after tooth extraction. It is necessary to obtain stable and long-term esthetics by combining connective tissue and free gingival grafts, in addition to hard tissue augmentation. It is important to consider the burden and level of satisfaction of patients, such as in terms of donor site morbidity in hard and soft tissue grafting, and to pay attention to appropriate indications to avoid overtreatment. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  10. Bone augmentation procedures in localized defects in the alveolar ridge: clinical results with different bone grafts and bone-substitute materials

    DEFF Research Database (Denmark)

    Jensen, Simon Storgård; Terheyden, Hendrik

    2009-01-01

    evidence except expert opinions. Any publication written in English and including 10 or more patients with at least 12 months of follow-up after loading of the implants was eligible for this review. The results were categorized according to the presenting defect type: (1) dehiscence and fenestration......-type defects, (2) horizontal ridge augmentations, (3) vertical ridge augmentations, and (4) maxillary sinus floor elevations using the lateral window technique or transalveolar approach. The review focused on: (1) the outcome of the individual grafting protocols and (2) survival rates of implants placed...... in the augmented bone. RESULTS AND CONCLUSION: Based on 2,006 abstracts, 424 full-text articles were evaluated, of which 108 were included. Eleven studies were randomized controlled clinical trials. The majority were prospective or retrospective studies including a limited number of patients and short observation...

  11. Alveolar ridge preservation immediately after tooth extraction.

    Science.gov (United States)

    Feller, L; Khammissa, R A G; Bouckaert, M; Lemmer, J

    2013-10-01

    Ridge preservation procedures immediately after tooth extraction, are commonly used with a view to minimising remodelling and shrinkage of the alveolar ridge, associated with socket healing. These procedures may sometimes be effective, but they cannot completely prevent reduction in dimension of the ridge. Certain biomater als used may actually hamper normal deposition of bone within the healing socket, reducing bone trabeculae that can integrate with the implant surface. However, in extraction sockets in alveolar ridges of low bone density, particles of implanted bone substitute incorporated in the healing bone, may enhance the mechanical support for the implant, provided by normal healed bone of low trabecular density alone. This paper reviews biological rationales and procedures for ridge preservation immediately after extraction and comments on their clinical use.

  12. Alveolar Ridge Carcinoma. Two Cases Report

    International Nuclear Information System (INIS)

    Pupo Triguero, Raul J; Vivar Bauza, Miriam; Alvarez Infante, Elisa

    2008-01-01

    Two cases with alveolar ridge carcinoma due to prosthetist traumatism are discussed in this paper, after 9 and 10 years of using dental prosthesis. Both patients began with disturbance in the alveolar ridge. The clinical examination and biopsy showed a well differenced carcinoma. The treatment was radical surgery and radiotherapy in the first patient, and conservative surgery with radiotherapy in the second case .The patients had xerostomia after radiotherapy and the woman had difficulties with mastication. The advantages and disadvantages of the treatment were discussed, focused on the prevention and treatment for oral

  13. Short vs longer implants in mandibular alveolar ridge augmentated using osteogenic distraction: one year follow-up of a randomized split-mouth trial.

    Science.gov (United States)

    Bernardi, Sara; Gatto, Roberto; Severino, Marco; Botticelli, Gianluca; Caruso, Silvia; Rastelli, Claudio; Lupi, Ettore; Quiroz Rojas, Adolfo; Iacomino, Enzo; Falisi, Giovanni

    2018-02-13

    Aim of the study was to evaluate the reliability of 6 mm long implants compared to normal length implants placed in vertical augmented atrophic posterior mandible, supporting cemented single crowns. Thirty-six patients with bilateral posterior edentulous mandible and presented a bone availability height less than 9 mm from the mandibular canal were enrolled for the participation to this study. Patient hemi-arches were randomized to receive both 6 mm-long and normal length implants (10 mm). The technique used for the vertical bone augmentation was the "sandwich" technique, using a bone substitute block as graft. The data outcomes at 1 year post-loading follow-up were the loss of implants and the complications. Eighty-six 6 mm long implants and eighty-four normal implants were inserted. Five short implants and thirteen normal implants were lost. In 28 patients complications occurred, and in 21 cases the complication was present on the side of the ridge vertical augmentation. From the statistical analysis the association between the side of the ridge augmentation and the side of occurrence of the complication was statistically significant (p implants can be the preferred choice to vertical bone augmentation for the placement of longer implants in the rehabilitation of edentulous posterior mandibles. These initial results must be confirmed by larger and longer follow-ups of 5 years or more.

  14. Alveolar ridge preservation in the esthetic zone.

    Science.gov (United States)

    Jung, Ronald E; Ioannidis, Alexis; Hämmerle, Christoph H F; Thoma, Daniel S

    2018-02-27

    In the esthetic zone, in the case of tooth extraction, the clinician is often confronted with a challenge regarding the optimal decision-making process for providing a solution using dental implants. This is because, after tooth extraction, alveolar bone loss and structural and compositional changes of the covering soft tissues, as well as morphological alterations, can be expected. Ideally, the therapeutic plan starts before tooth extraction and it offers three options: spontaneous healing of the extraction socket; immediate implant placement; and techniques for preserving the alveolar ridge at the site of tooth removal. The decision-making process mainly depends on: (i) the chosen time-point for implant placement and the ability to place a dental implant; (ii) the quality and quantity of soft tissue in the region of the extraction socket; (iii) the remaining height of the buccal bone plate; and (iv) the expected rates of implant survival and success. Based on scientific evidence, three time-periods for alveolar ridge preservation are described in the literature: (i) soft-tissue preservation with 6-8 weeks of healing after tooth extraction (for optimization of the soft tissues); (ii) hard- and soft-tissue preservation with 4-6 months of healing after tooth extraction (for optimization of the hard and soft tissues); and (iii) hard-tissue preservation with > 6 months of healing after tooth extraction (for optimization of the hard tissues). © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. The Effects of Alveolar Ridge Preservation: A Meta-Analysis.

    Science.gov (United States)

    Willenbacher, Maximillian; Al-Nawas, Bilal; Berres, Manfred; Kämmerer, Peer W; Schiegnitz, Eik

    2016-12-01

    The aim of this article was to analyze the horizontal, vertical, and histological effects of alveolar ridge preservation (ARP) versus the ones of unassisted socket healing, in the format of an up-to-date review and meta-analysis. An extensive electronic search in the electronic databases of the National Library of Medicine was conducted for articles published up to June 2014 to identify literature presenting data on the topic of ARP. Only randomized controlled trials, controlled clinical trials, and prospective trials were included for meta-analysis. After screening 903 abstracts from the electronic database, we included 64 studies in qualitative and 18 in quantitative synthesis. Quality assessment characterized a medium risk of bias for the included literature. The meta-analysis showed a mean difference between test and control groups of approximately 1.31 to 1.54 mm in bucco-oral bone width and 0.91 to 1.12 mm in bone height. Additionally, the intergroup difference in percentage of vital bone was assessed to be inconclusive across the included studies. Implants could be inserted into the determined position without further augmentation in 90.1% of the experimental sites, while this was the case in only 79.2% of the control sockets. Resorption of the alveolar ridge cannot be totally stopped by ARP, while it still can be prevented compared with unassisted healing. No reliable predictions on the histological effects could be made due to limited data. Further on, no recommendation for a specific technique of ARP could be made. In conclusion, there is still need for ongoing research on the topic, even though the lower percentage of implant sites that needed additional augmentation in test sockets seemed to bring a patient benefit. © 2015 Wiley Periodicals, Inc.

  16. Application of Platelet-Rich Fibrin and Injectable Platelet-Rich Fibrin in Combination of Bone Substitute Material for Alveolar Ridge Augmentation - a Case Report

    Directory of Open Access Journals (Sweden)

    Chenchev Ivan L.

    2017-09-01

    Full Text Available Background: Different barrier membranes and augmentation techniques are used in oral surgery to recover lost bone structures with varied success. Recently, a combination between bone graft materials and Platelet-Rich-Fibrin (PRF is implemented in the periodontology and implantology.

  17. Alveolar ridge preservation and biologic width management for ...

    African Journals Online (AJOL)

    Alveolar bone atrophy is a chronically progressive, irreversible process which results in bone loss in both the buccal, lingual and apico-coronal region. Without bone preservation measures, bone resorption is experienced and continues for life. Preservation of alveolar ridge is indicated when a tooth-supported fixed partial ...

  18. The Clinical Effectiveness of Alveolar Ridge Preservation in the Maxillary Anterior Esthetic Zone-A Retrospective Study.

    Science.gov (United States)

    Lee, Albert Ming Hsien; Poon, Choy Yoke

    2017-04-01

    The primary aim was to investigate whether ridge preservation done at extraction will preserve at least 6 mm of alveolar ridge width in the anterior maxillary zone and obviate the need for secondary bone augmentation during implant insertion. Sixty patients with single implants placed in the anterior maxillary zone were classified in two groups. In the test group, 40 patients underwent ridge preservation at the time of tooth extraction, while the remaining 20 patients in the control group did not. Preimplant CBCT was evaluated to investigate if at least 6 mm of alveolar ridge width existed before implant insertion. The records were studied to investigate if secondary bone augmentation was done during implantation. The mean patient age was 48.4 years. In the test group, mean healing time before implant placement was 5.0 ± 3.7 months (2 to 22 months); in the control groups, 13.0 + 12.7 months (1.2 to 38 months). In the test group, 82.5% of the subjects had a preimplant alveolar ridge width measuring at least 6 mm. In comparison, only 35% of the subjects in the control group had a preimplant alveolar ridge width measuring at least 6 mm. The odds of having at least 6 mm preimplant alveolar ridge width was significantly higher than the control group (p preservation material. There was no significant difference in the alveolar ridge width between these two materials (p = 1) CONCLUSION: Ridge preservation was effective in providing a sufficient ridge width in the anterior maxilla at the time of implantation and reduced the need for further bone augmentation. The results of this study give the clinician insight into whether ridge preservation is required during extraction in the anterior maxilla in preparation for an implant restoration. (J Esthet Restor Dent 29:137-145, 2017). © 2016 Wiley Periodicals, Inc.

  19. Comparison of Bone Resorption Rates after Intraoral Block Bone and Guided Bone Regeneration Augmentation for the Reconstruction of Horizontally Deficient Maxillary Alveolar Ridges

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    B. Alper Gultekin

    2016-01-01

    Full Text Available Purpose. Bone atrophy after tooth loss may leave insufficient bone for implant placement. We compared volumetric changes after autogenous ramus block bone grafting (RBG or guided bone regeneration (GBR in horizontally deficient maxilla before implant placement. Materials and Methods. In this retrospective study, volumetric changes at RBG or GBR graft sites were evaluated using cone-beam computed tomography. The primary outcome variable was the volumetric resorption rate. Secondary outcomes were bone gain, graft success, and implant insertion torque. Results. Twenty-four patients (28 grafted sites were included (GBR, 15; RBG, 13. One patient (RBG suffered mucosal dehiscence at the recipient site 6 weeks after surgery, which healed spontaneously. Mean volume reduction in the GBR and RBG groups was 12.48 ± 2.67% and 7.20 ± 1.40%, respectively. GBR resulted in significantly more bone resorption than RBG (P0.05. Conclusions. Both RBG and GBR hard-tissue augmentation techniques provide adequate bone graft volume and stability for implant insertion. However, GBR causes greater resorption at maxillary augmented sites than RBG, which clinicians should consider during treatment planning.

  20. Effect of Alveolar Ridge Preservation after Tooth Extraction

    Science.gov (United States)

    Avila-Ortiz, G.; Elangovan, S.; Kramer, K.W.O.; Blanchette, D.; Dawson, D.V.

    2014-01-01

    Alveolar ridge preservation strategies are indicated to minimize the loss of ridge volume that typically follows tooth extraction. The aim of this systematic review was to determine the effect that socket filling with a bone grafting material has on the prevention of postextraction alveolar ridge volume loss as compared with tooth extraction alone in nonmolar teeth. Five electronic databases were searched to identify randomized clinical trials that fulfilled the eligibility criteria. Literature screening and article selection were conducted by 3 independent reviewers, while data extraction was performed by 2 independent reviewers. Outcome measures were mean horizontal ridge changes (buccolingual) and vertical ridge changes (midbuccal, midlingual, mesial, and distal). The influence of several variables of interest (i.e., flap elevation, membrane usage, and type of bone substitute employed) on the outcomes of ridge preservation therapy was explored via subgroup analyses. We found that alveolar ridge preservation is effective in limiting physiologic ridge reduction as compared with tooth extraction alone. The clinical magnitude of the effect was 1.89 mm (95% confidence interval [CI]: 1.41, 2.36; p preservation. PMID:24966231

  1. Postextraction Alveolar Ridge Preservation: Biological Basis and Treatments

    OpenAIRE

    Pagni, Giorgio; Pellegrini, Gaia; Giannobile, William V.; Rasperini, Giulio

    2012-01-01

    Following tooth extraction, the alveolar ridge undergoes an inevitable remodeling process that influences implant therapy of the edentulous area. Socket grafting is a commonly adopted therapy for the preservation of alveolar bone structures in combination or not with immediate implant placement although the biological bases lying behind this treatment modality are not fully understood and often misinterpreted. This review is intended to clarify the literature support to socket grafting in ord...

  2. Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

    NARCIS (Netherlands)

    Raghoebar, GM; Batenburg, RHK; Vissink, A; Reintsema, H

    1996-01-01

    Purpose: This study evaluated the applicability of intraorally harvested autogenous bone grafts for the augmentation of the narrow maxillary alveolar ridge to enable insertion of implants for single tooth replacement. Materials and Methods: Local defects of the anterior maxilla were reconstructed in

  3. Accelerated orthodontics with alveolar decortication and augmentation: a case report.

    Science.gov (United States)

    Yezdani, A Arif

    2012-01-01

    This case report reiterates the fact that selective alveolar decortication in conjunction with periodontal alveolar augmentation with a bone graft indubitably and efficaciously produces rapid orthodontic tooth movement. A 29-year-old woman presented with a Class I malocclusion and increased bidentoalveolar protrusion with increased spacing between the maxillary and mandibular incisors. She readily agreed to selective alveolar decortication in conjunction with periodontal alveolar augmentation with a bone graft when presented with the proposal that her malocclusion could be corrected in one-third the treatment time required for conventional orthodontics. A preadjusted edgewise appliance (Roth prescription, 0.022 x 0.028-inch slot) was placed prior to the surgical procedure. One week later, full-thickness labial and lingual flaps were reflected in the maxillary and mandibular arches. The alveolar bone was selectively decorticated and periodontally augmented with a bone graft. Starting 1 week postsurgically, orthodontic adjustments were carried out every 2 weeks. From bracketing to debracketing, the entire orthodontic treatment took 7 months. The rapid orthodontic tooth movement was attributed to the regional acceleratory phenomenon, triggered by selective alveolar decortication. The subsequent periodontal alveolar augmentation with the bone graft repaired the bony dehiscences and enhanced the bone volume and dramatically improved the patient's soft tissue profile.

  4. Nostril Base Augmentation Effect of Alveolar Bone Graft

    Directory of Open Access Journals (Sweden)

    Woojin Lee

    2013-09-01

    Full Text Available Background The aims of alveolar bone grafting are closure of the fistula, stabilization ofthe maxillary arch, support for the roots of the teeth adjacent to the cleft on each side.We observed nostril base augmentation in patients with alveolar clefts after alveolar bonegrafting. The purpose of this study was to evaluate the nostril base augmentation effect ofsecondary alveolar bone grafting in patients with unilateral alveolar cleft.Methods Records of 15 children with alveolar clefts who underwent secondary alveolar bonegrafting with autogenous iliac cancellous bone between March of 2011 and May of 2012 werereviewed. Preoperative and postoperative worm’s-eye view photographs and reconstructedthree-dimensional computed tomography (CT scans were used for photogrammetry. Thedepression of the nostril base and thickness of the philtrum on the cleft side were measuredin comparison to the normal side. The depression of the cleft side pyriform aperture wasmeasured in comparison to the normal side on reconstructed three-dimensional CT.Results Significant changes were seen in the nostril base (P=0.005, the philtrum length(P=0.013, and the angle (P=0.006. The CT measurements showed significant changes in thepyriform aperture (P<0.001 and the angle (P<0.001.Conclusions An alveolar bone graft not only fills the gap in the alveolar process but alsoaugments the nostril base after surgery. In this study, only an alveolar bone graft was performedto prevent bias from other procedures. Nostril base augmentation can be achieved byperforming alveolar bone grafts in children, in whom invasive methods are not advised.

  5. Postextraction alveolar ridge preservation: biological basis and treatments.

    Science.gov (United States)

    Pagni, Giorgio; Pellegrini, Gaia; Giannobile, William V; Rasperini, Giulio

    2012-01-01

    Following tooth extraction, the alveolar ridge undergoes an inevitable remodeling process that influences implant therapy of the edentulous area. Socket grafting is a commonly adopted therapy for the preservation of alveolar bone structures in combination or not with immediate implant placement although the biological bases lying behind this treatment modality are not fully understood and often misinterpreted. This review is intended to clarify the literature support to socket grafting in order to provide practitioners with valid tools to make a conscious decision of when and why to recommend this therapy.

  6. Alveolar ridge atrophy related to facial morphology in edentulous patients

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    Kuć J

    2017-09-01

    Full Text Available Joanna Kuć,1 Teresa Sierpińska,2 Maria Gołębiewska1 1Department of Prosthodontics, 2Department of Dental Technology, Medical University of Bialystok, Bialystok, Poland Objectives: The morphology of the alveolar process determines the retention and stability of prosthetic restorations, thereby determining the result of the therapy. Considering that the edentulous jaws may be affected by the atrophy process, it was hypothesized that the morphology of the alveolar process of the maxilla may be dependent on the anterior facial height and anatomy of the mandible. Subjects and methods: Twenty-five healthy edentulous Caucasian individuals were randomly chosen. Each subject underwent a lateral cephalogram before and after prosthetic rehabilitation. During exposition, newly made prostheses were placed in the patient’s mouth. Teeth remained in maximal intercuspidation. Morphological parameters were evaluated according to the Ricketts, McNamara, and Tallgren’s method. Results: An inversely proportional association was observed between patient age and the distal part of the maxilla. A statistically significant connection was noted between the vertical dimension of alveolar ridge and anterior total and lower facial height conditioned by prosthetic rehabilitation. Conclusion: The height of the lateral part of the alveolar ridge of the maxilla remains in connection with the anterior total and lower facial height obtained in the course of prosthetic rehabilitation. The vertical dimension of the alveolar ridge of the maxilla seems to be in close relationship with the morphology of the lower jaw. Keywords: anterior facial height, cephalometric analysis, complete dentures, vertical occlusal dimension

  7. Determinants of alveolar ridge preservation differ by anatomic location.

    Science.gov (United States)

    Leblebicioglu, Binnaz; Salas, Mabel; Ort, Yirae; Johnson, Ashley; Yildiz, Vedat O; Kim, Do-Gyoon; Agarwal, Sudha; Tatakis, Dimitris N

    2013-04-01

    To investigate and compare outcomes following alveolar ridge preservation (ARP) in posterior maxilla and mandible. Twenty-four patients (54 ± 3 years) with single posterior tooth extraction were included. ARP was performed with freeze-dried bone allograft and collagen membrane. Clinical parameters were recorded at extraction and re-entry. Harvested bone cores were analysed by microcomputed tomography (micro-CT), histomorphometry and immunohistochemistry. In both jaws, ARP prevented ridge height loss, but ridge width was significantly reduced by approximately 2.5 mm. Healing time, initial clinical attachment loss and amount of keratinized tissue at extraction site were identified as determinants of ridge height outcome. Buccal plate thickness and tooth root length were identified as determinants of ridge width outcome. In addition, initial ridge width was positively correlated with ridge width loss. Micro-CT revealed greater mineralization per unit volume in new bone compared with existing bone in mandible (p < 0.001). Distributions of residual graft, new cellular bone and immature tissue were similar in both jaws. Within the limitations of this study, the results indicate that in different anatomic locations different factors may determine ARP outcomes. Further studies are needed to better understand determinants of ARP outcomes. © 2013 John Wiley & Sons A/S.

  8. A review on alveolar ridge preservation following tooth extraction.

    Science.gov (United States)

    Horowitz, Robert; Holtzclaw, Danny; Rosen, Paul S

    2012-09-01

    The question that clinicians face is whether the use of bone replacement grafts and/or barrier membranes enhance their ability to provide for the future placement of a dental implant or to maximize ridge dimensions following the extraction of a tooth versus no additional treatments. The evidence was obtained by search of Entrez PubMed and manual search of The International Journal of Oral and Maxillofacial Implants, The International Journal of Periodontics & Restorative Dentistry, Clinical Oral Implant Research, The Journal of Periodontology, The Journal of Clinical Periodontology, and The Compendium of Continuing Education in Dentistry. Key search words included Guided Bone Regeneration, Dental Extraction, Tooth Extraction, Bone Replacement Graft, Alveolar Ridge. The years of search included from January 2011 through February 2012. The recurring theme was that there was considerable heterogeneity to study designs, time periods, and methods of evaluation. This created great difficulty in trying to answer with good high-quality evidence questions about the techniques and materials to be used for maximizing regeneration at the time of tooth extraction or in which situations this ought to be used. There appears to be consensus from the reviewed literature supporting ridge preservation techniques as a whole. Multiple studies demonstrated less ridge resorption occurring when alveolar ridge preservation procedures were used versus the placement of no graft material in fresh alveolar sockets. The analysis did not show any grafting materials demonstrating a clear benefit over any others or that a barrier membrane is necessary. The evidence is also too premature about whether socket preservation efforts require primary closure. In the emerging area of growth factors, there is no high-quality evidence to either support or refute their use. Tooth extraction is one of the most widely performed procedures in dentistry today and it has been historically well documented that

  9. Effects of alveolar ridge preservation on delayed implant osseointegration.

    Science.gov (United States)

    Shao, Shan; Li, Bin; Xue, Hui-Min; Huang, Hai-Yun; Liu, Gang-Li

    2015-01-01

    To evaluate the effects of alveolar ridge preservation with Bio-Oss bone substitute (Geistlich Pharma) on delayed implant osseointegration. The 3rd and 4th left and right mandibular premolars were extracted from four adult healthy male and female dogs. For the experimental group, we randomly selected two extraction sockets in each dog to be filled with Bio-Oss bone substitute (Geistlich Pharma). The two remaining extraction sockets remained untreated and served as the control group. Three months after Bio-Oss placement, dental implants were inserted into the alveolar bone of the experimental group and the control group. The osteogenic activity of the bone around the implants was assessed by evaluating the histological morphology and by estimating histomorphometric parameters at 3 and 6 months after delayed implantation. At 3 months, Goldner's trichrome staining analysis showed that the bone-implant contact rate and mineralised bone area around the implant were significantly higher in the experimental group (75.98% ± 8.97% and 69.52% ± 9.63%, respectively) than in the control group (56.13% ± 8.18% and 52.82% ± 7.25%, respectively; P alveolar ridge preservation by using Bio-Oss placement can promote osseointegration of delayed implantation. This may be a promising option for clinical use.

  10. Influence of platelet-rich fibrin on alveolar ridge preservation.

    Science.gov (United States)

    Suttapreyasri, Srisurang; Leepong, Narit

    2013-07-01

    The aim of this study was to investigate the influence of platelet-rich fibrin (PRF) on early wound healing and preservation of the alveolar ridge shape following tooth extraction. In this clinical trial, 20 symmetrical, premolar extraction sockets using split-mouth design were randomly selected with PRF or blood clot. The evaluations of wound healing, alveolar ridge contour changes, and crestal bone resorption were performed in dental casts and periapical radiographs (T0, initial; T1, 1 week; T2, 2 weeks; T4, 4 weeks; T6, 6 weeks; T8, 8 weeks). Platelet-rich fibrin clinically showed early healing of soft tissue covering socket orifices in the first 4 weeks. At the first week, the horizontal resorption on buccal aspect of PRF (1.07 ± 0.31 mm) was significantly less than that of the control (1.81 ± 0.88 mm). Platelet-rich fibrin demonstrated the tendency to enter the steady stage after the fourth week following tooth extraction, whereas in the control group the progression of buccal contour contraction was still detected through the eighth week. Radiographically, the overall resorption of marginal bone levels at mesial and distal to the extraction site in PRF (0.70, 1.23 mm) was comparable to that of the control (1.33, 1.14 mm). Although the PRF group demonstrated faster bone healing compared with the control, no statistically significant difference was detected. This preliminary result demonstrated neither better alveolar ridge preservation nor enhanced bone formation of PRF in the extraction socket. The use of PRF revealed limited effectiveness by accelerated soft-tissue healing on the first 4 weeks.

  11. Alveolar ridge preservation with autologous particulated dentin-a case series.

    Science.gov (United States)

    Valdec, Silvio; Pasic, Pavla; Soltermann, Alex; Thoma, Daniel; Stadlinger, Bernd; Rücker, Martin

    2017-12-01

    Ridge preservation can be performed with autologous bone, alloplastic bone substitute material or a combination of both. Dentin is similar to bone in its chemical composition. In its use as bone substitute material, it undergoes a remodelling process and transforms to bone. The presented case report introduces a technique in which the extraction socket is augmented with autologous, particulated dentin. The fractured, non-savable mesial incisor of the upper jaw was carefully extracted in axial direction. After the extraction, the tooth was cleared from remaining periodontal tissue. The vital pulp tissue or a root canal filling, enamel and cementum were also removed. Following the particulation of the remaining dentin in a bone mill, the dentin particles were immediately filled orthotope into the alveolar socket. The soft tissue closure was performed with a free gingival graft of the palate. After an observation period of 4 months, an implant was placed in the augmented area, which osseointegrated successfully and could be restored prosthodontically in the following. The results of this method showed a functional and aesthetic success. The pre-implantological, autologous ridge preservation with dentin could be performed successfully. For the establishment of dentin as augmentation material for jaw augmentation procedures, a prospective, clinical trial is now necessary.

  12. Post traumatic immediate GBR: alveolar ridge preservation after a comminuted fracture of the anterior maxilla.

    Science.gov (United States)

    Kim, Yongsoo; Leem, Dae Ho

    2015-04-01

    Without a proper intervention, a crushed alveolar process fracture can cause significant dimensional changes on affected hard and soft tissue that lead to difficult circumstances for post traumatic bone augmentation and dental implant placement. We present herein the cases of immediate guided bone regeneration (GBR) for the maxillary anterior alveolar process with comminuted fracture. Shortly after the hospital visit, guided bone regeneration was conducted for three patients using only xenograft material and bone fragments from traumatic site, without an additional donor site. Resorbable collagen membrane was used on the bone graft site, and titanium mesh was also used if significant bone loss were expected. Radiographic evaluation 6 months after GBR confirmed that all three cases had sufficiently preserved alveolar bone which is clinically required for implant placement. Dental implant installation was carried out for two patients and no specific findings were noted in follow-up after the placement. In this method, additional operation sites for bone collection are not necessary and the number of surgical steps before implant placement can be reduced. Furthermore, this immediate intervention can effectively minimize the alveolar ridge shrinkage of anterior maxilla after injury. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Partial Extraction Therapies (PET) Part 1: Maintaining Alveolar Ridge Contour at Pontic and Immediate Implant Sites.

    Science.gov (United States)

    Gluckman, Howard; Salama, Maurice; Du Toit, Jonathan

    2016-01-01

    Buccopalatal collapse of the postextraction ridge is a significant challenge in restorative and implant dentistry. A variety of ridge preservation techniques using tissue and augmentative materials have been proposed in the literature. A slightly different approach is to use the tooth itself. Root submergence has been reported in the literature for more than 4 decades, and it has been demonstrated that the submerged tooth root retains the periodontal tissues and preserves the bone in pontic sites or below dentures to retain the ridge. The socket-shield technique entails preparing a tooth root section simultaneous to immediate implant placement and has demonstrated histologic and clinical results that are highly promising to esthetic implant treatment. The pontic shield technique preserves the alveolar ridge at sites intended for pontic development where the root submergence technique is not possible. The aforementioned techniques collectively may be termed partial extraction therapies (PET), a term newly introduced into the literature and clinical environment. This article is a review of these ridge preservation therapies, providing a classification and a guide to their application.

  14. Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

    Directory of Open Access Journals (Sweden)

    Zeeshan Sheikh

    2015-05-01

    Full Text Available Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses.

  15. Systemic Osteoporosis and Reduction of the Edentulous Alveolar Ridge

    Directory of Open Access Journals (Sweden)

    Srđan D. Poštić

    2013-09-01

    Full Text Available Systemic osteoporosis can damage skeletal bones to different degrees or remain persistent in intensity. The aim of this study was to determine the intensity and correlation of the osteoporotic changes in the bone density of the skeleton and body mass index (BMI with a reduction in edentulous mandibles. Material and Methods: In this study, 89 edentulous patients with decreased bone density comprised the experimental group, and 43 edentulous patients with normal bone densities formed the control. The age of the patients ranged between 53 and 73 years. Radiographs of the hands and panoramic radiographs were done for all the patients. The values of BMI, metacarpal index , density of lumbar spine (L2-L4, in the phalanx and segments of the mandibles as well as the heights of the edentulous alveolar ridges were measured, assessed and calculated.Results: The lowest value of the total skeletal density was established in the osteoporotic patients on the basis of the average T-score of -2.5 in men, and - 2.6 in women. Minimum values of the heights of the edentulous ridges (right/left, in mm were measured in both osteoporotic female (21.84/22.39 and male (24.90/24.96 patients. By comparison of the densities of the metacarpal bones, proximal phalanx, segments of the edentulous mandibles and based on the numerical values of the heights of the edentulous ridges, χ²=3.81 was found in men and χ²=4.03 was found in women with normal bone densities; χ²=5.92 was found in men and χ²=6.25 was found in women with osteopenia; χ²=2.63 was found in men and χ²=3.85 was found in women with osteoporosis, on the P level of probability of 0.05. Conclusion: Systemic osteoporosis causes a decrease of the jawbone density and induces residual edentulous alveolar ridge reduction.

  16. Age-related new bone formation following the use of cancellous bone-block allografts for reconstruction of atrophic alveolar ridges.

    Science.gov (United States)

    Nissan, Joseph; Kolerman, Roni; Chaushu, Liat; Vered, Marilena; Naishlos, Sarit; Chaushu, Gavriel

    2018-02-01

    An age-related decrease in the number of osteogenic progenitor cells may compromise bone augmentation. Histomorphometrical assessment of age-related new bone formation, following atrophic alveolar ridge reconstruction, using cancellous bone-block allografts. Ninety-three consecutive patients (58 females and 35 males) were referred for implant-supported restoration of 122 severe atrophic alveolar ridges. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58), posterior maxilla (n= 32), and posterior mandible (n = 32). A bony deficiency of at least 3 mm horizontally and up to 3 mm vertically according to computerized tomography (CT) in the posterior mandible and anterior maxilla, served as inclusion criteria. In the posterior maxilla, a residual alveolar ridge up to 4 mm vertically according to CT served as inclusion criteria. Augmentation was performed by the use of cancellous bone-block allografts. Bone biopsies (9-month posterior maxilla, 4 months anterior maxilla and posterior mandible) of young (≤40 years) versus older (>40 years) patients were histomorphometrically evaluated. In the posterior maxilla, no statistically significant histomorphometric differences were noted. While at the anterior maxilla and posterior mandible, statistically significant more newly formed bone was found in young versus older individuals, respectively (38.6% vs 19.8%, P = 0.04 and 69% vs 31%, P = .05). New bone formation following residual alveolar ridge bone grafting is age-related. Longer bone consolidation and healing time may be recommended for older individuals. © 2017 Wiley Periodicals, Inc.

  17. Quality assessment of systematic reviews on alveolar ridge preservation.

    Science.gov (United States)

    De Buitrago, Juan G; Avila-Ortiz, Gustavo; Elangovan, Satheesh

    2013-12-01

    The authors conducted a study to assess the quality of systematic reviews (SRs) published on the topic of alveolar ridge preservation (ARP). The authors conducted a search for SRs on ARP on the basis of a set of eligibility criteria (only SRs involving ARP, with or without meta-analyses, written in English). The authors assessed the quality of the SRs independently of one another by using two established checklists. The authors selected eight SRs. The results of all of the SRs indicated that ARP was effective in preserving the ridge volume as compared with extraction alone, but it did not fully prevent bone-resorptive events. None of the SRs, however, received the highest possible score in either of the checklists. One SR that had a score of 5 (of a possible 11) using one checklist and 5 (of a possible 14) using the other checklist had the lowest overall score. The results of this assessment revealed that a significant proportion of the investigators in the SRs did not include non-English language articles, perform hand searching of published literature or evaluate the gray literature. Assessment of publication bias and reporting of conflicts of interest also was lacking in some studies. Practical Implications. Although ARP appears to be an effective approach to preventing resorption after tooth extraction, significant structural and methodological variability exists among SRs on this topic. Future SRs on ARP should consider the use of quality assessment checklists to minimize methodological shortcomings for better dissemination of scientific evidence.

  18. Alveolar Ridge Preservation Using Leukocyte and Platelet-Rich Fibrin: A Report of a Case

    Directory of Open Access Journals (Sweden)

    Mogammad Thabit Peck

    2011-01-01

    Full Text Available In order for a dental implant to be restored optimally, it must be placed in an ideal anatomic position. However, this is not always possible, since physiological wound healing after tooth removal, often results in hard and soft tissue changes which ultimately compromises ideal implant placement. With the aim of minimising the need for tissue augmentation, several alveolar ridge preservation (ARP techniques have been developed. These often require the use of grafting material and therefore increase the risk of disease transmission. Leukocyte and platelet-rich fibrin (L-PRF is a newly developed platelet concentrate that is prepared from the patient's own blood. Clinical research has indicated that it improves wound healing and stimulates bone formation. We present a case where L-PRF was successfully used in an ARP procedure to facilitate implant placement in a compromised extraction socket.

  19. Soft tissue expansion before vertical ridge augmentation: Inflatable silicone balloons or self-filling osmotic tissue expanders?

    Directory of Open Access Journals (Sweden)

    Prasad Vijayrao Dhadse

    2014-01-01

    Full Text Available Recent advances in periodontal plastic surgical procedures allow the clinician to reconstruct deficient alveolar ridges in more predictable ways than previously possible. Placement of implant/s in resorbed ridges poses numerous challenges to the clinician for successful esthetic and functional rehabilitation. The reconstruction frequently utilizes one or combination of periodontal plastic surgical procedures in conjunction with autogenous bone grafting, allogenic bone block grafting, ridge split techniques, distraction osteogenesis, or guided bone regeneration (GBR for most predictable outcomes. Current surgical modalities used in reconstruction of alveolar ridge (horizontal and/or vertical component often involve the need of flap transfer. Moreover, there is compromise in tissue integrity and color match owing to different surgical site and the tissue utilized is insufficient in quantity leading to post surgical graft exposition and/or loss of grafted bone. Soft tissue expansion (STE by implantation of inflatable silicone balloon or self filling osmotic tissue expanders before reconstructive surgery can overcome these disadvantages and certainly holds a promise for effective method for generation of soft tissue thereby achieving predictable augmentation of deficient alveolar ridges for the implant success. This article focuses and compares these distinct tissue expanders for their clinical efficacy of achieving excess tissue that predominantly seems to be prerequisite for ridge augmentation which can be reasonably followed by successful placement of endosseous fixtures.

  20. Simplified type 3 implant placement, after alveolar ridge preservation: a case study.

    Science.gov (United States)

    Cecchetti, F; Germano, F; Bartuli, F N; Arcuri, L; Spuntarelli, M

    2014-01-01

    Alveolar ridge, after tooth extraction, could reduce its volume up to 50% in buccal-lingual width in the first twelve months and residual dimensions could interfere with correct three dimensional placement of implants and influence negatively treatment outcomes with regard to function and aesthetic aspects. Over the last decades, several approaches have been proposed and tested in order to prevent ridge volumetric contraction and provide maximum bone availability for implant procedure. This article presents a case study with a single anterior tooth replacement, illustrating socket seal technique followed by a type 3 timing implant placement. Immediately after tooth extraction, residual socket was grafted using Deproteinized Bovine Bone Mineral and a free gingival punch harvested from palate. After 3 months, a root-form titanium implant was inserted without additional regenerative procedures. Follow-up examination revealed favourable preservation of soft tissue width and height in the aesthetic area. Socket seal approach maximizes soft tissue healing, preserving ridge envelope and the subsequent implant placement, furthermore, results simplified, as any augmentation techniques are required. Clinical advantages of this method include predictable preservation of the soft tissues, favourable healing features, easy handling of graft materials and a positive benefit-cost ratio.

  1. Healing of extraction sockets and augmented alveolar defects following 1-year treatment with bisphosphonate.

    Science.gov (United States)

    Khojasteh, Arash; Behnia, Hossein; Morad, Golnaz; Dashti, Seyedeh Ghazaleh; Dehghan, Mohammad Mehdi; Shahab, Shahriyar; Abbas, Fatemeh Mashhadi

    2013-01-01

    To assess the effect of bisphosphonates on healing of extraction sockets and augmented alveolar defects, 12 adult female mongrel dogs were assigned to 2 experimental groups and a control group. The experimental groups received oral alendronate (ALN, 3.5 mg/kg/wk) or IV pamidronate (PAM, 1 mg/kg/wk) for 12 months. Animals were randomly tested for serum C-terminal telopeptide of collagen I (CTx). The right first and second premolars were extracted. After 8 weeks, extraction sites were evaluated for healing. Subsequently, 3-wall defects were created in ridges and filled with human mineralized cortical particulate bone. Two months post-augmentation, animals were sacrificed and mandibles were collected for cone-beam computed tomography (CBCT) and histomorphometric appraisal. The obtained data were compared using 1-way ANOVA test. CTx test results in both experimental groups were comparable (alveolar bone in the PAM group and the upper rim of the alveoli in the ALN group. Histologically, bone sequestra from the PAM group demonstrated empty osteocyte lacunae, while in the ALN group areas of necrotic bone along with evidence of active bone remodeling was distinguished. Eight weeks post-augmentation, the experimental groups showed no evidence of bone formation in the augmented area, while bone formation ratio was measured to be 18.32% in the control group. The mean amount of pixel intensity calculated from the CBCT images of the ALN, PAM, and control group was 113.69 ± 11.04, 124.94 ± 4.72, and 113.69 ± 6.63, respectively. Pixel intensity in PAM-treated group was significantly higher than both other groups. This study demonstrated that 1-year treatment with ALN/PAM was associated with impairment of post-extraction and post-augmentation bone healing in dogs.

  2. Role of Cone Beam Computed Tomography in Rehabilitation of a Traumatised Deficient Maxillary Alveolar Ridge Using Symphyseal Block Graft Placement

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    Shipra Arora

    2013-01-01

    Full Text Available Deficiencies in the alveolar ridges cause multiple problems in achieving aesthetic and functional outcome of implant therapy and are commonly restored by using onlay graft from intraoral source. Careful assessment of the recipient as well as the donor site using cone beam computed tomography (CBCT is a prerequisite to ideal treatment planning. This paper highlights the critical role of CBCT in planning a successful rehabilitation of traumatised deficient anterior maxillary alveolar ridge using autogenous block graft from mandibular symphysis, followed by implant placement. A 21-year-old male reported with missing right maxillary lateral incisor due to traumatic avulsion 6 months back. A concavity was found on the labial aspect of edentulous area. Serial transplanar images on CBCT revealed gross irregular radiolucency in place of labial cortical plate. Using CBCT, size of the required block was estimated, and mandibular symphyseal area was evaluated for the feasibility of harvesting a graft of suitable dimension. Onlay block graft was harvested from mandibular symphysis and placed at the edentulous site to augment the alveolar ridge. Implants were placed 5 months later and loaded successfully after osseointegration. After 1 year of followup, implant-based prosthesis is working well, without any complications.

  3. [Mandibular ridge augmentation with hydroxylapatite and its extension].

    Science.gov (United States)

    Huang, H; Mercier, P

    1996-01-01

    The results of 5 years follow-up of 84 cases of mandibular residual ridge augmented with hydroxlapatite (HA), followed by ridge extension, are reported. The first surgical procedures, subperiosteal HA insertion, and the second stage of total lowering of the floow of the mouth, vestibuloplasty and skin graft are detailedly described. The ridge is augmented by the first surgery, disturbance of the fraenums of the lip, buccal and tongue and muscles are eliminated by the second surgery, to increase denture retention and stability, improve wear resisting of tissue covered over the artifical ridge and eliminate pain and uncomfort when wearing denture. The results of five years follow-up show that two stages reconstruction are better than HA insertion only. HA is a kind of ideal material of bone replacement, which is not resorbed in most cases.

  4. Simultaneous Ridge Augmentation and Accelerated Molar Uprighting for Implant Site Development: Two Case Reports with a Split-Mouth Design.

    Science.gov (United States)

    Wang, Chin-Wei; Chou, Michelle Yuching; Chen, Rebecca; Rowe, Todd; Masoud, Mohamed; Kim, David M; Intini, Giuseppe

    Well-coordinated interdisciplinary dental treatments provide the best esthetic, functional, and long-term results for patients. However, the length of such treatment, which may involve orthodontics, ridge augmentation, and dental implants, often deters patients from pursuing them. The two case reports presented here aim to present the advantage of simultaneous orthodontic molar uprighting and ridge augmentation procedures for future implant site development. Selective decortication of the alveolar bone, performed simultaneously with bone grafting, can accelerate the tooth uprighting process and synergistically reduce treatment duration. Two cases with bilaterally missing mandibular first molars were treated with this approach. In both patients, surgically accelerated uprighting of molars occurred 1.6 times faster than the contralateral site, where no surgery was performed. Additionally, ridge augmentation was successfully achieved with 2.5 to 5 mm of horizontal bone gain during the molar uprighting process.

  5. Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site development.

    Science.gov (United States)

    Atieh, Momen A; Alsabeeha, Nabeel H M; Payne, Alan G T; Duncan, Warwick; Faggion, Clovis M; Esposito, Marco

    2015-05-28

    Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used. To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets. The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 22 July 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2014, Issue 6), MEDLINE via OVID (1946 to 22 July 2014), EMBASE via OVID (1980 to 22 July 2014), LILACS via BIREME (1982 to 22 July 2014), the Meta Register of Current Controlled Trials (to 22 July 2014), ClinicalTrials.gov (to 22 July 2014), the World Health Organization International Clinical Trials Registry Platform (to 22 July 2014), Web of Science Conference Proceedings (1990 to 22 July 2014), Scopus (1966 to 22 July 2014), ProQuest Dissertations and Theses (1861 to 22 July 2014) and OpenGrey (to 22 July 2014). A number of journals were also handsearched. Trial authors were contacted to identify unpublished randomised controlled trials. There were no restrictions regarding language and date of publication in the searches of the electronic databases. We included all randomised controlled trials (RCTs) on the use of alveolar ridge preservation techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the

  6. Restoration of the maxillary anterior tooth using immediate implantation with simultaneous ridge augmentation

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    Park Jun-Beom

    2010-01-01

    Full Text Available Atrophy is most severe during the first month of post-extraction in the anterior maxilla with the degree of horizontal bone resorption being nearly twice as high as that of vertical bone resorption. The loss of the buccal alveolar plate following tooth extraction may lead to palatal implant positioning of the implants. Thus, immediate or early implant placement in the extraction socket has been suggested, because it would reduce the time period and the number of surgical intervention and yield higher patient satisfaction compared with delayed placed implants. However, placement of an implant immediately after tooth extraction may result in a gap between the occlusal portion of the implant and the surrounding alveolar bone crest. In this case report, an implant-supported restoration which is in harmony with the surrounding hard and soft tissue was created by the immediate implant placement with ridge augmentation in anterior region with high satisfaction from the patient.

  7. Combined influence of implant diameter and alveolar ridge width on crestal bone stress: a quantitative approach.

    Science.gov (United States)

    Yu, Wonjae; Jang, Yoon-Je; Kyung, Hee-Moon

    2009-01-01

    To quantitatively evaluate the combined influence of implant diameter and alveolar ridge width on crestal bone stress. ITI solid-screw implants, 10 mm in length and 3.3, 4.1, and 4.8 mm in diameter, and the alveolar bone were modeled using axisymmetric finite elements. Four different alveolar ridge geometries were selected for each implant: 5-, 6-, 7-, and 8-mm-wide ridges for the 3.3-mm implants; 6-, 7-, 8-, and 9-mm-wide ridges for the 4.1-mm implants; and 7-, 8-, 9-, and 10-mm-wide ridges for the 4.8-mm implants. A nonaxial oblique load of 100 N was applied at 30 degrees to the implant axis. Regression analysis was used to avoid ambiguity when estimating the peak stress occurring at the coronal contact point between the implant and the crestal bone, ie, the singularity point. Peak stresses were dependent on both implant diameter and alveolar ridge width. Substantially lower stresses were recorded around the implants placed in narrower ridges. A regression analysis may be used to quantify the peak stress at the singularity point. An implant with a diameter that is at least half the ridge width is recommended to reduce the stress concentration in the crestal bone.

  8. [Evaluation with different measuring methods for the alveolar bone change of ridge preservation in molar sites].

    Science.gov (United States)

    Zhao, Li-ping; Zhan, Ya-lin; Hu, Wen-jie; Xu, Tao; Wei, Yi-ping; Zhen, Min; Wang, Cui

    2016-02-18

    To investigate the changes of the vertical height and width of the alveolar bone six months after the alveolar ridge preservation in periodontal compromised molar sites of severe alveolar bone defects with clinical direct measurement, parallel periapical radiographs, and cone-beam computed tomography (CBCT), and to analyze the effect of the three different methods of measurement. In this study, 20 subjects requiring tooth extraction on account of periodontal disease with a total of 23 extracted molars were enrolled. Extractions were performed atraumatically and patients were received alveolar ridge preservation procedure with Bio-Oss and Bio-Gide. Clinical direct measurements were taken after tooth extraction and during the implant surgery 6 months later, CBCT scans and parallel periapical radiographs were taken immediately after ridge preservation and 6 months later. The changes of alveolar ridge width and vertical height after six months were measured and analyzed through the above-mentioned three methods and the similarities and differences of the measured effect were compared. There were no significant difference of alveolar vertical height in the center of the extraction sites, the center of distal aspect, and distobuccal aspect between the clinical direct measurements and the CBCT measurements (P>0.05), alveolar vertical height in other points and alveolar width measurements were statically significant (Palveolar increased significantly and the changes of alveolar vertical height of clinical direct and CBCT measurement were (6.15 ± 1.73) mm and (6.59 ± 2.53) mm, respectively. The measurements of the width of the alveolar bone were (8.45 ± 1.18) mm and (8.52 ± 1.27) mm, respectively. The measurements of the two methods were not statistically significant (P>0.05). The change of the alveolar height in the center of the extraction socket after six months measured by parallel periapical was (5.84 ± 4.28) mm, which was closed to the clinical direct measurement

  9. Effect of alveolar ridge preservation after tooth extraction: a systematic review and meta-analysis.

    Science.gov (United States)

    Avila-Ortiz, G; Elangovan, S; Kramer, K W O; Blanchette, D; Dawson, D V

    2014-10-01

    Alveolar ridge preservation strategies are indicated to minimize the loss of ridge volume that typically follows tooth extraction. The aim of this systematic review was to determine the effect that socket filling with a bone grafting material has on the prevention of postextraction alveolar ridge volume loss as compared with tooth extraction alone in nonmolar teeth. Five electronic databases were searched to identify randomized clinical trials that fulfilled the eligibility criteria. Literature screening and article selection were conducted by 3 independent reviewers, while data extraction was performed by 2 independent reviewers. Outcome measures were mean horizontal ridge changes (buccolingual) and vertical ridge changes (midbuccal, midlingual, mesial, and distal). The influence of several variables of interest (i.e., flap elevation, membrane usage, and type of bone substitute employed) on the outcomes of ridge preservation therapy was explored via subgroup analyses. We found that alveolar ridge preservation is effective in limiting physiologic ridge reduction as compared with tooth extraction alone. The clinical magnitude of the effect was 1.89 mm (95% confidence interval [CI]: 1.41, 2.36; p preservation. © International & American Associations for Dental Research.

  10. Outcomes of Alveolar Ridge Preservation With Recombinant Human Bone Morphogenetic Protein-2: A Systematic Review.

    Science.gov (United States)

    Moslemi, Neda; Khoshkam, Vahid; Rafiee, Sahar; Bahrami, Naghmeh; Aslroosta, Hoori

    2018-02-01

    The main focused question of this systematic review was as follows: Does the application of recombinant human bone morphogenetic protein-2 (rhBMP-2) placed in extraction sockets reduce the alveolar ridge changes? A systematic literature search was performed up to February 2017. Clinical studies published in English were included. Outcome variables of interest were as follows: changes in alveolar ridge width and height, the quality of new bone, patient's safety, adverse events, and postoperative complications. Seven articles were included. Because of the vast heterogeneity and high risk of bias among the studies, performing a meta-analysis deemed not feasible. Application of rhBMP-2 in the extraction socket was more effective in the reduction of ridge width compared with that of ridge height. The superiority of 1.5 mg/mL rhBMP-2/absorbable collagen sponge over the carrier alone on alveolar ridge width/height remodeling was more significant when it was applied in the sockets with ≥50% buccal bone dehiscence. The limited available data showed that rhBMP-2 did not improve the quality of new bone. Antibodies against rhBMP-2 were detected in the serum in 1 trial. Within the limits of this review, 1.5 mg/mL rhBMP-2 might be beneficial for preserving the alveolar ridge width within extraction sockets given as to whether the cost-effectiveness is justifiable. Studies with lower risk of bias should be performed to confirm the above findings.

  11. Augmentation of residual alveolar bone height with tissue engineering for dental implant placement

    Directory of Open Access Journals (Sweden)

    S M Balaji

    2014-01-01

    Full Text Available The challenge of correcting deficient vertical alveolar height for dental implant placement has been there since dental implants came in to regular clinical placement. The ability of various methods to increase the residual alveolar height has met with varying results. The primary reason is that the techniques were not quite successful in maintaining the required residual alveolar height. Use of Bone Morphogentic Protein, especially rhBMP-2 has been met with high degree of success in deficient vertical alveolar height in a mandibular ridge. The demonstration of this using a case has been presented here.

  12. Limited Evidence Suggests That Alveolar Ridge Preservation is More Favorable Than Unassisted Socket Healing in Minimizing Alveolar Ridge Dimensional Changes After Extraction.

    Science.gov (United States)

    Tu, Victor; Kumar, Satish

    2018-03-01

    Alveolar ridge preservation after tooth extraction: a Bayesian Network meta-analysis of grafting materials efficacy on prevention of bone height and width reduction. Iocca O, Farcomeni A, Pardiñas Lopez S, Talib HS. J Clin Periodontol 2017; 44(1):104-14. Self-funded by the authors and their institutions TYPE OF STUDY/DESIGN: Meta-analysis and Bayesian network meta-analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Localized ridge augmentation in the anterior maxilla using titanium mesh, an alloplast, and a nano-bone graft: a case report.

    Science.gov (United States)

    Alagl, Adel S; Madi, Marwa

    2018-01-01

    Alveolar ridge deficiency is considered a major limitation for successful implant placement, as well as for the long-term success rate, especially in the anterior maxillary region. Various approaches have been developed to increase bone volume. Among those approaches, inlay and onlay grafts, alveolar ridge distraction, and guided bone regeneration have been suggested. The use of titanium mesh is a reliable method for ridge augmentation. We describe a patient who presented with a localized, combined, horizontal and vertical ridge defect in the anterior maxilla. The patient was treated using titanium mesh and alloplast material mixed with a nano-bone graft to treat the localized ridge deformity for future implant installation. The clinical and radiographic presentation, as well as relevant literature, are presented.

  14. [Contributions of edentulous mandibular alveolar ridge height and denture adhesive to complete denture retention].

    Science.gov (United States)

    Zeng, Xingqi; Chen, Xinmin; Peng, Yan; Xu, Chao; Men, Qinglin

    2011-10-01

    The present paper is to investigate the relationship between height and stress-bearing area of mandibular alveolar ridge, their influence on retention of complete denture, and the effectiveness of denture adhesive (DA). Five mandibular edentulous models of different heights and a rabbit palate model were prepared in Die-Stone. Measurements were made on the heights and stress-bearing areas of mandibular alveolar ridge, the retention force of mandibular models 15 min after DA administration, and the retention force on the rabbit palate before and after adhering. All available data were analyzed statistically. Linear regression relationship was demonstrated between ridge height and bearing area, ridge height and retention force, and bearing area and retention force (Pridge directly correlate with the retention of complete denture, and DA significantly improves the retention ability of complete denture.

  15. Grafts for Ridge Preservation

    Science.gov (United States)

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

    Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome. PMID:26262646

  16. Histological Features and Biocompatibility of Bone and Soft Tissue Substitutes in the Atrophic Alveolar Ridge Reconstruction

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    Carlo Maiorana

    2016-01-01

    Full Text Available The reconstruction of the atrophic alveolar ridges for implant placement is today a common procedure in dentistry daily practice. The surgical reconstruction provides for the optimization of the supporting bone for the implants and a restoration of the amount of keratinized gingiva for esthetic and functional reasons. In the past, tissue regeneration has been performed with autogenous bone and free gingival or connective tissue grafts. Nowadays, bone substitutes and specific collagen matrix allow for a complete restoration of the atrophic ridge without invasive harvesting procedures. A maxillary reconstruction of an atrophic ridge by means of tissue substitutes and its histological features are then presented.

  17. Provisional prostheses during ridge augmentation and implant dentistry.

    Science.gov (United States)

    Livada, Rania; Hottel, Timothy L; Shiloah, Jacob

    2013-01-01

    Recent advancements in ridge augmentation and bone regeneration have expanded the pool of patients that could benefit from dental implants. However, providing the patient with a temporary prosthesis during the wound healing phase without impairing the process is a challenging task. This article summarizes available information pertaining to provisional prostheses, both tooth-supported and soft tissue-supported, that may meet the patient needs. The advantages and disadvantages of each class of prosthesis, along with indications and contraindications, were taken into consideration to aid the restorative dentist in choosing the optimal provisional for their patients.

  18. Predictors of Alveolar Process Remodeling Following Ridge Preservation in High-Risk Patients.

    Science.gov (United States)

    Cosyn, Jan; Cleymaet, Roberto; De Bruyn, Hugo

    2016-04-01

    (1) To clinically evaluate horizontal remodeling of the alveolar process (hard and soft tissues) following ridge preservation in high-risk patients and (2) to identify predictors of such remodeling. Periodontally healthy nonsmoking patients with a failing tooth in the anterior maxilla (15-25) were selected for a prospective case series. All were in need of a single implant and demonstrated high risk for aesthetic complications given an incomplete buccal bone wall and/or thin-scalloped gingival biotype. Following flapless tooth extraction, ridge preservation was performed using one or more collagen-enriched, bovine-derived block grafts (Geistlich Bio-Oss® Collagen® 100 mg, Geistlich Pharma AG, Wolhusen, Switzerland) without the additional use of membranes or soft tissue grafts. The change in buccopalatal dimension of the alveolar process between baseline (prior to tooth extraction) and 4 months was assessed on the basis of superimposed occlusal slides. Regression analysis was performed to identify predictors of alveolar process remodeling. Forty-two patients (21 females, 21 males; mean age 38) met the selection criteria and consented to the treatment. Mean alveolar process remodeling was 14% (SD 7, range 4-30) with minimal remodeling (≤ 10%) in 16 patients (38%) and advanced remodeling (>20%) in 10 patients (24%). A single implant could be installed in all subjects without additional guided bone regeneration. Connective tissue grafting was performed later on in the treatment for aesthetic purposes, hereby compensating for tissue loss at the buccal aspect. Predictors of alveolar process remodeling were tooth location (central incisors and cuspids > laterals incisors and premolars), tooth abscess (p = .025), and buccal bone loss (p = .035). Alveolar process remodeling seems inevitable yet acceptable following ridge preservation in high-risk patients. Proper case selection may reduce the incidence of advanced remodeling. © 2014 Wiley Periodicals, Inc.

  19. Dimensional alterations of extraction sites after different alveolar ridge preservation techniques - a volumetric study.

    Science.gov (United States)

    Thalmair, Tobias; Fickl, Stefan; Schneider, David; Hinze, Marc; Wachtel, Hannes

    2013-07-01

    The aim of this randomized controlled clinical study was to assess soft tissue contour changes after different alveolar ridge preservation procedures. Following tooth extraction, 30 patients were randomly assigned to the following treatments (Tx) - Tx 1: xenogenic bone substitute (pre-hydrated collagenated cortico-cancellous porcine bone) and free gingival graft; Tx 2: free gingival graft alone; Tx 3: xenogenic bone substitute; Tx 4: no further treatment (control). Impressions were obtained before tooth extraction (baseline) and 4 months after surgery. Cast models were optically scanned, digitally superimposed and horizontal measurements of the contour alterations between time points were performed using digital imaging analysis. All groups displayed contour shrinkage at the buccal aspect ranging from a mean horizontal reduction of -0.8 ± 0.5 mm (Tx 1) to -2.3 ± 1.1 mm (control). Statistically significant differences were found between Tx 1 and Tx 4 as well as Tx 2 and Tx 4. A significant positive influence of the free gingival graft on the maintenance of the ridge width was recorded (p alveolar ridge preservation techniques were not able to entirely compensate for alveolar ridge reduction. Covering the orifice of the extraction socket with a free gingival tissue graft seems to have the potential to limit but not avoid the post-operative external contour shrinkage based on optical scans. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. A randomized controlled evaluation of alveolar ridge preservation following tooth extraction using deproteinized bovine bone mineral and demineralized freeze-dried bone allograft.

    Science.gov (United States)

    Sadeghi, Rokhsareh; Babaei, Maryam; Miremadi, S Asghar; Abbas, Fatemeh Mashadi

    2016-01-01

    Alveolar ridge preservation could be performed immediately following tooth extraction to limit dimensional changes of alveolar process due to bone resorption. The aim of this study was to compare the clinical and histologic outcomes of socket preservation using two different graft materials; deproteinized bovine bone mineral (DBBM) and demineralized freeze-dried bone allograft (DFDBA) with absorbable collagen membrane. Twenty extraction sockets in 20 patients were randomly divided into 2 treatment groups: 10 sockets were augmented with DBBM and collagen membrane whereas 10 sockets were filled with DFDBA and covered by collagen membrane. Primary closure was achieved over extraction sockets by flap advancement. Horizontal and vertical ridge dimensional changes were assessed at baseline and after 4-6 months at the time of implant placement. For histological and histomorphometrical analysis, bone samples were harvested from the augmented sites with trephine during implant surgery. All data were analyzed using SPSS version 18 (α=0.05). Clinical measurements revealed that average horizontal reduction was 2.3 ± 0.64 mm for DFDBA and 2.26 ± 0.51 mm for DBBM. Mean vertical ridge resorption at buccal side was 1.29 ± 0.68 mm for DFDBA and 1.1 ± 0.17 mm for DBBM. Moreover, mean vertical ridge reduction at lingual site was 0.41 ± 0.38 mm and 0.35 ± 0.34 mm for DFDBA and DBBM, respectively. No significant differences were seen between two groups in any of those clinical parameters. Histologic analysis showed statistically significant more new bone deposition for DFDBA compared to DBBM (34.49 ± 3.19 vs. 18.76 ± 3.54) (P alveolar ridge preservation after tooth extraction, but there was more new bone formation and less residual graft particles in DFDBA group than in DBBM group.

  1. Horizontal alveolar ridge expansion followed by immediate placement of implants and rehabilitation with zirconia prosthesis

    Directory of Open Access Journals (Sweden)

    Tatiana Miranda Deliberador

    2017-01-01

    Full Text Available In recent years, there have been a growing number of procedures involving dental implants. Most cases, though, are characterized by bone atrophy, especially horizontal atrophy. This clinical case aims to report a technique for the expansion of the horizontal alveolar ridge. A longitudinal fracture was created in the alveolar ridge to expand the bone, followed by immediate insertion of dental implants along with a particulate allogeneic bone graft. Eight implants were placed in the maxilla, and after 12 months, a surgical reopening was performed, along with rehabilitation with a protocol-type prosthesis, for which a zirconia infrastructure was made. The patient was observed during a 10-month follow-up period in which an effective osseointegration of all implants was achieved as a result of such a technique. The split-crest technique followed by the immediate placement of implants and a particulate allogeneic bone graft proved to be effective, with a predictable osseointegration.

  2. Alveolar ridge expansion-assisted orthodontic space closure in the mandibular posterior region.

    Science.gov (United States)

    Ozer, Mete; Akdeniz, Berat Serdar; Sumer, Mahmut

    2013-12-01

    Orthodontic closure of old, edentulous spaces in the mandibular posterior region is a major challenge. In this report, we describe a method of orthodontic closure of edentulous spaces in the mandibular posterior region accelerated by piezoelectric decortication and alveolar ridge expansion. Combined piezosurgical and orthodontic treatments were used to close 14- and 15-mm-wide spaces in the mandibular left and right posterior areas, respectively, of a female patient, aged 18 years and 9 months, diagnosed with skeletal Class III malocclusion, hypodontia, and polydiastemas. After the piezoelectric decortication, segmental and full-arch mechanics were applied in the orthodontic phase. Despite some extent of root resorption and anchorage loss, the edentulous spaces were closed, and adequate function and esthetics were regained without further restorative treatment. Alveolar ridge expansion-assisted orthodontic space closure seems to be an effective and relatively less-invasive treatment alternative for edentulous spaces in the mandibular posterior region.

  3. Horizontal alveolar ridge expansion followed by immediate placement of implants and rehabilitation with zirconia prosthesis.

    Science.gov (United States)

    Deliberador, Tatiana Miranda; Verbicaro, Thalyta; Minerva, Leonel; Scariot, Rafaela; Giovanini, Allan Fernando; Zielak, João César

    2017-01-01

    In recent years, there have been a growing number of procedures involving dental implants. Most cases, though, are characterized by bone atrophy, especially horizontal atrophy. This clinical case aims to report a technique for the expansion of the horizontal alveolar ridge. A longitudinal fracture was created in the alveolar ridge to expand the bone, followed by immediate insertion of dental implants along with a particulate allogeneic bone graft. Eight implants were placed in the maxilla, and after 12 months, a surgical reopening was performed, along with rehabilitation with a protocol-type prosthesis, for which a zirconia infrastructure was made. The patient was observed during a 10-month follow-up period in which an effective osseointegration of all implants was achieved as a result of such a technique. The split-crest technique followed by the immediate placement of implants and a particulate allogeneic bone graft proved to be effective, with a predictable osseointegration.

  4. Alveolar ridge expansion-assisted orthodontic space closure in the mandibular posterior region

    OpenAIRE

    Ozer, Mete; Akdeniz, Berat Serdar; Sumer, Mahmut

    2013-01-01

    Orthodontic closure of old, edentulous spaces in the mandibular posterior region is a major challenge. In this report, we describe a method of orthodontic closure of edentulous spaces in the mandibular posterior region accelerated by piezoelectric decortication and alveolar ridge expansion. Combined piezosurgical and orthodontic treatments were used to close 14- and 15-mm-wide spaces in the mandibular left and right posterior areas, respectively, of a female patient, aged 18 years and 9 month...

  5. Alveolar ridge dimensional changes following ridge preservation procedure with novel devices: part 3 - histological analysis in non-human primate model.

    Science.gov (United States)

    Su, Yingying; Tang, Jianxia; Min, Seiko; Guo, Lijia; Liu, Yitong; Xie, Yilin; Xiong, Jimin; Wang, Songlin; Araújo, Mauricio G; Zadeh, Homayoun H; Liu, Yi

    2017-11-01

    This study sought to investigate the histological changes following tooth extraction, ridge preservation and augmentation, using novel devices designed to obturate the oral orifice of extraction sockets (SocketKAP™) and provide structural support for sockets with defective bony walls (SocketKAGE™) in a non-human primate model. Six Macaca fascicularis were imaged by cone beam computed tomography to register their preoperative alveolar bone. Three teeth were extracted in each animal, yielding intact socket walls and were divided into three intervention groups: unassisted healing negative control (Group A); SocketKAP™ (Group B); filled with anorganic bovine bone mineral (ABBM) + SocketKAP™ (Group C). Three additional teeth were extracted in each animal, followed by surgical resection of the entire buccal alveolar bone and divided into three groups: negative control (Group D); SocketKAP™ + SocketKAGE™ (Group E); ABBM + SocketKAP™ + SocketKAGE™ (Group F). Animals were euthanized after 12 weeks, and treatment sites were examined by histology and histomorphometric analysis. Control sockets with unassisted healing (Groups A and D) underwent severe loss of bone width, height and total area (approximately 40-60% loss). Application of SocketKAP™ in sites with intact walls, as well as SocketKAP™ plus SocketKAGE™ in sites with defective buccal walls lead to higher preservation of alveolar bone height after 12 weeks post-intervention. Addition of ABBM leads to the highest degree of alveolar bone dimensional preservation. Control sites with unassisted healing (Groups A and D), as well as sites treated with extraction socket devices (Groups B and E) without ABBM yielded higher percentage of vital bone, compared with sites filled with ABBM (Groups C and F). No adverse histological responses were noted to SocketKAP™ or SocketKAGE™ devices. SocketKAP™ + SocketKAGE™ devices proved effective in reducing post-extraction alveolar bone resorption

  6. Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

    Science.gov (United States)

    Pang, Chaoyuan; Ding, Yuxiang; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui; Zhang, Guoliang; Hu, Kaijin

    2014-09-01

    To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

  7. PDGF-metronidazole-encapsulated nanofibrous functional layers on collagen membrane promote alveolar ridge regeneration

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    Ho MH

    2017-08-01

    Full Text Available Ming-Hua Ho,1 Hao-Chieh Chang,2,3 Yu-Chia Chang,3 Jeiannete Claudia,1 Tzu-Chiao Lin,2 Po-Chun Chang2,3 1Department of Chemical Engineering, College of Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 2Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan; 3Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan Abstract: This study aimed to develop a functionally graded membrane (FGM to prevent infection and promote tissue regeneration. Poly(L-lactide-co-D,L-lactide encapsulating platelet-derived growth factor (PDLLA-PDGF or metronidazole (PDLLA-MTZ was electrospun to form a nanofibrous layer on the inner or outer surface of a clinically available collagen membrane, respectively. The membrane was characterized for the morphology, molecule release profile, in vitro and in vivo biocompatibility, and preclinical efficiency for alveolar ridge regeneration. The PDLLA-MTZ and PDLLA-PDGF nanofibers were 800–900 nm in diameter, and the thicknesses of the functional layers were 20–30 µm, with sustained molecule release over 28 days. All of the membranes tested were compatible with cell survival in vitro and showed good tissue integration with minimal fibrous capsule formation or inflammation. Cell proliferation was especially prominent on the PDLLA-PDGF layer in vivo. On the alveolar ridge, all FGMs reduced wound dehiscence compared with the control collagen membrane, and the FGM with PDLLA-PDGF promoted osteogenesis significantly. In conclusion, the FGMs with PDLLA-PDGF and PDLLA-MTZ showed high biocompatibility and facilitated wound healing compared with conventional membrane, and the FGM with PDLLA-PDGF enhanced alveolar ridge regeneration in vivo. The design represents a beneficial modification, which may be easily adapted for future clinical use. Keywords: tissue engineering, platelet-derived growth factor, metronidazole, alveolar process

  8. Radiographic alveolar bone changes following ridge preservation with two different biomaterials.

    Science.gov (United States)

    Mardas, Nikos; D'Aiuto, Francesco; Mezzomo, Luis; Arzoumanidi, Marina; Donos, Nikolaos

    2011-04-01

    The aim of this randomized controlled trial was to evaluate radiographical bone changes following alveolar ridge preservation with a synthetic bone substitute or a bovine xenograft. Alveolar ridge preservation was performed in 27 patients randomized in two groups. In the test group (n=14), the extraction socket was treated with Straumann bone ceramic(®) (SBC) and a collagen barrier membrane (Bio-Gide(®)), whereas in the control group (n=13) with deproteinized bovine bone mineral and the same barrier. Standardized periapical X-rays were taken at 4 time points, BL: after tooth extraction, GR: immediately after socket grafting, 4M: 16 weeks, 8M: 32 weeks post-operatively. The levels of the alveolar bone crest at the mesial (Mh), and distal (Dh) and central aspects of the socket were measured at all time points. All the radiographs obtained were subtracted from the follow-up images. The gain, loss and unchanged areas in terms of grey values were tested for significant difference between the two groups. In the test group, the Mh and Dh showed a mean difference (± standard deviation) of 0.9 ± 1.2 and 0.7 ± 1.8 mm, respectively, among BL-8M. In the control group, the Mh and Dh showed a mean difference of 0.4 ± 1.3 and 0.7 ± 1.3 mm, respectively (P>0.05). Both treatments presented similar gain in grey values between BL-GR, BL-4M and BL-8M. The SBC presented less loss in grey values between BL-4M and BL-8M (Palveolar bone changes when used for alveolar ridge preservation. © 2011 John Wiley & Sons A/S.

  9. A digital evaluation of alveolar ridge preservation at implants placed immediately into extraction sockets: an experimental study in the dog.

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    Favero, Giacomo; Lang, Niklaus P; Romanelli, Piero; Pantani, Fabio; Caneva, Marco; Botticelli, Daniele

    2015-01-01

    To compare with pristine sites bone resorption and soft tissue adaptation at implants placed immediately into extraction sockets (IPIES) in conjunction with deproteinized bovine bone mineral (DBBM) particles and a collagen membrane. The mesial root of the third premolar in the left side of the mandible was endodontically treated (Test). Flaps were elevated, the tooth hemi-sectioned, and the distal root removed to allow the immediate installation of an implant into the extraction socket in a lingual position. DBBM particles were placed into the defect and on the outer contour of the buccal bony ridge, concomitantly with the placement of a collagen membrane. A non-submerged healing was allowed. The premolar on the right side of the mandible was left in situ (control). Ground sections from the center of the implant as well as from the center of the distal root of the third premolar of the opposite side of the mandible were obtained. The histological image from the implant site was superimposed to that of the contralateral pristine distal alveolus, and dimensional variation evaluated for the hard tissue and the alveolar ridge. After 3 months of healing, both histological and photographic evaluation revealed a reduction of hard and soft tissue dimensions. The contour augmentation performed with DBBM particles and a collagen membrane at the buccal aspects of implants placed IPIES was not able to maintain the tissue volume. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Alveolar ridge dimensional changes following ridge preservation procedure using SocketKAP(™) : exploratory study of serial cone-beam computed tomography and histologic analysis in canine model.

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    Ryu, Kyung-Ho; Min, Seiko; You, Hyung-Keun; Sin, Yeon-Woo; Lee, Wan; Lee, Jun; Kiss, Alex; Almohaimeed, Mohammad; Zadeh, Homayoun H

    2016-09-01

    The aim of this pilot study was to examine the kinetics of alterations in alveolar ridge width and height following tooth extraction with and without ridge preservation, using anorganic bovine bone mineral (ABBM) and a novel device (SocketKAP(™) ) designed for obturation of socket orifice. Maxillary left and right PM1 and mandibular right PM2 and PM4 were extracted on six beagle dogs and treated as follows: Group A: negative control; Group B: SocketKAP(™) alone; Group C: ABBM + SocketKAP(™) . Serial cone-beam computed tomography (CBCT) was taken at 0-, 1-, 2-, 4-, 8- and 12-week intervals to calculate the rate of alveolar bone loss, followed by histologic and histomorphometric analyses at 12 weeks. Across group outcomes were compared. Without additional intervention, the crestal-most 3 mm of alveolar bone width lost approximately 0.21-0.28 mm per week. The rate of alveolar buccal bone height loss was 0.19 mm per week. Comparatively, in group C, the alveolar bone was relatively stable, with loss of only 0.003-0.13 mm of width and 0.12 mm of height per week. These differences were statistically significant. The alveolar bone in sites treated by SocketKAP(™) alone was significantly different from control only at select time points and locations of the ridge, presumably due to small sample size. Without additional intervention, tooth extraction was accompanied by rapid loss of alveolar ridge width and height. Applications of SocketKAP(™) and ABBM were effective in reducing alveolar crestal width and height loss following tooth extraction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Clinical effect of platelet-rich fibrin on the preservation of the alveolar ridge following tooth extraction.

    Science.gov (United States)

    Zhang, Yingdi; Ruan, Zheng; Shen, Minhua; Tan, Luanjun; Huang, Weiqin; Wang, Lei; Huang, Yuanliang

    2018-03-01

    The aim of the present study was to evaluate the clinical efficacy of platelet-rich fibrin (PRF) in preserving the alveolar ridge following human tooth extraction. A total of 28 patients were divided into two groups: The experimental and control groups (n=14 each). Following tooth extraction, the experimental group was implanted with PRF membrane, whereas the control group was not. The gingival healing effect was assessed at 7 days, 1 and 3 months later. Cone-beam computed tomography was performed immediately and at 3 months following tooth extraction. The changes in alveolar ridge height, width, and bone mineral density were compared between the two groups. The alveolar bone was removed using the ring drill during the implant surgery at 3 months following tooth extraction. Histomorphometric evaluation was performed to compare new bone formation between groups. The patients in the experimental group reportedly felt better compared with the patients in the control group. The healing of gingival tissue was better in the experimental group than in the control group. A significantly greater novel bone area was observed in the PRF group compared with the control group (Palveolar ridge height, lingual/palatal alveolar ridge height and alveolar ridge width between the two groups. These results suggested that PRF was advantageous in human alveolar ridge preservation with ease of use and simple handling. Histological analysis of novel bone formation confirmed that PRF increased the quality of the novel bone and enhanced the rate of bone formation, despite the effect of PRF was not significant to reduce alveolar bone resorption in the extraction socket alone.

  12. Alveolar ridge dimensional changes following ridge preservation procedure: part-2 - CBCT 3D analysis in non-human primate model.

    Science.gov (United States)

    Omran, Mostafa; Min, Seiko; Abdelhamid, Alaa; Liu, Yi; Zadeh, Homayoun H

    2016-07-01

    The aim of this study was to evaluate the efficacy of ridge preservation involving novel devices used for obturation of socket orifice (Socket cap; SocketKAP(™) ) and resorbable cage used for space maintenance in sites with facial wall dehiscence (Socket cage; SocketKAGE(™) ). Eight teeth were extracted in each of six Macaca fascicularis non-human primates. Six intervention groups consisted of the following: Group A: intact socket negative control. Group B: intact socket: socket cap. Group C: intact socket filled with anorganic bovine bone mineral (ABBM) + socket cap. Group D: dehiscence: negative control. Group E: dehiscence: socket cap + socket cage. Group F: dehiscence: filled with ABBM + socket cap + socket cage. CBCT scans were obtained preoperatively and at 6 and 12 weeks following intervention. The pre- and postoperative scans were superimposed, to quantify 3D volumetric alveolar bone changes. Volumetric bone loss occurred in all sockets, not only within the cretal zone (0-3 mm) to the ridge crest, as has been commonly reported by other investigators, but significant bone loss was also detected in the zone which was 3-6 mm apical to the alveolar crest. For intact sockets, socket cap + ABBM led to significantly greater percentages of remaining bone volume when compared to groups A and B. A significant difference favoring socket cap + socket cage + ABBM treatment was observed for sockets with facial dehiscence defects compared to groups D and E. Socket cap in conjunction with ABBM appears effective in limiting post-extraction volumetric bone loss in intact sockets, while socket cap + socket cage + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Aumento del reborde alveolar residual mediante técnica de rollo Increase of residual alveolar ridge using roll technique

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    Miguel Ángel Simancas Pallares

    2011-03-01

    Full Text Available La pérdida dentaria, asociada a factores sistémicos, patológicos y traumáticos, promueve el proceso de reabsorción ósea de los rebordes residuales y genera problemas funcionales, como la falta de estabilidad y retención de las prótesis dentarias removibles, y disturbios estéticos y psicológicos. Estos defectos varían en dependencia de la cantidad de pérdida ósea y de tejidos blandos que hayan alcanzado. En la actualidad son descritas diversas técnicas que permiten corregir estos defectos. Una de ellas es la técnica del rollo, la cual demuestra muy buenos resultados al aumentar el tamaño del reborde alveolar y disminuir los defectos estéticos que causa sobre todo en el sector anterior. El objetivo del presente artículo es describir el caso clínico de un paciente con pérdida ósea en el sector anterior, tipo III según Seibert, rehabilitado con prótesis parcial fija y sometido a un procedimiento quirúrgico con la técnica del rollo. Se alcanzaron los objetivos planteados y proporciona una mejoría estética así como una mejora en su calidad de vida. Se demostró que con esta técnica se obtienen resultados predecibles que devuelven la estética en zonas de alta exigencia por parte de los pacientes.Tooth loss associated with systemic factors, pathological and traumatic conditions, promotes the bone resorption of residual ridges, this, creates functional problems such as lack of stability and retention of removable dentures as well as aesthetic and psychological disturbances. These defects vary depending on the amount of bone loss and soft tissue they reach. At present there are described various techniques that can correct these defects. One of these is the roll technique which shows very good results by increasing the size of the alveolar ridge and decrease aesthetic defects in the anterior area of the maxilla. The aim of this article is to describe a case of a patient with Seibert bone loss type III, rehabilitated with

  14. A comparison of different compressive forces on graft materials during alveolar ridge preservation.

    Science.gov (United States)

    Cho, In-Woo; Park, Jung-Chul; Shin, Hyun-Seung

    2017-02-01

    Following tooth extraction, alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. Although previous studies have demonstrated the effects of ARP, few if any studies have investigated the compressive force applied during grafting. The aim of this study was to determine the effects of different compressive forces on the graft materials during ARP. After tooth extraction, sockets were filled with deproteinized bovine bone mineral with 10% porcine collagen and covered by a resorbable collagen membrane in a double-layered fashion. The graft materials were compressed using a force of 5 N in the test group (n=12) and a force of 30 N in the control group (n=12). A hidden X suture was performed to secure the graft without primary closure. Cone-beam computed tomography (CBCT) was performed immediately after grafting and 4 months later, just before implant surgery. Tissue samples were retrieved using a trephine bur from the grafted sites during implant surgery for histologic and histomorphometric evaluations. Periotest values (PTVs) were measured to assess the initial stability of the dental implants. Four patients dropped out from the control group and 20 patients finished the study. Both groups healed without any complications. The CBCT measurements showed that the ridge volume was comparably preserved vertically and horizontally in both groups ( P >0.05). Histomorphometric analysis demonstrated that the ratio of new bone formation was significantly greater in the test group ( P 0.05). The application of a greater compressive force on biomaterials during ARP significantly enhanced new bone formation while preserving the horizontal and vertical dimensions of the alveolar ridge. Further studies are required to identity the optimal compressive force for ARP.

  15. Effectiveness of three different alveolar ridge preservation techniques: a pilot randomized controlled trial.

    Science.gov (United States)

    Avila-Ortiz, Gustavo; Rodriguez, Juan Carlos; Rudek, Ivan; Benavides, Erika; Rios, Hector; Wang, Hom-Lay

    2014-01-01

    The aim of this pilot study was to obtain preliminary data regarding the effectiveness of three different alveolar ridge preservation modalities as compared with a control. Subjects in need of single-rooted tooth extraction were recruited and randomly allocated to one of four treatment groups: group 1 (control)--collagen plug; group 2--socket grafting and polytetrafluoroethylene (PTFE) barrier; group 3--socket grafting, buccal overbuilding, and PTFE barrier; group 4--socket grafting, collagen barrier, and PTFE barrier. The grafting material used in all groups was an allograft. At 16 weeks, surgical reentry was performed, and a bone core biopsy was harvested for histomorphometric analysis. A cone beam computed tomography scan was obtained at baseline and before surgical reentry. Clinical (keratinized mucosa [KM] and buccolingual ridge width [RW] changes) and volumetric outcomes were statistically analyzed. A total of 20 patients were recruited (5 patients per group). KM and buccolingual RW changes were minimal during the 16-week healing period for all groups, with no statistically significant differences. Volumetric analyses revealed comparable alveolar ridge resorption values for groups 1, 2, and 4 (3%, 7%, and 5%, respectively), while group 3 exhibited more reduction (16%). Histomorphometric analysis revealed the presence of adequate average values of mineralized tissue (group 1, 46.4%; group 2, 28.88%; group 3, 48.81%; group 4, 41.13%). Based on the clinical and volumetric outcomes, none of the ridge preservation modalities was superior to the control. The combination allograft (freeze-dried bone allograft and demineralized freeze-dried bone allograft) employed in this study appears to be a safe and adequate biomaterial for intraoral grafting.

  16. A Case Report of Ridge Augmentation using Onlay Interpositional Graft: An Approach to Improve Prosthetic Prognosis of a Deficit Ridge

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    Devanand Shetty

    2014-01-01

    Full Text Available Background: Periodontal therapy has developed beyond the scope of the treatment of periodontal pathoses. Periodontal plastic surgery consists of the reconstructive procedures designed to enhance the both function and esthetics. Deficient ridges pose a severe problem to the restorative dentist in restoring the natural form, function and esthetics of the prosthesis replacing the natural dentition. Depending upon the severity, location of these defects and the prosthetic option chosen, hard and soft tissue ridge augmentation or non-surgical approach or a combination may help to address them. The present clinical report describes a soft tissue ridge augmentation of a localized ridge defect in maxillary aesthetic region using onlay interpositional graft followed by fixed partial denture.

  17. Corticotomy-assisted decompensation for augmentation of the mandibular anterior ridge.

    Science.gov (United States)

    Kim, Seong-Hun; Kim, Insoo; Jeong, Do-Min; Chung, Kyu-Rhim; Zadeh, Homayoun

    2011-11-01

    This article introduces a technique combining corticotomy and orthodontic forces, or accelerated osteogenic orthodontics, for use in patients with a Class III occlusion and a thin alveolus who will undergo orthognathic surgery. Two adults with Class III malocclusion undergoing anterior decompensation for mandibular setback surgery were selected. The first patient was treated with accelerated osteogenic orthodontics and conventional decompensation. The second patient was treated with accelerated osteogenic orthodontics and decompensation with a temporary skeletal anchorage device in concert with guided tissue regeneration. Decortication of bone was performed to the mandibular teeth with a low-speed round bur and piezosurgery. After hemostasis, bone graft material was placed into the decorticated area. In the severely thin alveolar ridge, a rigid scaffold was applied for immobilization of graft material. After approximation of the flap, an immediate orthodontic force was applied to the teeth to initiate rapid tooth movement. Rapid tooth movement into predetermined positions for orthognathic surgery was accomplished in all mandibular anterior teeth. Preoperative 3-dimensional imaging showed dehiscences on the facial aspects of the mandibular anterior teeth. Postoperative imaging demonstrated coverage of the denuded roots with radiodense material. The accelerated osteogenic orthodontic technique is a safe and effective treatment option for mandibular anterior decompensation treatment of these patients. When combined with a temporary skeletal anchorage device and bone augmentation, this technique facilitated the decompression of the mandibular anterior teeth in severely compromised dentitions. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  18. Alveolar ridge preservation using resorbable bioactive ceramic composite: a histological study.

    Science.gov (United States)

    Al-Sabbagh, Mohanad; Burt, John; Barakat, Ahmed; Kutkut, Ahmad; El-Ghannam, Ahmed

    2013-07-01

    The purpose of this study was to histologically evaluate newly generated vital bone using porous granules of bioactive and resorbable silica-calcium phosphate nanocomposite (SCPC) in extraction sockets. Six patients with a non-restorable maxillary central incisor requiring extraction followed by implant placement participated in the study. Extraction sockets were grafted with granules of SCPC. After 6 months, a bone core sample was retrieved from the center of the healed socket for histologic analysis, and dental implants were placed. Alveolar bone width was clinically assessed immediately after tooth extraction and 6 months after bone grafting, at the time of implant placement. Alveolar bone height was radiographically assessed immediately after tooth extraction and 6 months after extraction. Histomorphometric analyses of sockets grafted with SCPC for 6 months revealed 46.8% +/- 14% new vital bone and 2.5% +/- 1.5% graft material remnants. In these sockets, the mean bone height resorption over the 6-month period of healing was 1.6 mm +/- 1.5 mm. The mean bone width resorption of 2 mm +/- 0.7 mm was found at the bone crest. The results of this study suggest that SCPC graft material reduces the amount of change in alveolar ridge dimensions after tooth extraction and facilitates the regeneration of new vital bone.

  19. Alveolar ridge preservation using autogenous tooth graft versus beta-tricalcium phosphate alloplast: A randomized, controlled, prospective, clinical pilot study.

    Science.gov (United States)

    Joshi, Chaitanya Pradeep; Dani, Nitin Hemchandra; Khedkar, Smita Uday

    2016-01-01

    A randomized, prospective clinical, radiographical, and histological study was conducted to evaluate healing after alveolar ridge preservation technique using two different graft materials, namely, a novel autogenous graft material i. e., autogenous tooth graft (ATG) and beta-tricalcium phosphate (β-TCP) alloplast. Fifteen patients undergoing extraction of at least three teeth were selected. Atraumatic extractions were performed. Of the three extraction sockets, one was grafted with ATG, other with β-TCP, and the third was left ungrafted. Cone-beam computed tomography scans were taken immediately after grafting and 4 months postoperatively to check the changes in alveolar crest height and width at all the sites. Three patients in whom implant placement was done after complete healing; bone samples were harvested using a 3 mm diameter trephine during osteotomy preparation from both the ridge preserved sites and studied histologically. There was a statistically significant difference when the changes in width and height of alveolar crest were compared within all the three groups ( P alveolar crest height and width. Histological analysis also showed the same trend with more new bone formation at ATG-grafted sites as compared to β-TCP-grafted sites. Postextraction, ridge preservation leads to more predictable maintenance of alveolar ridge height and width. ATG as compared to β-TCP provided superior results. Based on this, we conclude that ATG material can serve as a better alternative to conventional bone graft materials.

  20. Distracción osteogénica alveolar como método de aumento del reborde alveolar Alveolar osteogenic distraction as method to increase the alveolar ridge

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    Denia Morales Navarro

    2011-03-01

    , disadvantages and complications. A bibliographic review was made by database search of reference systems as MEDLINE and PubliMed using the descriptors "alveolar distraction" o "osteogenic distraction". The published bibliographic sources mainly over 5 years concluding that this technique is an excellent alternative for the bone and soft tissues formation in zones of alveolar atrophy including three stages: latency, distraction and consolidation; being a foreseeable method and with low rates of bone reabsorption compared to other techniques of increase of alveolar ridge. It has its main indication in implant therapy to provide bone volume. We must to individualize each case and to use the more appropriate method according the clinical and personal features of patient. A proper case selection and a better understand of technique are essential to achieve successful results by alveolar osteogenic distraction. In Cuba the alveolar distraction has been not much applied being necessary to expand the studies on this subject matter.

  1. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

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    Farah Asa’ad

    2016-01-01

    Full Text Available To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration.

  2. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

    Science.gov (United States)

    Asa'ad, Farah; Giannì, Aldo Bruno; Giannobile, William V.; Rasperini, Giulio

    2016-01-01

    To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. PMID:27366149

  3. Comparison of alveolar ridge preservation method using three dimensional micro-computed tomographic analysis and two dimensional histometric evaluation

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    Park, Young Seok; Kim, Sung Tae; Oh, Seung Hee; Park, Hee Jung; Lee, Sophia; Kim, Taeil; Lee, Young Kyu; Heo, Min Suk [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2014-06-15

    This study evaluated the efficacy of alveolar ridge preservation methods with and without primary wound closure and the relationship between histometric and micro-computed tomographic (CT) data. Porcine hydroxyapatite with polytetrafluoroethylene membrane was implanted into a canine extraction socket. The density of the total mineralized tissue, remaining hydroxyapatite, and new bone was analyzed by histometry and micro-CT. The statistical association between these methods was evaluated. Histometry and micro-CT showed that the group which underwent alveolar preservation without primary wound closure had significantly higher new bone density than the group with primary wound closure (P<0.05). However, there was no significant association between the data from histometry and micro-CT analysis. These results suggest that alveolar ridge preservation without primary wound closure enhanced new bone formation more effectively than that with primary wound closure. Further investigation is needed with respect to the comparison of histometry and micro-CT analysis.

  4. Evaluation of “Autogenous Bioengineered Injectable PRF – Tooth graft” combination (ABIT in reconstruction of maxillary alveolar ridge defects: CBCT volumetric analysis

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    Lydia Nabil Melek

    2017-01-01

    Full Text Available Background: Extracted human teeth were suggested as a source for autogenous bone grafts, especially that they have similar chemical composition to bone. In order to accelerate healing of bone graft over the bony defect, numerous techniques utilizing platelet and fibrinogen concentrations have been introduced in the literature. Objectives: To evaluate clinically and radiographically the use of autogenous tooth bone graft material in combination with injectable platelet-rich fibrin for reconstruction of resorbed maxillary alveolar ridge. Patients and methods: This study was conducted in ten patients indicated for extraction of maxillary anterior or premolar teeth and having maxillary ridge deficiency. Implants were placed after a period of 3 months of bone grafting. The patients were selected from those attending the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Alexandria University. Results: Clinically, all the patients showed uneventful healing. Radiographically, the results show 30% increase in mean bone density in the period of six months when compared to pre-operative readings. The grafted site showed an increase in the mean volume by 23.47% three months post-operative when compared to the base line measurements preoperatively. Radiographic evaluation of the alveolar ridge after 3 months of grafting showed a significant mean increase in the ridge width and height at the grafted site. Conclusion: Autogenous fresh demineralized tooth graft that is prepared at the chairside after extractions could be considered as the gold standard for socket preservation, bone augmentation in sinuses or filling bone defects, in patients having non restorable teeth indicated for extraction. The adjuvant use of injectable PRF with its high growth factor content may contribute to more favorable and predictable bone formation at the grafted site.

  5. The hidden X suture: a technical note on a novel suture technique for alveolar ridge preservation.

    Science.gov (United States)

    Park, Jung-Chul; Koo, Ki-Tae; Lim, Hyun-Chang

    2016-12-01

    The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by 1.56±0.90 mm in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by 0.25±0.66 mm. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure ( P preserving horizontal width and minimizing vertical reduction in comparison to X suture ( P preserving the width of KT and the dimensions of the alveolar ridge after ARP.

  6. Alveolar Ridge Preservation After Tooth Extraction with DFDBA and Platelet Concentrates: A Radiographic Retrospective Study.

    Science.gov (United States)

    Baniasadi, Behrang; Evrard, Laurence

    2017-01-01

    The purpose of this study was to evaluate vertical alveolar bone loss 3 months after tooth extraction when a technique of ridge preservation was applied using a particulate demineralized freeze-dried bone allograft 300 - 500 µm associated with platelet concentrates (platelet-rich-fibrin) in the form of gel and membranes. A retrospective radiological clinical study was conducted on 56 patients for whom 95 extractions had been performed immediately followed by alveolar filling. Among the patients, 17 were smokers and 16 were provided with an immediate removable temporary prosthesis after extractions. Vertical bone loss was measured radiologically by panoramic X-ray before extractions and by a computed tomography scan 3 months after, at the level of mid-buccal bone wall, by two independent observers. For statistical analysis, Student's t-test was performed to compare the mean bone loss between mono- and pluri-radicular teeth and to compare the mean bone loss between tobacco users versus non users and finally to compare the mean bone loss between individuals that had provisional removable prosthesis and those that had not. Three months after tooth extraction, the mean of vertical loss of the mid-buccal bone wall was 0.72 (SD 0.71) mm (5.53% SD 5.19). No significant difference between bone loss at mono-radicular and pluri-radicular teeth (P = 0.982) was observed. There was no significant correlation between tobacco habits and bone loss (P = 0.2), nor between provisional removable prosthesis and bone loss (P = 0.786). These results indicate a good potential for the technique using Demineralized Freeze-Dried Bone Allograft 300 - 500 µm and platelet concentrates in alveolar bone preservation.

  7. A radiographic study on the prevalence of knife-edge residual alveolar ridge at proposed dental implant sites

    International Nuclear Information System (INIS)

    AlFaleh, Wafaa

    2009-01-01

    Dental implants are widely used in restoration of completely or partially edentulous dental arches. Before placement of endosseous implants in the jaws, both the quantity and quality of the residual ridge must be assessed radiographically. Remodeling activity after tooth extraction is localized primarily at the crestal area of the residual ridges, resulting in reduction of the height of bone and creation of various three-dimensional shapes of the residual ridges. When bone resorption at the lingual and buccal aspects is greater than that at the crestal area, a knife-edge type of residual ridge develops. The aim of this study was to evaluate the prevalence of the knife-edge morphology of the residual alveolar bone at proposed implant sites in partially or completely edentulous patients. Computed tomography (CT) cross-sectional images of the upper and lower jaws were assessed at the proposed sites before implant placement. Images of 258 proposed implant sites belonging to 30 patients were assessed radiographically. In 120 proposed implant sites out of 258 (46.5%), the residual alveolar ridge had a knife-edge configuration, the majority belonging to completely edentulous patients who lost their teeth more than ten years previously. High prevalence of knife-edge ridge was found, therefore, replacement of missing teeth by immediate implant is recommended to prevent atrophy or knife-edge morphology of the residual ridge. (author)

  8. Microcomputed tomographic analysis of the alveolar ridge alteration around extraction sites with and without immediate implants placement: in vivo study.

    Science.gov (United States)

    Al-Hezaimi, Khalid; Al-Shabeeb, Munirah Saleh; Al-Askar, Mansour; Javed, Fawad; Nooh, Nasser; Al-Rasheed, Abdulaziz; Babay, Nadir; Al-Hamdan, Khalid Saleh; Wang, Hom Lay

    2014-04-01

    The aim was to assess the alveolar ridge alteration around extraction sites with and without immediate implants according to extraction socket classification (ESC) using microcomputed tomography (micro-CT). Ten beagle dogs (mean age and weight: 24 ± 0.83 months and 13.8 ± 0.49 kg, respectively) were randomly divided into three groups according to the ESC. In Group 1 (ESC-I), bilateral first and third premolars were extracted and replaced with immediate implants. In Group 2 (ESC-II), two adjacent premolars were extracted with one immediate implant placement in the mesial socket in the maxilla and in the distal socket in the mandible. In Group 3 (ESC-III), three adjacent teeth were extracted and an immediate implant was placed in the central socket. Primary closure was achieved using resorbable sutures. Buccal sites with dehiscence defects were excluded. After 4 months, subjects were sacrificed and alveolar ridge widths were measured at 1 mm interval in axial and sagittal views, using micro-CT in sites with and without immediate implants. In sites without immediate implant placement, alveolar ridge width was significantly higher in Group 1(6.1 ± 1.35mm) than Group 3 (4.14 ± 1.53 mm) (p immediate implant placement, the alveolar ridge width was higher among sites in Group 1 (6.4 ± 3.8 mm) than Group 2 (4.8 ± 0.46 mm) (p immediate implant placement at 1 mm thickness, there was no significant difference in the alveolar ridge widths. With the exception of Group 1 (ESC-I), immediate implant placement did not prevent or minimize bone remodeling in extraction sites according to ESC. © 2012 Wiley Periodicals, Inc.

  9. A methodological approach to assessing alveolar ridge preservation procedures in humans: hard tissue profile.

    Science.gov (United States)

    Lambert, France; Vincent, Kim; Vanhoutte, Vanessa; Seidel, Laurence; Lecloux, Geoffrey; Rompen, Eric

    2012-09-01

    Multiple surgical protocols using biomaterials have been proposed to limit the typical post-extraction bone resorption. However, because of the heterogeneity of the studies, particularly the differences in assessment methods, it is difficult to determine the superiority of one technique over another. The objective of this study was to describe a new radiographic method to draw a map of alveolar bone remodelling after alveolar ridge preservation procedures to compare different surgical techniques more accurately. The newly developed measuring method was applied to a case series describing a specific preservation technique. Fourteen extraction sites (in 14 patients) located in the upper anterior maxilla were treated with bovine hydroxyapatite (0.25- to 1-mm particles) and a saddled connective tissue graft. A radiographic three-dimensional assessment of the hard tissues was performed at baseline and 3 months after the procedure. Standardized horizontal measurements were taken at three corono-apical levels (-2, -5 and -9 mm) and at three mesio-distal levels (mesial, centre and distal) in the buccal and palatal aspects. Vertical measurements were also recorded in nine regions superior to the alveolar crest. The measurements were performed by two independent observers and intra- and inter-observer effects were evaluated. No inter- and intra-observer effects were found when analysing the measurements from these two observers. The horizontal dimension of the crest decreased by 1.6 mm (20%) in the cervical regions (-2 mm level), decreased moderately, by 1 mm (12%), at the -5 mm level and decreased very little, 0.5 mm (6%), at the apical (-8 mm) level. The losses were always significantly higher in the buccal than in the palatal aspect. Buccally, the maximal bone remodelling at the cervical level remained below 1 mm. Vertical bone resorption was homogeneous andalveolar ridge preservation technique (BHA+saddle connective tissue graft). © 2012 John Wiley & Sons A/S.

  10. Accelerated osteogenic orthodontics technique: a 1-stage surgically facilitated rapid orthodontic technique with alveolar augmentation.

    Science.gov (United States)

    Wilcko, M Thomas; Wilcko, William M; Pulver, Jeffrey J; Bissada, Nabil F; Bouquot, Jerry E

    2009-10-01

    Demineralization of a thin layer of bone over a root prominence after corticotomy surgery can optimize the response to applied orthodontic forces. This physiologic response is consistent with the regional acceleratory phenomenon process. When combined with alveolar augmentation, one is no longer strictly at the mercy of the original alveolar volume and osseous dehiscences, and fenestrations can be corrected over vital root surfaces. This is substantiated with computerized tomographic and histologic evaluations. Two case reports are presented that demonstrate the usefulness of the accelerated osteogenic orthodontics technique in de-crowding and space closing for the correction of dental malocclusions. Orthodontics is combined with full-thickness flap reflection, selective alveolar decortication, ostectomy, and bone grafting to accomplish complete orthodontic treatment. Rapid tooth movement was demonstrated in both cases and stability up to 8 years of retention. The accelerated osteogenic orthodontics technique provides for efficient and stable orthodontic tooth movement. Frequently, the teeth can be moved further in one third to one fourth the time required for traditional orthodontics alone. This is a physiologically based treatment consistent with a regional acceleratory phenomenon and maintaining an adequate blood supply is essential.

  11. Gummy Smile Correction Using Lingual Orthodontics and Augmented Corticotomy in Extremely Thin Alveolar Housing.

    Science.gov (United States)

    Nahm, Kyung-Yen; Shin, Seung-Yun; Ahn, Hyo-Won; Kim, Seong-Hun; Nelson, Gerald

    2017-10-01

    Tooth movement out of anatomic limitations was assisted by augmented corticotomy using deproteinized bovine bone mineral. Lip protrusion can be reduced by premolar extraction followed by retraction of the anterior teeth. Surgical intervention is appropriate when the alveolar bone housing of the anterior region is insufficient for the tooth movement. In this patient, corticotomy in upper palatal area and anterior segmented osteotomy in the mandible were performed. Anatomic limitation to the retraction was expanded by xenograft. An antero-posterior lingual appliance was used to bodily retract the upper anterior teeth. The gummy smile was resolved by intrusion of upper entire arch using 2 mid-palatal temporary skeletal anchorage devices. New bone formation was observed on palatal side of upper anterior teeth. The teeth were moved into augmented area without fenestration or vitality loss. Lip protrusion was resolved, and the gummy smile was effectively improved. Orthodontic tooth movement beyond the limitation of the alveolar bone housing can be achieved with surgical assistance, which can be performed under local anesthesia. Without orthognathic surgery, the gummy smile can be reduced using an antero-posterior lingual retractor with mid-palatal skeletal anchorage.

  12. Alveolar ridge preservation using autogenous tooth graft versus beta-tricalcium phosphate alloplast: A randomized, controlled, prospective, clinical pilot study

    Directory of Open Access Journals (Sweden)

    Chaitanya Pradeep Joshi

    2016-01-01

    Full Text Available Background: A randomized, prospective clinical, radiographical, and histological study was conducted to evaluate healing after alveolar ridge preservation technique using two different graft materials, namely, a novel autogenous graft material i. e., autogenous tooth graft (ATG and beta-tricalcium phosphate (β-TCP alloplast. Materials and Methods: Fifteen patients undergoing extraction of at least three teeth were selected. Atraumatic extractions were performed. Of the three extraction sockets, one was grafted with ATG, other with β-TCP, and the third was left ungrafted. Cone-beam computed tomography scans were taken immediately after grafting and 4 months postoperatively to check the changes in alveolar crest height and width at all the sites. Three patients in whom implant placement was done after complete healing; bone samples were harvested using a 3 mm diameter trephine during osteotomy preparation from both the ridge preserved sites and studied histologically. Results: There was a statistically significant difference when the changes in width and height of alveolar crest were compared within all the three groups (P < 0.05. Among three sites, ATG-grafted sites showed the most superior results with a minimal reduction in alveolar crest height and width. Histological analysis also showed the same trend with more new bone formation at ATG-grafted sites as compared to β-TCP-grafted sites. Conclusion: Postextraction, ridge preservation leads to more predictable maintenance of alveolar ridge height and width. ATG as compared to β-TCP provided superior results. Based on this, we conclude that ATG material can serve as a better alternative to conventional bone graft materials.

  13. Ridge expansion alone or in combination with guided bone regeneration to facilitate implant placement in narrow alveolar ridges: a retrospective study.

    Science.gov (United States)

    Tang, Yu-Long; Yuan, Jing; Song, Ying-Liang; Ma, Wei; Chao, Xie; Li, De-Hua

    2015-02-01

    To evaluate the long-term outcomes of ridge expansion technique in dealing with horizontal bony insufficiency of alveolar ridges for implant placement. During the period 2004-2009, 168 patients with width insufficiency of alveolar ridges were treated using the ridge expansion technique to obtain an improved bony base for implant placement. Depending on the severity of width insufficiency, the surgical procedures were classified into two groups: ridge expansion alone (Group 1) and ridge expansion in combination with guided bone regeneration (Group 2). After 4-6 months of unloaded healing, the implants were restored. The patients were followed up until 2013 with clinical and radiographic examinations. Among the 168 patients, 11 patients underwent a fracture of labial/buccal bony plate during surgery, which was corrected by changing the procedure into bone grafting, yielding a surgical failure rate of 6.5%. In the remaining 157 patients successfully treated by ridge expansion alone or in combination with GBR, 226 implants were simultaneously placed as planned. No implant failed over 2.8 years (6 months to 8 years) of follow-up, yielding a cumulative implant survival rate of 100% in each group. Six implants in Group 1 and 4 implants in Group 2, although osseointegrated and in function, did not fulfill success criteria: Cumulative implants' success rates were 93.2% in Group 1 and 95.6% in Group 2. The mean marginal bone losses during the first year in Group 1 and Group 2 were 0.69 and 0.43 mm, respectively, followed by an annual loss of ~ 0.06 and 0.07 mm, respectively, in the following years. No clinical parameter was abnormal. Twenty-two (10.4%) implants were exposed to peri-implant mucositis, whereas 19 (11.0%) implant-supported restorations were involved in prosthetic complications. The preliminary results of this retrospective study indicate that ridge expansion alone or in combination with GBR can be considered an effective and safe procedure for treatment of

  14. Hard and soft tissue changes following alveolar ridge preservation: a systematic review.

    Science.gov (United States)

    MacBeth, Neil; Trullenque-Eriksson, Anna; Donos, Nikolaos; Mardas, Nikos

    2017-08-01

    Two focused questions were addressed within this systematic review. Q1) What is the effect of alveolar ridge preservation on linear and volumetric alveolar site dimensions, keratinised measurements, histological characteristics and patient-based outcomes when compared to unassisted socket healing. Q2) What is the size effect of these outcomes in three different types of intervention (guided bone regeneration, socket grafting and socket seal). An electronic search (MEDLINE, EMBASE, Cochrane Central Register LILACS, Web of Science) and hand-search was conducted up to June 2015. Randomised controlled trials (RCT) and controlled clinical trials (CCT); with unassisted socket healing as controls: were eligible in the analysis for Q1. RCTs, CCTs and large prospective case series with or without an unassisted socket healing as control group were eligible in the analysis for Q2. Nine papers (8 RCTs and 1 CCTs) were included in the analysis for Q1 and 37 papers (29 RCTs, 7 CCTs and 1 case series) for Q2. The risk for bias was unclear or high in most of the studies. Q1: the standardised mean difference (SMD) in vertical mid-buccal bone height between ARP and a non-treated site was 0.739 mm (95% CI: 0.332 to 1.147). The SMD when proximal vertical bone height and horizontal bone width was compared was 0.796mm (95% CI: -1.228 to 0.364) and 1.198 mm (95% CI: -0.0374 to 2.433). Examination of ARP sites revealed significant variation in vital and trabecular bone percentages and keratinised tissue width and thickness. Adverse events were routinely reported, with three papers reporting a high level of complications in the test and control groups and two papers reporting greater risks associated with ARP. No studies reported on variables associated with the patient experience in either the test or the control group. Q2: A pooled effect reduction (PER) in mid-buccal alveolar ridge height of -0.467 mm (95% CI: -0.866 to -0.069) was recorded for GBR procedures and -0.157 mm (95% CI

  15. Systemic non-malignant osteoporosis and reduction of edentulous alveolar ridges

    Directory of Open Access Journals (Sweden)

    Poštić Srđan D

    2014-01-01

    Full Text Available Introduction. Systemic osteoporosis damages skeletal bones to different degrees. The aim of this study was to determine the intensity and correlation of the osteoporotic changes in the bone density of the skeleton and body mass index (BMI with a reduction in edentulous mandibles, and to assess possibility of reparation of layers of mandibles with increase of mineral content in jaws of patients affected by osteoporosis. Material and Methods. In this study, 99 edentulous patients with decreased bone density comprised the experimental group, and 48 edentulous patients with normal bone densities formed the control. The age of the examined patients was 69.02 ± 7,9, range 53-74 of females and 69.11 ± 7.1, range 59-76 years. Radiographs of the hands and panoramic radiographs were done for all the patients. The values of BMI, metacarpal index, density of lumbar spine (L2-L4, in the phalanx and in segments of the mandibles as well as the edentulous alveolar ridges heights were measured, assessed and calculated. Results. The lowest value of the total skeletal density was established in the osteoporotic patients on the basis of the average T-score of- 2.5 in men, and - 2.6 in women. Minimum values of the edentulous ridges heights (right/left, in mm were measured in both osteoporotic females (21.84/22.39 and males 24.90/24.96 patients. By comparison of the densities of the metacarpal bones, proximal phalanx, segments of the edentulous mandibles and based on the numerical values of the edentulous ridges heights, x2 = 3.81 was found in men and x2 = 4.03 was found in women with normal bone densities; x2 = 5.92 was found in men and x2 = 6.25 was found in women with osteopenia; x2 = 2.63 was found in men and x2 = 3.85 was found in women with osteoporosis, on the level of probability of 0.05. After application of calcium and calcitonin in solutions, moderate increment of density (p < 0.05; p < 0.01 was verified, compensating up to 4% of total loss of mass

  16. SYSTEMIC NON-MALIGNANT OSTEOPOROSIS AND REDUCTION OF EDENTULOUS ALVEOLAR RIDGES

    Directory of Open Access Journals (Sweden)

    Postic D. Srdjan

    2014-04-01

    Full Text Available Introduction. Systemic osteoporosis damages skeletal bones to different degrees. The aim of this study was to determine the intensity and correlation of the osteoporotic changes in the bone density of the skeleton and body mass index (BMI with a reduction in edentulous mandibles, and to assess possibility of reparation of layers of mandibles with increase of mineral content in jaws of patients affected by osteoporosis. Material and Methods. In this study, 99 edentulous patients with decreased bone density comprised the experimental group, and 48 edentulous patients with normal bone densities formed the control. The age of the examined patients was 69.02 ± 7,9, range 53–74 of females and 69.11 ± 7.1, range 59–76 years. Radiographs of the hands and panoramic radiographs were done for all the patients. The values of BMI, metacarpal index , density of lumbar spine (L2–L4, in the phalanx and in segments of the mandibles as well as the edentulous alveolar ridges heights were measured, assessed and calculated. Results. The lowest value of the total skeletal density was established in the osteoporotic patients on the basis of the average T-score of – 2.5 in men, and – 2.6 in women. Minimum values of the edentulous ridges heights (right/left, in mm were measured in both osteoporotic females (21.84/22.39 and males 24.90/24.96 patients. By comparison of the densities of the metacarpal bones, proximal phalanx, segments of the edentulous mandibles and based on the numerical values of the edentulous ridges heights χ2 = 3.81 was found in men and χ2 = 4.03 was found in women with normal bone densities; χ 2= 5.92 was found in men and χ2=6.25 was found in women with osteopenia; χ2= 2.63 was found in men and χ2 = 3.85 was found in women with osteoporosis, on the level of probability of 0.05. After application of calcium and calcitonin in solutions, moderate increment of density (p < 0.05; p < 0.01 was verified, compensating up to 4% of total loss

  17. Clinical effects of acrylic resilient denture liners applied to mandibular complete dentures on the alveolar ridge.

    Science.gov (United States)

    Kimoto, S; Kimoto, K; Gunji, A; Kawai, Y; Murakami, H; Tanaka, K; Syu, K; Aoki, H; Toyoda, M; Kobayashi, K

    2007-11-01

    The purpose of this study was to investigate whether resilient denture liners has the potential to decrease problems affecting the alveolar ridge mucosa during the first adjustment session following the initial fitting of the denture. Interventions were complete denture treatment with permanent acrylic resilient denture liner dentures (RLD) in mandibles and conventional heat-activated acrylic resin dentures (ARD) in mandibles. Maxillary dentures were fabricated with conventional heat-activated ARD. Seventy-four subjects were randomly allocated to the RLD and ARD groups by random permuted blocks within the strata method after obtaining written informed consent. A randomized controlled parallel clinical trial with two hospital centres was conducted from April 2004 to July 2006. The problems were comprehensively evaluated by three outcomes with subjective and objective factors as follows: (i) numbers of sore spots, (ii) duration of wearing dentures and (iii) pain perception with 100 mm Visual Analog Scale. The numbers of sore spots in the mandibular support and border areas for the RLD group were significantly less than those for the ARD groups (P < 0.05). The RLD wearers were able to wear their dentures an additional day longer than the ARD wearers (P < 0.05). The maxillary and mandibular pain ratings for the RLD group were significantly lower than those for the ARD group (P < 0.05). Application of resilient denture liners to mandibular complete dentures provided edentulous patients with fewer problems affecting the alveolar during the first adjustment session following the initial fitting of the denture when compared with conventional denture treatments.

  18. [Evaluation of alveolar ridge reconstruction and esthetic result following immediate implant].

    Science.gov (United States)

    Wang, Ying; Lin, Ye; Chen, Bo; Zhang, Yu; Di, Ping

    2016-02-18

    To evaluate the bone alteration subject to remodeling and analyze the esthetic result following immediate implant placement of incisors. In this study, 20 patients (13 women, 7 men) were involved, who needed implants for incisors of maxilla. The patients received 23 immediate implants totally. On the day of surgery and 6 months after the implants were placed, Cone beam CT (CBCT) was taken. The thickness of the alveolar ridge and the vertical change of marginal bone levels onthe mesial and distal aspects of theimplants were measured using the computer software (PlanmecaRomexis Viewer 3.6.0.R). The evaluation of esthetic result by labial convexity score (LCS) and papilla index score (PIS) were analyzed pre-operation and one year after the final crown was delivered. The statistics with paired-t test for the measurement data and Willcoxon test for rating data were done by SPSS 20.0. The survival rate in the two-year follow-up was 100%. The measuring point 1 (MP1), MP2, MP3 and MP4 (0, 2, 4, 6 mm apical to the implant platform, respectively) got significant alterations after 6 months of the follow-up. These differences were statistically significant (PAnkylos System and Replace System, respectively, and the difference was not statistical significant . The esthetic results were quite acceptable. Before treatment, 18 incisors rated 3 for LCS, and 2 incisors rated 4 for LCS;after final restoration, only 5 incisors rated 3 for LCS, and 14 incisors rated 2 for LCS. Before treatment, 15 incisors rated 3 for PIS; after final restoration, 13 incisors rated 3 for PIS. There was no statistically significant difference for the PIS pre-operation and 1 year after final restoration, while there was statistically significant negative change for LCS. Even following the proper surgical technique, the alveolar ridge wall still can't be maintained after immediate implant placed in fresh socket of incisors. The inter-dental papilla could be well maintained, while due to the remodeling of

  19. Hard and Soft Tissue Management of a Localized Alveolar Ridge Atrophy with Autogenous Sources and Biomaterials: A Challenging Clinical Case

    OpenAIRE

    C. Maiorana; D. Andreoni; P. P. Poli

    2016-01-01

    Particularly in the premaxillary area, the stability of hard and soft tissues plays a pivotal role in the success of the rehabilitation from both a functional and aesthetic aspect. The present case report describes the clinical management of a localized alveolar ridge atrophy in the area of the upper right canine associated with a thin gingival biotype with a lack of keratinized tissue. An autogenous bone block harvested from the chin associated with heterologous bone particles was used to re...

  20. Polyhedral microcrystals encapsulating bone morphogenetic protein 2 improve healing in the alveolar ridge.

    Science.gov (United States)

    Matsumoto, Goichi; Ueda, Takayo; Sugita, Yoshihiko; Kubo, Katsutoshi; Mizoguchi, Megumi; Kotani, Eiji; Oda, Naoki; Kawamata, Shin; Segami, Natsuki; Mori, Hajime

    2015-08-01

    Atelocollagen sponges incorporating polyhedra encapsulating bone morphogenetic protein 2 (BMP-2) were implanted into lateral bone defects in the mandible. Half of the bone defects on the left side were treated with atelocollagen sponges containing 1.8 × 10(7) BMP-2 polyhedra, and half were treated with sponges containing 3.6 × 10(6) BMP-2 polyhedra. As controls, we treated the right-side bone defects in each animal with an atelocollagen sponge containing 5 µg of recombinant human BMP-2 (rhBMP-2) or 1.8 × 10(7) empty polyhedral. After a healing period of six months, whole mandibles were removed for micro-computed tomography (CT) and histological analyses. Micro-CT images showed that more bone had formed at all experimental sites than at control sites. However, the density of the new bone was not significantly higher at sites with an atelocollagen sponge containing BMP-2 polyhedra than at sites with an atelocollagen sponge containing rhBMP-2 or empty polyhedra. Histological examination confirmed that the BMP-2 polyhedra almost entirely replaced the atelocollagen sponges and connected the original bone with the regenerated bone. These results show that the BMP-2 delivery system facilitates the regeneration of new bone in the mandibular alveolar bone ridge and has an advance in the technology of bone regeneration for implant site development. © The Author(s) 2015.

  1. Photoelastic Stress Analysis Surrounding Implant-Supported Prosthesis and Alveolar Ridge on Mandibular Overdentures

    Directory of Open Access Journals (Sweden)

    Dorival Pedroso da Silva

    2010-01-01

    Full Text Available The purpose of this research was to evaluate the maximum stress around osseointegrated implants and alveolar ridge, in a mandible with left partial resection through a photoelastic mandibular model. The first group consisted of two implants: traditional model (T, implants placed in the position of both canines; fulcrum model (F, implants placed in the position of left canine CL and right lateral incisor LiR. Both models linked through a bar and clips. The second group was consisted of three implants, with implants placed in the position of both canines (CR and CL and the right lateral incisor (LiR, which composed four groups: (1 model with 3 “O” rings, (2 model 2 ERAs, bar with clips, (3 model 2 ERAs bar without clips; (4 model “O” ring bar and ERA. An axial and an oblique load of 6.8 kgf was applied on a overdenture at the 1st Pm, 2nd Pm, and 1st M. Results showed that the area around the left canine (CL was practically free of stress; the left lateral incisor (LiL developed only small tensions, and low stress in all the other cases; the right canine tooth suffered the largest concentrations of stress, mainly with the ERA retention mechanism.

  2. Alveolar ridge preservation techniques: a systematic review and meta-analysis of histological and histomorphometrical data.

    Science.gov (United States)

    De Risi, Valeria; Clementini, Marco; Vittorini, Gianluca; Mannocci, Alice; De Sanctis, Massimo

    2015-01-01

    The aim of this article was to systematically review histological and histomorphometrical data from literature that provide information regarding the effect of alveolar ridge preservation procedures on healing after tooth extraction in humans. The MEDLINE-PubMed and the Cochrane CENTRAL databases were searched up to September 2012; 38 papers were selected from 646 founded. A meta-analysis was performed regarding the variations in the mean percentage of Bone, Connective Tissue and Residual Graft Material between three different types of Procedures. The highest value regarding bone percentages is produced at 3 months by Procedures with Allografts (54.4%), while the lowest is obtained, at 5 months, by those using Xenografts (23.6%). Referring to connective tissue, the highest and lowest values are shown at 7 months, with Allografts (67%) and Alloplasts (27.1%), respectively. Regarding residual graft material, the lowest rates are displayed by Procedures with Allografts (12.4-21.11%), while those using Xenografts and Alloplasts showed the best results at 7 months (37.14 and 37.23%). No statistical difference was found. With the limitations due to the features of the selected papers, no major histological and histomorphometrical differences arose among different procedures or when compared to spontaneous healing. Thus, it might be argued that in preserved sites it is unnecessary to wait over 3 to 4 months prior to implant insertion. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. A contemporary approach for treatment planning of horizontally resorbed alveolar ridge: Ridge split technique with simultaneous implant placement using platelet rich fibrin membrane application in mandibular anterior region

    Directory of Open Access Journals (Sweden)

    Prathahini S Parthiban

    2017-01-01

    Full Text Available Treatment of edentulous sites with horizontal atrophy represents a clinical situation in which the positioning of endosseous implants might be complex or sometimes impossible without a staged regenerative approach. This case report presents management of horizontally deficient mandibular anterior ridge with a contemporary approach to treatment planning and application of platelet-rich fibrin membrane for ridge split technique and simultaneous implant placement. Implants in anterior mandibular area are considered to be most predictable, stable, with high success rate and patients' satisfaction with implant esthetics. In contrast to traditional ridge augmentation techniques, ridge splitting allows for immediate implant placement following surgery and eradicates the possible morbidity from a second surgical site.

  4. Prospective Clinical and Radiographic Study of Alveolar Ridge Preservation Combining Freeze-Dried Bone Allograft With Two Xenogeneic Collagen Matrices.

    Science.gov (United States)

    Parashis, Andreas O; Hawley, Charles E; Stark, Paul C; Ganguly, Rumpa; Hanley, James B; Steffensen, Bjorn

    2016-04-01

    Tooth extractions are followed by significant dimensional changes in the alveolar crest that may preclude implant placement. This randomized, controlled, prospective compares the preservation of soft and hard tissue dimensional changes after alveolar ridge preservation (ARP) using two membranes consisting of collagen matrix (CM) or extracellular matrix (ECM) as barriers over freeze-dried bone allograft (FDBA). Standardized clinical and radiographic measurements of soft and hard tissues were recorded by means of a stent before and 4 months after ARP. The surgery entailed sulcular incisions with minimal flap elevation and repositioning without advancement. Of 11 patients in the CM group and 12 in the ECM group who completed the study, gingival thickness (GT) increased from 0.1 to 0.2 mm for both groups along with a 0.5-mm decrease in the width of keratinized tissue after healing. Reductions in ridge width were most pronounced on the coronal aspect, 1.8 mm for CM and 2.0 mm for ECM, whereas vertical reduction was most pronounced on the buccal aspect, 0.7 to 1.0 mm. Differences between groups were not statistically significant. However, significant correlation for changes in GT (P = 0.001) and crestal bone width (P = 0.002) with preoperative buccal plate thickness (BPT) was observed. Both xenogeneic collagen matrices combined with FDBA were effective in maintaining soft tissues and minimizing ridge resorption in all dimensions after ARP. BPT was an important determinant for amount of change in crestal GT and ridge width.

  5. Scar Tissue Formation Following Alveolar Ridge Preservation: A Case Control Study.

    Science.gov (United States)

    Fickl, Stefan; Kauffmann, Frederic; Stappert, Christian F; Kauffmann, Anke; Schlagenhauf, Ulrich

    The aim of this retrospective case control study was to compare a porcine collagen matrix (Mucograft Seal, Geistlich) with a free gingival punch graft with respect to size, invagination, and color of resulting soft tissue scar formation. Following definition of inclusion and exclusion criteria, 22 patients were retrospectively included in this study. The patients were divided into two groups. In group A, the extraction socket was filled with bovine bone mineral (Bio-Oss, Geistlich) and covered with a free gingival punch graft. In group B, the extraction socket was filled with bovine bone mineral (Bio-Oss) and covered with porcine collagen matrix. After final prosthetic reconstruction (18 implant-retained crowns and 4 fixed partial dentures), two independent examiners evaluated the size, invagination, and color of the soft tissue scar using a modified scar-evaluation scale originally developed for dermal wounds (lower values correspond to less scarring). Patient satisfaction was recorded using a questionnaire. Patient records were screened for frequency and costs of scar removal treatment. The average scar score for groups A and B was 1.33 and 4.3, respectively, revealing significantly less scarring in group B (P = .000295). Frequency and costs of scar removal treatment were statistically significantly higher in Group A (P = .000234). Patient satisfaction was not statistically significantly different between the treatment groups (P = .711 for group A and P = .809 for group B. The results suggest that alveolar ridge preservation using bovine bone mineral and porcine collagen matrix leads to less scar tissue formation when compared with bovine bone mineral and free gingival punch grafts from the palate.

  6. A preliminary study of local administration of dexamethasone after tooth extraction: Better preservation of residual alveolar ridge?

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    Poštić Srđan D.

    2014-01-01

    Full Text Available Background/Aim. It is important that the height of the edentulous alveolar ridge after tooth extraction remains at a reasonable acceptable level for as long as possible. The aim of this study was to report preliminary results of the clinical effect of local oral submucous administration of dexamethasone after tooth extractions in order to prepare alveolar supporting tissues for acceptance of removable dentures. Methods. In a total of 15 patients (11 partially and 4 completely edentulous the quantity of 0.25 mL to 0.5 mL of dexamethasone was injected bucally and orally in the region of the tooth socket after complicated extractions. Results. Healing of extraction wounds was uneventful in all the patients, without pain or local inflammation. Conclusion. Dexamethasone can be locally applied to oral tissues to prevent post-extraction inflammation and extensive resorption of the residual alveolar ridge. The obtained results are promising for patients undergoing classic prosthodontic rehabilitation soon after tooth extraction, demonstrating that there are no adverse effects after local oral corticosteroids administration. [Projekat Ministarstva nauke Republike Srbije, br. 175021

  7. A preliminary study on local administration of dexamethasone after tooth extraction--Better preservation of residual alveolar ridge?

    Science.gov (United States)

    Poštić, Srdjan D; Todorović, Ljubomir

    2014-05-01

    It is important that the height of the edentulous alveolar ridge after tooth extraction remains at a reasonable acceptable level for as long as possible. The aim of this study was to report preliminary results of the clinical effect of local oral submucous administration of dexamethasone after tooth extractions in order to prepare alveolar supporting tissues for acceptance of removable dentures. In a total of 15 patients (11 partially and 4 completely edentulous) the quantity of 0.25 mL to 0.5 mL of dexamethasone was injected bucally and orally in the region of the tooth socket after complicated extractions. Healing of extraction wounds was uneventful in all the patients, without pain or local inflammation. Dexamethasone can be locally applied to oral tissues to prevent post-extraction inflammation and extensive resorption of the residual alveolar ridge. The obtained results are promising for patients undergoing classic prosthodontic rehabilitation soon after tooth extraction, demonstrating that there are no adverse effects after local oral corticosteroids administration.

  8. Influence of preservation of the alveolar ridge on delayed implants after extraction of teeth with different defects in the buccal bone.

    Science.gov (United States)

    Pang, Chaoyuan; Ding, Yuxiang; Hu, Kaijin; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui

    2016-02-01

    Our aim was to evaluate the influence of preservation of the alveolar ridge on delayed implants with different defects in the buccal bone. We enrolled 60 patients who had one posterior mandibular tooth extracted. Cone-beam computed tomography (CT) was used to measure the buccal bone defects in the alveolar ridge before the tooth was extracted (level A=3 to 5 mm, and level B=more than 5 mm). After the tooth had been extracted, the socket either had the alveolar ridge preserved (trial group) or it was left to heal spontaneously (control group). The changes in the dimensions of the alveolar ridge from preoperatively to 6 months postoperatively were evaluated by cone-beam CT. Suitable implants were inserted 6 months later, and their length and diameter recorded. The implant stability quotient was evaluated for the following 3 months. The dimensions of the bone in the alveolar ridge in the trial group were significantly less than those in the control groups in both levels. Fifty-seven patients required implants (except 3 in level B in the control group). There were more longer and wider implants in the trial group than in the control group in Level B. 3 months after implantation, there were no significant differences in implant stability quotients between the groups, though in the control group, Level B, the mean (SD) value was 69.50 (1.00) while in the other groups values were all above 70 at 3 months. We conclude that when the defect in the buccal bone was more than 5mm, the alveolar ridge preservation demonstrated a remarkable effect in preserving the alveolar ridge dimension and delayed implantation. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. The effect of a flapless alveolar ridge preservation procedure with or without a xenograft on buccal bone crest remodeling compared by histomorphometric and microcomputed tomographic analysis.

    Science.gov (United States)

    de Barros, Raquel Rezende Martins; Novaes, Arthur Belém; de Carvalho, Jessica Pires; de Almeida, Adriana Luisa Gonçalves

    2017-08-01

    This study evaluated buccal bone crest remodeling, socket composition after healing, and dimensional ridge preservation after flapless tooth extraction procedures with or without a xenograft comparing histomorphometric and microcomputed tomographic (micro-CT) data. The mandibular premolars of eight dogs were extracted without flaps. One socket on each side received a grafting material (test group), and the other remained only with a blood clot (control group). Twelve weeks after treatment, buccal bone crest, alveolar ridge dimensions, and composition were analyzed by histomorphometry and micro-CT. Two- and three-dimensional evaluations showed better results for the grafted group when compared to the non-grafted group. The flapless alveolar ridge preservation procedure with deproteinized bovine bone material enhanced buccal bone crest, alveolar ridge dimensions and bone formation when compared to sockets with the blood clot only, as observed by histomorphometric and micro-CT analysis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Comparison of allografts and xenografts used for alveolar ridge preservation. A clinical and histomorphometric RCT in humans.

    Science.gov (United States)

    Serrano Méndez, Carlos Alberto; Lang, Niklaus Peter; Caneva, Martina; Ramírez Lemus, Gloria; Mora Solano, Gerardo; Botticelli, Daniele

    2017-08-01

    Several types of bone grafts are used in ridge preservation procedures. To compare the healing of allografts and xenografts applied for alveolar ridge preservation. Twenty volunteers in need of extraction of a single-rooted tooth prior to implant installation were randomized into two groups. One group received a deproteinized cancellous bovine bone xenograft embedded in a 10% collagen matrix and the other a demineralized freeze-dried cortical bone allograft. A collagen membrane was used to cover the grafts, flaps were sutured. At baseline and 6 months later, clinical measurements including vertical and horizontal bone dimensions were taken. Histomorphometric analysis was performed. Both groups showed shrinkage of bone dimensions. At mesial, center and distal sites, the vertical changes in dimension were -0.6, 0.5, and -0.1 mm for the allograft and -1.1, -0.4, and -0.9 mm for the xenograft. The horizontal changes in dimensions were -1.4 mm for the allograft and -2.6 mm for the xenograft. New bone and residual graft material were 25.5 ± 10.1% and 33.8 ± 9.4% at the allograft and 35.3 ± 16.8% and 22.2 ± 13.4% at the xenograft sites. None of the differences was statistically significant. Both grafting materials are suitable for the preservation of the alveolar ridge. © 2017 Wiley Periodicals, Inc.

  11. Predictive value of ridge dimensions on autologous bone graft resorption in staged maxillary sinus augmentation surgery using Cone-Beam CT.

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    Klijn, R J; van den Beucken, J J J P; Bronkhorst, E M; Berge, S J; Meijer, G J; Jansen, J A

    2012-04-01

    No studies are available that provide predictive parameters regarding the expected amount of resorption after maxillary sinus augmentation surgery using autologous bone grafts. Therefore, the aim of this study was to determine parameters influencing the outcome of the bone graft resorption process. In 20 patients, three-dimensional analysis of alveolar ridge dimensions and bone graft volume change in the atrophic posterior maxilla was performed by Cone-Beam Computerized Tomography imaging. Ridge dimensions were assessed before maxillary sinus augmentation surgery. Bone graft volumes were compared after maxillary sinus floor augmentation surgery and a graft healing interval of several months. To analyze the relation between bone volume changes with the independent variables, patients' gender, age, alveolar crest height and width, and graft healing time interval, a multi-level extension of linear regression was applied. A residual bone height of 6.0 mm (SD = 3.6 mm) and 6.2 mm (SD = 3.6 mm) was found at the left and right sides, respectively. Moreover, alveolar bone widths of 6.5 mm (SD = 2.2 mm) and 7.0 mm (SD = 2.3 mm) at the premolars, and 8.8 mm (SD = 2.2 mm) and 8.9 mm (SD = 2.5 mm) at the molars regions were found at the left and right site, respectively. Bone graft volume decreased by 25.0% (SD = 21.0%) after 4.7 months (SD = 2.7, median = 4.0 months) of healing time. The variables "age" (P = 0.009) and mean alveolar crest "bone height" (P = 0.043), showed a significant influence on bone graft resorption. A decrease of 1.0% (SE = 0.3%) of bone graft resorption was found for each year the patient grew older, and an increase in bone graft resorption of 1.8% (SE = 0.8%) was found for each mm of original bone height before sinus floor augmentation. Graft resorption occurs when using autologous bone grafts for maxillary sinus augmentation. Alveolar crest bone height and patient age have a significant effect on graft

  12. Healing at implants placed in an alveolar ridge with a sloped configuration: an experimental study in dogs.

    Science.gov (United States)

    Abrahamsson, Ingemar; Welander, Maria; Linder, Elena; Berglundh, Tord

    2014-02-01

    To study healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration. Six Labrador dogs were used. Buccal bone defects were prepared in the mandible after extraction of premolars. Three months later, two test implants with a sloped marginal design and two control implants were placed in the chronic defect area with a sloped lingual-buccal configuration of each premolar region. The test implants were placed in such a way that the buccal margin of the implant coincided with the buccal bone crest. The lingual margin of the control implants was placed to a similar depth as the lingual margin of the test implants. Abutments were connected to the implants in the right mandibular premolar region and flaps were sutured around the neck of the abutments. In the left side of the mandible, cover screws were placed and the flaps were sutured to cover the implants. Biopsies were obtained 4 months later and prepared for histological examination. It was demonstrated that healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration resulted in the preservation of a vertical discrepancy between the lingual and buccal marginal bone levels around implants with either a regular cylindrical outline or a modified marginal portion that matched the slope of the alveolar ridge. As the marginal buccal portion of the control implants with a regular design had no bone support, it is suggested that implants with a modified marginal portion may be considered in recipient sites with a sloped lingual-buccal configuration. © 2012 Wiley Periodicals, Inc.

  13. Three-dimensional evaluation of root dimensions and alveolar ridge width of maxillary lateral incisors in patients with unilateral agenesis.

    Science.gov (United States)

    AlRushaid, Sharifah; Chandhoke, Taranpreet; Utreja, Achint; Tadinada, Aditya; Allareddy, Veerasathpurush; Uribe, Flavio

    2016-12-01

    The objective of this retrospective case-control study was to measure the maxillary lateral incisor root dimensions and quantify the labial and palatal bone in patients with unilateral maxillary lateral incisor agenesis (MLIA) after orthodontic treatment and compare them to non-agenesis controls using cone beam computed tomography. The labiopalatal and mesiodistal root dimensions, mesiodistal coronal dimensions, and labiopalatal bone and alveolar ridge widths of the maxillary lateral incisor were assessed on posttreatment cone beam computed tomography scans of 15 patients (mean age 16.5 ± 3.4 years, 9 females and 6 males) with maxillary lateral incisor agenesis and 15 gender-matched patients (mean age 16.08 ± 3.23 years) with no dental agenesis or anterior Bolton discrepancy. The Mann-Whitney test was used to distinguish any differences in root width, crown width, or changes in labial or palatal bone width between the two groups. The median labiopalatal root width was narrower in the MLIA group at the level of the cementoenamel junction (CEJ) to 8 mm apical of the CEJ compared to controls (p ≤ 0.009). The mesiodistal root width was significantly reduced in the MLIA group at the CEJ and at 4 mm apical to the CEJ. The labiopalatal alveolar ridge width was significantly decreased at 2 mm apical to the CEJ in MLIA group. The mesiodistal crown width was significantly smaller in the MLIA group at both the incisal edge and at the crown midpoint. The bone thickness was similar in both groups. Coronal and root dimensions in patients with MLIA were reduced compared to controls. Alveolar ridge width was also reduced in patients with MLIA, although bone thickness was not different than controls.

  14. Three-dimensional evaluation of root dimensions and alveolar ridge width of maxillary lateral incisors in patients with unilateral agenesis

    Directory of Open Access Journals (Sweden)

    Sharifah AlRushaid

    2016-10-01

    Full Text Available Abstract Background The objective of this retrospective case-control study was to measure the maxillary lateral incisor root dimensions and quantify the labial and palatal bone in patients with unilateral maxillary lateral incisor agenesis (MLIA after orthodontic treatment and compare them to non-agenesis controls using cone beam computed tomography. Methods The labiopalatal and mesiodistal root dimensions, mesiodistal coronal dimensions, and labiopalatal bone and alveolar ridge widths of the maxillary lateral incisor were assessed on posttreatment cone beam computed tomography scans of 15 patients (mean age 16.5 ± 3.4 years, 9 females and 6 males with maxillary lateral incisor agenesis and 15 gender-matched patients (mean age 16.08 ± 3.23 years with no dental agenesis or anterior Bolton discrepancy. The Mann-Whitney test was used to distinguish any differences in root width, crown width, or changes in labial or palatal bone width between the two groups. Results The median labiopalatal root width was narrower in the MLIA group at the level of the cementoenamel junction (CEJ to 8 mm apical of the CEJ compared to controls (p ≤ 0.009. The mesiodistal root width was significantly reduced in the MLIA group at the CEJ and at 4 mm apical to the CEJ. The labiopalatal alveolar ridge width was significantly decreased at 2 mm apical to the CEJ in MLIA group. The mesiodistal crown width was significantly smaller in the MLIA group at both the incisal edge and at the crown midpoint. The bone thickness was similar in both groups. Conclusions Coronal and root dimensions in patients with MLIA were reduced compared to controls. Alveolar ridge width was also reduced in patients with MLIA, although bone thickness was not different than controls.

  15. Flapless alveolar ridge preservation utilizing the "socket-plug" technique: clinical technique and review of the literature.

    Science.gov (United States)

    Kotsakis, Georgios; Chrepa, Vanessa; Marcou, Nicolas; Prasad, Hari; Hinrichs, James

    2014-12-01

    It has been documented that after every extraction of one or more teeth, the alveolar bone of the respective region undergoes resorption and atrophy. Therefore, ridge preservation techniques are often employed after tooth extraction to limit this phenomenon. The benefits of a flapless procedure include maintenance of the buccal keratinized gingiva, prevention of alterations to the gingival contours, and migration of the mucogingival junction that are often experienced after raising a flap. The purpose of this article is to review the literature concerning flapless ridge preservation techniques with the aid of collagen plugs for occlusion of the socket. The term "socket-plug" technique is introduced to describe these techniques. The basic steps of the "socket-plug" technique consist of atraumatic tooth extraction, placement of the appropriate biomaterials in the extraction site, preservation of soft tissue architecture employing a flapless technique, and placement and stabilization of the collagen plug. A case example is presented that illustrates the steps used in this technique.

  16. Lateral ridge split and immediate implant placement in moderately resorbed alveolar ridges: How much is the added width?

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    Amin Rahpeyma

    2013-01-01

    Full Text Available Background: Lateral ridge split technique is a way to solve the problem of the width in narrow ridges with adequate height. Simultaneous insertion of dental implants will considerably reduce the edentulism time. Materials and Methods: Twenty-five patients who were managed with ridge splitting technique were enrolled. Thirty-eight locations in both jaws with near equal distribution in quadrants received 82 dental fixtures. Beta Tricalcium phosphate (Cerasorb® was used as biomaterial to fill the intercortical space. Submerged implants were used and 3 months later healing caps were placed. Direct bone measurements before and after split were done with a Collis. Patients were clinically re-evaluated at least 6 months after implant loading. All the data were analyzed by Statistical Package for Social Sciences (SPSS software version 11.5 (SPSS Inc, Chicago Illinois, USA. Frequency of edentulous spaces and pre/post operative bone width was analyzed. Paired t-test was used for statistical analysis. Difference was considered significant if P value was less than 0.05. Results: Mean value for presplit width was 3.2 ± 0.34 mm while post-split mean width was 5.57 ± 0.49 mm. Mean gain in crest ridge after ridge splitting was 2 ± 0.3 mm. Statistical analysis showed significant differences in width before and after operation ((P < 0.05. All implants (n = 82 survived and were in full function at follow up (at least 6 months after implant loading. Conclusion: Ridge splitting technique in both jaws showed the predictable outcomes, if appropriate cases selected and special attention paid to details; then the waiting time between surgery and beginning of prosthodontic treatment can be reduced to 3 month.

  17. Augmented corticotomy combined with accelerated orthodontic forces in class III orthognathic patients: morphologic aspects of the mandibular anterior ridge with cone-beam computed tomography.

    Science.gov (United States)

    Coscia, Giuseppe; Coscia, Vincenzo; Peluso, Vincenzo; Addabbo, Francesco

    2013-10-01

    This study used cone-beam computed tomography to evaluate morphologic changes of the mandibular anterior ridge after using augmented corticotomy plus accelerated orthodontia to decompensate mandibular incisors in patients with surgical skeletal Class III. Fourteen patients (8 men, 6 women; mean age, 26.14 yr) with skeletal Class III were treated before orthognathic surgery with a technique that combined corticotomy, bone grafting, and accelerated orthodontic forces to decompensate the lower incisors. Three-dimensional cone-beam computed tomograms were taken before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). Measurements of the amount of vertical alveolar bone changes and horizontal bone thickness at the midroot and root apex levels of the mandibular incisors were evaluated. All patients showed significant proclination of the mandibular incisors at T1. The mean alveolar bone thickness from T0 to T1 increased buccally at the midroot and apex levels, showing statistically significant horizontal bone augmentation at the labial side of the lower anterior mandibular teeth (P orthodontics, such as marginal bone loss and gingival recession. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Dimensional changes of the post extraction alveolar ridge, preserved with Leukocyte- and Platelet Rich Fibrin: A clinical pilot study.

    Science.gov (United States)

    Anwandter, Andreas; Bohmann, Stephanie; Nally, Mauricio; Castro, Ana B; Quirynen, Marc; Pinto, Nelson

    2016-09-01

    This clinical trial explored the clinical and radiographic dimensional changes of the alveolar ridge in the first 4 months after tooth extraction in combination with the application of Leukocyte- and Platelet Rich Fibrin (L-PRF). Eighteen single rooted maxillary and mandibular sockets were filled with L-PRF without soft tissue closure. Clinical measurements (bone sounding) were performed using a customized acrylic stent and radiographic measurements were accomplished using Cone Beam Computed Tomography (CBCT), immediately after tooth extraction and after 4 months. The clinical observations indicated a mean horizontal resorption of 1.18±2.4mm (p=0.8) at the crest, 1.25±2.0mm (p=0.57) and 0.83±2.0mm (p=0.78) at 2mm and 4mm apical to the crest, respectively. The buccal plate demonstrated a mean vertical loss of 0.44±3.5mm (p=0.9), the centre of the socket had a significant filling of 5.72±3.6mm (p=0.0001) and the oral cortical plate had a mean vertical gain of 0.09mm±1.57mm (p=0.9). The radiographic analysis demonstrated a mean vertical bone loss of 0.27±2.5mm (p=0.9) on the buccal and of 0.03±1.6mm (p=0.9) at the oral crest. The width of the alveolar ridge had a mean loss of 1.33mm±1.43mm. Within the limitations of this pilot study, it can be concluded that L-PRF might show clinical benefits for ridge preservation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Alveolar ridge dimensional changes following ridge preservation procedure with novel devices: Part 1--CBCT linear analysis in non-human primate model.

    Science.gov (United States)

    Min, Seiko; Liu, Yi; Tang, Jianxia; Xie, Yilin; Xiong, Jimin; You, Hyung-Keun; Zadeh, Homayoun H

    2016-01-01

    This study sought to investigate dimensional changes to the alveolar bone following extraction and application of novel devices used for obturation of socket orifice (socket cap) and space maintenance in sockets with facial dehiscence (socket cage). Six Macaca fascicularis had six teeth each removed according to the following intervention groups (groups A-C intact alveolar bone; D-E facial dehiscence): negative control (A); socket obturated with cap (B); filled with anorganic bovine bone mineral (ABBM) + socket cap (C); dehiscence negative control (D); socket cap + socket cage (E); ABBM + socket cap + socket cage (F). Serial CBCT scans at preoperatively, 6 and 12 weeks following intervention were compared to quantify linear alveolar bone alterations. Without therapeutic intervention, intact sockets exhibited significant reduction in width at the crestal 2 mm of the ridge crest within 6 weeks. Compared with the negative control sites which lost up to 52% of crestal bone width, sites treated with socket cap + ABBM lost at most 4% of bone width at the crestal 2 mm. Similar results were seen in the dehiscence groups, with the combination of socket cap + socket cage + ABBM maintaining the greatest socket width and height dimensions. Results from the current non-human primate study suggest that the socket cap and socket cage devices, when used in conjunction with xenograft proved effective in minimizing post-extraction socket width loss and height seen in both intact sockets and sockets with facial dehiscence defects. © 2015 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

  20. Alveolar Ridge Preservation with nc-HA and d-PTFE Membrane: A Clinical, Histologic, and Histomorphometric Study.

    Science.gov (United States)

    Laurito, Domenica; Lollobrigida, Marco; Gianno, Francesca; Bosco, Sandro; Lamazza, Luca; De Biase, Alberto

    Alveolar ridge preservation has become a very common procedure following tooth extraction. This study presents a clinical, histologic, and histomorphometric analysis of postextraction bone changes using nanocrystalline hydroxyapatite (nc-HA) and exposed high-density polytetrafluoroethylene (d-PTFE) membrane. A total of 10 extraction sockets were treated. Clinical measurements were taken after tooth extraction with a customized acrylic stent to ensure the same measurement points. At 6 months, clinical measurements were repeated and bone specimens taken. An overall bone reduction was observed. The histologic and histomorphometric analysis revealed newly formed bone (25.92% ± 18.78%), soft tissue (28.55% ± 9.73%), and residual graft particles (15.43% ± 11.08%). Further studies are necessary to evaluate the efficacy of this technique over the long term.

  1. Hard and Soft Tissue Management of a Localized Alveolar Ridge Atrophy with Autogenous Sources and Biomaterials: A Challenging Clinical Case

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    C. Maiorana

    2016-01-01

    Full Text Available Particularly in the premaxillary area, the stability of hard and soft tissues plays a pivotal role in the success of the rehabilitation from both a functional and aesthetic aspect. The present case report describes the clinical management of a localized alveolar ridge atrophy in the area of the upper right canine associated with a thin gingival biotype with a lack of keratinized tissue. An autogenous bone block harvested from the chin associated with heterologous bone particles was used to replace the missing bone, allowing for a prosthetic driven implant placement. Soft tissues deficiency was corrected by means of a combined epithelialized and subepithelial connective tissue graft. The 3-year clinical and radiological follow-up demonstrated symmetric gingival levels of the upper canines, with physiological peri-implant probing depths and bone loss. Thus, the use of autogenous tissues combined with biomaterials might be considered a reliable technique in case of highly aesthetic demanding cases.

  2. Regenerative Needs Following Alveolar Ridge Preservation Procedures in Compromised and Noncompromised Extraction Sockets: A Cone Beam Computed Tomography Study.

    Science.gov (United States)

    Koutouzis, Theofilos; Lipton, David

    2016-01-01

    The aim of this study was to evaluate the necessity for additional regenerative procedures following healing of compromised and noncompromised extraction sockets with alveolar ridge preservation procedures through the use of virtual implant imaging software. The cohort was comprised of 87 consecutive patients subjected to a single maxillary tooth extraction with an alveolar ridge preservation procedure for subsequent implant placement. Patients were divided into two main groups based on the integrity of the buccal bone plate following teeth extraction. Patients in the compromised socket (CS) group (n = 52) had partial or complete buccal bone plate loss, and patients in the noncompromised socket (NCS) group (n = 35) exhibited no bone loss of their socket walls following tooth extraction. Following 4 to 6 months of healing, all patients had a cone beam computed tomography (CBCT) study. Root-formed implants were placed virtually in an ideal prosthetic position. The number of implants per group and location (anterior, premolar, molar) exhibiting exposed buccal implant surface was calculated. In the CS group, 5 out of 19 anterior implants (26.3%), 4 out of 14 premolar implants (28.5%), and 7 out of 19 molar implants (36.8%) had exposed buccal surfaces. In the NCS group, 4 out of 9 anterior implants (44.4%), 2 out of 9 premolar implants (22.2%), and 4 out of 17 molar implants (23.5%) had exposed buccal surfaces. There were no statistically significant differences for intragroup and intergroup comparisons (χ² test, P > .05). This study failed to find statistically significant differences in the frequency of implants with exposed buccal surfaces placed virtually, following treatment of compromised and noncompromised sockets. A high proportion (22% to 44%) of sites had implants that potentially needed additional regenerative procedures.

  3. A lateral ridge augmentation study to evaluate a synthetic membrane for guided bone regeneration: an experiment in the canine mandible.

    Science.gov (United States)

    Vierra, Matthew; Mau, Lian Ping; Huynh-Ba, Guy; Schoolfield, John; Cochran, David L

    2016-01-01

    To evaluate guided bone regeneration outcomes in defects protected with an in situ formed polyethylene glycol (PEG) hydrogel membrane as compared to a non-cross-linked collagen membrane (CM). Four mandibular alveolar ridge defects were created in eight hound dogs. Regenerative procedures were randomly allocated to one of four groups consisting of freeze-dried bone allograft, which is referred to in this study as freeze-dried bone xenograft (FDBX) + PEG, autogenous bone (AB) + PEG, AB + CM, and AB alone. After 8 weeks, titanium dental implants were placed into augmented sites. After 8 weeks of allowed time for osseointegration, the animals were sacrificed to harvest block specimens for bone-to-implant contact (BIC) and ridge width histomorphometric analysis. Polyethylene glycol membranes had an exposure rate of 50% as compared to 12.5% for sites grafted with CM. Regenerative outcomes with respect to implant placement were least favorable for FDBX + PEG which had implants placed in 37.5% of augmented sites compared to 100% implant placement for all other groups. No statistically significant differences were noted between groups for ridge width measurements in implant and non-implant histologic sections (P > 0.05). Buccal BIC (%) values between treatment groups also failed to reach statistical significant difference (FDBX + PEG [60.2 ± 9.4]; AB + PEG [58.8 ± 8.5]; AB + CM [57.9 ± 12.8]; AB [61.0 ± 10.2]). When used in conjunction with FDBX, PEG had unpredictable bone formation and in most cases negatively impacted future implant placement. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. A randomized, controlled, multicentre clinical trial of post-extraction alveolar ridge preservation.

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    Scheyer, Eric Todd; Heard, Rick; Janakievski, Jim; Mandelaris, George; Nevins, Marc L; Pickering, Stephen R; Richardson, Christopher R; Pope, Bryan; Toback, Gregory; Velásquez, Diego; Nagursky, Heiner

    2016-12-01

    To compare the effectiveness of two-ridge preservation treatments. Forty subjects with extraction sockets exhibiting substantial buccal dehiscences were enrolled and randomized across 10 standardized centres. Treatments were demineralized allograft plus reconstituted and cross-linked collagen membrane (DFDBA + RECXC) or deproteinized bovine bone mineral with collagen plus native, bilayer collagen membrane (DBBMC + NBCM). Socket dimensions were recorded at baseline and 6 months. Wound closure and soft tissue inflammation were followed post-operatively, and biopsies were retrieved for histomorphometric analysis at 6 months. Primary endpoint: at 6 months, extraction socket horizontal measures were significantly greater for DBBMC + NBCM (average 1.76 mm greater, p = 0.0256). Secondary and Exploratory endpoints: (1) lingual and buccal vertical bone changes were not significantly different between the two treatment modalities, (2) histomorphometric % new bone and % new bone + graft were not significantly different, but significantly more graft remnants remained for DBBMC; (3) at 1 month, incision line gaps were significantly greater and more incision lines remained open for DFDBA + RECXC; (4) higher inflammation at 1 week tended to correlate with lower ridge preservation results; and (5) deeper socket morphologies with thinner bony walls correlated with better ridge preservation. Thirty-seven of 40 sites had sufficient ridge dimension for implant placement at 6 months; the remainder were DFDBA + RECXC sites. DBBMC + NBCM provided better soft tissue healing and ridge preservation for implant placement. Deeper extraction sockets with higher and more intact bony walls responded more favourably to ridge preservation therapy. © 2016 The Authors. Journal of Clinical Periodontology Published by John Wiley & Sons Ltd.

  5. Hard and soft tissue changes around implants installed in regular-sized and reduced alveolar bony ridges. An experimental study in dogs.

    Science.gov (United States)

    Baffone, Gabriele; Lang, Niklaus P; Pantani, Fabio; Favero, Giovanni; Ferri, Mauro; Botticelli, Daniele

    2015-01-01

    To study bony and soft tissue changes at implants installed in alveolar bony ridges of different widths. In 6 Labrador dogs, the mandibular premolars and first molars were extracted, and a buccal defect was created in the left side at the third and fourth premolars by removing the buccal bone and the inter-radicular and interdental septa. Three months after tooth extraction, full-thickness mucoperiosteal flaps were elevated, and implants were installed, two at the reduced (test) and two at the regular-sized ridges (control). Narrow or wide abutments were affixed to the implants. After 3 months, biopsies were harvested, and ground sections prepared for histological evaluation. A higher vertical buccal bony crest resorption was found at the test (1.5 ± 0.7 mm and 1.0 ± 0.7 mm) compared to the control implants (1.0 ± 0.5 mm and 0.7 ± 0.4 mm), for both wide and narrow abutment sites. A higher horizontal alveolar resorption was identified at the control compared to the test implants. The difference was significant for narrow abutment sites. The peri-implant mucosa was more coronally positioned at the narrow abutment, in the test sites, while for the control sites, the mucosal adaptation was more coronal at the wide abutment sites. These differences, however, did not reach statistical significance. Implants installed in regular-sized alveolar ridges had a higher horizontal, but a lower vertical buccal bony crest resorption compared to implants installed in reduced alveolar ridges. Narrow abutments in reduced ridges as well as wide abutments in regular-sized ridges yielded less soft tissue recession compared to their counterparts. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Alveolar Ridge Preservation Using a Novel Synthetic Grafting Material: A Case with Two-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Peter Fairbairn

    2018-01-01

    Full Text Available This case report highlights the use of a novel in situ hardening synthetic (alloplastic, resorbable, bone grafting material composed of beta tricalcium phosphate and calcium sulfate, for alveolar ridge preservation. A 35-year-old female patient was referred by her general dentist for extraction of the mandibular right first molar and rehabilitation of the site with a dental implant. The nonrestorable tooth was “atraumatically” extracted without raising a flap, and the socket was immediately grafted with the synthetic biomaterial and covered with a hemostatic fleece. No membrane was used, and the site was left uncovered without obtaining primary closure, in order to heal by secondary intention. After 12 weeks, the architecture of the ridge was preserved, and clinical observation revealed excellent soft tissue healing without loss of attached gingiva. At reentry for placement of the implant, a bone core biopsy was obtained, and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological analysis revealed pronounced bone regeneration while high levels of primary implant stability were recorded. The implant was successfully loaded 12 weeks after placement. Clinical and radiological follow-up examination at two years revealed stable and successful results regarding biological, functional, and esthetic parameters.

  7. Alveolar Ridge Preservation Using a Novel Synthetic Grafting Material: A Case with Two-Year Follow-Up.

    Science.gov (United States)

    Fairbairn, Peter; Leventis, Minas; Mangham, Chas; Horowitz, Robert

    2018-01-01

    This case report highlights the use of a novel in situ hardening synthetic (alloplastic), resorbable, bone grafting material composed of beta tricalcium phosphate and calcium sulfate, for alveolar ridge preservation. A 35-year-old female patient was referred by her general dentist for extraction of the mandibular right first molar and rehabilitation of the site with a dental implant. The nonrestorable tooth was "atraumatically" extracted without raising a flap, and the socket was immediately grafted with the synthetic biomaterial and covered with a hemostatic fleece. No membrane was used, and the site was left uncovered without obtaining primary closure, in order to heal by secondary intention. After 12 weeks, the architecture of the ridge was preserved, and clinical observation revealed excellent soft tissue healing without loss of attached gingiva. At reentry for placement of the implant, a bone core biopsy was obtained, and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological analysis revealed pronounced bone regeneration while high levels of primary implant stability were recorded. The implant was successfully loaded 12 weeks after placement. Clinical and radiological follow-up examination at two years revealed stable and successful results regarding biological, functional, and esthetic parameters.

  8. Bimaxillary protrusion with an atrophic alveolar defect: orthodontics, autogenous chin-block graft, soft tissue augmentation, and an implant.

    Science.gov (United States)

    Chiu, Grace S C; Chang, Chris H N; Roberts, W Eugene

    2015-01-01

    Bimaxillary protrusion in a 28-year-old woman was complicated by multiple missing, restoratively compromised, or hopeless teeth. The maxillary right central incisor had a history of avulsion and replantation that subsequently evolved into generalized external root resorption with Class III mobility and severe loss of the supporting periodontium. This complex malocclusion had a discrepancy index of 21, and 8 additional points were scored for the atrophic dental implant site (maxillary right central incisor). The comprehensive treatment plan included extraction of 4 teeth (both maxillary first premolars, the maxillary right central incisor, and the mandibular right first molar), orthodontic closure of all spaces except for the future implant site (maxillary right central incisor), augmentation of the alveolar defect with an autogenous chin-block graft, enhancement of the gingival biotype with a connective tissue graft, and an implant-supported prosthesis. Orthodontists must understand the limitations of bone grafts. Augmented alveolar defects are slow to completely turn over to living bone, so they are usually good sites for implants but respond poorly to orthodontic space closure. However, postsurgical orthodontic treatment is often indicated to optimally finish the esthetic zone before placing the final prosthesis. The latter was effectively performed for this patient, resulting in a total treatment time of about 36 months for comprehensive interdisciplinary care. An excellent functional and esthetic result was achieved. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  9. Alveolar ridge augmentation in rats by combined hydroxylapatite and osteoinductive material

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1991-01-01

    The purpose of this study was to examine if increased bony ingrowth developed when hydroxylapatite was implanted together with an osteoinductive substrate. Dense hydroxylapatite granules (HA) (Calcitite, Calcitek, San Diego, CA, USA) were mixed with equal volumes of allogenic, demineralized...... an osteoinductive nor an osteoconductive effect. The newly formed bone induced from the implanted allogenic, demineralized, lyophilized dentin or bone was never found in close contact with the HA and did not incorporate the implant....

  10. Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation

    DEFF Research Database (Denmark)

    Pinholt, E M; Ruyter, I E; Haanaes, H R

    1992-01-01

    characteristics obtained by chemical analysis and infrared spectrometry. None of the apatites caused osteoinduction or osteoconduction; fibrous encapsulation with multinuclear giant cells was observed around all four types. One of the apatites was fluorapatite and not hydroxylapatite, as claimed...

  11. Alveolar ridge augmentation in rats by combined hydroxylapatite and osteoinductive material

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1991-01-01

    The purpose of this study was to examine if increased bony ingrowth developed when hydroxylapatite was implanted together with an osteoinductive substrate. Dense hydroxylapatite granules (HA) (Calcitite, Calcitek, San Diego, CA, USA) were mixed with equal volumes of allogenic, demineralized, lyop...

  12. Distracción osteogénica alveolar: una alternativa en la reconstrucción de rebordes alveolares atróficos: Descripción de 10 casos Alveolar distraction osteogenesis: an alternative in the reconstruction of atrophic alveolar ridges: Report of 10 cases

    Directory of Open Access Journals (Sweden)

    P.E. Maurette O’Brien

    2004-02-01

    Full Text Available La distracción osteogénica alveolar (DOA es un método alternativo para la reconstrucción de rebordes alveolares atróficos que ofrece un resultado previsible y que disminuye los tiempo de espera entre la reconstrucción del reborde alveolar atrófico y la colocación de los implantes óseo-integrados, en comparación con los métodos tradicionalmente utilizados. Fueron atendidos 10 pacientes que presentaban deficiencia de reborde alveolar mandibular y/o maxilar por medio de distracción osteogénica, utilizando un dispositivo yuxtaoseo (Conexión Implant System® - SP-Brasil. Todos los pacientes fueron atendidos de forma ambulatoria, bajo anestesia local y sedación conciente, comenzando la activación del dispositivo a los 7 días posteriores a la instalación, con un patrón de activación de 1 mm diarios hasta alcanzar la altura ósea deseada. Posteriormente se aguardaron 10 semanas como parte del periodo de consolidación ósea y se realizo la colocación de los implantes oseointegrados y local y el retiro del dispositivo de distracción, pudiéndose comprobar clínica y radiográficamente la ganancia de la altura y volumen óseo necesario para la rehabilitación por medio de implantes.The alveolar distraction osteogenesis is an alternative method for the reconstruction of atrophic alveolar ridges with success, that decrease the time of wait between the reconstruction of the alveolar ridge and the placement of the osseointegrated implants in comparison with the traditionally used methods. 10 patients that presented deficiency of the alveolar ridge in the maxilla and/or mandible were assisted by means of distraction osteogenesis, using a juxtaosseous device (Conexion Implant System® - SP-Brazil. All the patients were assisted of form ambulatory, under local anesthesia and conscientious sedation, beginning the activation from the device 7 days later to the installation, with a pattern of activation 1 mm diary until reaching the wanted

  13. Custom-Made Computer-Aided-Design/Computer-Aided-Manufacturing Biphasic Calcium-Phosphate Scaffold for Augmentation of an Atrophic Mandibular Anterior Ridge

    Directory of Open Access Journals (Sweden)

    Francesco Guido Mangano

    2015-01-01

    Full Text Available This report documents the clinical, radiographic, and histologic outcome of a custom-made computer-aided-design/computer-aided-manufactured (CAD/CAM scaffold used for the alveolar ridge augmentation of a severely atrophic anterior mandible. Computed tomographic (CT images of an atrophic anterior mandible were acquired and modified into a 3-dimensional (3D reconstruction model; this was transferred to a CAD program, where a custom-made scaffold was designed. CAM software generated a set of tool-paths for the manufacture of the scaffold on a computer-numerical-control milling machine into the exact shape of the 3D design. A custom-made scaffold was milled from a synthetic micromacroporous biphasic calcium phosphate (BCP block. The scaffold closely matched the shape of the defect: this helped to reduce the time for the surgery and contributed to good healing. One year later, newly formed and well-integrated bone was clinically available, and two implants (AnyRidge, MegaGen, Gyeongbuk, South Korea were placed. The histologic samples retrieved from the implant sites revealed compact mature bone undergoing remodelling, marrow spaces, and newly formed trabecular bone surrounded by residual BCP particles. This study demonstrates that custom-made scaffolds can be fabricated by combining CT scans and CAD/CAM techniques. Further studies on a larger sample of patients are needed to confirm these results.

  14. A methodological approach to assessing alveolar ridge preservation procedures in humans: soft tissue profile.

    Science.gov (United States)

    Vanhoutte, Vanessa; Rompen, Eric; Lecloux, Geoffrey; Rues, Stefan; Schmitter, Marc; Lambert, France

    2014-03-01

    The aesthetic results of implant restoration in the anterior maxilla are particularly related to the soft tissue profile. Although socket preservation techniques appear to reduce bone remodelling after tooth extraction, there is still few investigations assessing the external soft tissue profile after such procedures. The goal of this study was to describe an accurate technique to evaluate soft tissue contour changes after performing socket preservation procedures. The secondary objective was to apply the newly developed measuring method to a specific socket preservation using a "saddled" connective tissue graft combined with the insertion of slowly resorbable biomaterials into the socket. A total of 14 patients needing tooth replacement in the aesthetic region were included to receive a socket preservation procedure using a connective tissue graft. Impressions were taken before the tooth extraction (baseline) and at 2, 4, and 12 weeks after the procedure. The corresponding plaster casts were scanned, and the evolution of the soft tissue profile in relation to the baseline situation was assessed using imaging software. The measuring technique allowed assessing the soft tissue profiles accurately at different levels of the alveolar process. The insertion of a saddled connective tissue appeared to compensate for the horizontal and vertical bone remodelling after a socket preservation procedure in most regions of the alveolar crest. After 12 weeks, the only significant change was located in the more cervical and central region of the alveolar process and reached a median drop of 0.62 mm from baseline. Within the limitations of this study, we found that a saddled connective tissue graft combined with a socket preservation procedure could almost completely counteract the bone remodelling in terms of the external soft tissue profile. The minor changes found in the cervical region might disappear with the emergence profile of the prosthodontic components. The described

  15. Alveolar Ridge Preservation Using Allografts and Dense Polytetrafluoroethylene Membranes With Open Membrane Technique in Unhealthy Extraction Socket.

    Science.gov (United States)

    Cheon, Gi-Beom; Kang, Kyung Lhi; Yoo, Mi-Kyung; Yu, Jeoung-A; Lee, Dong-Woon

    2017-08-01

    We evaluated the effectiveness of the open membrane technique using a high-density polytetrafluoroethylene (dPTFE) membrane with freeze-dried bone allografts in damaged sockets for alveolar ridge preservation (ARP). This retrospective study included 26 sites from 20 patients who had received ARP for the placement of dental implants. ARP was conducted using dPTFE membrane with allografts on the day of extraction without primary closure. When the membrane was removed after 4 weeks, the newly formed reddish tissue at the grafted site was checked (first outcome, clinical evaluation). Four months after membrane removal, a core biopsy was performed from the center of the grafted site before implant placement (second outcome, histomorphometric evaluation). Radiographic measurements of alveolar bone changes between implant prosthesis delivery and the 1-year follow-up were obtained (third outcome, radiographic evaluation). A total of 23 sites from 18 patients had no complications during the follow-up period. Three sites from two patients were excluded because of early membrane removal. Newly formed reddish tissue was found at 15 sites, and partially formed tissue was found at 8 sites. Although we were unable to harvest bone core from all sites, histomorphometric analysis in 11 patients indicated that the mean area of new bone was 28.48% ± 6.60%, that of the remaining graft particle was 27.68% ± 9.18%, and that of fibrous tissue was 43.84% ± 6.98%. The mean loss of marginal bone was 0.13 ± 0.06 mm at the mesial area and 0.15 ± 0.06 mm at the distal area, as assessed using radiographic evaluations. The results of this nonrandomized study suggest that this technique may be an appropriate procedure for ARP. Further studies with a control group and more subjectives can be designed based on this study.

  16. [Application of xenograft for alveolar ridge preservation in posterior sites: a randomized controlled clinical trial].

    Science.gov (United States)

    Lei, Chi; Wu, Hui; Lin, Ye; Di, Ping; Chen, Bo; Hu, Xiulian

    2015-09-01

    To investigate the effect of ridge preservation with Bio-Oss Collagen and Bio-Gide in posterior sites. From May 2010 to July 2013, 16 patients with bilateral posterior teeth planned to be extracted and replaced by implants were enrolled. One of the sockets was randomly selected and presserved with Bio-Oss Collagen and Bio-Gide (intervention group). The contralateral socket was left to heal spontaneously (control group). Cone-beam (CBCT) scans were performed immediately after the extraction and 6 month later. The bone cores were collected during the implant placement surgery and analyzed by micro-computed tomography. After 6 month healing, the vertical and horizontal dimensional alteration of the treatment group were (0.55 ± 1.05) mm and (-0.99 ± 0.94) mm respectively, while the vertical and horizontal change of control group were (-0.71 ± 1.41) mm and (-2.26 ± 1.29) mm respectively. The micro-computed tomography results showed that there was no significant difference in new bone volume between control and intervention groups. Applying Bio-Oss Collagen and Bio-Gide for ridge preservation in posterior sites resulted in less vertical and horizontal bone resorption of sockets following extraction.

  17. Comparison of alveolar ridge preservation methods using three-dimensional micro-computed tomographic analysis and two-dimensional histometric evaluation.

    Science.gov (United States)

    Park, Young-Seok; Kim, Sungtae; Oh, Seung-Hee; Park, Hee-Jung; Lee, Sophia; Kim, Tae-Il; Lee, Young-Kyu; Heo, Min-Suk

    2014-06-01

    This study evaluated the efficacy of alveolar ridge preservation methods with and without primary wound closure and the relationship between histometric and micro-computed tomographic (CT) data. Porcine hydroxyapatite with polytetrafluoroethylene membrane was implanted into a canine extraction socket. The density of the total mineralized tissue, remaining hydroxyapatite, and new bone was analyzed by histometry and micro-CT. The statistical association between these methods was evaluated. Histometry and micro-CT showed that the group which underwent alveolar preservation without primary wound closure had significantly higher new bone density than the group with primary wound closure (Palveolar ridge preservation without primary wound closure enhanced new bone formation more effectively than that with primary wound closure. Further investigation is needed with respect to the comparison of histometry and micro-CT analysis.

  18. Intervention for replacing missing teeth: Alveolar ridge preservation techniques for dental implant site development - evidence summary of Cochrane review.

    Science.gov (United States)

    Jayaraman, Srinivasan

    2015-01-01

    The Cochrane reviews have transparent reporting of the methodology to clarify the reader the methods used for writing the review; hence, each review becomes a large volume of scientific literature. This evidence summary of the Cochrane review published in 2015 for the question, what are the clinical effects (preservation of both width and height of bone, esthetic outcomes, complications, and failure of implant) for different alveolar ridge preservation techniques (ARP) and materials used in patients planning implant placement following extraction after 6 months follow-up. This review provides evidence for efficacy of different ARP techniques, materials, and superiority of one over the other. It also tries to settle the controversy of timing of placement of implant after grafting. Of the 8 included studies from 50, two trials provide moderate evidence for xenografts versus extraction favoring xenografts in preserving the width and height of bone by 1.97 mm (2.48-1.46) and 2.60 mm (3.43-1.76), respectively in pooled estimates of meta-analysis. Using different material, five-trial were found; of which, two trials provide moderate evidence for alloplast versus xenografts favoring alloplast in preserving the width by 0.44 mm (0.90-0.02) and low-grade evidence for height of bone by 0.35 mm (0.86-0.16) in pooled estimates of meta-analysis. There is a paucity of randomized controlled trial to address other primary and secondary outcomes addressed in this review.

  19. Posterior alveolar ridge resorption in bar-retained mandibular overdentures: 10-year results of a prospective clinical trial.

    Science.gov (United States)

    Raedel, Michael; Lazarek-Scholz, Kristina; Marré, Birgit; Boening, Klaus W; Walter, Michael H

    2015-12-01

    Data on posterior alveolar ridge resorption (PARR) in patients with two implant supported mandibular overdentures is very heterogeneous. The aim of this prospective study was to observe the PARR after ten years for a study population treated with a titanium bar retained overdenture on two IMZ-implants. The data pool consisted of digital and digitized conventional panoramic radiographs taken prior to implant placement and at follow up appointments. Digital measurements were carried out following an established procedure ("Tuebingen method" by Gomez-Roman). For each patient a linear regression was calculated resulting in a relative area related PARR-value per year. A simplified geometrical scenario was used for the estimation of absolute bone height losses. Data of 23 patients was available. The mean observation period was 9.4 years (±2.4 years). An average area related PARR-rate of 1.02% per year was observed with high individual differences ranging from 0.15% and 2.63% per year. The estimated average ten year vertical bone loss in the chewing center was 1.5 mm. Posterior bone resorption was found to be in the range previously reported for different implant restorations and therefore does not represent a particular problem of two implant bar retained overdentures. The results strengthen the two implant concept. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Effects of a putty-form hydroxyapatite matrix combined with the synthetic cell-binding peptide P-15 on alveolar ridge preservation.

    Science.gov (United States)

    Neiva, Rodrigo F; Tsao, Yi-Pin; Eber, Robert; Shotwell, Jeffrey; Billy, Edward; Wang, Hom-Lay

    2008-02-01

    Various grafting materials have been used for preservation of the dimensions of the residual alveolar ridge following tooth extraction. The purpose of this study was to evaluate clinical, histomorphometric, and radiographic healing 4 months after tooth extraction with or without placement of a putty-form anorganic bovine-derived hydroxyapatite matrix combined with a synthetic cell-binding peptide P-15 (Putty P15) to determine the effect on alveolar ridge preservation following exodontia. Twenty-four consecutive subjects in need of extraction of maxillary premolars were recruited. Recruited subjects were randomly assigned to the test (Putty P15 and bioabsorbable collagen wound dressing material) or control (bioabsorbable collagen wound dressing material only) group. Data were recorded at 1, 2, 4, 8, and 16 weeks after ridge preservation procedures. At 16 weeks, a reentry surgery was performed, clinical measurements were repeated, and bone core biopsies were obtained for histomorphometric analysis prior to dental implant placement. The control group had a mean reduction in ridge height of -0.56 +/- 1.04 mm, whereas alveolar ridge height appeared to remain unchanged in the test group (0.15 +/- 1.76). The test group showed a mean reduction in ridge width of -1.31 +/- 0.96 mm, whereas the mean value for the control group was -1.43 +/- 1.05 mm. No statistical significance was observed between the groups. Mean bone density was significantly superior in the test group (2.08 +/- 0.65 versus 3.33 +/- 0.65). Histomorphometric analyses revealed similar percentages of bone vitality (test: 29.92% +/- 8.46%; control: 36.54% +/- 7.73%). Comparable percentages of bone marrow and fibrous tissue also were observed (test: 65.25% +/- 6.41%; control: 62.67% +/- 7.41%). Only 6.25% of the Putty P15 particles remained at 4 months in the analyzed biopsies. A favorable response was observed when Putty P15 was applied to extraction sockets, suggesting that it may be useful for alveolar ridge

  1. A novel augmented reality system for displaying inferior alveolar nerve bundles in maxillofacial surgery.

    Science.gov (United States)

    Zhu, Ming; Liu, Fei; Chai, Gang; Pan, Jun J; Jiang, Taoran; Lin, Li; Xin, Yu; Zhang, Yan; Li, Qingfeng

    2017-02-15

    Augmented reality systems can combine virtual images with a real environment to ensure accurate surgery with lower risk. This study aimed to develop a novel registration and tracking technique to establish a navigation system based on augmented reality for maxillofacial surgery. Specifically, a virtual image is reconstructed from CT data using 3D software. The real environment is tracked by the augmented reality (AR) software. The novel registration strategy that we created uses an occlusal splint compounded with a fiducial marker (OSM) to establish a relationship between the virtual image and the real object. After the fiducial marker is recognized, the virtual image is superimposed onto the real environment, forming the "integrated image" on semi-transparent glass. Via the registration process, the integral image, which combines the virtual image with the real scene, is successfully presented on the semi-transparent helmet. The position error of this navigation system is 0.96 ± 0.51 mm. This augmented reality system was applied in the clinic and good surgical outcomes were obtained. The augmented reality system that we established for maxillofacial surgery has the advantages of easy manipulation and high accuracy, which can improve surgical outcomes. Thus, this system exhibits significant potential in clinical applications.

  2. Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study

    Science.gov (United States)

    Paraud Freixas, Andres; Han, Chang-Hun; Bechara, Sohueil; Tawil, Isaac

    2016-01-01

    Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i–Gen®, MegaGen, Gyeongbuk, Republic of Korea) were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89). The most frequent complications were mild postoperative edema (12/25 patients: 48%) and discomfort after surgery (10/25 patients: 40%); these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%): one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based) and a peri-implant marginal bone loss of 0.43 mm (±0.15) were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes. PMID:27999799

  3. Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study

    Directory of Open Access Journals (Sweden)

    Raquel Zita Gomes

    2016-01-01

    Full Text Available Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i–Gen®, MegaGen, Gyeongbuk, Republic of Korea were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89. The most frequent complications were mild postoperative edema (12/25 patients: 48% and discomfort after surgery (10/25 patients: 40%; these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%: one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based and a peri-implant marginal bone loss of 0.43 mm (±0.15 were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes.

  4. Ridge preservation with or without an osteoinductive allograft: a clinical, radiographic, micro-computed tomography, and histologic study evaluating dimensional changes and new bone formation of the alveolar ridge.

    Science.gov (United States)

    Brownfield, Lauren A; Weltman, Robin L

    2012-05-01

    The aim of this randomized, controlled clinical trial is to determine whether ridge preservation using an osteoinductive allograft (test) would prevent ridge resorption and promote bone maturation compared to extraction alone (control). Seventeen patients (20 total sites), in need of a non-molar extraction and delayed implant placement were randomly selected to receive either ridge preservation or extraction alone. A cone-beam computed tomography was completed with a radiographic stent in place before extraction and 10 to 12 weeks postoperatively for dimensional and buccal plate analyses. Bone cores were taken for micro-computed tomography (microCT) and histologic analyses. Resorption of the alveolar ridge occurred at all sites with no statistically significant differences found between test and control sites. A significant correlation was found between the initial buccal plate thickness and the loss of vertical ridge height. microCT and histologic analyses found a mean new bone volume of 44.9% with microCT and 37.4% with histology in test sites and 39% and 35.5%, respectively, in control sites. The residual graft volume was 2.4% with microCT and 4.5% with histology. Test and control sites lost similar amounts of alveolar ridge, with the loss of buccolingual width occurring predominantly at the expense of the buccal bone. A thicker buccal plate was associated with less ridge loss in the vertical dimension. The percentage of new bone was not statistically significant between either the test or control sites, using either microCT or histologic analyses.

  5. Assessment of Temperature Rise and Time of Alveolar Ridge Splitting by Means of Er:YAG Laser, Piezosurgery, and Surgical Saw: An Ex Vivo Study

    Directory of Open Access Journals (Sweden)

    Jacek Matys

    2016-01-01

    Full Text Available The most common adverse effect after bone cutting is a thermal damage. The aim of our study was to evaluate the bone temperature rise during an alveolar ridge splitting, rating the time needed to perform this procedure and the time to raise the temperature of a bone by 10°C, as well as to evaluate the bone carbonization occurrence. The research included 60 mandibles (n=60 of adult pigs, divided into 4 groups (n=15. Two vertical and one horizontal cut have been done in an alveolar ridge using Er:YAG laser with set power of 200 mJ (G1, 400 mJ (G2, piezosurgery unit (G3, and a saw (G4. The temperature was measured by K-type thermocouple. The highest temperature gradient was noted for piezosurgery on the buccal and lingual side of mandible. The temperature rises on the bone surface along with the increase of laser power. The lower time needed to perform ridge splitting was measured for a saw, piezosurgery, and Er:YAG laser with power of 400 mJ and 200 mJ, respectively. The temperature rise measured on the bone over 10°C and bone carbonization occurrence was not reported in all study groups. Piezosurgery, Er:YAG laser (200 mJ and 400 mJ, and surgical saw are useful and safe tools in ridge splitting surgery.

  6. Intervention for replacing missing teeth: Alveolar ridge preservation techniques for dental implant site development - evidence summary of Cochrane review

    Directory of Open Access Journals (Sweden)

    Srinivasan Jayaraman

    2015-01-01

    Full Text Available The Cochrane reviews have transparent reporting of the methodology to clarify the reader the methods used for writing the review; hence, each review becomes a large volume of scientific literature. This evidence summary of the Cochrane review published in 2015 for the question, what are the clinical effects (preservation of both width and height of bone, esthetic outcomes, complications, and failure of implant for different alveolar ridge preservation techniques (ARP and materials used in patients planning implant placement following extraction after 6 months follow-up. This review provides evidence for efficacy of different ARP techniques, materials, and superiority of one over the other. It also tries to settle the controversy of timing of placement of implant after grafting. Of the 8 included studies from 50, two trials provide moderate evidence for xenografts versus extraction favoring xenografts in preserving the width and height of bone by 1.97 mm (2.48–1.46 and 2.60 mm (3.43–1.76, respectively in pooled estimates of meta-analysis. Using different material, five-trial were found; of which, two trials provide moderate evidence for alloplast versus xenografts favoring alloplast in preserving the width by 0.44 mm (0.90–0.02 and low-grade evidence for height of bone by 0.35 mm (0.86–0.16 in pooled estimates of meta-analysis. There is a paucity of randomized controlled trial to address other primary and secondary outcomes addressed in this review.

  7. A new method to standardize CBCT for quantitative evaluation of alveolar ridge preservation in the mandible: a case report and review of the literature.

    Science.gov (United States)

    Xia, Yang; Xie, Lizhe; Zhou, Yi; Song, Tianxi; Zhang, Feimin; Gu, Ning

    2015-12-01

    Cone-beam computerized tomography (CBCT) is an effective technique for assessment of changes to the alveolar ridge (AR). However, its accuracy and reliability could be improved by standardization of imaging positions to remain unchanged during measurements. In this study, an alveolar ridge preservation procedure was performed on a left third molar (38) socket by filling it with a radiotransparent synthetic bone graft, mineralized collagen (MC). Photographic, X-ray and CBCT images were captured before and 3, 6 and 12 months after surgery. A new method was developed to standardize CBCT for quantitative evaluation. Obtained CBCT images showed good comparability. The post-extraction alveolar width and height were both over 95% of the original values, but some resorption of the lingual bone wall (>50%) and inter-crestal bone (>30%). It is concluded that an effective positional standardization method was developed for CBCT assessment of AR dimensional changes in the posterior mandible. The use of MC in combination with a collagen membrane improved dimensional preservation of the AR.

  8. Alveolar ridge preservation with an open-healing approach using single-layer or double-layer coverage with collagen membranes.

    Science.gov (United States)

    Choi, Ho-Keun; Cho, Hag-Yeon; Lee, Sung-Jo; Cho, In-Woo; Shin, Hyun-Seung; Koo, Ki-Tae; Lim, Hyun-Chang; Park, Jung-Chul

    2017-12-01

    The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were -1.7±0.5 mm in the SL group and -1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures.

  9. Combination of Bone Graft and Resorbable Membrane for Alveolar Ridge Preservation: a Systematic Review, Meta-analysis and Trial Sequential Analysis.

    Science.gov (United States)

    Troiano, Giuseppe; Zhurakivska, Khrystyna; Lo Muzio, Lorenzo; Laino, Luigi; Cicciù, Marco; Lo Russo, Lucio

    2017-09-12

    Alveolar ridge preservation (ARP) techniques are aimed to reduce the resorption after tooth extraction. The combination of a graft material covered with a resorbable membrane represent one of the most common strategies performed in the clinical practice. The aim of this systematic review was to analyse evidence regarding potential benefits of ARP procedures performed with allogenic/xenogenic grafts in combination with a resorbable membrane coverage in comparison to a spontaneous healing. Electronic databases were screened independently by two authors in order to select studies suitable for inclusion in this revision. Horizontal Ridge Width Reduction (HRWR) and Vertical Ridge Height Reduction (VRHR) were investigated as primary outcomes and Volume Changes (VC) as secondary outcome. Meta-analysis was performed using the inverse of variance test with a random effect model. Adjustment for type I and II errors and analysis of the power of evidence was performed with Trial Sequential analysis (TSA). 7 studies met the inclusion criteria and were included in the quantitative synthesis. Meta-analysis revealed that the combination therapy resulted in a lower rate of resorption for both HRWR (-2.19 mm with 95% Confidence Interval (CI) [-2.67, -1.71]) and VRHR (-1.72 mm with 95% CI [-2.14, -1.30]). For VC no meta-analysis was performed due to insufficient data. Analysis of the power of the evidence performed with TSA, showed that the number of both studies and sockets analyzed is sufficient to validate such findings, despite the high rate of heterogeneity. The use of bone graft covered by a resorbable membrane is able to decrease the rate of alveolar ridge horizontal and vertical resorption after tooth extraction. The power and reliability of the evidences are strong enough to confirm the above-mentioned findings, despite the high rate of heterogeneity of included studies.

  10. Lateral Ridge Augmentation Using Autogenous Block Grafts and Guided Bone Regeneration: A 10-Year Prospective Case Series Study.

    Science.gov (United States)

    Chappuis, Vivianne; Cavusoglu, Yeliz; Buser, Daniel; von Arx, Thomas

    2017-02-01

    The use of autogenous block grafts harvested from intraoral donor sites has proven to be effective for the reconstruction of horizontal bone defects. The objective of this study was to analyze implant success and the rate of block graft resorption 10 years after ridge augmentation to elucidate contributing factors influencing graft maintenance. A staged horizontal block graft augmentation was performed in 52 implant sites exhibiting severe horizontal bone atrophy using autogenous block grafts protected by DBBM and collagen membranes. The crest width was assessed intraoperatively at surgery and at re-entry after 6 months. At the 10 year reexamination clinical and radiographic parameters were assessed using cone beam computed tomography. The 10-year implant success rate amounted to 98.1%, with minimal peri-implant bone loss (-0.17 mm for the maxilla, -0.09 mm for the mandible). The surface resorption rate after 10 years was 7.7% (0.38 mm). Grafts originating from the chin demonstrated significantly better graft maintenance at 10 years compared to retromolar grafts. Recipient site and age had no significant impact on graft resorption, whereas females showed more bone loss at the 10-year examination. Lateral ridge augmentation using autogenous block grafts and guided bone regeneration demonstrated a favorable success rate of 98.1% with minimal block graft resorption of 7.7% after 10 years. Modulating factors were origin of the graft and gender. © 2016 Wiley Periodicals, Inc.

  11. MICROECOLOGY OF THE MUCOUS MEMBRANE OF THE ALVEOLAR RIDGES IN THE PERIOD OF ADAPTATION TO COMPLETE DENTURES

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    Yanishen I. V.,

    2016-06-01

    quantitative composition of the biocenosis. It is established that the microflora of the alveolar ridge in patients with edentulous consisted of associations of yeasts from 2-5 representatives of the microbial world. It is established that in patients of the experimental group on the 7th day of withdrawal 3-component microbial associations has decreased in 1.3 times, whereas the 4-component associations were recorded in 1.4 times more often compared with the initial period of observation. For patients with adhesive frequency of detection of 2-component microbial associations 30-the day of the research was 1.3 times higher than prior to the setting of the prosthesis. Identify 5 component associations for 30-the day, has decreased in 2 times. In patients without adhesive (control group 4-component microbial associations in the mouth after a week of adaptation to the prosthesis were detected in 1.6 times, and 30 days – in 2 times more often than to prosthetics. The weight 5 component associations through the week remained at the initial level, while after 30 days has increased in 1,5 times. The structure microbiocenosis the mucous of the oral cavity patients with edentulism are represented 13 genera of bacteria and morilioid fungi of the genus Candida, allocated in secondary amounts by lg (2,5±0,19 to lg (5,4±0,17 CFU/g. When adhesive between denture base and mucosa of the alveolar ridge frequency of withdrawal and the density of microbial colonization in the adaptation period were not statistically different. But the density of the microbial population among the control group increased 1.5 times for Enterococcus spp, 1.4 for the Klebsiella spp and 1.6 times for yeast fungi Candida spp. Found a significant decrease in microbial density of the representatives of the resident microflora in 1.4 times for Neisseria spp, 1.6-fold for Lactobacillus spp (p<0.05. Conclusion. The results of these studies indicate significant changes of qualitative and quantitative structure of

  12. Reconstruction of a Severely Atrophied Alveolar Ridge by Computer-Aided Gingival Simulation and 3D-Printed Surgical Guide: A Case Report.

    Science.gov (United States)

    Song, In-Seok; Lee, Mi-Ran; Ryu, Jae-Jun; Lee, Ui-Lyong

    2017-08-17

    Dental implants positioned in severely atrophied anterior maxillae require esthetic or functional compromises. This case report describes the rehabilitation of a severely atrophied alveolar ridge with a three-dimensional (3D) computer-aided design/computer-aided manufacture (CAD/CAM) surgical guide. A 50-year-old woman had a severely atrophied anterior maxilla with unfavorably positioned dental implants. Functional and esthetic prosthodontic restoration was difficult to achieve. An anterior segmental osteotomy was planned to reposition the dental implants. A 3D surgical guide was designed for precise relocation of the segment. The surgical guide firmly grasped the impression copings of the dental implants, minimizing surgical errors. Three-dimensional gingival simulation was used preoperatively to estimate the appropriate position of the gingiva. Rigid fixation to the surrounding bone allowed immobilization of the implant-bone segment. Satisfactory esthetic and functional outcomes were attained 6 months after surgery. Finally, a severely atrophied alveolar ridge with unfavorably positioned dental implants was recovered with minimal esthetic and functional deterioration using gingival simulation and a 3D CAD/CAM surgical guide.

  13. Regenerative potential of leucocyte- and platelet-rich fibrin. Part B: sinus floor elevation, alveolar ridge preservation and implant therapy. A systematic review.

    Science.gov (United States)

    Castro, Ana B; Meschi, Nastaran; Temmerman, Andy; Pinto, Nelson; Lambrechts, Paul; Teughels, Wim; Quirynen, Marc

    2017-02-01

    To analyse the effect of leucocyte- and platelet-rich fibrin (L-PRF) on bone regeneration procedures and osseointegration. An electronic and hand search was conducted in three databases (MEDLINE, EMBASE and Cochrane). Only randomized clinical trials, written in English where L-PRF was applied in bone regeneration and implant procedures, were selected. No follow-up restrictions were applied. A total of 14 articles were included and processed. Three subgroups were created depending on the application: sinus floor elevation (SFE), alveolar ridge preservation and implant therapy. In SFE, for a lateral window as well as for the trans-alveolar technique, histologically faster bone healing was reported when L-PRF was added to most common xenografts. L-PRF alone improved the preservation of the alveolar width, resulting in less buccal bone resorption compared to natural healing. In implant therapy, better implant stability over time and less marginal bone loss were observed when L-PRF was applied. Meta-analyses could not be performed due to the heterogeneity of the data. Despite the lack of strong evidence found in this systematic review, L-PRF might have a positive effect on bone regeneration and osseointegration. © 2016 The Authors. Journal of Clinical Periodontology Published by John Wiley & Sons Ltd.

  14. Carcinoma de células escamosas em rebordo alveolar inferior: diagnóstico e tratamento odontológico de suporte Squamous cell carcinoma in lower alveolar ridge: diagnosis and odontologic support treatment

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    Filipe Ivan Daniel

    2006-08-01

    Full Text Available O carcinoma epidermóide é a neoplasia maligna mais comum de cavidade oral e estruturas adjacentes. Apresenta maior incidência no gênero masculino, após a quarta década de vida, e tem como principais fatores etiológicos os usos crônicos de tabaco e álcool. Neste trabalho é relatado um caso de carcinoma de células escamosas do rebordo alveolar inferior, que não é uma região preferencial para esse tipo de patologia. Também é discutida a importância do cirurgião-dentista na equipe de profissionais que assiste esses pacientes, tanto no diagnóstico precoce quanto no manejo das alterações estomatológicas advindas da terapia antineoplásica.Squamous cell carcinoma is the most common malignant neoplasm in oral cavity and adjacent structures. Its prevalence is higher in males, after the fourth decade, and the main etiologic associated factors are smoking and alcohol. This study reports a case of squamous cell carcinoma arising from the lower alveolar ridge, a non-preferential site for this pathology. It also discusses the importance of the dentist in the team of professionals assisting these patients, in early diagnosis and treatment of the stomatological alterations due to antineoplastic therapy.

  15. Immediate provisionalization of dental implants placed in healed alveolar ridges and extraction sockets: a 5-year prospective evaluation.

    Science.gov (United States)

    Cooper, Lyndon F; Reside, Glenn J; Raes, Filiep; Garriga, Joan Soliva; Tarrida, Luis Giner; Wiltfang, Jörg; Kern, Matthias; De Bruyn, Hugo

    2014-01-01

    This 5-year prospective multicenter study compared implant survival and success, peri-implant health and soft tissue responses, crestal bone level stability, and complication rates following immediate loading of single OsseoSpeed implants placed in anterior maxillary healed ridges or extraction sockets. Individuals requiring anterior tooth replacement with single implants were treated and immediately provisionalized. Definitive all-ceramic crowns were placed at 12 weeks. Implant survival, bone levels, soft tissue levels, and peri-implant health were monitored for 5 years. One hundred thirteen patients received implants in fresh sockets (55) and healed ridges (58). After 5 years, 45 and 49 patients remained for evaluation, respectively. During the first year, three implants failed in the extraction socket group (94.6% survival) and one implant failed in the healed ridge group (98.3% survival); this difference was not significant. No further implant failures were recorded. After 5 years, the interproximal crestal bone levels were located a mean of 0.43 ± 0.63 mm and 0.38 ± 0.62 mm from the reference points of implants in sockets and healed ridges (not a significant difference). In both groups, papillae increased over time and peri-implant mucosal zenith positions were stable from the time of definitive crown placement in sockets and healed ridges. Compared to flap surgery for implants in healed ridges, flapless surgery resulted in increased peri-implant mucosal tissue dimension (average, 0.78 ± 1.34 mm vs 0.19 ± 0.79 mm). After 5 years, the bone and soft tissue parameters that characterize implant success and contribute to dental implant esthetics were similar following the immediate provisionalization of implants in sockets and healed ridges. The overall tissue responses and reported implant survival support the immediate provisionalization of dental implants in situations involving healed ridges and, under ideal circumstances, extraction sockets.

  16. Comparative Alveolar Ridge Preservation Using Allogenous Tooth Graft versus Free-dried Bone Allograft: A Randomized, Controlled, Prospective, Clinical Pilot Study.

    Science.gov (United States)

    Joshi, Chaitanya Pradeep; D'Lima, Cynthia Bernardo; Samat, Urmila Chandrashekhar; Karde, Prerna Ashok; Patil, Agraja Ganpat; Dani, Nitin Hemchandra

    2017-01-01

    For the first time in India, allografts from human extracted teeth were prepared. A randomized, prospective, clinicoradiographical, histological study was conducted to evaluate their efficacy in comparison with freeze-dried bone allograft (FDBA) in alveolar ridge preservation. Graft preparation: with written consent, teeth were collected from three donors (full mouth extraction cases). Once donors' serums were tested negative for HIV, HBV, HCV, and Venereal disease research laboratory (VDRL), mineralized whole tooth allograft (WTA) and dentin allograft (DA) were prepared using the standard protocol of Tissue Bank at Tata Memorial Hospital, Mumbai, India. In this randomized controlled trial, 15 patients undergoing extraction of at least four teeth were selected. In each patient after atraumatic extractions, one socket was grafted with WTA, second with DA, third with FDBA, and fourth was left ungrafted (control site). All the sites were covered with chorion membrane. To estimate three-dimensional alveolar crest changes, cone beam computed tomography scans were taken immediately after grafting and 4 months postoperatively. Bone biopsies using 3 mm trephine bur were obtained from four patients at the time of implant placement and evaluated histologically. Clinically uneventful healing was observed at all sites. Compared to other sites, WTA and DA consistently showed superior results demonstrating least reduction in alveolar crest height and width which was statistically significant ( P < 0.05). Between WTA and DA sites, there was no statistically significant difference. Histological analysis also confirmed more new bone formation at WTA and DA sites. Rather than disposing extracted human teeth as a biomedical waste (common practice), they can be collected from suitable systemically healthy donors. With the help of tissue bank, they can be processed into an allograft, serving as an excellent alternative to conventional allografts.

  17. Alveolar bone width preservation after decoronation of ankylosed anterior incisors.

    Science.gov (United States)

    Lin, Shaul; Schwarz-Arad, Dvorah; Ashkenazi, Malka

    2013-12-01

    The aim of the study was to assess the alteration of alveolar ridge dimensions after decoronation procedures in children and adolescents at least 1 year after surgery. Twelve children who underwent decoronation of ankylosed maxillary anterior incisors with at least 1 year after surgery follow-up were recalled for reevaluation. All decoronations were performed when the ankylosed teeth were submerged 1-1.5 mm. During the recall appointment, impressions of the upper arch were obtained. The bucco-palatal alveolar dimensions of the decoronated teeth were measured on the cast at the mid-mesiodistal distance from the missing tooth and were compared with the distance from the contralateral healthy incisor. Overall, 12 children (9 male and 3 female) were reevaluated up to 82 months after decoronation (mean, 49.58 ± 24 months). The mean age of the patients at the time of trauma was 9.83 ± 2.8 years. The average bucco-palatal dimension of the alveolar ridge at the mid-decoronation area was 9 ± 1 mm compared with 10.17 ± 0.9 mm at the contralateral homologous tooth (difference of 1.67 ± 1.12, P = .004). The findings show a positive statistical correlation between the duration of the follow-up period and the bucco-palatal dimension of the alveolar ridge (P = .027). Although decoronation of ankylosed young permanent incisors resulted in a decrease in the bucco-palatal dimension with time, it did not prevent additional alveolar growth that occurs with age in a developing child and thus may help maintain the alveolar bone ridge width, height, and continuity and assist in future rehabilitation with less invasive ridge augmentation procedures required for implant placement. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. A clinical and histomorphometric study of calcium sulfate compared with freeze-dried bone allograft for alveolar ridge preservation.

    Science.gov (United States)

    Toloue, Samira M; Chesnoiu-Matei, Ioana; Blanchard, Steven B

    2012-07-01

    Many materials have been found to be effective in ridge preservation. The purpose of this study is to determine whether calcium sulfate (CS) is as effective as freeze-dried bone allograft (FDBA) in preserving postextraction ridge dimensions and to evaluate the amount of new bone formation and graft clearance through histologic analysis. Thirty-one extraction sites were selected. Postextraction clinical measurements were made, and sites were divided randomly into the test group (CS) or the control group (FDBA). After graft placement, all individuals received the same postoperative treatment and instructions. Participants were recalled after 3 months, measurements were made, and sites were re-entered. Bone samples were harvested and analyzed with histologic methodology for new bone formation and remaining residual graft. Thirteen test and 15 control sites were evaluated. There was no significant change in vertical ridge height before or after surgery within the test and control groups (P = 0.57, P = 0.68, respectively). There was a significant decrease in bucco-lingual ridge width for both groups (P = 0.0003, P = 0.0075, respectively), but the difference between groups was not significant (P = 0.11). Histologic analysis revealed an average of 32% new bone formation with 2.5% graft remaining for the test group and 16.7% new bone formation with 21% graft remaining for the control. Results indicate that CS is as effective as FDBA in preserving postextraction ridge dimensions in non-molar extraction sites. There is greater clearance of CS with more new bone formation after ≈3 months compared with FDBA in these sites. This paper received the Maynard K. Hine Award for Excellence in Dental Research presented by the Indiana Section of the American Association for Dental Research and supported by Procter & Gamble.

  19. Ridge augmentation with soft tissue procedures in aesthetic dentistry: first clinical results measured with a new kind of moire technique

    Science.gov (United States)

    Studer, Stephan P.; Bucher, Andreas; Mueller, Felix

    1993-09-01

    The oral health of the Swiss population was significantly improved by the successful prevention of dental caries and periodontitis. Along with the healthy dentition the demand for aesthetic dentistry is increasing. Removable partial dentures are becoming less accepted. Therefore, to substitute lost teeth by permanent fixed partial prosthesis (bridges), the often deformed alveolar ridge has to be operated, either to improve the aesthetic appearance or to make it possible to restore the missing teeth by a fixed cemented bridge. The aim of this paper is (1) to evaluate whether the moire technique is an appropriate and handy method, and (2) to validate the precision of the new method. The measuring system consisted of a moire projector with an integrated phase shift device and a moire viewer with a CCD video camera, connected to a frame grabber in a personal computer. a highly versatile software was allowed to control the system as well as to grab the moire images using the four-phase shift technique in order to compute the phase image of the actual object. The new technique was validated with one solid test object measured by a 3D coordination, high precision measuring machine.

  20. Interdisciplinary approach to enhance the esthetics of maxillary anterior region using soft- and hard-tissue ridge augmentation in conjunction with a fixed partial prosthesis

    Directory of Open Access Journals (Sweden)

    Shaleen Khetarpal

    2018-01-01

    Full Text Available Favorable esthetics is one of the most important treatment outcomes in dentistry, and to achieve this, interdisciplinary approaches are often required. Ridge deficiencies can be corrected for both, soft- and hard-tissue discrepancies. To overcome such defects, not only a variety of prosthetic options are at our disposal but also several periodontal plastic surgical techniques are available as well. Various techniques have been described and revised, over the year to correct ridge defects. For enhancing soft-tissue contours in the anterior region, the subepithelial connective tissue graft is the treatment of choice. A combination of alloplastic bone graft in adjunct to connective tissue graft optimizes ridge augmentation and minimizes defects. The present case report describes the use of vascular interpositional connective tissue graft in combination with alloplastic bone graft for correction of Seibert's Class III ridge deficiency followed by a fixed partial prosthesis to achieve a better esthetic outcome.

  1. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series

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    Minas D. Leventis

    2016-01-01

    Full Text Available Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP granules coated with poly(lactic-co-glycolic acid (PLGA were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques.

  2. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series

    Science.gov (United States)

    Leventis, Minas D.; Fairbairn, Peter; Kakar, Ashish; Leventis, Angelos D.; Margaritis, Vasileios; Lückerath, Walter; Horowitz, Robert A.; Rao, Bappanadu H.; Lindner, Annette; Nagursky, Heiner

    2016-01-01

    Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic acid) (PLGA) were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone) in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material) while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques. PMID:27190516

  3. Clinical prospective study of a modified technique to extend the keratinized gingiva around implants in combination with ridge augmentation: one-year results.

    Science.gov (United States)

    Stimmelmayr, Michael; Stangl, Martin; Edelhoff, Daniel; Beuer, Florian

    2011-01-01

    The aim of this study was to evaluate the effectiveness of a modified surgical technique to extend the keratinized gingiva around implants in augmented mandibles and the stability of the technique after 1 year. Implants were inserted in mandibles in combination with ridge augmentation and extension of deficient buccal keratinized gingiva (BKT) with free gingival grafts (FGGs), in which the keratinized local gingiva (KLG) was transferred toward the lingual. In group 1, implants were placed simultaneous with ridge augmentation, and FGGs were performed at the time of uncovering the implants. In group 2, the implants were placed after ridge augmentation, and FGGs were performed at the time of implant placement with nonsubmerged healing. The width of KLG and FGG, as well as the width of the BKT and lingual keratinized gingiva (LKT), were measured 4 weeks, 3 months, and 1 year after soft tissue grafting. Seventy implants (46 in group 1, 24 in group 2) were placed in 29 patients with a mean age of 54.4 years. The mean width of KLG was 2.90 mm preoperatively (3.00 mm for group 1, 2.75 mm for group 2). Mean FGG was 4.60 mm in group 1 and 4.70 mm in group 2. For group 1 the mean width of BKT was 3.70 mm after 1 year. In contrast, group 2 showed mean BKT of 3.30 mm after 1 year. The resultant overall gain in BKT was 3.50 mm at 1 year. The LKT exhibited significantly more atrophy in group 1 (0.35 mm at 1 year) than in group 2 (0.05 mm at 1 year). The combination of ridge augmentation with the presented modified surgical technique resulted in the stable extension of keratinized gingiva around implants for 1 year.

  4. Orthodontic tooth movement after extraction of previously autotransplanted maxillary canines and ridge augmentation.

    Science.gov (United States)

    Collett, A R; Fletcher, B

    2000-12-01

    A case report is detailed in which autotransplanted maxillary canines were removed and the spaces closed. Substantial surrounding bone loss was associated with the upper right canine, and a bone graft was needed to reestablish normal dentoalveolar ridge morphology. Bone was taken from the maxillary tuberosity and placed in the canine extraction site, fixed with a bone screw, and covered with GoreTex. Seven months after placement of the bone graft, the GoreTex and stabilizing screw were removed to allow for consolidation of the bone. The upper left canine and lower second premolars were extracted, and fixed appliances were placed in both arches to align the teeth and close the spaces. Protraction of the upper right first premolar and retraction of the lateral incisor into the graft site were kept slow and constant with continued periodontal assessment. During the space closure, there was some concern that the bone in the graft site might resorb, leaving the teeth with compromised periodontal support. However, no significant periodontal attachment loss occurred despite ongoing concern about the amount of keratinized tissue. Perhaps the relatively slow rate of tooth movement provided for bone to be maintained and recreated ahead of the tooth. Almost complete closure of the upper canine extraction spaces was achieved. The upper premolars were substituted for the maxillary canines, and unfavorable prosthetic options were thus avoided. The lower arch was aligned, and the extraction spaces completely closed.

  5. Alveolar bone resorption after tooth extraction

    OpenAIRE

    Dimova, Cena; Popovski, Stipica

    2012-01-01

    Alveolar ridge resorption has long been considered an unavoidable consequence of tooth extraction. Atrophy of the alveolar bone may cause significant esthetic and surgical problems in implantation, as well as at prosthetic and restorative dentistry. Alveolar ridge prophylaxis immediately upon tooth extraction may reduce such sequelae for both, the treating dentist and the patient. Attempts to reduce alveolar bone resorption have included the placement of natural roots, root analogues, and...

  6. Alveolar ridge preservation with a free gingival graft in the anterior maxilla: volumetric evaluation in a randomized clinical trial.

    Science.gov (United States)

    Karaca, Ç; Er, N; Gülşahı, A; Köseoğlu, O T

    2015-06-01

    The aim of this study was to evaluate and compare the dimensional changes in maxillary extraction sockets that have healed spontaneously and those treated with free gingival grafts. Ten subjects with at least two maxillary anterior teeth scheduled for extraction were selected for this study. Two maxillary teeth were allocated randomly to either the test group or the control group. In the test group, the extraction socket was covered with a free gingival graft harvested from the palate, while in the control group the sockets healed spontaneously. Cone beam computed tomography (CBCT) scans were taken on the day of extraction and at 3 months postoperative. Soft tissue healing of the extraction sockets was assessed visually by clinical inspection. Hard tissue measurements were obtained from the CBCT scans. After 3 months of healing, the control sockets had lost height in the buccal and lingual crestal bones (-1.03 and -0.56mm, respectively); however, the height in the buccal and lingual crestal bones was preserved at the test sites (+0.06 and +0.25mm, respectively). This difference between the two groups was statistically significant (P0.05). The authors propose that covering the orifice of the extraction socket with a free gingival graft can result in preservation of the alveolar bone height. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  7. Pressure produced on the residual maxillary alveolar ridge by different impression materials and tray design: an in vivo study.

    Science.gov (United States)

    Reddy, Subash M; Mohan, Chenthil Arun; Vijitha, D; Balasubramanian, R; Satish, A; Kumar, Mahendira

    2013-12-01

    Increased ridge resorption may occur due to inappropriate pressure applied during final impression making phase of complete denture fabrication. This study was done to evaluate the pressure applied on the residual ridge while making impressions with two tray designs (with and without spacer) using, zinc oxide eugenol and light body polyvinyl siloxane impression material. Five edentulous subjects were randomly selected. For each of the five subjects four maxillary final impressions were made and were labelled as, Group A-Impression made with tray without spacer using zinc oxide eugenol impression, Group B-Impression made with tray with spacer using zinc oxide eugenol impression material, Group C-Impression made with tray without spacer using light body polyvinyl siloxane impression material, Group D-Impression made with tray with spacer using light body polyvinyl siloxane impression material. During the impression procedure a closed hydraulic system was used to remotely measure the pressures produced in three areas. The pressure produced were calibrated according to the micro strain record. Statistical comparisons of readings were done using t test and ANOVA. The acquired data revealed that ZOE produced an average pressures value of 26.534 and 72.05 microstrain, while light body PVS produced 11.430 and 37.584 microstrain value with and without spacer respectively. Significantly high values were recorded on the vault of the palate when using trays without spacer. The use of light body polyvinyl siloxane and zinc oxide eugenol impression material showed insignificant difference. Within the limitations of this study, tray design has a significantly effected on the pressures produced, while the impression materials does not have any significant difference.

  8. Flap versus flapless procedure for ridge preservation in alveolar extraction sockets: a histological evaluation in a randomized clinical trial.

    Science.gov (United States)

    Barone, Antonio; Borgia, Valentina; Covani, Ugo; Ricci, Massimiliano; Piattelli, Adriano; Iezzi, Giovanna

    2015-07-01

    The aim of this study was to evaluate and compare the histological and histomorphometric features of two different procedures carried out in extraction socket grafting; namely, the flapped and flapless technique. Patients considered eligible for the study were randomized to receive tooth extraction and ridge preservation with the porcine bone and collagen membrane, with a full thickness mucoperiosteal flap and primary soft tissue closure (control group), or, with a flapless procedure and a secondary soft tissue closure (test group). After 3 months of healing, the surgical re-entry procedure was performed and implants were inserted in the test as well as in the control sites. Bone core samples were harvested from both groups and processed to be observed under light microscopy. Outcome variables were percentages of newly formed bone, residual graft particles and marrow spaces. Thirty-four patients were enrolled in the study. All of the scheduled implants were placed. Histological and histomorphometrical analyses did not report significant differences between the two groups (with P-values ranging from 0.690 to 0.917). The mean percentages of newly formed bone, soft tissues and residual grafted particles were 22.5 and 22.5%, 59.3 and 59.4%, and 18.6 and 18.2% respectively for flap and flapless approach. No histological and histomorphometrical differences were observed when comparing the flap and the flapless technique for tooth extraction and socket grafting procedures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Single implants in the aesthetic region preceded by local ridge augmentation; a 10-year randomized controlled trial

    NARCIS (Netherlands)

    Meijndert, Caroliene M.; Raghoebar, Gerry M.; Meijndert, Leo; Stellingsma, Kees; Vissink, Arjan; Meijer, Henny J.A.

    OBJECTIVES: The aim of this randomized controlled trial was to assess the 10-year effects of three different augmentation techniques (augmentation with chin bone, augmentation with chin bone plus a membrane and augmentation with a bone substitute plus a membrane) for implant-supported restorations

  10. Environmental particulate (PM2.5 augments stiffness-induced alveolar epithelial cell mechanoactivation of transforming growth factor beta.

    Directory of Open Access Journals (Sweden)

    Marilyn M Dysart

    Full Text Available Dysfunctional pulmonary homeostasis and repair, including diseases such as pulmonary fibrosis (PF, chronic obstructive pulmonary disease (COPD, and tumorigenesis have been increasing over the past decade, a fact that heavily implicates environmental influences. Several investigations have suggested that in response to increased transforming growth factor--beta (TGFβ signaling, the alveolar type II (ATII epithelial cell undergoes phenotypic changes that may contribute to the complex pathobiology of PF. We have previously demonstrated that increased tissue stiffness associated with PF is a potent extracellular matrix (ECM signal for epithelial cell activation of TGFβ. The work reported here explores the relationship between tissue stiffness and exposure to environmental stimuli in the activation of TGFβ. We hypothesized that exposure of ATII cells to fine particulate matter (PM2.5 will result in enhanced cell contractility, TGFβ activation, and subsequent changes to ATII cell phenotype. ATII cells were cultured on increasingly stiff substrates with or without addition of PM2.5. Exposure to PM2.5 resulted in increased activation of TGFβ, increased cell contractility, and elongation of ATII cells. Most notably, on 8 kPa substrates, a stiffness greater than normal but less than established fibrotic lung, addition of PM2.5 resulted in increased cortical cell stiffness, enhanced actin staining and cell elongation; a result not seen in the absence of PM2.5. Our work suggests that PM2.5 exposure additionally enhances the existing interaction between ECM stiffness and TGFβ that has been previously reported. Furthermore, we show that this additional enhancement is likely a consequence of intracellular reactive oxygen species (ROS leading to increased TGFβ signaling events. These results highlight the importance of both the micromechanical and biochemical environment in lung disease initiation and suggest that individuals in early stages of lung

  11. To assess the efficacy of socket plug technique using platelet rich fibrin with or without the use of bone substitute in alveolar ridge preservation: a prospective randomised controlled study.

    Science.gov (United States)

    Girish Kumar, N; Chaudhary, Rupanzal; Kumar, Ish; Arora, Srimathy S; Kumar, Nilesh; Singh, Hem

    2018-02-06

    The purpose of this study is to evaluate the efficacy of Platelet Rich Fibrin (PRF) as a socket plug with or without use of Plaster of Paris (POP) as bone substitute to preserve the alveolar ridge post-extraction. A prospective randomised single blind controlled study, was conducted for 18 months from November 2014 to May 2016 on 48 patients requiring extraction. All teeth were extracted atraumatically using periotomes and luxators without raising mucoperiosteal flap. Sockets were randomly allotted to groups A, B and C. Group A sockets were chosen as control, where figure of eight suture was placed. In group B sockets, PRF obtained by centrifugation was used as a socket plug and stabilised with figure of eight suture. Group C sockets were filled with POP and then covered with PRF. The socket was then closed with a figure of eight suture. Patients were informed of need for 6 months follow-up. Ninety sockets in 48 patients were subjected to our study. We found that results in the sockets where we have grafted POP showed better ridge preservation and post-operative comfort even though the difference in ridge resorption between the three groups was not statistically significant. Powered by Editorial Manager® and ProduXion Manager® from the Aries Systems Corporation. Atraumatic extraction may minimise the post-operative pain and discomfort to patient as well as the post-extraction alveolar height and width changes. The use of PRF and/or bone substitute even though clinically contributes to better post-operative healing and minimal loss of alveolar width and height, the values were not statistically significant.

  12. Using virtual ridge augmentation and 3D printing to fabricate a titanium mesh positioning device: A novel technique letter.

    Science.gov (United States)

    Al-Ardah, Aladdin; Alqahtani, Nasser; AlHelal, Abdulaziz; Goodacre, Brian; Swamidass, Rajesh; Garbacea, Antoanela; Lozada, Jaime

    2018-03-02

    This technique describes a novel approach for planning and augmenting a large bony defect using a titanium mesh (TiMe). A 3-dimensional (3D) surgical model was virtually created from a cone beam computed tomography (CBCT) and wax-pattern of the final prosthetic outcome. The required bone volume (horizontally and vertically) was digitally augmented and then 3D printed to create a bone model. The 3D model was then used to contour the TiMe in accordance with the digital augmentation. With the contoured / preformed TiMe on the 3D printed model a positioning jig was made to aid the placement of the TiMe as planned during surgery. Although this technique does not impact the final outcome of the augmentation procedure, it allows the clinician to virtually design the augmentation, preform and contour the TiMe, and create a positioning jig reducing surgical time and error.

  13. Bone resorption and complications in alveolar distraction osteogenesis.

    Science.gov (United States)

    Ettl, Tobias; Gerlach, Till; Schüsselbauer, Thomas; Gosau, Martin; Reichert, Torsten E; Driemel, Oliver

    2010-10-01

    Distraction osteogenesis presents an alternative procedure for augmentation of atrophic alveolar bone prior to inserting dental implants. The aim of this retrospective study was to evaluate complications of this method with specific focus on bone resorption during the consolidation period and the follow-up period after dental implant insertion into distracted bone. Thirty partially edentulous patients underwent a total of 36 vertical alveolar distractions with an extraosseous distraction system. Eleven devices were placed in the maxilla and 25 in the mandible. Eighty-two dental implants were inserted after a mean consolidation period of 4.5 months. Treatment results were evaluated by means of panoramic radiographs for distraction follow-up and periapical radiographs for implant follow-up. The mean length of the transport segment was 19 mm. The average alveolar height achieved was 6.4 mm with a mean resorption of 1.8 mm (21.1%) at the time of dental implant insertion. Main problems comprised oral displacement of the transport segment (n = 15) and inadequate soft tissue extension (n = 13). Eighty-two dental implants were inserted with an overall survival rate of 95.1% after 45.8 months. For periimplant marginal bone, an average resorption of 3.5 mm was recorded 50.4 months after implant insertion. Although alveolar distraction osteogenesis seems to be an effective tool to treat vertical defects of the alveolar ridge, it is not an uncomplicated procedure. A combination with vestibular augmentation of autogenous bone grafts should be considered. Overcorrection of 20% may compensate bone relapse during the consolidation period of the distracted alveolar bone. Further bone resorption after dental implantation is common.

  14. Comparative, randomized, double-blind clinical study of alveolar ridge preservation using an extracellular matrix-based dental resorbable membrane in the extraction socket.

    Science.gov (United States)

    Chang, Hyeyoon; Kim, Sulhee; Hwang, Jin Wook; Kim, Sungtae; Koo, Ki-Tae; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Lee, Jong-Ho; Rhyu, In-Chul

    2017-06-01

    The aim of this study was to radiographically and clinically compare the effect of extracellular matrix (ECM) membranes on dimensional alterations following a ridge preservation procedure. One of 2 different ECM membranes was applied during a ridge preservation procedure. A widely used ECM membrane (WEM; Bio-Gide, Geistlich Biomaterials, Wolhusen, Switzerland) was applied in the treatment group and a newly developed ECM membrane (NEM; Lyso-Gide, Oscotec Inc., Seongnam, Korea) was applied in the control group. Cone-beam computed tomography (CBCT) scans and alginate impressions were obtained 1 week and 6 months after the ridge preservation procedure. Results were analyzed using the independent t -test and the nonparametric Mann-Whitney U test. There were no significant differences between the ECM membranes in the changes in the dimension, width, and height of the extraction socket or the quantity of bone tissue. The NEM showed comparable clinical and radiographic results to the WEM following the ridge preservation procedure.

  15. Long-term effects of vertical bone augmentation: a systematic review

    Directory of Open Access Journals (Sweden)

    Johan Anton Jochum Keestra

    2016-02-01

    Full Text Available ABSTRACT Extraction, periodontitis, or trauma can cause a reduction on the alveolar ridge. This could result in an insufficient alveolar bone width and height. Different techniques of vertical bone augmentation are described in literature. However, nowadays there is not enough evidence against lateral augmentation procedures to verify if these techniques are stable over a long period of time. Objective This review analyses the different techniques that are used to vertically augment the bone and evaluate if these techniques are stable over a long period of time. Material and Methods The MEDLINE-PubMed database was searched from its earliest records until December 22, 2014. The following search term was used: Alveolar Ridge augmentation [MESH]. Several journals were hand searched and some authors were contacted for additional information. The primary outcome measure that was analyzed was marginal bone level change around dental implants in the augmented sites, and the secondary outcomes were survival and success rates of dental implants placed in the augmented sites. Results The search yielded 203 abstracts. Ultimately, 90 articles were selected, describing 51 studies meeting the eligibility criteria. The marginal bone level change for the inlay technique and vertical guided bone regeneration are in agreement with the success criteria. Alveolar distraction showed more marginal bone level change after the first year of loading, and for the inlay technique very few studies were available. Conclusions Based on the available data in the current existing studies with a follow-up period of at least 4 to 5 years, one can summarize that there seems to be a trend that the onlay technique, alveolar distraction, and vertical guided bone regeneration are stable for at least 4 to 5 years.

  16. A Randomized Split-Mouth Clinical Trial on Effectiveness of Amnion-Chorion Membranes in Alveolar Ridge Preservation: A Clinical, Radiologic, and Morphometric Study.

    Science.gov (United States)

    Hassan, Muyeenul; Prakasam, Sivaraman; Bain, Carol; Ghoneima, Ahmed; Liu, Sean Shih-Yao

    Recent case reports suggest that amnion-chorion membranes (ACM) and dense polytetrafluoroethylene membranes (dPTFE) can be left exposed during ridge preservation. The aim of this study was to compare the effectiveness of these membranes in ridge preservation, particularly when they are intentionally left exposed. A split-mouth, single-blind, randomized trial design was used to compare treatments with the two membranes in 22 nonmolar sites on the same arch. Ridge dimensions were recorded clinically and with cone beam computed tomography prior to and 3 months after ridge preservation. Postoperative discomfort was recorded with Visual Analog Scale (VAS) forms. Mixed‑model analysis of variance was used to test significance. Clinical and radiographic ridge dimensions were not significantly different between the two treatments. ACM sites had significantly more osteoid and higher bone volume density but significantly less graft particles and bone surface density compared with dPTFE. Mineralized bone area and soft tissue area were not significantly different between the two treatments. ACM sites had significantly lower postoperative VAS scores compared with dPTFE. Intentionally exposed ACM is equally effective in ridge preservation compared with dPTFE. Additionally, ACM use may aid in reducing postoperative VAS scores, and potentially result in better quality of bone available for implant placement, as evidenced by improved histomorphometric measures.

  17. Clinical and radiographic characteristics of single-tooth replacements preceded by local ridge augmentation : a prospective randomized clinical trial

    NARCIS (Netherlands)

    Meijndert, L.; Raghoebar, G. M.; Meijer, H. J. A.; Vissink, A.

    2008-01-01

    To assess in a randomized-clinical trial the influence of three augmentation techniques (chinbone with or without a Bio-Gide((R)) membrane and Bio-Oss((R)) with a Bio-Gide((R)) membrane) on the clinical and radiographic characteristics of hard and soft tissues around implants and adjacent teeth in

  18. An open randomized controlled clinical trial to evaluate ridge preservation and repair using SocketKAP(™) and SocketKAGE(™) : part 2 - three-dimensional alveolar bone volumetric analysis of CBCT imaging.

    Science.gov (United States)

    Abdelhamid, Alaa; Omran, Mostafa; Bakhshalian, Neema; Tarnow, Dennis; Zadeh, Homayoun H

    2016-06-01

    The aims of this study were (i) to evaluate the efficacy of ridge preservation and repair procedures involving the application of SocketKAP(™) and SocketKAGE(™) devices following tooth removal and (ii) to evaluate alveolar bone volumetric changes at 6 months post-extraction in intact sockets or those with facial wall dehiscence defects using 3-dimensional pre- and postoperative CBCT data. Thirty-six patients required 61 teeth extracted. Five cohorts were established: Group A: Intact Socket Negative Control Group B: Intact Socket + SocketKAP(™) Group C: Intact Socket Filled with Anorganic Bovine Bone Mineral (ABBM) + SocketKAP(™) Group D: Facial Dehiscence Socket Negative Control Group E: Facial Dehiscence Socket Filled with ABBM + SocketKAP(™) + SocketKAGE(™) . Preoperative CBCT scans were obtained followed by digital subtraction of the test teeth. At 6 months post-extraction, another CBCT scan was obtained. The pre- and postoperative scans were then superimposed, allowing highly accurate quantitative determination of the 3D volumetric alveolar bone volume changes from baseline through 6 months. Significant volumetric bone loss occurred in all sockets, localized mainly in the 0-3 mm zone apical to the ridge crest. For intact sockets, SocketKAP(™) + ABBM treatment led to a statistically significant greater percentage of remaining mineralized tissue volume when compared to negative control group. A significant difference favoring SocketKAP(™) + SocketKAGE(™) + ABBM treatment was observed for sockets with facial dehiscence defects compared to the negative control group. SocketKAP(™) , with ABBM, appears effective in limiting post-extraction volumetric bone loss in intact sockets, while SocketKAP(™) + SocketKAGE + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla

    Science.gov (United States)

    Berberi, Antoine N.; Sabbagh, Joseph M.; Aboushelib, Moustafa N.; Noujeim, Ziad F.; Salameh, Ziad A.

    2014-01-01

    Purpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Materials and Methods: Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Results: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P implant after cementation of the provisional (P immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites. PMID:24550840

  20. A 5-year comparison of marginal bone level following immediate loading of single-tooth implants placed in healed alveolar ridges and extraction sockets in the maxilla.

    Science.gov (United States)

    Berberi, Antoine N; Sabbagh, Joseph M; Aboushelib, Moustafa N; Noujeim, Ziad F; Salameh, Ziad A

    2014-01-01

    The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol. Thirty-six patients in need of a single-tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden). Implants were placed either in healed ridges (group I) or immediately into fresh extraction sockets (group II). Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36, and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implant. Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study. The mean change in marginal bone loss (MBL) after implant placement was 0.26 ± 0.161 mm for 1 year, and 0.26 ± 0.171 mm for 3 years, and 0.21 ± 0.185 mm for 5 years in extraction sockets and was 0.26 ± 0.176 mm for 1 year and 0.21 ± 0.175 mm for 3 years, and 0.19 ± 0.172 mm for 5 years in healed ridges group. Significant reduction of marginal bone was more pronounced in implants inserted in healed ridges (P implant after cementation of the provisional (P immediately loaded implants placed either in extraction sockets or healed ridges were similar. Functional loading technique by using prefabricated abutment placed during the surgery time seems to maintain marginal bone around implant in both healed and fresh extraction sites.

  1. The effect of resorbable membranes on one-stage ridge augmentation in anterior single-tooth replacement: A randomized, controlled clinical trial.

    Science.gov (United States)

    Jonker, Brend P; Wolvius, Eppo B; van der Tas, Justin T; Pijpe, Justin

    2018-02-01

    To evaluate the effect of resorbable membranes on one-stage ridge augmentation procedures in small (2-4 mm) buccal bony dehiscences in anterior maxillary single-tooth replacement. Patients with a buccal bony dehiscence after implant placement in the esthetic zone were randomly allocated to one-stage ridge augmentation with (M+) or without a membrane (M-). Second-phase surgery was performed after 8 weeks, and follow-up was performed 1, 6, and ≥12 months after loading. Outcomes included implant survival and success, complications, clinical and radiographic parameters, esthetic results and patient satisfaction. Fifty-two patients were randomized to one-stage ridge augmentation with (n = 25) or without use of a membrane (n = 27). No significant differences in implant survival and success have been observed. The risk of having a small mucosal dehiscence was more than six times higher in the M+ group than in the M- group (RR 6.24, 95% CI 0.81 to 48.21). At the last follow-up, the bleeding index (BI) was marginally higher in the M+ group (14/9/2/0) compared to the M- group (24/2/0/0) (U = 205, Z = -2.97, p = .003, r = .42). The median change in marginal bone level was statistically lower in the M+ group (0.06 mm) than the M- group (0.60 mm) at last follow-up (U = 120, Z = -2.73 a p = .006 r = .42). Total pink esthetic index (PES) and white esthetic score (WES) and combined PES/WES were not significantly different between treatment groups at more than 12 months after loading. Only the subcategory root convexity/soft tissue color scored significantly lower in the M+ group (1.5) compared to the M- group (2.0) at the last follow-up (U = 172, Z = -2.34, p = .019 r = .34). No differences were found in patient satisfaction. The use of a resorbable membrane in small buccal bony dehiscences in anterior maxillary single-tooth replacement resulted in less marginal bone loss, but showed more mucosal dehiscences, higher bleeding scores and lower

  2. Applicability of equine hydroxyapatite collagen (eHAC) bone blocks for lateral augmentation of the alveolar crest. A histological and histomorphometric analysis in rats

    NARCIS (Netherlands)

    Zecha, P. J.; Schortinghuis, J.; van der Wal, J. E.; Nagursky, H.; van den Broek, K. C.; Sauerbier, S.; Vissink, A.; Raghoebar, G. M.

    This study assessed the mechanical characteristics, biocompatibility and osteoconductive properties of an equine hydroxyapatite collagen (eHAC) bone block when applied as a bone substitute for lateral augmentation of rat mandible. 96 rats underwent lateral augmentation of the mandible, using two

  3. Comparative evaluation of a biomimic collagen/hydroxyapatite/β-tricaleium phosphate scaffold in alveolar ridge preservation with Bio-Oss Collagen

    Science.gov (United States)

    Wang, Tong; Li, Qing; Zhang, Gui-feng; Zhou, Gang; Yu, Xin; Zhang, Jing; Wang, Xiu-mei; Tang, Zhi-hui

    2016-06-01

    Bone scaffolds are critical in current implant and periodontal regeneration approaches. In this study, we prepared a novel composite type-I collagen and hydroxyapatite (HA)/β-tricaleium phosphate (TCP) scaffold (CHTS) by incorporating type-I collagen and bovine calcined bone granules, prepared as a mixture of 50% HA and 50% TCP, by freeze drying. We then characterized the CHTS and determined its cytotoxic effects. Additionally, ridge preservation experiments were carried out to evaluate the clinical effects of the CHTS. The results demonstrated that the composite scaffolds had good surface morphology and no cytotoxicity. Additionally, an in vivo experiment in an animal model showed that the CHTS performed equally as well as Bio-Oss Collagen, a widely used bone graft in ridge preservation. These findings revealed that the CHTS, which contained natural constituents of bone, could be used as a scaffold for bone regeneration and clinical use.

  4. A 5- Year Comparison of Marginal Bone Level Following Immediate Loading of Single-Tooth Implants Placed in Healed Alveolar Ridges and Extraction Sockets in the Maxilla.

    Directory of Open Access Journals (Sweden)

    Antoine Nicolas Berberi

    2014-01-01

    Full Text Available AbstractPurpose: The aim of present investigation was to evaluate marginal bone level after 5-year follow-up of implants placed in healed ridges and fresh extraction sockets in maxilla with immediate loading protocol.Materials and Methods: Thirty-six patients in need of a single tooth replacement in the anterior maxilla received 42 Astra Tech implants (Astra Tech Implant system™, Dentsply Implants, Mölndal, Sweden. Implants were placed in healed ridges (group I or immediately into extraction sockets (group II. Implants were restored and placed into functional loading immediately by using a prefabricated abutment. Marginal bone level relative to the implant reference point was recorded at implant placement, crown cementation, 12, 36 and 60 months following loading using intra-oral radiographs. Measurements were made on the mesial and distal sides of each implantResults: Overall, two implants were lost from the group II, before final crown cementation: they were excluded from the study and all remaining implants osseointegrated successfully after 5 years of functional loading. The mean change in marginal bone loss after implant placement was 0.267±0.161 for one year, and 0.265±0.171 for three years and 0.213±0.185 for five years in extraction sockets and was 0.266±0.176 for one year and 0.219±0.175 for three years and 0.194±0.172 for five years in healed ridges group. Significant reduction of marginal bone loss was more pronounced in implants inserted in healed ridges (P

  5. Alveolar ridge preservation with the socket-plug technique utilizing an alloplastic putty bone substitute or a particulate xenograft: a histological pilot study.

    Science.gov (United States)

    Mahesh, Lanka; Venkataraman, Narayan; Shukla, Sagrika; Prasad, Hari; Kotsakis, Georgios A

    2015-04-01

    Following tooth extraction, ridge preservation procedures are employed to regenerate bone in the extraction socket, limit consequent ridge resorption, and provide a stable base for implant placement. The purpose of this study is to histologically evaluate and compare bone regeneration in extraction sockets grafted with either a putty alloplastic bone substitute or particulate anorganic bovine xenograft utilizing the socket-plug technique. Nineteen patients underwent 20 tooth extractions and ridge preservation following a standardized protocol. Ten sites were grafted with calcium phosphosilicate putty (CPS group) and the remaining 10 with anorganic bovine bone substitute (BO group). Patients were recalled after 4-6 months to evaluate the bone regeneration and to proceed with implant placement. A bone core was obtained during the implant procedure from each site and was used for histologic analysis. Histomorphometry revealed that residual graft values were significantly higher in the BO group (25.60% ± 5.89%) compared to the CPS group (17.40% ± 9.39%) (P preservation using a putty calcium phosphosilicate alloplastic bone substitute demonstrates more timely graft substitution and increased bone regeneration when compared to an anorganic bovine bone xenograft.

  6. Management of the flabby ridge using a modified window technique and polyvinylsiloxane impression material

    Directory of Open Access Journals (Sweden)

    Nawaf Labban

    2018-01-01

    Full Text Available Flabby ridge is a common clinical finding affecting the alveolar ridges of the mandibular or maxillary arches. The anterior region of maxilla is the most affected area in edentulous patients. Dentures on flabby ridges have compromised stability, support, and retention unless adequate measures for its management are employed. Methods applied for flabby ridge management, include surgical removal and augmentation, special impression techniques, balanced distribution of occlusal loads and implant therapy. Special impressions often involve window technique for static impression of flabby area, which present multiple challenges. The purpose of this technique report is to present a modified window technique for the impression of anterior maxillary flabby tissues for improved and controlled application of polyvinylsiloxane impression material that are routinely available in dental practice.

  7. In Vivo Evaluation of 3D-Printed Polycaprolactone Scaffold Implantation Combined with β-TCP Powder for Alveolar Bone Augmentation in a Beagle Defect Model

    OpenAIRE

    Su A. Park; Hyo-Jung Lee; Keun-Suh Kim; Sang Jin Lee; Jung-Tae Lee; Sung-Yeol Kim; Na-Hee Chang; Shin-Young Park

    2018-01-01

    Insufficient bone volume is one of the major challenges encountered by dentists after dental implant placement. This study aimed to evaluate the efficacy of a customized three-dimensional polycaprolactone (3D PCL) scaffold implant fabricated with a 3D bio-printing system to facilitate rapid alveolar bone regeneration. Saddle-type bone defects were surgically created on the healed site after extracting premolars from the mandibles of four beagle dogs. The defects were radiologically examined u...

  8. In Vivo Evaluation of 3D-Printed Polycaprolactone Scaffold Implantation Combined with β-TCP Powder for Alveolar Bone Augmentation in a Beagle Defect Model

    Directory of Open Access Journals (Sweden)

    Su A. Park

    2018-02-01

    Full Text Available Insufficient bone volume is one of the major challenges encountered by dentists after dental implant placement. This study aimed to evaluate the efficacy of a customized three-dimensional polycaprolactone (3D PCL scaffold implant fabricated with a 3D bio-printing system to facilitate rapid alveolar bone regeneration. Saddle-type bone defects were surgically created on the healed site after extracting premolars from the mandibles of four beagle dogs. The defects were radiologically examined using computed tomography for designing a customized 3D PCL scaffold block to fit the defect site. After fabricating 3D PCL scaffolds using rapid prototyping, the scaffolds were implanted into the alveolar bone defects along with β-tricalcium phosphate powder. In vivo analysis showed that the PCL blocks maintained the physical space and bone conductivity around the defects. In addition, no inflammatory infiltrates were observed around the scaffolds. However, new bone formation occurred adjacent to the scaffolds, rather than directly in contact with them. More new bone was observed around PCL blocks with 400/1200 lattices than around blocks with 400/400 lattices, but the difference was not significant. These results indicated the potential of 3D-printed porous PCL scaffolds to promote alveolar bone regeneration for defect healing in dentistry.

  9. Effect of buccal gap distance on alveolar ridge alteration after immediate implant placement: a microcomputed tomographic and morphometric analysis in dogs.

    Science.gov (United States)

    Pluemsakunthai, Warunee; Le, Bach; Kasugai, Shohei

    2015-02-01

    The buccal bone resorption and the deformation of soft tissue contour are major problems of immediate implant treatment. This study aims to examine the changes of alveolar bone and soft tissue after immediate implant placement in different buccal gap distances. Eight implants were placed randomly in the mandibular premolar sockets of 6 hybrid dogs with 1, 2, and 3 mm buccal gap distances. The dogs were killed after 2 or 4 months for morphometric and microcomputed tomography analyses. After 2 months, the 3-mm group had the highest buccal bone volume (BV), buccal bone/soft tissue thickness, and the lowest bone resorption. The wider the buccal gap, the more buccal bone and soft tissue were formed in this experimental setting. After 4 months, the buccal BV had decreased significantly in the 1-mm and the 2-mm groups, whereas the 3-mm group resisted to buccal bone resorption. This difference was more pronounced at the crest. The 3 mm is the optimal gap distance among the groups examined, which drastically influences the healing of bone and soft tissue surrounding the implants.

  10. Pulmonary alveolar proteinosis

    Science.gov (United States)

    PAP; Alveolar proteinosis; Pulmonary alveolar phospholipoproteinosis; Alveolar lipoproteinosis phospholipidosis ... PAP is unknown. In others, it occurs with lung infection or an immune problem. It also can ...

  11. Distracción osteogénica. Una alternativa para la reconstrucción de rebordes alveolares en sector mandibular. Meta-análisis

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    Iván Manotas

    2013-10-01

    Full Text Available Title: Distraction osteogenic. An alternative for reconstruction in sector mandibular alveolar ridge. Meta-analysis.ResumenLa distracción osteogénica es una técnica quirúrgica utilizada para la reconstrucción de reborde alveolar, para incrementar cantidades de hueso y tejidos blandos como consecuencia del desplazamiento gradual de fracturas óseas quirúrgicamente realizadas. Como las técnicas de distracción generan hueso nuevo y evitan por tanto la morbilidad del traslado de injertos, se trata de un procedimiento que presenta muchas ventajas en comparación con los otros tipos de tratamientos realizados en esta clase de deformidades óseas. Mediante este artículo de revisión de literatura queremos demostrar que es el tratamiento ideal cuando se trata de reducir la deformidad ósea. (DUAZARY 20112 No. 1, 49 - 59AbstractDistraction osteogenesis is a surgical technique which is used for the reconstruction of the alveolar ridge, to increase amounts of bone and soft tissue due to the gradual displacement of bone fractures surgically performed. Because distraction techniques generate new bone avoids the morbidity of moving grafts, this technique has many advantages over other types of treatment carried out in such bone deformities, which by this article were view literature demonstrate that the treatment issue when it comes to reducing bone deformity.Keywords: Osteogénesis distraction; alveolar ridge augmentation; bone lengthening.

  12. A Rational Approach to Sinus Augmentation: The Low Window Sinus Lift

    Directory of Open Access Journals (Sweden)

    Terry Zaniol

    2017-01-01

    Full Text Available Sinus augmentation is a well-known approach to treating alveolar bone ridge atrophy in the posterior maxilla. The preparation of the lateral window is crucial. Its size, design, and position in the vestibular sinus wall may affect the intra- and postsurgical complication rates and affect the intrasurgical activity of both surgeons and assistants. The present paper describes a rational technique that also exploits the guided surgery approach for design and preparation of a lateral window for sinus augmentation, the Low Window Sinus Lift. To illustrate the use of this approach, a case is presented in which the 50-year-old patient had the left maxillary first molar extracted, followed two months later by sinus augmentation and placement of three implants. One year after delivery of the definitive prosthesis, all three implants were successful, and the prosthesis was fully functional. Controlled studies should be undertaken to assess whether this technique provides significant advantages compared to other sinus augmentation approaches.

  13. Evaluación clínica y radiográfica de la técnica de distracción osteogénica en la reconstrucción de rebordes alveolares atróficos en la región anterior del maxilar superior A clinical and radiographic evaluation of the distraction osteogenesis technique for the reconstruction of atrophic alveolar ridges in the anterior region of the upper maxilla

    Directory of Open Access Journals (Sweden)

    M.E. Allais de Maurette

    2005-06-01

    Full Text Available Este estudio tiene como objetivo evaluar clínica y radiográficamente la técnica de distracción osteogénica alveolar en la región anterior del maxilar superior y las posibles complicaciones que pueden aparecer durante el tratamiento. Fueron evaluados 15 pacientes, sometidos a reconstrucción alveolar del maxilar superior en la región anterior con distracción osteogénica, usando un distractor yuxtaóseo. Del total de 15 pacientes encontramos que 13 pacientes (86,6% obtuvieron un éxito total de la técnica, obteniendo una ganancia ósea real media de 7,04 mm; en 1 paciente (6,66% fue parcial (2,62 mm y en 1 paciente (6,66% se evidenció un fracaso en la técnica, al alcanzar solo 0,76 mm debido a problemas en la activación del distractor. En cuanto a las complicaciones surgidas durante el tratamiento fueron divididas en complicaciones menores, toda aquella que no interfirió en el éxito del tratamiento, y que estuvieron presentes en 8 pacientes (53,33%, y complicaciones mayores aquellas que no permitieron la rehabilitación con implantes, y que fue encontrado solo en 1 paciente (6,66%. La técnica de distracción osteogénica alveolar, demostró ser eficaz en la reconstrucción de rebordes alveolares atróficos con un éxito de 93,33%, presentado pequeñas complicaciones que pueden ser solventadas por medio de un seguimiento por parte del profesional.This study evaluates clinically and radiographically the distraction osteogenesis technique for the reconstruction of atrophic alveolar ridges in the anterior maxilla region, and the possible complications that arise during treatment. Fifteen patients were evaluated, clinically and radiographically, that had been treated with alveolar distraction osteogenesis in the anterior region, using a juxta-osseous distractor. In 13 patients (86.6% the technique was completely successful, there being an effective bone gain of 7,04 mm. In 1 patient (6.66% this was partial (2.62 mm and in 1 patient (6

  14. Alveolar socket preservation with demineralised bovine bone mineral and a collagen matrix.

    Science.gov (United States)

    Maiorana, Carlo; Poli, Pier Paolo; Deflorian, Matteo; Testori, Tiziano; Mandelli, Federico; Nagursky, Heiner; Vinci, Raffaele

    2017-08-01

    The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm ( P =0.005) and 0.46 mm ( P =0.004), respectively. Histologically, residual xenograft particles (31.97%±3.52%) were surrounded by either newly formed bone (16.02%±7.06%) or connective tissue (50.67%±8.42%) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good re-epithelialisation of the soft tissues during a 6-month healing period.

  15. Lecture notes on ridge regression

    OpenAIRE

    van Wieringen, Wessel N.

    2015-01-01

    The linear regression model cannot be fitted to high-dimensional data, as the high-dimensionality brings about empirical non-identifiability. Penalized regression overcomes this non-identifiability by augmentation of the loss function by a penalty (i.e. a function of regression coefficients). The ridge penalty is the sum of squared regression coefficients, giving rise to ridge regression. Here many aspect of ridge regression are reviewed e.g. moments, mean squared error, its equivalence to co...

  16. Augmentation procedures using bone substitute materials or autogenous bone - a systematic review and meta-analysis.

    Science.gov (United States)

    Al-Nawas, Bilal; Schiegnitz, Eik

    2014-01-01

    Bone substitute materials (BSM) are described as a reasonable alternative to autologous bone (AB) to simplify the grafting procedure. In a systematic review and meta-analysis, the influence of BSM compared to AB on treatment success in augmentation procedures of the edentulous jaw was analysed. Literature analysis resulted in only two studies addressing reconstruction of the totally edentulous jaw using BSM. Therefore the literature analysis was extended to partially and totally edentulous jaws. The following augmentation procedures were analysed: maxillary sinus floor augmentation (MSFA) and vertical and/or lateral alveolar ridge augmentation; guided bone regeneration (minor and contained defects) were excluded. Meta-analysis was implemented using the literature from the years 2000 to early 2014 and only studies with a mean follow-up of at least 10 months were included. After screening 843 abstracts from the electronic database, 52 studies in qualitative and 14 in quantitative synthesis were included. In studies examining MSFA, the mean implant survival rate was 98.6% ± 2.6 for BSM, 88.6 ± 4.1% for BSM mixed with AB and 97.4 ± 2.2% for AB alone. For MSFA, meta-analysis showed a trend towards a higher implant survival when using BSM compared to AB, however the difference was not statistically significant ([OR], 0.59; [CI], 0.33-1.03). No statistically significant difference in implant survival for MSFA between BSM mixed with AB and AB was seen ([OR], 0.84; [CI], 0.5-1.42). Concerning ridge augmentation, the mean implant survival rate was 97.4 ± 2.5% for BSM, 100 ± 0% for BSM mixed with AB and 98.6 ± 2.9% for AB alone. Metaanalysis revealed no statistically significant difference in implant survival for ridge augmentation using BSM or AB ([OR], 1.85; [CI], 0.38 to 8.94). For BSM mixed with AB versus AB alone, a meta-analysis was not possible due to missing data. Within the limitation of the meta-analytical approach taken, implant survival seems to be

  17. L-PRF block for bone augmentation procedure: a proof-of-concept study.

    Science.gov (United States)

    Cortellini, Simone; Castro, Ana B; Temmerman, Andy; Vandessel, Jeroen; Pinto, Nelson; Jacobs, Reinhilde; Quirynen, Marc

    2018-02-08

    The objective of this proof-of-concept study was to investigate the effects of a new GBR technique with a tissue engineering approach. This single cohort observational study evaluated the outcome of the L-PRF block for horizontal bone augmentation in the maxilla. The L-PRF block is prepared by mixing a particulated biomaterial with chopped L-PRF membranes at a 50:50 ratio and adding Liquid Fibrinogen to glue all together. Horizontal augmentation was assessed linearly and volumetrically immediately after surgery and 5-8 months later by matching consecutive CBCTs. Ten patients (mean age of 50,7 years (±17,2)) representing 15 sites with horizontal alveolar deficiencies were included. Superimposition of pre-operative and post-healing CBCT scans showed an average linear horizontal bone gain of 4,6 mm (±2,3), 5,3 mm (±1,2) and 4,4 mm (±2,3), measured at 2, 6 and 10 mm from the alveolar crest, respectively. The volumetric gain was 1,05 cm 3 (±0,7) on average. The resorption rate after 5-8 months was 15,6% (±6,7) on average. L-PRF block may be a suitable technique to augment deficient alveolar ridges. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Horizontal bone augmentation by means of guided bone regeneration.

    Science.gov (United States)

    Benic, Goran I; Hämmerle, Christoph H F

    2014-10-01

    The development of bone augmentation procedures has allowed placement of dental implants into jaw bone areas lacking an amount of bone sufficient for standard implant placement. Thus, the indications for implants have broadened to include jaw regions with bone defects and those with a bone anatomy that is unfavorable for implant anchorage. Of the different techniques, the best documented and the most widely used method to augment bone in localized alveolar defects is guided bone regeneration. A large body of evidence has demonstrated the successful use of guided bone regeneration to regenerate missing bone at implant sites with insufficient bone volume and the long-term success of implants placed simultaneously with, or after, guided bone regeneration. However, the influence of guided bone regeneration on implant survival and success rates, and the long-term stability of the augmented bone, remain unknown. Many of the materials and techniques currently available for bone regeneration of alveolar ridge defects were developed many years ago. Recently, various new materials and techniques have been introduced. Many of them have, however, not been sufficiently documented in clinical studies. The aim of this review was to present the scientific basis of guided bone regeneration and the accepted clinical procedures. A classification of bone defects has been presented, aiming at simplifying the decision-making process regarding the choice of strategy for bone augmentation. Finally, an outlook into actual research and the possible future options related to bone augmentation has been provided. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Predictive value of ridge dimensions on autologous bone graft resorption in staged maxillary sinus augmentation surgery using Cone-Beam CT.

    NARCIS (Netherlands)

    Klijn, R.J.; Beucken, J.J.J.P van den; Bronkhorst, E.M.; Berge, S.J.; Meijer, G.J.; Jansen, J.B.M.J.

    2012-01-01

    INTRODUCTION: No studies are available that provide predictive parameters regarding the expected amount of resorption after maxillary sinus augmentation surgery using autologous bone grafts. Therefore, the aim of this study was to determine parameters influencing the outcome of the bone graft

  20. Horizontal bone-augmentation procedures in implant dentistry: prosthetically guided regeneration.

    Science.gov (United States)

    Chiapasco, Matteo; Casentini, Paolo

    2018-02-25

    The rehabilitation of partially or totally edentulous patients with implant-supported prostheses has become routine, with excellent long-term outcome. A proper implant position is mandatory to achieve good functional and esthetic outcome and may require an adequate amount of alveolar bone and surrounding soft tissue. When this is lacking because of atrophy, sequelae of periodontal disease, traumas or congenital malformations, increased bone volume and/or keratinized mucosa can be obtained by guided bone regeneration, bone-grafting techniques and alveolar bone expansion. This article presents an evidence-based, prosthetically driven approach for the treatment of edentulous ridges with horizontal defects. The classification of bony defects, the main augmentation techniques, the selection criteria among different surgical procedures for different types of bony defects, and the advantages, disadvantages and limitations of each technique, are described in detail. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Ridge preservation with the use of Bio-Oss collagen: A 6-month study in the dog.

    Science.gov (United States)

    Araújo, Maurício G; Lindhe, Jan

    2009-05-01

    In previous short-term studies, it was observed that while the placement of biomaterial in alveolar sockets may promote bone formation and ridge preservation, the graft may in fact also delay healing. The objective of the present experiment was to evaluate the more long-term effect on hard tissue formation and the amount of ridge augmentation that can occur by the placement of a xenogeneic graft in extraction sockets of dogs. Five beagle dogs were used. The third mandibular premolars were hemi-sected. The distal roots were carefully removed. A graft consisting of Bio-Oss collagen was placed in one socket while the contra-lateral site was left without grafting. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections - two from the mesial root and two from the healed socket - were prepared, stained and examined under a microscope. The placement of Bio-Oss collagen in the fresh extraction socket served as a scaffold for tissue modeling but did not enhance new bone formation. In comparison with the non-grafted sites, the dimension of the alveolar process as well as the profile of the ridge was better preserved in Bio-Oss-grafted sites. The placement of a biomaterial in an extraction socket may modify modeling and counteract marginal ridge contraction that occurs following tooth removal.

  2. A method for measuring post-extraction alveolar dimensional changes with volumetric computed tomography.

    Science.gov (United States)

    Bontá, Hernán; Galli, Federico G; Caride, Facundo; Carranza, Nelson

    2012-01-01

    The aim of this study is to present a predictable method for evaluating dimensional changes in the alveolar ridge through cone beam computed tomography (CT). Twenty subjects with single-rooted tooth extraction indication were selected for this preliminary report, which is part of a larger ongoing investigation. After extraction, two CT scans were performed; the first within 24 hours post-extraction (TC1) and the second 6 months (TC2) later. A radiographic guide with a radiopaque element placed along the tooth axis was developed to locate the same plane of reference in two different CT scans. For each patient, backtrack analysis was performed in order to establish the reproducibility error of a predetermined point in space between two CT scans. Briefly, an anatomical landmark was selected and its coordinates to the radiopaque marker were recorded. One week later, the coordinates were followed backwards in the same CT scan to obtain the position where the reference point should be located. A similar process was carried out between two different CT scans taken 6 months apart. The distance between the anatomical reference and the obtained point of position was calculated to establish the accuracy of the method. Additionally, a novel method for evaluating dimensional changes of the alveolus after tooth extraction is presented. The backtrack analysis determined an average within-examiner discrepancy between both measurements from the same CT scan of 0.19 mm. SD +/- 0.05. With the method presented herein, a reference point in a CT scan can be accurately backtracked and located in a second CT scan taken six months later. Taken together they open the possibility of calculating dimensional changes that occur in the alveolar ridge over time, such as post-extraction alveolar resorption, or the bone volume gained after different augmentation procedures.

  3. Bone graft healing in alveolar osteoplasty in patients with unilateral lip, alveolar process, and palate clefts.

    Science.gov (United States)

    Rychlik, Dariusz; Wójcicki, Piotr

    2012-01-01

    Secondary osteoplasty by means of autogenic spongy bone grafting is the most common procedure used in the reconstruction of the continuity of the maxillary alveolar process. The aim of the study was to analyze retrospectively the effect of certain factors on the course of the bone graft healing process in patients with unilateral complete clefts of the lip, alveolar process, and palate. The investigations involved 62 children aged 8 to 14 years (mean age, 11 years) with unilateral complete cleft of the lip, alveolar process, and palate operated on at the Clinic of Plastic Surgery in Polanica Zdrój from November 2007 to April 2009. All the procedures consisted in the reconstruction of the maxillary alveolar process by means of autogenic spongy bone grafting from the iliac bone. The analysis was performed on the basis of computed tomography scans presenting maxillary alveolar processes in the horizontal cross-sectional planes performed on the second or third postoperative day and after 6 months. They were used as the basis for the measurement of the volume and density (condensation) of the bone graft, the surface of its adhesion to the maxillary alveolar bone, and the volume and density of the healed bone. The following correlation coefficients were determined: between the adhesion surface of the bone to the alveolar bone and the volume of the healed bone, between the adhesion surface of the bone to the alveolar bone and the density of the healed bone, and between the density of the graft and the volume of the healed bone. Increasing the surface of the graft adhesion to the bone ridges of the alveolar cleft contributes to increased volume of the healed bone and slows down the increase in its density (on 6-month follow-up). Crushing of the bone graft increases its resorption and reduces volume of the healed bone.

  4. Proteinosis alveolar pulmonar Pulmonary alveolar proteinosis

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    Concepción Sánchez Infante

    2011-12-01

    Full Text Available La proteinosis alveolar pulmonar es una enfermedad respiratoria crónica, caracterizada por alteración en el metabolismo del surfactante, lo que determina su acumulación anormal en el espacio alveolar. Es una enfermedad extremadamente rara. Se han reportado solamente 500 casos en la literatura. Se describió por primera vez en 1958. Se presenta un caso de proteinosis alveolar pulmonar en un lactante de 2 meses, con desnutrición proteico energética, que ingresa por dificultad respiratoria e hipoxemia, y, con imágenes radiológicas de tipo retículo-nodulillar, en vidrio deslustrado, en el cual se plantea inicialmente el diagnóstico de bronconeumonía. Ante la evolución desfavorable y no respuesta al tratamiento, se realizó un estudio para descartar enfermedades pulmonares crónicas. El paciente fallece y se confirma el diagnóstico por anatomía patológica. Se realiza una revisión del tema.The pulmonary alveolar proteinosis is a chronic respiratory disease characterized by surfactant metabolism alteration determining its abnormal accumulation in the alveolar space. It is a disease very rare and in literature only 500 cases have been reported; it was described for the first time in 1958. This is a case presentation of pulmonary alveolar proteinosis in an infant aged 2 months with energetic protein malnutrition admitted due to respiratory difficulty and hypoxemia and with radiologic images of the reticulonodulillary, in frosting glass, where initially is made the diagnosis of bronchopneumonia. In the face of unfavorable evolution and no response to treatment, a study was conducted to rule out chronic pulmonary diseases. Patient died confirming the diagnosis according to the pathologic anatomy. A review on subject is carried out.

  5. Three-Dimensional Radiological Assessment of Alveolar Bone Volume Preservation Using Bovine Bone Xenograft.

    Science.gov (United States)

    Al Qabbani, Ali; Al Kawas, Sausan; A Razak, Noor Hayati; Al Bayatti, Saad Wahby; Enezei, Hamid Hammad; Samsudin, A Rani; Sheikh Ab Hamid, Suzina

    2018-03-01

    Alveolar bone is critical in supporting natural teeth, dental implants as well as a removable and fixed prosthesis. Alveolar bone volume diminishes when its associated natural tooth is lost. The aim of this study is to evaluate the effectiveness of bovine bone granules on alveolar bone socket augmentation for ridge preservation following atraumatic tooth extraction. Twenty medically fit patients (12 males and 8 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of 1 mandibular premolar tooth were divided randomly and equally into 2 groups. In control group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In group II, the empty extraction socket wound was filled with lyophilized bovine bone xenograft granules 0.25 to 1 mm of size, 1 mL/vial. A resorbable pericardium membrane was placed to cover the defect. Clinical and 3-dimensional radiological assessments were performed at day 0, 3 months, and 9 months postoperative. There were no clinical differences in general wound healing between the groups. Comparisons within the groups showed a significant difference of bone resorption of 1.49 mm (95% confidence interval, 0.63-2.35) at 3 months, and further resorption of 1.84 mm (P ≤ 0.05) at 9 months in the control group. No significant changes of bone resorption were observed in group II during the same time interval. Comparison between groups showed a significant difference of bone resorption at 3 and 9 months (2.40 and 2.88 mm, respectively). The use of lyophilized demineralized bovine bone granules in socket preservation to fill in the extraction socket seems essential in preserving the alveolar bone dimension as it showed excellent soft and hard tissue healing. This study concludes that the alveolar bone socket exhibited a dynamic process of resorption from the first day of tooth extraction. Evidence shows the possibility of using bovine bone granules routinely in socket volume

  6. Oral health-related quality of life changes after placement of immediately loaded single implants in healed alveolar ridges or extraction sockets: a 5-year prospective follow-up study.

    Science.gov (United States)

    Raes, Stefanie; Raes, Filiep; Cooper, Lyndon; Giner Tarrida, Luis; Vervaeke, Stijn; Cosyn, Jan; De Bruyn, Hugo

    2017-06-01

    The impact of single implants on oral health-related quality of life (OHRQoL) is scarcely investigated, especially when combined with immediate placement and loading in extraction sockets. The aim was to describe prospectively the changes of OHRQoL with single implants placed in the esthetic zone in healed ridges or in extraction sockets after 5 years. Ninety-six patients, enrolled at three clinical centers, received 102 single implants placed in a healed ridge (n = 54 implants/50 patients) or in extraction sockets (n = 48 implants/46 patients). Implants were immediately provisionalized, and permanent crowns were cemented after 12 weeks. Oral health impact profile questionnaires (OHIP-14) were completed before surgery, after 1 (provisional crown), 6 (permanent crown), 12 and 60 months, respectively. The overall OHIP-14 score pertains to seven domains with two items each and was assessed on a Likert scale of 0-4 (0 = never and 4 = very often). The evolution of the total OHIP-14 score and changes within all OHIP domains over time and between groups were assessed with a linear mixed-effect model analysis. After 5 years, overall implant survival was 98%. The total OHIP-14 score for both groups combined decreased from 0.50 at baseline to 0.17 at 6 months (P < 0.001), indicative of improvement. For both groups, this remained stable up to 5 years (P = 0.41). However, after 5 years, the total OHIP-14 score revealed a statistically significantly higher improvement in the healed group compared with the extraction group (P = 0.027). Missing a single tooth in the maxillary esthetic zone leads to limited OHRQoL problems as reflected by a low overall OHIP score. However, OHRQoL improves less in the extraction group, reflecting that replacing a missing tooth is perceived as more beneficial than replacing a present tooth. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Implants in reconstructed bone: a comparative study on the outcome of Straumann® tissue level and bone level implants placed in vertically deficient alveolar ridges treated by means of autogenous onlay bone grafts.

    Science.gov (United States)

    Chiapasco, Matteo; Casentini, Paolo; Zaniboni, Marco

    2014-02-01

    To evaluate: (1) the survival rate of Straumann® Tissue Level and Bone Level implants placed in atrophic edentulous jaws previously reconstructed by means of autogenous onlay bone grafts; (2) to compare peri-implant bone resorption values over time. From 2005 to 2010, 50 patients presenting with vertical or tridimensional defects of the edentulous ridges were treated with autogenous bone grafts. Three to 7 months afterward, 192 implants were placed (Group A: 97 Tissue Level implants; Group B: 95 Bone Level implants) in the reconstructed areas. After a further waiting period of 2 to 3 months, patients were rehabilitated with implant-supported fixed prostheses. The follow-up ranged from 12 to 68 months after the start of prosthetic loading (mean: 33 months). No implants were removed (survival rate: 100%), but in Group B 13 implants (8 placed in iliac grafts, 2 placed in ramus grafts, and 3 placed in calvarial grafts) presented peri-implant bone resorption values higher than those proposed by Albrektsson and colleagues. for successful implants: the overall implant success rate was then 100% for Group A and 86.8% for Group B. No prosthetic failures were recorded, thus leading to a 100% prostheses success rate. No significant differences were found between the two types of implants as far as implant survival rate is concerned, but results from this study seem to demonstrate that Tissue Level implants may present better long-term results in terms of peri-implant bone maintenance, as compared with Bone Level implants, when placed in reconstructed areas. © 2012 Wiley Periodicals, Inc.

  8. Silver Nanoparticles in Alveolar Bone Surgery Devices

    Directory of Open Access Journals (Sweden)

    Stefano Sivolella

    2012-01-01

    Full Text Available Silver (Ag ions have well-known antimicrobial properties and have been applied as nanostrategies in many medical and surgical fields, including dentistry. The use of silver nanoparticles (Ag NPs may be an option for reducing bacterial adhesion to dental implant surfaces and preventing biofilm formation, containing the risk of peri-implant infections. Modifying the structure or surface of bone grafts and membranes with Ag NPs may also prevent the risk of contamination and infection that are common when alveolar bone augmentation techniques are used. On the other hand, Ag NPs have revealed some toxic effects on cells in vitro and in vivo in animal studies. In this setting, the aim of the present paper is to summarize the principle behind Ag NP-based devices and their clinical applications in alveolar bone and dental implant surgery.

  9. [Establishment and experimental study of alveolar preservation before dental implantation in Beagle dogs].

    Science.gov (United States)

    Han, Xue-song; Li, Xiu-juan; Huang, Yuan-liang; Zhu, Guo-guang; You, Su-lan; Tan, Luan-jun

    2013-02-01

    To establish the model of alveolar ridge preservation after tooth extraction for dental implant replacement, and to observe the effect of tissue engineered bone on osseointegration. Isolated BMSCs were expanded and osteogenically induced in vitro. The tissue engineering complex was constructed with BMSCs/A-PCPC in vitro. Six extraction sockets, with three on each side, were created in the mandibles of four Beagle dogs by extracting the second, third and fourth premolars. BMSCs/A-PCPC were placed on one side of the extraction sockets, while autogenous bone, A-PCPC and nothing were placed on the other side as control. X-ray and CT scans were conducted 1day, 4 and 12 weeks after operation to detect the change of the alveolar ridge. The bone of sockets were harvested at 8-week post-implantation and subject to histological for evaluating. SPSS17.0 software package was used for data analysis. Radiographs demonstrated higher radiodensity in group of complex than in simple materials group, autogenous bone group after 4 weeks. Hard tissue biopsy at 12-week showed that bone activity of BMSCs/A-PCPC complex was better than the other groups. Spiral CT analysis showed that alveolar ridge of each group experienced a certain degree of absorption. At 12-week, the alveolar ridge height reduction values in A-PCPC group was smaller than in A-PCPC group, autogenous bone group and blank group (Ppreservation of alveolar ridge.

  10. Alveolar bone loss and mineralization in the pig with experimental periodontal disease

    Directory of Open Access Journals (Sweden)

    Mandee Yang

    2018-03-01

    Full Text Available Objective: To address how experimental periodontal disease affects alveolar bone mass and mineral apposition in a young pig model. Materials and methods: Seven three-month-old pigs were periodically inoculated with 4 types of periodontal bacteria, along with a ligature around the last maxillary deciduous molar for 8 weeks to induce periodontal disease (PG. Eight same-aged pigs served as the control (CG. Segmentations of 3D cone-beam CT images were performed to quantify volumes of the total alveolar bone, alveolar ridge, and all roots of the target molar. Calcein and alizarin were administered for labeling mineral apposition before euthanasia. The harvested molar blocks were sectioned and examined under epifluorescence. The inter-label distance between the two vital markers at regional bone surfaces were measured and mineral apposition rate (MAR was calculated. Results: A significant reduction of total alveolar bone volume was seen in PG with the major loss at the alveolar ridge. MAR was significantly higher at the root furcation region than those at both buccal and palatal ridges in CG. Compared with CG, PG animals showed more interrupted labeled bands with significantly lower MAR at the furcation region. MARs were positively associated with both the volumes of total alveolar bone and ridge in CG, but only with the total alveolar bone in PG. Conclusions: In young growing pigs, mineral apposition is region specific. The experimental periodontal disease not only leads to alveolar bone loss, but also perturbs mineral apposition for new bone formation, thus impairing the homeostasis of alveolar bone remodeling. Keyword: Dentistry

  11. The combined use of rhBMP-2/ACS, autogenous bone graft, a bovine bone mineral biomaterial, platelet-rich plasma, and guided bone regeneration at nonsubmerged implant placement for supracrestal bone augmentation. A case report.

    Science.gov (United States)

    Sclar, Anthony G; Best, Steven P

    2013-01-01

    This case report presents the clinical application and outcomes of the use of a combined approach to treat a patient with a severe alveolar defect. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier, along with autogenous bone graft, bovine bone mineral, platelet-rich plasma, and guided bone regeneration, were used simultaneous with nonsubmerged implant placement. At 1 year postsurgery, healthy peri-implant soft tissues and radiographically stable peri-implant crestal bone levels were observed along with locally increased radiographic bone density. In addition, a cone beam computed tomography (CBCT) scan demonstrated apparent supracrestal peri-implant bone augmentation with the appearance of normal alveolar ridge contours, including the facial bone wall.

  12. New ridge parameters for ridge regression

    OpenAIRE

    Dorugade, A.V.

    2014-01-01

    Hoerl and Kennard (1970a) introduced the ridge regression estimator as an alternative to the ordinary least squares (OLS) estimator in the presence of multicollinearity. In ridge regression, ridge parameter plays an important role in parameter estimation. In this article, a new method for estimating ridge parameters in both situations of ordinary ridge regression (ORR) and generalized ridge regression (GRR) is proposed. The simulation study evaluates the performance of the proposed estimator ...

  13. Augmented postcard

    OpenAIRE

    Bernik , Aleš

    2012-01-01

    The aim of this thesis is the examination of augmented reality technology, which allows us mixing real and virtual elements. Augmented reality is a relatively new technology which is becoming more widespread, thanks to a fairly reasonable price of smart phones. Here we presents the types of augmented reality, the necessary technology and their advantages and disadvantages, its current use in applications, and software for building augmented reality applications. The thesis is mainly focuse...

  14. Multiple Congenital Epulis of the Mandibular Ridge: A Case Report

    Directory of Open Access Journals (Sweden)

    Mohammad Gharavi

    2011-01-01

    Full Text Available Congenital epulis is a very rare benign soft-tissue tumor of uncertain histogenesis, which is also known as “gingival granular cell tumor of the newborn”. It occurs almost exclusively as a single tumor along the alveolar ridge of the maxilla in newborn females. Although congenital epulis is strikingly similar to the more common adult granular cell tumor histologically, in contrast to the latter congenital epulis cells are negative for S-100 protein. This case report describes a 15-day-old female infant with multiple congenital epulis of the mandibular alveolar ridge.

  15. Pulmonary alveolar microlithiasis

    Directory of Open Access Journals (Sweden)

    Surender Kashyap

    2013-01-01

    Full Text Available Pulmonary alveolar microlithiasis (PAM is a rare, chronic lung disease with bilateral intra-alveolar calcium and phosphate deposition throughout the lung parenchyma with predominance to lower and midzone. Although, etiology and pathogenesis of PAM is not fully understood, the mutation in SLC34A2 gene that encodes a sodium-phosphate co-transporter in alveolar type II cells resulting in the accumulation and forming of microliths rich in calcium phosphate (due to impaired clearance are considered to be the cause of the disease. Chest radiograph and high-resolution CT of thorax are nearly pathognomonic for diagnosing PAM. HRCT demonstrates diffuse micronodules showing slight perilobular predominance resulting in calcification of interlobular septa. Patients with PAM are asymptomatic till development of hypoxemia and cor-pulmonale. No therapy has been proven to be beneficial except lung transplantation.

  16. Alveolar bone resorption after primary tooth loss has a negative impact on straightforward implant installation in patients with agenesis of the lower second premolar.

    Science.gov (United States)

    Bertl, Kristina; Bertl, Michael H; Heimel, Patrick; Burt, Maria; Gahleitner, André; Stavropoulos, Andreas; Ulm, Christian

    2018-02-01

    To compare the alveolar bone dimensions in patients with lower second premolar (P2) agenesis prior to and after primary molar loss on CT scans, and assess the possibility for straightforward implant placement. Alveolar bone dimensions were evaluated on 150 mandibular CT scans in three groups: (i) agenesis of P2, with the primary tooth in situ, and regularly erupted first premolar (P1) and molar (M1) (AW); (ii) agenesis of P2, without the primary tooth in situ for ≥3 m, but regularly erupted P1 and M1 (AWO); and (iii) P1, P2, and M1 regularly erupted (CTR). The possibility of straightforward placement of an implant 3.5 or 4.3 mm in Ø × 10 mm long was digitally simulated and compared to the actually performed treatment. Buccolingual width (7.3 ± 2.0 mm) at the coronal aspect of the ridge in the AWO group was statistically significantly smaller comparing with both the AW (9.2 ± 1.4 mm) and the CTR (9.5 ± 1.1 mm) group; width reduction appeared to be mainly due to "collapse" of the buccal aspect of the ridge. Simulated straightforward placement of implants with a diameter of 3.5 or 4.3 mm was possible in 62% and 56% of the cases in the AWO vs. 86% and 84% in the AW group (p = .006 and .002, respectively). Straightforward implant placement was actually possible in all patients (22) in the AW group, while 28% (11 of 39) of the patients in the AWO group needed additional hard tissue augmentation. Significant dimensional differences exist in the alveolar ridge, especially in the coronal part, at lower P2 agenesis sites missing the primary tooth for ≥3 m, when compared to P2 agenesis sites with the primary tooth in situ. It seems thus reasonable to advise that the primary second molar should be kept as long as possible, in order to facilitate straightforward implant installation and reduce the probability of additional bone augmentation procedures. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Effect of single and contiguous teeth extractions on alveolar bone remodeling: a study in dogs.

    Science.gov (United States)

    Al-Askar, Mansour; O'Neill, Rory; Stark, Paul C; Griffin, Terrence; Javed, Fawad; Al-Hezaimi, Khalid

    2013-08-01

    Tooth extraction is associated with dimensional changes in the alveolar ridge. The aim was to examine the effect of single versus contiguous teeth extractions on the alveolar ridge remodeling. Five female beagle dogs were randomly divided into three groups on the basis of location (anterior or posterior) and number of teeth extracted - exctraction socket classification: group 1 (one dog): single-tooth extraction; group 2 (two dogs): extraction of two teeth; and group 3 (two dogs): extraction of three teeth in four anterior sites and four posterior sites in both jaws. The dogs were sacrificed after 4 months. Sagittal sectioning of each extraction site was performed and evaluated using microcomputed tomography. Buccolingual or palatal bone loss was observed 4 months after extraction in all three groups. The mean of the alveolar ridge width loss in group 1 (single-tooth extraction) was significantly less than those in groups 2 and 3 (p < .001) (multiple teeth extraction). Three-teeth extraction (group 3) had significantly more alveolar bone loss than two-teeth extraction (group 2) (p < .001). The three-teeth extraction group in the upper and lower showed more obvious resorption on the palatal/lingual side especially in the lower group posterior locations. Contiguous teeth extraction caused significantly more alveolar ridge bone loss as compared with when a single tooth is extracted. © 2011 Wiley Periodicals, Inc.

  18. Alveolar Bone Expansion for Implant Placement in Compromised Aesthetic Zone – Case Series

    Science.gov (United States)

    Mohamed, Jumshad B; Alam, Md Nazish; Singh, Gurudeep; Chandrasekaran, S.N

    2014-01-01

    Implant placement and restoration of compromised alveolar ridges in the aesthetic zone has always been a challenge to the oral implantologists. The use of bone expanders and bone condensers without the use of traditional drilling sequences in this scenario is becoming popular because of its predictable results. Xenograft along with Platelet-rich fibrin (PRF) used as scaffold also provides growth factors to accelerate both soft and hard tissue healing as well as regeneration. The paper highlights this combined approach in the placement of implants in compromised alveolar ridges with good results. All implants were successfully restored and followed up for one year. PMID:24701543

  19. Clinical application of autogenous partially demineralized dentin matrix prepared immediately after extraction for alveolar bone regeneration in implant dentistry: a pilot study.

    Science.gov (United States)

    Minamizato, T; Koga, T; I, Takashi; Nakatani, Y; Umebayashi, M; Sumita, Y; Ikeda, T; Asahina, I

    2018-01-01

    The aim of this study was to examine the efficacy and safety of autogenous partially demineralized dentin matrix (APDDM) prepared onsite, for clinical application in bone regeneration procedures related to implant dentistry, including socket preservation, alveolar ridge augmentation, and maxillary sinus floor augmentation. In this study, 16 patients underwent dental implant placement using APDDM transplantation. There were no systemic or local complications (including surgical site infection) in any of the cases, and oral rehabilitation using dental implants was successful in all cases for at least 2 years after attachment of the suprastructure. This report describes the clinical application of APDDM prepared immediately after tooth extraction to bone augmentation, taking advantage of the relatively short preparation time due to partial demineralization. APDDM, as introduced in this study, is an efficient, safe, and reasonable bone substitute. Consequently, this material has the potential to become one of the options as a bone substitute in implant dentistry. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. The Efficacy of Immediate Implant Placement in Extraction Sockets for Alveolar Bone Preservation: A Clinical Evaluation Using Three-Dimensional Cone Beam Computerized Tomography and Resonance Frequency Analysis Value.

    Science.gov (United States)

    Qabbani, Ali Al; Razak, Noor Hayati A; Kawas, Sausan Al; Sheikh Abdul Hamid, Suzina; Wahbi, Saad; Samsudin, A R

    2017-06-01

    The aim of this study was to determine the efficacy of immediate implant placement with alveolar bone augmentation on socket preservation following atraumatic tooth extraction and comparing it with a tooth alveolar socket that was allowed to heal in a conventional way.Twenty medically fit patients (8 males and 12 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of mandibular premolar teeth were divided randomly and equally into 2 groups. In Group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In Group II, the immediate implant was placed and the gap between the implant and the inner buccal plate surface of the socket wall was filled with lyophilized bovine bone granules and the wound was covered with pericardium membrane. The patients were followed up clinically and radiologically for regular reviews at 1 week, 3 months, and 9 months postoperative. Cone beam computerized tomography images of the alveolar ridge and socket were analyzed to determine the structural changes of the alveolar ridge. Resonance frequency analysis was measured at 9 months for Group II to assess the degree of secondary stability of the implants by using Osstell machine.A significant difference of bone resorption of 1.49 mm (confidence interval, CI 95%, 0.63-2.35) was observed within the control group at 3 months, and 1.84 mm (P ≤ 0.05) at 9 months intervals. No significant changes of bone resorption were observed in Group II. Comparison between groups showed a highly significant difference at 3 months; 2.56 mm (CI 95% 4.22-0.90) and at 9 months intervals; 3.2 mm (CI 95%, 4.70-1.62) P ≤ 0.001 between Group I and II. High resonance frequency analysis values were observed at 9 months postoperative in Group II.In conclusion, the insertion of immediate implants in fresh extraction sockets together with grafting the circumferential gap between the bony socket wall and the implant surface with bovine

  1. Augmented Reality

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter Bech; Rahn, Annette

    2015-01-01

    This chapter describes the use of iPad-facilitated application of augmented reality in the teaching of highly complex anatomical and physiological subjects in the training of nurses at undergraduate level. The general aim of the project is to investigate the potentials of this application in terms...... of augmented reality are discussed....

  2. AUGMENTED REALITY

    DEFF Research Database (Denmark)

    Skov, Kirsten; Bahn, Anne Louise

    2017-01-01

    Projektets grundlæggende idé er udvikling af visuel, æstetisk læring med Augmented Reality, hvor intentionen er at bidrage med konkrete undersøgelser og udforskning af begrebet Augmented Reality – herunder koblingen mellem det analoge og digitale i forhold til læring, multimodalitet og it...

  3. Immediate Loading of One-Piece Implants in Conjunction with a Modified Technique of Inferior Alveolar Nerve Lateralization: 10 Years Follow-Up

    OpenAIRE

    Eldibany, Riham; Rodriguez, Joaquin G.

    2014-01-01

    This report describes a treatment modification for a patient presented with severely resorbed bilateral edentulous posterior mandible and mobility of the anterior teeth. There was less than 8 mm of bone between the crest of the alveolar ridge and the mandibular canal as revealed by radiographic examination. A modified technique for inferior alveolar nerve lateralization (IANL) in conjunction with ridge expansion was performed using threaded bone expanders, which allowed for better primary sta...

  4. Proteinosis alveolar pulmonar

    Directory of Open Access Journals (Sweden)

    Concepción Sánchez Infante

    2011-12-01

    Full Text Available La proteinosis alveolar pulmonar es una enfermedad respiratoria crónica, caracterizada por alteración en el metabolismo del surfactante, lo que determina su acumulación anormal en el espacio alveolar. Es una enfermedad extremadamente rara. Se han reportado solamente 500 casos en la literatura. Se describió por primera vez en 1958. Se presenta un caso de proteinosis alveolar pulmonar en un lactante de 2 meses, con desnutrición proteico energética, que ingresa por dificultad respiratoria e hipoxemia, y, con imágenes radiológicas de tipo retículo-nodulillar, en vidrio deslustrado, en el cual se plantea inicialmente el diagnóstico de bronconeumonía. Ante la evolución desfavorable y no respuesta al tratamiento, se realizó un estudio para descartar enfermedades pulmonares crónicas. El paciente fallece y se confirma el diagnóstico por anatomía patológica. Se realiza una revisión del tema.

  5. Alveolar development and disease.

    Science.gov (United States)

    Whitsett, Jeffrey A; Weaver, Timothy E

    2015-07-01

    Gas exchange after birth is entirely dependent on the remarkable architecture of the alveolus, its formation and function being mediated by the interactions of numerous cell types whose precise positions and activities are controlled by a diversity of signaling and transcriptional networks. In the later stages of gestation, alveolar epithelial cells lining the peripheral lung saccules produce increasing amounts of surfactant lipids and proteins that are secreted into the airspaces at birth. The lack of lung maturation and the associated lack of pulmonary surfactant in preterm infants causes respiratory distress syndrome, a common cause of morbidity and mortality associated with premature birth. At the time of birth, surfactant homeostasis begins to be established by balanced processes involved in surfactant production, storage, secretion, recycling, and catabolism. Insights from physiology and engineering made in the 20th century enabled survival of newborn infants requiring mechanical ventilation for the first time. Thereafter, advances in biochemistry, biophysics, and molecular biology led to an understanding of the pulmonary surfactant system that made possible exogenous surfactant replacement for the treatment of preterm infants. Identification of surfactant proteins, cloning of the genes encoding them, and elucidation of their roles in the regulation of surfactant synthesis, structure, and function have provided increasing understanding of alveolar homeostasis in health and disease. This Perspective seeks to consider developmental aspects of the pulmonary surfactant system and its importance in the pathogenesis of acute and chronic lung diseases related to alveolar homeostasis.

  6. Stress distribution prevents ischaemia and bone resorption in residual ridge.

    Science.gov (United States)

    Maruo, Yukinori; Nishigawa, Goro; Irie, Masao; Oka, Morihiko; Hara, Tetsuya; Suzuki, Kazuomi; Minagi, Shogo

    2010-11-01

    Intensive mechanical stress and/or inflammation are known to induce alveolar bone resorption. This study investigated whether a distribution of mechanical stress would reduce residual ridge resorption or improve ischaemia. Thirty rats were divided into six experimental groups (n=5). The control group received no intentional stimulation, but rats in the experimental groups wore denture stimulators made of acrylic resin or a soft lining material. The stimulator transmitted masticatory pressure to the rats' palates for four weeks. The four types of soft lining materials investigated in this study dispersed the applied pressure, with compressive stress ranging from 20.8 to 90.8kPa. Volumes of blood flow and bone resorption of denture foundations were measured every week for 4 weeks. Statistical evaluation of these results was performed using two-way ANOVA and Holm-Sidak test within 5% error limits. Non-viscoelastic material clearly induced bone resorption and ischaemia of denture foundations, while viscoelastic materials reduced these phenomena to different extents according to their viscoelastic properties. Ischaemia in the alveolar ridge preceded residual ridge resorption, because the amount of residual ridge resorption and blood flow rate showed a simple linear regression. Animal model of this study suggested that a distribution or reduction of mechanical stress could improve blood flow and decrease alveolar ridge resorption. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Breast Augmentation

    Science.gov (United States)

    ... augmentation About Doctors & Departments Care at Mayo Clinic Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  8. Effects of Human Adipose-derived Stem Cells and Platelet-rich Plasma on Healing Response of Canine Alveolar Surgical Bone Defects

    Directory of Open Access Journals (Sweden)

    Reyhaneh Shafieian

    2017-11-01

    Full Text Available Background: Due to the known disadvantages of autologous bone grafting, tissue engineering approaches have become an attractive method for ridge augmentation in dentistry. To the best of our knowledge, this is the first study conducted to evaluate the potential therapeutic capacity of PRP-assisted hADSCs seeded on HA/TCP granules on regenerative healing response of canine alveolar surgical bone defects. This could offer a great advantage to alternative approaches of bone tissue healing-induced therapies at clinically chair-side procedures. Methods: Cylindrical through-and-through defects were drilled in the mandibular plate of 5 mongrel dogs and filled randomly as following: I- autologous crushed mandibular bone, II- no filling material, III- HA/TCP granules in combination with PRP, and IV- PRP-enriched hADSCs seeded on HA/TCP granules. After the completion of an 8-week period of healing, radiographic, histological and histomorphometrical analysis of osteocyte number, newly-formed vessels and marrow spaces were used for evaluation and comparison of the mentioned groups. Furthermore, the buccal side of mandibular alveolar bone of every individual animal was drilled as normal control samples (n=5. Results: Our results revealed that hADSCs subcultured on HA/TCP granules in combination with PRP significantly promoted bone tissue regeneration as compared with those defects treated only with PRP and HA/TCP granules (P

  9. The use of bone block allografts in sinus augmentation, followed by delayed implant placement: A case series

    Directory of Open Access Journals (Sweden)

    Eurico D Aloja

    2013-01-01

    Full Text Available Purpose: This article reports the clinical outcomes observed in a large number of patients receiving block bone allograft used for sinus augmentation and delayed implant placement. Patients and Methods: In total, 28 patients (13 males with a mean age of 49.8 ± 10.1 years (range: 33-67 years were included in this case series. All selected patients suffered from severe alveolar ridge atrophy in the posterior maxilla and required bone augmentation procedures, followed by implant placement after 6 months. All patients were followed for 18 months after the grafting, with scheduled monthly visits and/or more frequent visits if required. The survival rates for both the bone blocks and placed implants were then evaluated. Results: A total of 42 blocks and 90 implants were placed. Only one bone graft and 5 implants failed; the survival rate was 97.2% and 95.5% for the bone grafts and implants, respectively. The graft failed due to the onset of post-surgical infectious sinusitis, while in some patients′ implants showed absence of osteointegration at the end of the healing phase. Of note, all failed implants were observed in heavy smokers; in all other patients, blocks and implants were successful. Conclusions: This preliminary case series suggests that the grafting of bone allograft followed by delayed implant placement may be a promising strategy for sinus augmentation. More extended and larger follow-up studies are needed to confirm this preliminary data.

  10. Augmented reality

    Directory of Open Access Journals (Sweden)

    Patrik Pucer

    2011-08-01

    Full Text Available Today we can obtain in a simple and rapid way most of the information that we need. Devices, such as personal computers and mobile phones, enable access to information in different formats (written, pictorial, audio or video whenever and wherever. Daily we use and encounter information that can be seen as virtual objects or objects that are part of the virtual world of computers. Everyone, at least once, wanted to bring these virtual objects from the virtual world of computers into real environments and thus mix virtual and real worlds. In such a mixed reality, real and virtual objects coexist in the same environment. The reality, where users watch and use the real environment upgraded with virtual objects is called augmented reality. In this article we describe the main properties of augmented reality. In addition to the basic properties that define a reality as augmented reality, we present the various building elements (possible hardware and software that provide an insight into such a reality and practical applications of augmented reality. The applications are divided into three groups depending on the information and functions that augmented reality offers, such as help, guide and simulator.

  11. Alveolar socket healing: what can we learn?

    Science.gov (United States)

    Araújo, Mauricio G; Silva, Cléverson O; Misawa, Mônica; Sukekava, Flavia

    2015-06-01

    Tooth extraction induces a series of complex and integrated local changes within the investing hard and soft tissues. These local alterations arise in order to close the socket wound and to restore tissue homeostasis, and are referred to as '"socket healing". The aims of the present report were twofold: first, to describe the socket-healing process; and, second, to discuss what can be learned from the temporal sequence of healing events, in order to improve treatment outcomes. The socket-healing process may be divided into three sequential, and frequently overlapping, phases: inflammatory; proliferative; and modeling/remodeling. Several clinical and experimental studies have demonstrated that the socket-healing process promotes up to 50% reduction of the original ridge width, greater bone resorption at the buccal aspect than at the lingual/palatal counterpart and a larger amount of alveolar bone reduction in the molar region. In conclusion, tooth extraction, once a simple and straightforward surgical procedure, should be performed in the knowledge that ridge reduction will follow and that further clinical steps should be considered to compensate for this, when considering future options for tooth replacement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Lip Augmentation.

    Science.gov (United States)

    DeJoseph, Louis M; Agarwal, Anurag; Greco, Timothy M

    2018-05-01

    This article examines 6 questions about lip augmentation answered by 3 experts in their field of facial plastic surgery. The topics covered include high-yield areas such as injection, surgical enhancement, rhytid resurfacing, implants, complications, and technique changes over the years. All the authors answered these questions in a "How I do it" manner to provide the reader with a true understanding of their thoughts and techniques. This article provides a practical resource to all physicians and practitioners performing lip augmentation on some of the most common questions and issues. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. The clinical value of membranes in bone augmentation procedures in oral implantology: 
A systematic review of randomised controlled trials

    NARCIS (Netherlands)

    Jonker, Brend P.; Roeloffs, Maarten W. K.; Wolvius, Eppo B.; Pijpe, Justin

    2016-01-01

    To determine the clinical value of membranes in bone augmentation procedures such as ridge augmentation with simultaneous (one-stage) and delayed (two-stage) implant placement, sinus augmentation surgery, ridge preservation and immediate implant placement. In April 2016, Embase, Medline (Ovid-SP),

  14. Augmented Reality

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Radmer, Ole

    2017-01-01

    Artiklen præsenterer resultater fra pilotafprøvning i 7.-klasses fysik/kemi og biologi af to Augmented Reality (AR)-apps til naturfagsundervisning. Muligheder og udfordringer ved lærerens stilladsering af elevernes undersøgende samtale og modelleringskompetence er undersøgt med interview...

  15. Breast Augmentation

    African Journals Online (AJOL)

    1974-04-13

    Apr 13, 1974 ... Previous articles'·3 detailed the technique and the indi- cations for breast augmentation. This article deals ... or subcutaneous mastectomy are excluded. In this series, a Dow-Corning, Dacron-backed, ..... is not considered a major procedure, or in any way difficult to perform, judgement is all-important, and ...

  16. Ridge Regression: A Panacea?

    Science.gov (United States)

    Walton, Joseph M.; And Others

    1978-01-01

    Ridge regression is an approach to the problem of large standard errors of regression estimates of intercorrelated regressors. The effect of ridge regression on the estimated squared multiple correlation coefficient is discussed and illustrated. (JKS)

  17. Chin augmentation.

    Science.gov (United States)

    Choe, K S; Stucki-McCormick, S U

    2000-01-01

    The primary goal of facial aesthetic surgery is to restore, enhance, and rejuvenate the aging face to a more youthful appearance, achieving balance and harmony. The mental area must be addressed in order to have a complete synthesis of the face. The concept of augmenting the mental area with implants has evolved so significantly that it now stands by itself as an important procedure. Various autogenous implants for chin augmentation have been in use for over 100 years but have complications. The advent of synthetic materials has given rise to various types of alloplastic implants: Gore-Tex, Medpor, Supramid, Silastic, and Mersilene. No one implant is perfect for every face. This article overviews several alloplastic implants--their advantages, disadvantages, and complications, in addition to the different techniques of preparing and delivering the implants.

  18. Augmented reality

    OpenAIRE

    Jecha, Jakub

    2011-01-01

    This thesis is focused on a technology called Augmented reality, especially on its use in marketing. The main objective of the thesis is to define why this technology is a suitable tool for marketing and to assess its use in real conditions. This is achieved by defining specific devices and use cases of this technology in practice, whereas evaluation of its use in real enviroment is based on statistics. The contribution of the thesis is objective evaluation of this technology and provision of...

  19. Alveolar cleft bone grafts: results and imprecisions of the dental radiograph.

    Science.gov (United States)

    Lee, C; Crepeau, R J; Williams, H B; Schwartz, S

    1995-12-01

    Alveolar cleft bone grafts customarily have been evaluated by one-dimensional dental radiographic measurements. Based on the dental radiograph, remarkable successes with just a single bone graft have been reported in the literature. At the Montreal Children's Hospital, the experience with 101 alveolar bone grafts in 62 cleft lip and palate patients was retrospectively reviewed to determine (1) the precision of dental radiographs at evaluating the clinical outcome, (2) the effect of dental maturation on alveolar bone grafts, and (3) the effect of augmentation bone grafts. The dental radiograph significantly overestimated the number of clefts that could be managed orthodontically (p orthodontic closure of the dental gap. Bone grafts performed during the preeruptive canine dentition yielded significantly better results (p < 0.05, chi-squared test). With each subsequent augmentation bone-graft procedure performed, there existed a trend toward improved dental arch stability and radiographic and clinical outcomes.

  20. Reduction of Adipose Tissue Formation by the Controlled Release of BMP-2 Using a Hydroxyapatite-Coated Collagen Carrier System for Sinus-Augmentation/Extraction-Socket Grafting

    Directory of Open Access Journals (Sweden)

    Jung-Seok Lee

    2015-11-01

    Full Text Available The effects of hydroxyapatite (HA-coating onto collagen carriers for application of recombinant human bone morphogenetic protein 2 (rhBMP-2 on cell differentiation in vitro, and on in vivo healing patterns after sinus-augmentation and alveolar socket-grafting were evaluated. In vitro induction of osteogenic/adipogenic differentiation was compared between the culture media with rhBMP-2 solution and with the released rhBMP-2 from the control collagen and from the HA-coated collagen. Demineralized bovine bone and collagen/HA-coated collagen were grafted with/without rhBMP-2 in sinus-augmentation and tooth-extraction-socket models. Adipogenic induction by rhBMP-2 released from HA-coated collagen was significantly reduced compared to collagen. In the sinus-augmentation model, sites that received rhBMP-2 exhibited large amounts of vascular tissue formation at two weeks and increased adipose tissue formation at eight weeks; this could be significantly reduced by using HA-coated collagen as a carrier for rhBMP-2. In extraction-socket grafting, dimensional reduction of alveolar ridge was significantly decreased at sites received rhBMP-2 compared to control sites, but adipose tissue was increased within the regenerated socket area. In conclusion, HA-coated collagen carrier for Escherichia coli-derived rhBMP-2 (ErhBMP-2 may reduce in vitro induction of adipogenic differentiation and in vivo adipose bone marrow tissue formation in bone tissue engineering by ErhBMP-2.

  1. The Pontic-Shield: Partial Extraction Therapy for Ridge Preservation and Pontic Site Development.

    Science.gov (United States)

    Gluckman, Howard; Du Toit, Jonathan; Salama, Maurice

    2016-01-01

    Augmentive ridge preservation techniques aim to manage the postextraction ridge. The partial extraction of teeth may better preserve the ridge form by maintaining the bundle bone-periodontal ligament apparatus. Root submergence has been demonstrated to retain the periodontal tissues and preserve the ridge beneath dentures or fixed prostheses. The socket-shield technique entails preparing a tooth root section simultaneous to immediate implant placement and has demonstrated histologic and clinical results contributory to esthetic implant treatment. A retrospective 10-patient case series treating 14 partial extraction sites demonstrates how a modification of the socket-shield technique can successfully develop pontic sites and preserve the ridge.

  2. Mobile Collaborative Augmented Reality: The Augmented Stroll

    OpenAIRE

    Renevier , Philippe; Nigay , Laurence

    2001-01-01

    International audience; The paper focuses on Augmented Reality systems in which interaction with the real world is augmented by the computer, the task being performed in the real world. We first define what mobile AR systems, collaborative AR systems and finally mobile and collaborative AR systems are. We then present the augmented stroll and its software design as one example of a mobile and collaborative AR system. The augmented stroll is applied to Archaeology in the MAGIC (Mobile Augmente...

  3. Graft-Free Sinus Augmentation Procedure: a Literature Review

    Directory of Open Access Journals (Sweden)

    Ginnady Pinchasov

    2014-04-01

    Full Text Available Objectives: The restoration of edentulous posterior maxilla with dental implants is challenging due to a deficient posterior alveolar ridge. Over the last decade an advance in the graftless bone augmentation procedures had occurred where the space left beneath the Schneiderian membrane is filled with blood clot in order to produce bone formation. The aim of present article is to review the scientific literature with respect to bone formation in the sinus, after membrane elevation procedure, without using any bone substitutes. Material and Methods: A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. The articles were searched from 1993 to 2013. English language articles with minimum one year patient follow-up and radiological and/or histological diagnostics of newly formed bone were included. Articles were excluded, if usage of bone graft or bone substitutes and/or usage of osteotome has been made during sinus lift operation. Results: A total of 19 studies were included: 2 studies were related to the sinus membrane’s osteogenic potential, 3 to the histological evidence of bone formation in monkeys and humans, 12 to the radiologic evidence of bone gain, and 2 to the space-maintaining management. 100% of the reviewed articles presented with increased bone formation and high implant survival rates resulting from the graft-free technique. Conclusions: It is clearly shown in the review that the potential of the maxillary sinus to heal and to form new bone without bone grafts or substitutes is of high nature.

  4. Treatment of sharp mandibular alveolar process with hybrid prosthesis

    Directory of Open Access Journals (Sweden)

    Sukaedi Sukaedi

    2010-09-01

    Full Text Available Background: Losing posterior teeth for a long time would occasionally lead to the sharpening of alveolar process. The removable partial denture usually have problems when used during mastication, because of the pressure on the mucosa under the alveolar ridge. Purpose: The purpose of this case report was to manage patients with sharp mandibular alveolar process by wearing hybrid prosthesis with extra coronal precision attachment retention and soft liner on the surface base beneath the removable partial denture. Case: A 76 years old woman visited the Prosthodontic Clinic Faculty of Dentistry Airlangga University. The patient had a long span bridge on the upper jaw and a free end acrylic removable partial denture on the lower jaw. She was having problems with mastication. The patient did not wear her lower denture because of the discomfort with it during mastication. Hence, she would like to replace it with a new removable partial denture. Case management: The patient was treated by wearing a hybrid prosthesis with extra coronal precision attachment on the lower jaw. Soft liner was applied on the surface of the removable partial denture. Hybrid prosthesis is a complex denture consisting of removable partial denture and fixed bridge. Conclusion: It concluded that after restoration, the patient had no problems with sharp alveolar process with her new denture, and she was able to masticate well.Latar belakang: Kehilangan geligi posterior dapat menimbulkan processus alveolaris tajam. Gigi tiruan sebagian lepasan mempunyai masalah selama pengunyahan karena adanya tekanan di mukosa di bawah alveolar ridge. Tujuan: Tujuan laporan kasus ini adalah untuk menjelaskan cara menangani pasien yang mempunyai prosesus alveolaris yang tajam di rahang bawah dengan dibuatkan protesis hybrid dengan daya tahan extra coronal precision attachment dan soft liner di permukaan bawah basis gigi tiruan sebagian lepasan. Kasus: Pasien wanita berumur 76 tahun datang di klinik

  5. Bone changes in ridge split with immediate implant placement: A systematic review

    Directory of Open Access Journals (Sweden)

    Mohamed M. Dohiem

    2015-12-01

    Conclusion: Alveolar ridge splitting might be considered a predictable approach that demonstrates a high implant survival rate, adequate horizontal bone gain and minimal postoperative complications. Weak evidence showed the effect of flap design and immediate implantation on marginal bone loss and survival rate.

  6. ARLearn: augmented reality meets augmented virtuality

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland; Kalz, Marco; Van Ulzen, Patricia; Specht, Marcus

    2012-01-01

    Ternier, S., Klemke, R., Kalz, M., Van Ulzen, P., & Specht, M. (2012). ARLearn: augmented reality meets augmented virtuality [Special issue]. Journal of Universal Computer Science - Technology for learning across physical and virtual spaces, 18(15), 2143-2164.

  7. Mishmash Impression Technique for Managing Maxillary Anterior Fibrous Ridge

    Directory of Open Access Journals (Sweden)

    Poonam Kulkarni

    2018-06-01

    Full Text Available Introduction: Flabby or fibrous ridge is one of the consequences of long term wearing of complete dentures. It can develop where hyperplasic soft tissue replaces the alveolar bone and is a common finding, particularly in the upper anterior region of long term denture wearers. Forces exerted during impression making can result in distortion of the mobile tissue unless managed appropriately; such flabby ridges adversely affect support, retention and stability of complete dentures. Many impression techniques have been developed to help overcome this problem. While these vary in the method applied, they are similar in their complexity, are often quite time-consuming to perform and rely on materials not commonly used in contemporary general dental practice. The purpose of this article is to describe an impression technique for flabby ridges usingrubber base impression materials, routinely available in general dental practice.

  8. Alveolar bone preservation subsequent to miniscrew implant placement in a canine model

    DEFF Research Database (Denmark)

    Melsen, Birte; Huja, Sarandeep; Chien, Hua-Hong

    2015-01-01

    -implant across the healing alveolar process results in increased density not only adjacent to the screws, but also in the region where a potential dental implant would be inserted. In humans, the insertion of transcortical screws may maintain bone when for various reasons insertion of a permanent dental implant......Abstract OBJECTIVE: To assess the effects of transcortical screws on alveolar (bone) ridge preservation following extraction. DESIGN: Four adult beagle dogs had mandibular premolars extracted bilaterally. After 6 weeks, using a split-mouth design, two transcortical screws were inserted unilaterally...... below the alveolar crest on the experimental side in the region of the extraction. The dogs were killed after 12 weeks. The bone at the extraction sites was analyzed using μCT and 3D analysis. A cylindrical core was placed around the actual and a virtual screw placed in the identical location...

  9. Improving oral rehabilitation through the preservation of the tissues through alveolar preservation

    OpenAIRE

    Afrashtehfar, Kelvin Ian; Kurtzman, Gregori Michael; Mahesh, Lanka

    2012-01-01

    When performing a tooth extraction, imminent collapse of the tissue by resorption and remodeling of the socket is a natural occurrence. The procedure for the preservation of the alveolar ridge has been widely described in the dental literatures and aims to maintain hard and soft tissues in the extraction site for optimal rehabilitation either with conventional fixed or removable prosthetics or implant-supported prosthesis.

  10. Improving oral rehabilitation through the preservation of the tissues through alveolar preservation.

    Science.gov (United States)

    Afrashtehfar, Kelvin Ian; Kurtzman, Gregori Michael; Mahesh, Lanka

    2012-08-01

    When performing a tooth extraction, imminent collapse of the tissue by resorption and remodeling of the socket is a natural occurrence. The procedure for the preservation of the alveolar ridge has been widely described in the dental literatures and aims to maintain hard and soft tissues in the extraction site for optimal rehabilitation either with conventional fixed or removable prosthetics or implant-supported prosthesis.

  11. Intravascular bronchio-alveolar tumor

    International Nuclear Information System (INIS)

    Mata, J.M.; Caceres, J.; Prat, J.; Lopez, J.I.; Velilla, O.

    1991-01-01

    In 1975 Dail and Liebow described the clinical and pathological characteristics of a pulmonary tumor which they dominated intravascular bronchio-alveolar tumor (IVBAT). Our aim is to acquaint radiologists with the existence of this tumor by describing the radiologic findings in 2 patients with IVBAT, 1 with hepatic involvement ant the other with pulmonary osteoarthropathy. (author). 7 refs.; 2 figs

  12. Human alveolar echinococcosis in Kyrgyzstan.

    Science.gov (United States)

    Usubalieva, Jumagul; Minbaeva, Gulnara; Ziadinov, Iskender; Deplazes, Peter; Torgerson, Paul R

    2013-07-01

    Human echinococcosis is a reportable disease in Kyrgyzstan. Between 1995 and 2011, human alveolar echinococcosis increased from 60 cases per year. The origins of this epidemic, which started in 2004, may be linked to the socioeconomic changes that followed the dissolution of the former Soviet Union.

  13. True Fibroma of Alveolar Mucosa

    Directory of Open Access Journals (Sweden)

    Shankargouda Patil

    2014-01-01

    Full Text Available Benign fibrous overgrowths are often found in the oral cavity, almost always being reactive/irritational in nature. However, benign mesenchymal neoplasms of the fibroblasts are extremely uncommon. Here we report a case of “True Fibroma of Alveolar Mucosa” for its rarity.

  14. Ridge regression revisited

    NARCIS (Netherlands)

    P.M.C. de Boer (Paul); C.M. Hafner (Christian)

    2005-01-01

    textabstractWe argue in this paper that general ridge (GR) regression implies no major complication compared with simple ridge regression. We introduce a generalization of an explicit GR estimator derived by Hemmerle and by Teekens and de Boer and show that this estimator, which is more

  15. The Milieu of Damaged Alveolar Epithelial Type 2 Cells Stimulates Alveolar Wound Repair by Endogenous and Exogenous Progenitors

    Science.gov (United States)

    Buckley, Susan; Shi, Wei; Carraro, Gianni; Sedrakyan, Sargis; Da Sacco, Stefano; Driscoll, Barbara A.; Perin, Laura; De Filippo, Roger E.

    2011-01-01

    Alveolar epithelial integrity is dependent upon the alveolar milieu, yet the milieu of the damaged alveolar epithelial cell type 2 (AEC2) has been little studied. Characterization of its components may offer the potential for ex vivo manipulation of stem cells to optimize their therapeutic potential. We examined the cytokine profile of AEC2 damage milieu, hypothesizing that it would promote endogenous epithelial repair while recruiting cells from other locations and instructing their engraftment and differentiation. Bronchoalveolar lavage and lung extract from hyperoxic rats represented AEC2 in vivo damage milieu, and medium from a scratch-damaged AEC2 monolayer represented in vitro damage. CINC-2 and ICAM, the major cytokines detected by proteomic cytokine array in AEC2 damage milieu, were chemoattractive to normoxic AECs and expedited in vitro wound healing, which was blocked by their respective neutralizing antibodies. The AEC2 damage milieu was also chemotactic for exogenous uncommitted human amniotic fluid stem cells (hAFSCs), increasing migration greater than 20-fold. hAFSCs attached within an in vitro AEC2 wound and expedited wound repair by contributing cytokines migration inhibitory factor and plasminogen activator inhibitor 1 to the AEC2 damage milieu, which promoted wound healing. The AEC2 damage milieu also promoted differentiation of a subpopulation of hAFSCs to express SPC, TTF-1, and ABCA3, phenotypic markers of distal alveolar epithelium. Thus, the microenvironment created by AEC2 damage not only promotes autocrine repair but also can attract uncommitted stem cells, which further augment healing through cytokine secretion and differentiation. PMID:21700959

  16. Ridge Regression Signal Processing

    Science.gov (United States)

    Kuhl, Mark R.

    1990-01-01

    The introduction of the Global Positioning System (GPS) into the National Airspace System (NAS) necessitates the development of Receiver Autonomous Integrity Monitoring (RAIM) techniques. In order to guarantee a certain level of integrity, a thorough understanding of modern estimation techniques applied to navigational problems is required. The extended Kalman filter (EKF) is derived and analyzed under poor geometry conditions. It was found that the performance of the EKF is difficult to predict, since the EKF is designed for a Gaussian environment. A novel approach is implemented which incorporates ridge regression to explain the behavior of an EKF in the presence of dynamics under poor geometry conditions. The basic principles of ridge regression theory are presented, followed by the derivation of a linearized recursive ridge estimator. Computer simulations are performed to confirm the underlying theory and to provide a comparative analysis of the EKF and the recursive ridge estimator.

  17. Part II. Minimizing alveolar bone loss during and after extractions. Protocol and techniques for alveolar bone preservation.

    Science.gov (United States)

    Iyer, Shankar; Haribabu, Prashanth Konatham; Xing, Yi

    2014-01-01

    Alveolar ridge resorption accelerates following extraction of teeth and the residual defect varies from socket to socket. This article proposes a new treatment oriented classification of extraction defects. It also reviews several graft materials and membranes that aid in the decision for selecting an appropriate socket preservation technique. The algorithm developed by the authors helps design a potentially successful treatment plan based on the classification of extraction defects, with choices ranging from no treatment to complex grafting procedures (i.e. allogenic block grafts). In addition, the principles of wound healing and the ideal time points for utilizing the various types of graft materials and implants are discussed. This socket preservation treatment algorithm will guide clinicians to employ surgical procedures using various biomaterials to promote a successful outcome.

  18. Breast augmentation surgery

    Science.gov (United States)

    ... care - open Images Breast lift (mastopexy) - series Breast reduction (mammoplasty) - series Breast augmentation - series References Maxwell GP, Gabriel A. Breast augmentation. In: Neligan PC, ed. Plastic Surgery . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2013: ...

  19. Ridge and Furrow Fields

    DEFF Research Database (Denmark)

    Møller, Per Grau

    2016-01-01

    Ridge and furrow is a specific way of ploughing which makes fields of systematic ridges and furrows like a rubbing washboard. They are part of an overall openfield system, but the focus in this paper is on the functionality of the fields. There are many indications that agro-technological reasons...... systems and the establishment of basic structures like villages (with churches) and townships and states (in northern Europe). The fields can be considered as a resilient structure lasting for 800 years, along with the same basic physical structures in society....

  20. Pulmonary alveolar microlithiasis in children

    International Nuclear Information System (INIS)

    Schmidt, H.; Loercher, U.; Kitz, R.; Zielen, S.; Ahrens, P.; Koenig, R.

    1996-01-01

    Two asymptomatic Turkish sibs are presented, a 4-year-old boy and his 7-year-old sister, with pulmonary alveolar microlithiasis (PAM) confirmed by transbronchial lung biopsy and bronchoalveolar lavage. Chest radiographs and high resolution CT demonstrated wide-spread intra-alveolar calcifications in both lungs. The lesions were sharply defined and less than 1 mm in diameter. CT documented a high concentration of microliths along the bronchovascular bundles, the intralobular fissue and the (sub)pleural lung parenchyma. The combination of bronchoalveolar lavage and roentgenographic appearance in high resolution CT are characteristic and pathognomonic, and can confirm the diagnosis. The more severe changes in the elder sib and the radiographic controls suggest that the pulmonary disease may be progressive in our patients. The described family of consanguineous, unaffected parents with two affected and one healthy child confirmed the autosomal recessive inheritance of PAM (McKusick 265100). In addition, the affected girl had autosomal recessive Waardenburg-anophthalmia syndrome (McKusick 206920), raising the question of whether this is a chance occurrence or possibly a contiguous gene syndrome. (orig.)

  1. Surgical techniques for alveolar socket preservation: a systematic review.

    Science.gov (United States)

    Vittorini Orgeas, Gianluca; Clementini, Marco; De Risi, Valeria; de Sanctis, Massimo

    2013-01-01

    To evaluate, through a systematic review of the literature, the efficacy of different surgical techniques in maintaining residual bone in the alveolar process following tooth extractions. MEDLINE/PubMed was searched through January 2010 and papers were selected according to the CONSORT statement and an independent three-stage screening process. The selected outcome variables were clinical width and height changes of the socket, and means and standard deviations were calculated from the included studies. For those studies that were randomized controlled trials, six meta-analyses were performed by dividing studies into three groups with regard to the use of barriers and grafting (barriers alone, graft alone, or both). Thirteen papers met the eligibility criteria and were included in the analyses. Statistically significant ridge preservation was found for studies that used barriers alone; the pooled weighted mean was 0.909 mm (95% confidence interval, 0.497554 to 1.320732 mm) for bone height, while the mean for bone width was 2.966 mm (95% confidence interval, 2.334770 to 3.598300 mm). Socket preservation procedures are effective in limiting horizontal and vertical ridge alterations in postextraction sites. The meta-analysis indicates that the use of barrier membranes alone might improve normal wound healing in extraction sites.

  2. Diffuse Alveolar Hemorrhage Associated with Warfarin Therapy

    OpenAIRE

    Kaya, Bülent; Yildiz, Ibrahim; Baha, Reshat Mehmet; Zeytun, Neslihan Ebru Eryaşar; Yetisgen, Azize

    2015-01-01

    Diffuse alveolar hemorrhage (DAH) is a life-threatening clinical pathologic syndrome caused by a variety of diseases. We report a case of DAH related to therapy of warfarin use. In this case report, we present the diffuse alveolar hemorrhage case as a rare and life-threatening complication of warfarin.

  3. Diffuse Alveolar Hemorrhage Associated with Warfarin Therapy.

    Science.gov (United States)

    Kaya, Bülent; Yildiz, Ibrahim; Baha, Reshat Mehmet; Zeytun, Neslihan Ebru Eryaşar; Yetisgen, Azize

    2015-01-01

    Diffuse alveolar hemorrhage (DAH) is a life-threatening clinical pathologic syndrome caused by a variety of diseases. We report a case of DAH related to therapy of warfarin use. In this case report, we present the diffuse alveolar hemorrhage case as a rare and life-threatening complication of warfarin.

  4. Diffuse Alveolar Hemorrhage Associated with Warfarin Therapy

    Directory of Open Access Journals (Sweden)

    Bülent Kaya

    2015-01-01

    Full Text Available Diffuse alveolar hemorrhage (DAH is a life-threatening clinical pathologic syndrome caused by a variety of diseases. We report a case of DAH related to therapy of warfarin use. In this case report, we present the diffuse alveolar hemorrhage case as a rare and life-threatening complication of warfarin.

  5. CT quantification of pulmonary alveolar microlithiasis

    International Nuclear Information System (INIS)

    Wurche, K.D.; Kubale, R.; Vallee, D.; Ostertag, H.

    1987-01-01

    Pulmonary alveolar microlithiasis is a rare, familial disease with massive symmetrical intra-alveolar calcium deposition. Conventional CT findings and CT measurements with a dual energy technique were carried out in a 26-year-old patient suffering from this disease. The importance of the findings in the differential diagnosis and for estimating the progression and prognosis of the disease is discussed. (orig.) [de

  6. Distraction of the alveolar crest

    NARCIS (Netherlands)

    Raghoebar, GM; Liem, RBS; Schoen, PJ; Vissink, A; Arnaud, E; Diner, PA

    2001-01-01

    The surgical procedure and clinical results of the Groningen Distraction Device (GDD) to augment the severely resorbed edentulous mandible are described. The GGD is non-voluminous, and consists of 2 distraction screws and I guide screw. Two months after the last day of distraction, both distraction

  7. Ridge: a computer program for calculating ridge regression estimates

    Science.gov (United States)

    Donald E. Hilt; Donald W. Seegrist

    1977-01-01

    Least-squares coefficients for multiple-regression models may be unstable when the independent variables are highly correlated. Ridge regression is a biased estimation procedure that produces stable estimates of the coefficients. Ridge regression is discussed, and a computer program for calculating the ridge coefficients is presented.

  8. Alveolar dimensional changes relevant to implant placement after minimally traumatic tooth extraction with primary closure.

    Science.gov (United States)

    Carranza, Nelson; Bonta, Hernan; Gualtieri, Ariel F; Rojas, Mariana A; Galli, Federico G; Caride, Facundo

    2016-09-01

    The purpose of this study is to evaluate the dimensional changes that occur in the alveolar ridge after minimally traumatic tooth extraction by means of computed tomography (CT), with special focus on the portion of bone supporting the gingival zenith. Twenty subjects with indication for singlerooted tooth extraction and preserved alveolar walls were selected for this study. After a minimally traumatic extraction, two CT scans were performed; the first within 24 hours postextraction (TC1) and the second 6 months (TC2) later. A radiographic guide with a radiopaque marker was used to obtain references that enabled accurate measurements over time, in both vertical and horizontal directions. The bone crest immediately apical to the gingival zenith was identified and termed "osseous zenith". The displacement of the osseous zenith in horizontal and vertical direction was analyzed and correlated with several alveolar anatomical variables with the aim of identifying possible predictors for bone remodeling. Dimensional changes that occur in postextraction sockets within a 6month period showed significant vertical and horizontal displacement of the osseous zenith (p 3 mm) should be expected. The present study suggests that the width of the alveolar crest at its midlevel, rather than crestal width, may be correlated with the displacement of the osseous zenith. Sociedad Argentina de Investigación Odontológica.

  9. Calculating a Stepwise Ridge Regression.

    Science.gov (United States)

    Morris, John D.

    1986-01-01

    Although methods for using ordinary least squares regression computer programs to calculate a ridge regression are available, the calculation of a stepwise ridge regression requires a special purpose algorithm and computer program. The correct stepwise ridge regression procedure is given, and a parallel FORTRAN computer program is described.…

  10. Submandibular fossa augmentation in implant dentistry.

    Science.gov (United States)

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2017-01-01

    There are two limiting factors for determining the dental implant fixture length in mandibular posterior edentulous region: Inferior dental canal and submandibular fossa. Submandibular fossa augmentation is a suggested way to overcome the problem of lingual undercut beneath the mylohyoid ridge in implant dentistry. Patients with lingual posterior bony undercut that interferes with the placement of a standard implant with a length of 10 mm were enrolled in this study. This method was used for eight patients in 10 sites. Increased implant length and decreasing the chance of sublingual hematoma due to lingual cortical plate perforation are the results of this study. Submandibular fossa augmentation is a new technique to improve the maneuver of oral surgeons to increase dental implant length in the presence of deep lingual bony undercut.

  11. Alveolar bone preservation subsequent to miniscrew implant placement in a canine model.

    Science.gov (United States)

    Melsen, B; Huja, S S; Chien, H-H; Dalstra, M

    2015-05-01

    To assess the effects of transcortical screws on alveolar (bone) ridge preservation following extraction. Four adult beagle dogs had mandibular premolars extracted bilaterally. After 6 weeks, using a split-mouth design, two transcortical screws were inserted unilaterally below the alveolar crest on the experimental side in the region of the extraction. The dogs were killed after 12 weeks. The bone at the extraction sites was analyzed using μCT and 3D analysis. A cylindrical core was placed around the actual and a virtual screw placed in the identical location on the control side. The bone volume within the cylinders was quantified. An insertion of a dental implant was simulated bilaterally at the insertion site. The height of the clinical crown and the alveolar crest were determined on both sides. The bone turnover was assessed histomorphometrically on un-decalcified bucco-lingual sections stained with basic fuchsine and toluidine blue. Comparison of the two sides revealed a significant difference both with regard to the bone volume and morphology. The transcortical screw caused an increase in bone density and less ridge atrophy. When simulating a dental implant placement on both sides, the bone preservation on the experimental side led to a need for a shorter clinical crown compared to the control side. A higher activity level of the bone in the experimental side was demonstrated histologically. In this dog model the insertion of a mini-implant across the healing alveolar process results in increased density not only adjacent to the screws, but also in the region where a potential dental implant would be inserted. In humans, the insertion of transcortical screws may maintain bone when for various reasons insertion of a permanent dental implant has to be postponed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Confronting an augmented reality

    OpenAIRE

    John Hedberg; Robert Fitzgerald; James Steele; Anna Wilson; Matt Bacon; Danny Munnerley

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial...

  13. Ridge regression processing

    Science.gov (United States)

    Kuhl, Mark R.

    1990-01-01

    Current navigation requirements depend on a geometric dilution of precision (GDOP) criterion. As long as the GDOP stays below a specific value, navigation requirements are met. The GDOP will exceed the specified value when the measurement geometry becomes too collinear. A new signal processing technique, called Ridge Regression Processing, can reduce the effects of nearly collinear measurement geometry; thereby reducing the inflation of the measurement errors. It is shown that the Ridge signal processor gives a consistently better mean squared error (MSE) in position than the Ordinary Least Mean Squares (OLS) estimator. The applicability of this technique is currently being investigated to improve the following areas: receiver autonomous integrity monitoring (RAIM), coverage requirements, availability requirements, and precision approaches.

  14. Ridge alterations following grafting of fresh extraction sockets in man. A randomized clinical trial.

    Science.gov (United States)

    Araújo, Mauricio G; da Silva, João Carlos Costa; de Mendonça, Arthur Furtado; Lindhe, Jan

    2015-04-01

    To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss(®) Collagen. Twenty-eight subjects with maxillary incisors, canines, and premolars scheduled for extraction were included. The tooth was carefully removed. The patients were randomly assigned to a test or a control group. In the test group patients, Bio-Oss(®) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed. Radiographic examination (cone beam computed tomograms, CBCT) was performed immediately after tooth extraction and socket treatment. Four months later, a new CBCT was obtained. In the radiographs, (i) the distance (mm) between base of the alveolar process (apex) and the buccal and palatal crests was determined, (ii) the outer profile of alveolar process of the experimental sites was outlined, and the cross section of the area (mm(2) ) determined. After 4 months of healing, the buccal and to a less extent also the palatal bone plate had become markedly reduced in height. The placement of a biomaterial in the socket failed to prevent resorption of the buccal and palatal bone walls. The cross-sectional area of the control ridge was reduced about 25% and of the test ridge with 3%. The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Effect of Alveolar Segmental Sandwich Osteotomy on Alveolar Height: A Preliminary Study.

    Science.gov (United States)

    Mehta, Karan S; Prasad, Kavitha; Shetty, Vibha; Ranganath, Krishnappa; Lalitha, R M; Dexith, Jayashree; Munoyath, Sejal K; Kumar, Vineeth

    2017-12-01

    Bone loss following extraction is maximum in horizontal dimension. Height is also reduced which is pronounced on the buccal aspect. Various surgical procedures are available to correct the bone volume viz. GBR, onlay bone grafting, alveolar distraction and sandwich osteotomy. Sandwich osteotomy has been found to increase the vertical alveolar bone height successfully. The objective of the study was to assess the effect of alveolar segmental sandwich osteotomy on alveolar height and crestal width. A prospective study was undertaken from December 2012 to August 2014. Seven patients with 12 implant sites with a mean age of 36 years were recruited. All seven patients with 12 implant sites underwent alveolar segmental sandwich osteotomy and interpositional bone grafting. Alveolar bone height was assessed radiographically preoperatively, immediate post-op, and at 3 months post-op. Alveolar bone width was assessed radiographically preoperatively and at 3 months post-op. Statistical significance was inferred at p  Sandwich osteotomy can be used as an alternative technique to increase alveolar bone height prior to implant placement. Moderate alveolar deficiency can be predictably corrected by this technique.

  16. Confronting an Augmented Reality

    Science.gov (United States)

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  17. Augmented Reality on Android

    OpenAIRE

    Chunghan Li; Chang-Shyh Peng; Daisy F. Sang

    2013-01-01

    Augmented Reality is an application which combines a live view of real-world environment and computer-generated images. This paper studies and demonstrates an efficient Augmented Reality development in the mobile Android environment with the native Java language and Android SDK. Major components include Barcode Reader, File Loader, Marker Detector, Transform Matrix Generator, and a cloud database.

  18. Enhanced alveolar monocytic phagocyte (macrophage) proliferation in tobacco and marijuana smokers

    Energy Technology Data Exchange (ETDEWEB)

    Barbers, R.G.; Evans, M.J.; Gong, H. Jr.; Tashkin, D.P. (Univ. of California-Los Angeles School of Medicine (USA))

    1991-05-01

    We tested the hypothesis that enhanced cell division accounted for the augmented numbers of monocytic phagocytes with characteristics attributed to alveolar macrophages (AM) found in the lungs of habitual tobacco (T) and marijuana (M) smokers. The monocytic phagocytes, that is, alveolar macrophages, were obtained by bronchoalveolar lavage (BAL) from 12 nonsmoking subjects; 10 subjects who smoked T only (TS); 13 subjects who smoked M only (MS); and 6 smokers of both T and M (MTS). The replication of these cells was determined by measuring the incorporation of ({sup 3}H)thymidine into the DNA of dividing cells and visually counting 2,000 cells on autoradiographically prepared cytocentrifuge cell preparations. This study demonstrated that the number of ({sup 3}H)thymidine-labeled monocytic phagocytes with characteristics of alveolar macrophages from either TS or MS have a higher proliferative index compared to cells (macrophages) from nonsmokers, p less than 0.05 by one-way ANOVA. The total number of BAL macrophages that are in mitosis in TS (17.90 +/- 4.50 labeled AM x 10(3)/ml) or MTS (10.50 +/- 4.20 labeled AM x 10(3)/ml) are 18- and 10-fold greater, respectively, than the number obtained from nonsmokers (1.01 +/- 0.18 labeled AM x 10(3)/ml). Interestingly, the number of ({sup 3}H)thymidine-labeled macrophages from MS (2.90 +/- 0.66 labeled AM x 10(3)/ml) are also greater than the number obtained from nonsmokers, although this is not statistically significant. The stimulus augmenting alveolar macrophage replication is as yet unknown but may likely be found in the T or M smoke.

  19. Enhanced alveolar monocytic phagocyte (macrophage) proliferation in tobacco and marijuana smokers

    International Nuclear Information System (INIS)

    Barbers, R.G.; Evans, M.J.; Gong, H. Jr.; Tashkin, D.P.

    1991-01-01

    We tested the hypothesis that enhanced cell division accounted for the augmented numbers of monocytic phagocytes with characteristics attributed to alveolar macrophages (AM) found in the lungs of habitual tobacco (T) and marijuana (M) smokers. The monocytic phagocytes, that is, alveolar macrophages, were obtained by bronchoalveolar lavage (BAL) from 12 nonsmoking subjects; 10 subjects who smoked T only (TS); 13 subjects who smoked M only (MS); and 6 smokers of both T and M (MTS). The replication of these cells was determined by measuring the incorporation of [ 3 H]thymidine into the DNA of dividing cells and visually counting 2,000 cells on autoradiographically prepared cytocentrifuge cell preparations. This study demonstrated that the number of [ 3 H]thymidine-labeled monocytic phagocytes with characteristics of alveolar macrophages from either TS or MS have a higher proliferative index compared to cells (macrophages) from nonsmokers, p less than 0.05 by one-way ANOVA. The total number of BAL macrophages that are in mitosis in TS (17.90 +/- 4.50 labeled AM x 10(3)/ml) or MTS (10.50 +/- 4.20 labeled AM x 10(3)/ml) are 18- and 10-fold greater, respectively, than the number obtained from nonsmokers (1.01 +/- 0.18 labeled AM x 10(3)/ml). Interestingly, the number of [ 3 H]thymidine-labeled macrophages from MS (2.90 +/- 0.66 labeled AM x 10(3)/ml) are also greater than the number obtained from nonsmokers, although this is not statistically significant. The stimulus augmenting alveolar macrophage replication is as yet unknown but may likely be found in the T or M smoke

  20. Optimizing anterior esthetics of a single-tooth implant through socket augmentation and immediate provisionalization: A case report with 7-year follow-up

    Directory of Open Access Journals (Sweden)

    Po-Sung Fu

    2012-10-01

    Full Text Available Tooth extraction inevitably accompanies alveolar ridge resorption with loss of pre-existing tissue morphology. Replacing missing teeth with dental implants has become popular, but restoring anterior teeth with implant-supported restorations is a technique-sensitive task and poses challenges for dentists. With the progress of implant dentistry, the demand for optimal esthetics has become linked with the desire for faster, easier techniques that shorten treatment time and also satisfy patients. Immediate provisionalization of a single-tooth implant provides significant benefits compared with traditional delayed protocols, such as aiding the contouring of peri-implant soft tissue and enhancing patient comfort and satisfaction. This article describes a meticulous approach to a hopeless maxillary central incisor with root fracture. The defect in the extraction socket was reconstructed using autogenous bone harvested from the chin. Four months later, an implant was installed and immediately restored. After another healing period of 6 months, the peri-implant soft tissue had been shaped and matured according to the contours of the provisional restoration. The emergence profile was used to duplicate the definitive restoration. Peri-implant esthetics was achieved through socket augmentation and immediate provisionalization of the implant. This treatment modality attained predictable and maintainable outcomes, both functionally and esthetically.

  1. [Cleft lip, alveolar and palate sequelae. Proposal of new alveolar score by the Alveolar Cleft Score (ACS) classification].

    Science.gov (United States)

    Molé, C; Simon, E

    2015-06-01

    The management of cleft lip, alveolar and palate sequelae remains problematic today. To optimize it, we tried to establish a new clinical index for diagnostic and prognostic purposes. Seven tissue indicators, that we consider to be important in the management of alveolar sequelae, are listed by assigning them individual scores. The final score, obtained by adding together the individual scores, can take a low, high or maximum value. We propose a new classification (ACS: Alveolar Cleft Score) that guides the therapeutic team to a prognosis approach, in terms of the recommended surgical and prosthetic reconstruction, the type of medical care required, and the preventive and supportive therapy to establish. Current studies are often only based on a standard radiological evaluation of the alveolar bone height at the cleft site. However, the gingival, the osseous and the cellular areas bordering the alveolar cleft sequelae induce many clinical parameters, which should be reflected in the morphological diagnosis, to better direct the surgical indications and the future prosthetic requirements, and to best maintain successful long term aesthetic and functional results. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Ridge Preservation for Implant Therapy: a Review of the Literature

    Science.gov (United States)

    Tomlin, Elizabeth M; Nelson, Shelby J; Rossmann, Jeffrey A

    2014-01-01

    Healing of the extraction socket after tooth removal involves retention of the blood clot followed by a sequence of events that lead to changes in the alveolar process in a three dimensional fashion. This normal healing event results in a minimal loss of vertical height (around 1 mm), but a substantial loss of width in the buccal-lingual plane (4-6 mm). During the first three months following extraction that loss has been shown to be significant and may result in both a hard tissue and soft tissue deformity affecting the ability to restore the site with acceptable esthetics. Procedures that reduce the resorptive process have been shown to be predictable and potentially capable of eliminating secondary surgery for site preparation when implant therapy is planned. The key element is prior planning by the dental therapist to act at the time of extraction to prevent the collapse of the ridge due to the loss of the alveolus. Several techniques have been employed as ridge preservation procedures involving the use of bone grafts, barrier membranes and biologics to provide a better restorative outcome. This review will explore the evidence behind each technique and their efficacy in accomplishing site preparation. The literature does not identify a single technique as superior to others; however, all accepted therapeutic procedures for ridge preservation have been shown to be more effective than blood clot alone in randomized controlled studies. PMID:24893595

  3. Augmented reality: a review.

    Science.gov (United States)

    Berryman, Donna R

    2012-01-01

    Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries.

  4. ENVIRONMENTAL BASELINE SURVEY REPORT FOR WEST BLACK OAK RIDGE, EAST BLACK OAK RIDGE, MCKINNEY RIDGE, WEST PINE RIDGE, AND PARCEL 21D IN THE VICINITY OF THE EAST TENNESSEE TECHNOLOGY PARK, OAK RIDGE, TENNESSEE

    Energy Technology Data Exchange (ETDEWEB)

    David A. King

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy’s (DOE’s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. The goal is to obtain all media no-further-investigation (NFI) determinations for the subject parcels considering existing soils. To augment the existing soils-only NFI determinations, samples of groundwater, surface water, soil, and sediment were collected to support all media NFI decisions. The only updates presented here are those that were made after the original issuance of the NFI documents. In the subject parcel where the soils NFI determination was not completed for approval (Parcel 21d), the full process has been performed to address the soils as well. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only NFI

  5. Perawatan Ortodontik Gigi Anterior Berjejal dengan Tulang Alveolar yang Tipis

    Directory of Open Access Journals (Sweden)

    Miesje K. Purwanegara

    2015-09-01

    Full Text Available Anterior teeth movement in orthodontic treatment is limited to labiolingual direction by very thin alveolar bone. An uncontrolled anterior tooth movement to labiolingual direction can cause alveolar bone perforation at its root segment. This case report is to remind us that alveolar bone thickness limits orthodontc tooth movement. A case of crowded anterior teeth with thin alveolar bone in malocclusion I is reported. This case is treated using adgewise orthodontic appliance. Protraction of anterior teeth is anticipated due to thin alveolar bone on the anterior surface. The conclusion is although the alveolar bone surrounding the crowded anterior teeth is thin, by controlling the movement the teeth reposition is allowed.

  6. Maxillary Sinus Floor Augmentation

    DEFF Research Database (Denmark)

    Starch-Jensen, Thomas; Jensen, Janek Dalsgaard

    2017-01-01

    Objectives: The objective of the present study is to present the current best evidence for enhancement of the vertical alveolar bone height and oral rehabilitation of the atrophic posterior maxilla with dental implants and propose some evidence-based treatment guidelines. Material and Methods...... perforation. Conclusions: The different surgical techniques for enhancement of the vertical alveolar bone height in the posterior part of the maxilla revealed high implant survival with a low incidence of complications. However, the indication for the various surgical techniques is not strictly equivalent...... the use of a graft material. Results: High implant survival rate and new bone formation was reported with the three treatment modalities. Perforation of the Schneiderian membrane was the most common complication, but the final implant treatment outcome was not influenced by a Schneiderian membrane...

  7. Comparison of digital panoramic radiography versus cone beam computerized tomography for measuring alveolar bone.

    Science.gov (United States)

    Tang, Zunan; Liu, Xianchu; Chen, Kejia

    2017-02-22

    Cone beam computerized tomography (CBCT) has been widely used in dental implanting. However, the local hospitals usually don't have access to CBCT due to the cost and medical investment, especially in West of China. The doctors in local hospitals have to make reasonable dental planting using orthopantomography (OPG) to reduce risks. Therefore, it is clinically meaningful to determine the magnification rate of OPG to obtain correct diagnosis. This study investigated the magnification rate of OPG in measuring different maxillofacial loci compared with CBCT. Eighty-six patients demanding dental implanting were scanned by CBCT and OPG. The vertical distance between the alveolar ridge crest of the maxillary first molar and the sinus bottom of the upper jaw, the distance between the alveolar ridge crest of the mandibular first molars and the top of nerviduct in the mandibular alveolar, and the distance between the alveolar ridge crest of the maxillary central incisors and the bottoms of the nasal cavities were measured. The horizontal distance in those loci were also measured. The distances derived from CBCT were used as reference. The distances between the two methods were compared using paired t-test. The magnification rates at these positions were calculated. The relationship between the data acquired from the two methods was analyzed Pearson correlation. The correlation coefficients (R) between the paired samples obtained from OPG and CBCT were highly related (P < 0.05) with R values varying from 0.840 and 0.959 in vertical distances and R values varying from 0.703 and 0.904 in horizontal distances. Compared with data obtained from CBCT, the mean vertical magnification rates were 11.38% and 12.95% vertically and 8.55% and 9.43% horizontally for the first molars in the right and left maxilla respectively; 7.26% and 6.35% vertically and 5.33% and 4.96% horizontally for the first molars in the right and left mandible respectively; and 5.55% and 4.84% vertically and

  8. Augmented Reality, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Augmented Reality systems come with many benefits derived by co-locating information with a user's environment through the use of one or more output modalities such...

  9. Exploration Augmentation Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Exploration Augmentation Module (EAM) project goal is to design and deliver a flight module that is to be deployed to Earth-Lunar Distant Retrograde Orbit (DRO)....

  10. Simple Implant Augmentation Rhinoplasty

    OpenAIRE

    Nguyen, Anh H.; Bartlett, Erica L.; Kania, Katarzyna; Bae, Sang Mo

    2015-01-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placeme...

  11. Augmented Reality for Smartphones

    OpenAIRE

    Butchart, Ben

    2011-01-01

    This report should help developers and content publishers who want to take advantage of the latest developments in smartphone and augmented reality (AR) technology to create novel and exciting new learning experiences. Not so long ago, augmented reality was an experimental technology that rarely left the lab and required a high level of technical expertise and knowledge to create new applications. Now, thanks to advances in smartphone hardware, AR technology is much more available and easily ...

  12. Confronting an augmented reality

    Directory of Open Access Journals (Sweden)

    John Hedberg

    2012-08-01

    Full Text Available How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial augmentation of reality links to existing theories of education and learning, focusing on ideas of cognitive dissonance and the confrontation of new realities implied by exposure to new and varied perspectives. We also discuss connections with broader debates brought on by the social and cultural changes wrought by the increased digitalisation of our lives, especially the concept of the extended mind. Rather than offer a prescription for augmentation, our intention is to throw open debate and to provoke deep thinking about what interacting with and creating an augmented reality might mean for both teacher and learner.

  13. Lateralization Technique and Inferior Alveolar Nerve Transposition

    Directory of Open Access Journals (Sweden)

    Angélica Castro Pimentel

    2016-01-01

    Full Text Available Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics.

  14. Measuring mandibular ridge reduction

    International Nuclear Information System (INIS)

    Steen, W.H.A.

    1984-01-01

    This thesis investigates the mandibular reduction in height of complete denture wearers and overdenture wearers. To follow this reduction in the anterior region as well as in the lateral sections of the mandible, an accurate and reproducible measuring method is a prerequisite. A radiologic technique offers the best chance. A survey is given of the literature concerning the resorption process after the extraction of teeth. An oblique cephalometric radiographic technique is introduced as a promising method to measure mandibular ridge reduction. The reproducibility and the accuracy of the technique are determined. The reproducibility in the positioning of the mandible is improved by the introduction of a mandibular support which permits a precise repositioning of the edentulous jaw, even after long periods of investigation. (Auth.)

  15. Immediate Loading of One-Piece Implants in Conjunction with a Modified Technique of Inferior Alveolar Nerve Lateralization: 10 Years Follow-Up

    Science.gov (United States)

    Eldibany, Riham; Rodriguez, Joaquin G.

    2014-01-01

    This report describes a treatment modification for a patient presented with severely resorbed bilateral edentulous posterior mandible and mobility of the anterior teeth. There was less than 8 mm of bone between the crest of the alveolar ridge and the mandibular canal as revealed by radiographic examination. A modified technique for inferior alveolar nerve lateralization (IANL) in conjunction with ridge expansion was performed using threaded bone expanders, which allowed for better primary stability and placing longer implants. A total of four postextraction implants were in the anterior region of the mandible. The mandible received a total of nine one-piece implants to allow for immediate nonfunctional loading. The definitive ceramometallic prosthesis was delivered 3 months postoperatively. The 10 years clinical and radiographic assessment showed minimal bone resorption around osseointegrated implants. One-piece implants showed great success rate and minimal bone resorption following the modified technique of IANL and immediate implantation. PMID:24624258

  16. Immediate loading of one-piece implants in conjunction with a modified technique of inferior alveolar nerve lateralization: 10 years follow-up.

    Science.gov (United States)

    Eldibany, Riham; Rodriguez, Joaquin G

    2014-03-01

    This report describes a treatment modification for a patient presented with severely resorbed bilateral edentulous posterior mandible and mobility of the anterior teeth. There was less than 8 mm of bone between the crest of the alveolar ridge and the mandibular canal as revealed by radiographic examination. A modified technique for inferior alveolar nerve lateralization (IANL) in conjunction with ridge expansion was performed using threaded bone expanders, which allowed for better primary stability and placing longer implants. A total of four postextraction implants were in the anterior region of the mandible. The mandible received a total of nine one-piece implants to allow for immediate nonfunctional loading. The definitive ceramometallic prosthesis was delivered 3 months postoperatively. The 10 years clinical and radiographic assessment showed minimal bone resorption around osseointegrated implants. One-piece implants showed great success rate and minimal bone resorption following the modified technique of IANL and immediate implantation.

  17. Alveolar Bone Fracture: Pathognomonic Sign for Clinical Diagnosis

    OpenAIRE

    Gutmacher, Zvi; Peled, Eli; Norman, Doron; Lin, Shaul

    2017-01-01

    Aim: Dental injuries, especially luxation and avulsion, are common. Dental trauma can cause alveolar bone fracture that can lead to tooth loss and malocclusion. Single tooth alveolar bone fractures are difficult to identify unless it protrudes through the overlying mucosa and can be visualized. Pain, malocclusion, and tooth mobility provide signs of suspected alveolar bone fractures. Integrity of the proximate alveolar bone should be examined for fractures where avulsion, luxation, or other t...

  18. Dimensional Ridge Preservation with a Novel Highly Porous TiO 2 Scaffold: An Experimental Study in Minipigs

    Directory of Open Access Journals (Sweden)

    Hanna Tiainen

    2012-01-01

    Full Text Available Despite being considered noncritical size defects, extraction sockets often require the use of bone grafts or bone graft substitutes in order to facilitate a stable implant site with an aesthetically pleasing mucosal architecture and prosthetic reconstruction. In the present study, the effect of novel TiO2 scaffolds on dimensional ridge preservation was evaluated following their placement into surgically modified extraction sockets in the premolar region of minipig mandibles. After six weeks of healing, the scaffolds were wellintegrated in the alveolar bone, and the convex shape of the alveolar crest was preserved. The scaffolds were found to partially preserve the dimensions of the native buccal and lingual bone walls adjacent to the defect site. A tendency towards more pronounced vertical ridge resorption, particularly in the buccal bone wall of the nongrafted alveoli, indicates that the TiO2 scaffold may be used for suppressing the loss of bone that normally follows tooth extraction.

  19. Accelerated decompensation of mandibular incisors in surgical skeletal class III patients by using augmented corticotomy: a preliminary study.

    Science.gov (United States)

    Ahn, Hyo-Won; Lee, Dong-Yeol; Park, Young-Guk; Kim, Seong-Hun; Chung, Kyu-Rhim; Nelson, Gerald

    2012-08-01

    Our objectives were to evaluate the amount of decompensation of the mandibular incisors and the change of periodontal support around them after corticotomy with bone augmentation before orthognathic surgery. Before orthognathic surgery for 15 skeletal Class III patients, orthodontic treatment was combined with corticotomy and bone augmentation labially to the anterior mandibular roots. Lateral cephalograms were taken before orthodontic treatment and before surgery (completion of preoperative orthodontic treatment). The amounts of mandibular incisor proclination, alveolar bone thickness, and periodontal support (gingival margin levels and augmentation pattern) were evaluated. Significant proclination of the mandibular incisors was shown after decompensation (P <0.001; incisor mandibular plane angle, 10.45°; incisor symphyseal plane angle, 10.74°). The incisor edge moved labially by 3.47 mm. The alveolar bone thickness increased by 1.56 mm at the root apex and 1.98 mm at the level of B-point (P <0.001). There was no gingival recession irrespective of the degree of proclination of the mandibular incisiors. Two types of bone augmentation pattern were evident. One was characterized by alveolar bone proclination proportional to the labial tipping of the mandibular incisors. Buccal alveolar bone at the cervical area was well maintained (60%, 9 subjects). The other showed greater increases in alveolar thickness at B-point than at the cervical area (40%, 6 subjects). The augmented corticotomy provided effective decompensation of the mandibular incisors in skeletal Class III patients while maintaining labial bone thickness and with no periodontal side effects. This technique reduces or eliminates the risk of moving the roots through the labial plate during decompensation with the associated risk of gingival recession. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  20. Basaloid Squamous Cell Carcinoma Involving the Alveolar Ridge, Buccal & Lingual Vestibule - A Case Report

    Directory of Open Access Journals (Sweden)

    Supriya Koshti

    2013-01-01

    Full Text Available Background: Basaloid squamous cell carcinoma of oral mucosa is a rare and aggressive variant of squamous cell carcinoma. They can be differentiated from squamous cell carcinomas by their distinct clinical and histopathological features. Methods: 45 year old female patient presented with extra oral exophytic mass and intra-oral ulcerative lesion on right buccal mucosa and vestibule. The patient was referred for routine blood examination and radiography followed by incisional biopsy. The biopsy specimen was fixed, processed and stained with Hematoxylin and Eosin for further microscopic examination. Results: On microscopic examination basaloid cells were seen proliferating along with dysplastic squamous cells in the connective tissue stroma. Conclusion: Based on the histopathological findings a diagnosis of ′Basaloid squamous cell carcinoma′ was made. The patient was referred to department of Oral and Maxillofacial Surgery for excision of the lesion followed by radiotherapy.

  1. Vertical Root Fracture: Preservation of the Alveolar Ridge Using Immediate Implants

    Directory of Open Access Journals (Sweden)

    Edmar de Oliveira Oya

    2014-01-01

    Full Text Available Teeth with vertical root fracture (VRF have complete or incomplete fractures that begin in the root and extend toward the occlusal surface. The most frequent causes of VRF originate from physical trauma, occlusal prematurity, inadequate endodontic treatment, and iatrogenic causes. Diagnose is difficult and delay can cause stomatognathic system problem. The purpose of this case report was to evaluate immediate implant placement after extraction of teeth with vertical root fracture. For the 1st case, the VRF in 1st left lower molar was confirmed during surgical flap and at the same time, the tooth was removed and immediate implant was placed. For the 2nd case, the VRF 1st left lower molar was confirmed during endodontic access and at the same appointment, the tooth was removed and the immediate implant is placed. Several studies have shown that immediate implants have similar success rates when compared with late implants. Consider that this approach is a safe procedure with favorable prognosis. In cases of VRF, the main factor to be considered is the presence of adequate bone support and immediate implants can preserve the vertical bone height, adding the fact that good patient compliance reduces the number of surgical interventions and promotes the functionality of stomatognathic system.

  2. Alveolar Bone Grafting in Cleft Patients from Bone Defect to Dental Implants.

    Science.gov (United States)

    Vuletić, Marko; Knežević, Predrag; Jokić, Dražen; Rebić, Jerko; Žabarović, Domagoj; Macan, Darko

    2014-12-01

    Cleft lip and palate is the most common congenital deformity affecting craniofacial structures. Orofacial clefts have great impact on the quality of life which includes aesthetics, function, psychological impact, dental development and facial growth. Incomplete fusion of facial prominences during the fourth to tenth week of gestation is the main cause. Cleft gaps are closed with alveolar bone grafts in surgical procedure called osteoplasty. Autogenic bone is taken from the iliac crest as the gold standard. The time of grafting can be divided into two stages: primary and secondary. The alveolar defect is usually reconstructured between 7 and 11 years and is often related to the development of the maxillary canine root. After successful osteoplasty, cleft defect is closed but there is still a lack of tooth. The space closure with orthodontic treatment has 50-75% success. If the orthodontic treatment is not possible, in order to replace the missing tooth there are three possibilities: adhesive bridgework, tooth transplantation and implants. Dental implant has the role of holding dental prosthesis, prevents pronounced bone atrophy and loads the augmentation material in the cleft area. Despite the fact that autologous bone from iliac crest is the gold standard, it is not a perfect source for reconstruction of the alveolar cleft. Bone morphogenic protein (BMP) is appropriate as an alternative graft material. The purpose of this review is to explain morphology of cleft defects, historical perspective, surgical techniques and possibilities of implant and prosthodontic rehabilitation.

  3. Teaching Alveolar Ventilation with Simple, Inexpensive Models

    Science.gov (United States)

    DiCarlo, Stephen E.

    2008-01-01

    When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day,…

  4. Alveolar proteinosis associated with aluminium dust inhalation.

    Science.gov (United States)

    Chew, R; Nigam, S; Sivakumaran, P

    2016-08-01

    Secondary alveolar proteinosis is a rare lung disease which may be triggered by a variety of inhaled particles. The diagnosis is made by detection of anti-granulocyte-macrophage colony-stimulating factor antibodies in bronchoalveolar lavage fluid, which appears milky white and contains lamellar bodies. Aluminium has been suggested as a possible cause, but there is little evidence in the literature to support this assertion. We report the case of a 46-year-old former boilermaker and boat builder who developed secondary alveolar proteinosis following sustained heavy aluminium exposure. The presence of aluminium was confirmed both by histological examination and metallurgical analysis of a mediastinal lymph node. Despite cessation of exposure to aluminium and treatment with whole-lung lavage which normally results in improvements in both symptoms and lung function, the outcome was poor and novel therapies are now being used for this patient. It may be that the natural history in aluminium-related alveolar proteinosis is different, with the metal playing a mediating role in the disease process. Our case further supports the link between aluminium and secondary alveolar proteinosis and highlights the need for measures to prevent excessive aluminium inhalation in relevant industries. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Ridges on Europa

    Science.gov (United States)

    1997-01-01

    This is the highest resolution picture ever taken of the Jupiter moon, Europa. The area shown is about 5.9 by 9.9 miles (9.6 by 16 kilometers) and the smallest visible feature is about the size of a football field. In this view, the ice-rich surface has been broken into a complex pattern by cross-cutting ridges and grooves resulting from tectonic processes. Sinuous rille-like features and knobby terrain could result from surface modifications of unknown origins. Small craters of possible impact origin range in size from less than 330 feet (100 meters) to about 1300 feet (400 meters) across are visible.This image was taken by the solid state imaging television camera aboard the Galileo during its fourth orbit around Jupiter, at a distance of 2060 miles (3340 kilometers). The picture is centered at 325 degrees West, 5.83 degrees North. North is toward the top of this image, with the sun shining from the right.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  6. Prototyping Augmented Reality

    CERN Document Server

    Mullen, Tony

    2011-01-01

    Learn to create augmented reality apps using Processing open-source programming language Augmented reality (AR) is used all over, and you may not even realize it. Smartphones overlay data onto live camera views to show homes for sale, restaurants, or historical sites. American football broadcasts use AR to show the invisible first-down line on the field to TV viewers. Nike and Budweiser, among others, have used AR in ads. Now, you can learn to create AR prototypes using 3D data, Processing open-source programming language, and other languages. This unique book is an easy-to-follow guide on how

  7. Growth of a tectonic ridge

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.W.; Messerich, J.A. [Geological Survey, Denver, CO (United States); Johnson, A.M. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences

    1997-12-31

    The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone and the ridge. They present data on the horizontal deformation at several scales associated with activity within the ridge and belt of shear zones and show the differential vertical uplifts. And, they conclude with a discussion of potential models for the observed deformation.

  8. Ridge regression and its degrees of freedom

    NARCIS (Netherlands)

    Dijkstra, Theo K.

    2014-01-01

    For ridge regression the degrees of freedom are commonly calculated by the trace of the matrix that transforms the vector of observations on the dependent variable into the ridge regression estimate of its expected value. For a fixed ridge parameter this is unobjectionable. When the ridge parameter

  9. Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

    Science.gov (United States)

    Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger

    2017-06-01

    Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

  10. Influence of balanced occlusion in complete dentures on the decrease in reduction of an edentulous ridge

    Directory of Open Access Journals (Sweden)

    Poštić Srđan D.

    2012-01-01

    Full Text Available Background/Aim. Balanced occlusal arrangement of artificial teeth and balanced occlusion is a specific type of occlusion that preserves the stability of complete dentures. Balanced occlusion comprises realization of tooth contacts at the working side as well as at the balancing side, at the same time. The aim of this study was to assess the influence of balanced occlusal arrangement of artificial teeth on the decrease in reduction of edentulous alveolar ridge. Methods. A longitudinal study on 91 fully edentulous patients was conducted using their panoramic radiographs and parameters of vertical dimension of edentulous ridges. All the patients were clinically examined by the same and a qualified dental practitioner. Numerical values of parameters of vertical dimensions of edentulous ridges and lines were statistically processed and compared using the Student’s t-test. Results. Vertical dimensions and heights of edentulous ridges were different after comparison of parameters in complete denture wearers with balanced occlusion and complete denture wearers without bilaterally balanced occlusion, as well as between male and female edentulous patients. Statistically significant differences of heights were established in complete denture wearers’ with a set of artificial teeth without balanced occlusion, at the baseline and 12 months after wearing of complete dentures. Conclusion. Balanced occlusion is a favored occlusal design in setting of artificial teeth in conventional complete dentures, which preserves edentulous ridge and influence the stability of dentures.

  11. Alveolar Bone Fracture: Pathognomonic Sign for Clinical Diagnosis.

    Science.gov (United States)

    Gutmacher, Zvi; Peled, Eli; Norman, Doron; Lin, Shaul

    2017-01-01

    Dental injuries, especially luxation and avulsion, are common. Dental trauma can cause alveolar bone fracture that can lead to tooth loss and malocclusion. Single tooth alveolar bone fractures are difficult to identify unless it protrudes through the overlying mucosa and can be visualized. Pain, malocclusion, and tooth mobility provide signs of suspected alveolar bone fractures. Integrity of the proximate alveolar bone should be examined for fractures where avulsion, luxation, or other tooth trauma is detected. Any suggestion of alveolar fractures should be further investigated with an appropriate radiograph. This case report shows a pathognomonic sign that detects and diagnosis single tooth alveolar bone fractures, i.e. , a localized hematoma crossing the attached gingiva from the free gingival margin to the vestibular mucosa. This should serve as a warning for localized alveolar bone fracture. A visualized hematoma and gentle, careful palpation may help detect covered fractures when the overlying mucosa is not perforated.

  12. Simultaneous Sinus Lifting and Alveolar Distraction of a Severely Atrophic Posterior Maxilla for Oral Rehabilitation with Dental Implants

    Directory of Open Access Journals (Sweden)

    Takahiro Kanno

    2012-01-01

    Full Text Available We retrospectively reviewed a new preimplantation regenerative augmentation technique for a severely atrophic posterior maxilla using sinus lifting with simultaneous alveolar distraction, together with long-term oral rehabilitation with implants. We also analyzed the regenerated bone histomorphologically. This study included 25 maxillary sinus sites in 17 patients. The technique consisted of alveolar osteotomy combined with simultaneous sinus lifting. After sufficient sinus lifting, a track-type vertical alveolar distractor was placed. Following a latent period, patient self-distraction was started. After the required augmentation was achieved, the distractor was left in place to allow consolidation. The distractor was then removed, and osseointegrated implants (average of 3.2 implants per sinus site, 80 implants were placed. Bone for histomorphometric analysis was sampled from six patients and compared with samples collected after sinus lifting alone as controls (n=4. A sufficient alveolus was regenerated, and all patients achieved stable oral rehabilitation. The implant survival rate was 96.3% (77/80 after an average postloading followup of 47.5 months. Good bone regeneration was observed in a morphological study, with no significant difference in the rate of bone formation compared with control samples. This new regenerative technique could be a useful option for a severely atrophic maxilla requiring implant rehabilitation.

  13. Augmented Reality i naturfagsundervisningen

    DEFF Research Database (Denmark)

    Radmer, Ole; Surland, Mogens; Nielsen, Birgitte Lund

    Augmented Reality (AR) giver ny mulighed for, at elever kan lave undersøgelser i naturfag med enkel teknologi, hvor animationer og simulationer kobles med det virkelige fænomen. I workshoppen kan I afprøve AR eksempler, udviklet i et internationalt EU projekt. Der vil være noget, der direkte kan...

  14. Augmented reality som wearable

    DEFF Research Database (Denmark)

    Buhl, Mie; Rahn, Annette

    2015-01-01

    Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR...

  15. Augmented Reality og kulturarv

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Kirkedahl Lysholm

    2013-01-01

    Museerne står overfor at skulle omfavne den digitale kultur i håndteringen af den store mængde viden, institutionerne repræsenterer. Augmented Reality-systemer forbinder ved hjælp af moderne teknologi det virtuelle med det virkelige, og kan derfor synes som en oplagt anvendelsesmulighed i...

  16. Collaboration in Augmented Reality

    NARCIS (Netherlands)

    Lukosch, S.; Billinghurst, M.; Alem, L.; Kiyokawa, K.

    2015-01-01

    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they

  17. Scaffold-based rhBMP-2 therapy in a rat alveolar defect model: implications for human gingivoperiosteoplasty.

    Science.gov (United States)

    Nguyen, Phuong D; Lin, Clarence D; Allori, Alexander C; Schachar, Jeffrey S; Ricci, John L; Saadeh, Pierre B; Warren, Stephen M

    2009-12-01

    Primary alveolar cleft repair has a 41 to 73 percent success rate. Patients with persistent alveolar defects require secondary bone grafting. The authors investigated scaffold-based therapies designed to augment the success of alveolar repair. Critical-size, 7 x 4 x 3-mm alveolar defects were created surgically in 60 Sprague-Dawley rats. Four scaffold treatment arms were tested: absorbable collagen sponge, absorbable collagen sponge plus recombinant human bone morphogenetic protein-2 (rhBMP-2), hydroxyapatite-tricalcium phosphate, hydroxyapatite-tricalcium phosphate plus rhBMP-2, and no scaffold. New bone formation was assessed radiomorphometrically and histomorphometrically at 4, 8, and 12 weeks. Radiomorphometrically, untreated animals formed 43 +/- 6 percent, 53 +/- 8 percent, and 48 +/- 3 percent new bone at 4, 8, and 12 weeks, respectively. Animals treated with absorbable collagen sponge formed 50 +/- 6 percent, 79 +/- 9 percent, and 69 +/- 7 percent new bone, respectively. Absorbable collagen sponge plus rhBMP-2-treated animals formed 49 +/- 2 percent, 71 +/- 6 percent, and 66 +/- 7 percent new bone, respectively. Hydroxyapatite-tricalcium phosphate treatment stimulated 69 +/- 12 percent, 86 +/- 3 percent (p scaffold. Radiomorphometrically, absorbable collagen sponge and hydroxyapatite-tricalcium phosphate scaffolds induced more bone formation than untreated controls. The rhBMP-2 added a small but significant histomorphometric osteogenic advantage to the hydroxyapatite-tricalcium phosphate scaffold.

  18. Injerto de tejido conectivo subpediculado con utilización de hidroxiapatita para aumento de reborde alveolar: reporte de un caso

    Directory of Open Access Journals (Sweden)

    Antonio José Díaz Caballero

    2013-10-01

    with marked bone loss in the anterior maxillary secondary to periodontal inflammatory processes with the subsequent loss of teeth premature organs, which leads to a loss of bone. It underwent surgery taking pieces of connective tissue donated by the same patient with the subsequent use of porous hydroxyapatite in the receiving area, thus increasing the roll which was atrophic. Furthermore, a successful response to biological materials and procedure, with an adequate clinical and radiographic response, it is recommended to use this material in the treatment of bone defects in vestibular aspects for its biocompatibility, because of its similarity to the bone. Whereas that open new horizons with the use of this material in this kind of condition.Keywords: Alveolar atrophy; connective tissue graft; Hydroxyapatite; alveolar ridge augmentation.

  19. Capillary Refill using Augmented Reality

    OpenAIRE

    Clausen, Christoffer

    2017-01-01

    Master's thesis in Computer science The opportunities within augmented reality is growing. Augmented reality is a combination of the real and the virtual world in real time, and large companies like Microsoft and Google is now investing heavily in the technology. This thesis presents a solution for simulating a medical test called capillary refill, by using augmented reality. The simulation is performed with an augmented reality headset called HoloLens. The HoloLens will recognise a mark...

  20. Rare Lung Diseases II: Pulmonary Alveolar Proteinosis

    Directory of Open Access Journals (Sweden)

    Stephen C Juvet

    2008-01-01

    Full Text Available The present article is the second in a series on rare lung diseases. It focuses on pulmonary alveolar proteinosis (PAP, a disorder in which lipoproteinaceous material accumulates in the alveolar space. PAP was first described in 1958, and for many years the nature of the material accumulating in the lungs was unknown. Major insights into PAP have been made in the past decade, and these have led to the notion that PAP is an autoimmume disorder in which autoantibodies interfere with signalling through the granulocyte-macrophage colony-stimulating factor receptor, leading to macrophage and neutrophil dysfunction. This has spurred new therapeutic approaches to this disorder. The discussion of PAP will begin with a case report, then will highlight the classification of PAP and review recent insights into the pathogenesis of PAP. The approach to therapy and the prognosis of PAP will also be discussed.

  1. AR DOC: Augmented reality documentaries

    DEFF Research Database (Denmark)

    Vistisen, Peter

    2014-01-01

    Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

  2. [Clinical research on repairing alveolar cleft with osteoinduction active material].

    Science.gov (United States)

    She, Xiao-ming; Zhang, Qian; Tian, Kun; Yang, Li; Xiong, Gui-fa

    2010-08-01

    To study the feasibility and authenticity of repairing alveolar defects in alveolar cleft patients with osteoinduction active material (OAM) in clinic. Twenty-seven cases of alveolar defect chosen from clinic were divided into two groups (test group and control group). For test group (12 cases), OAM was transplanted to repair the alveolar cleft. For control group (15 cases), autogenous ilium cancellous bone were transplanted into the defect region to repair alveolar cleft. At 6 months after operation, CT and three-dimensional reconstruction were used to observe alveolar appearance, and the effect and clinical success rate of recover alveolar cleft by using different repair material were compared. In the 27 cases, all the maxillary continuity was restored except two of test group and two of control group. There was no significant difference between test group and control group regarding the clinical success rate of the alveolar cleft repair (P = 1.000). OAM was used to repair the alveolar cleft that can result in new bone formations and the burgeon of canines from the bone grafted areas. There is no significant difference between OAM and autogenous ilium cancellous bone regarding the effect of the alveolar cleft repair.

  3. Constraints on ocean ridge basalt generation from Gakkel Ridge basalts

    Science.gov (United States)

    Langmuir, C. H.; Michael, P.; Standish, J.; Goldstein, S.

    2006-12-01

    The Gakkel Ridge that traverses the Arctic Ocean from Greenland to Siberia provides five "natural experiments" with respect to our understanding of melt generation and delivery at ocean ridges. (1) It is the deepest of the ocean ridges, and tests the global correlations of basalt chemistry with axial depth and the origin of such correlations. (2) It is the slowest spreading ridge, and tests the influence of ultra-slow spreading on magma generation without the complexity of oblique spreading or multiple transform offsets. (3) The samples are both on- and off-axis, allowing tests of the similarity of on- and off-axis volcanism. (4) It provides a test of the veined mantle disequilibrium melting hypothesis for MORB, since both ultra-slow spreading rate and great depth suggest minimum extents of melting, with the extent of melting decreasing progressively towards the east. (5) It tests segmentation models, because there are no transform offsets along the ridge, and the slow spreading rates should lead to maximum melt focusing along strike. The comprehensive major element, trace element and isotopic data set for the rocks obtained on the AMORE cruise allows investigation of all of these issues. (1) The Gakkel fits global depth-chemistry correlations, and major and trace element data as well as crustal thickness suggest small extents of melting in this region, decreasing towards the east. (2)Ultra-slow spreading leads to a thicker lithospheric lid and more garnet influence towards the east. The effects of thick lithosphere and mantle temperature on melting can be clearly distinguished in this region, and contrast with global systematics. This suggests that lithosphere variations are of minor importance in controlling the global array. (3) Off-axis samples are more diverse than on-axis samples, confirming the importance of off-axis volcanism at ultra-slow ridges. (4) Trace element data do not show an increase in a "veined component" towards the east as spreading rate

  4. Residual ridge dimensions at edentulous maxillary first molar sites and periodontal bone loss among two ethnic cohorts seeking tooth replacement.

    Science.gov (United States)

    Acharya, Aneesha; Hao, Jia; Mattheos, Nikos; Chau, Anson; Shirke, Prashant; Lang, Niklaus P

    2014-12-01

    To study residual ridge dimensions at edentulous first molar sites in relation to periodontal bone loss among cohorts of partially edentulous Asian Indian and Hong Kong Chinese subjects seeking tooth replacement. A total of 628 edentulous maxillary first molar sites were analyzed on Cone Beam Computed Tomography scans of 225 Asian Indian (I) and 232 Hong Kong Chinese (C) partially edentulous adults seeking tooth replacement. Age, ethnicity, gender, total tooth loss, the presence or absence of adjacent teeth, categories of periodontal status defined according to radiographic alveolar bone loss (P0: periodontal health, P1: incipient to moderate disease, P2: severe periodontal disease) and sinus membrane abnormalities were noted. Alveolar ridge height (RH), widths at 1 and 3 mm from crest (RW1; RW3), and relative position of the bone crest (RR) were measured. Prevalence of P2 status was most frequent in both cohorts(C: 50.4% I: 49.2%). P2 had lowest ridge heights; 13.1% C P2 and 14%I P2 had RH Periodontal status and sinus membrane abnormality increased the odds of RH periodontal disease was common among Asian Indian and Hong Kong Chinese subjects seeking tooth replacement and associated with lower available bone heights. Ethnicity, gender, sinus membrane thickening affected available bone height in the subsinus region, while the presence of adjacent teeth- and age-affected residual ridge width. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Augmenting Clozapine With Sertindole

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Emborg, Charlotte; Gydesen, Susanne

    2012-01-01

    . The study design was a 12-week, double-blind, randomized, placebo-controlled study including patients with International Statistical Classification of Diseases, 10th Revision schizophrenia (F20.0-F20.3) and treated with clozapine for at least 6 months who had not achieved sufficient response. Patients were...... Inventory, fasting glucose, lipids, and electrocardiogram. Clozapine augmentation with sertindole was not superior to placebo regarding total score or subscale score of the Positive and Negative Syndrome Scale, Clinical Global Impression, World Health Organization Quality of Life Brief, or Drug Attitude...... Inventory. No increased adverse effects compared with placebo were found. Four patients randomized to sertindole experienced a significant worsening of psychosis, and 2 of them required psychiatric admission. Metabolic parameters were unchanged during the study, but augmentation of clozapine with sertindole...

  6. Optical biosensor based on silicon nanowire ridge waveguide

    Science.gov (United States)

    Gamal, Rania; Ismail, Yehia; Swillam, Mohamed A.

    2015-02-01

    Optical biosensors present themselves as an attractive solution for integration with the ever-trending lab-on-a-chip devices. This is due to their small size, CMOS compatibility, and invariance to electromagnetic interference. Despite their many benefits, typical optical biosensors rely on evanescent field detection, where only a small portion of the light interacts with the analyte. We propose to use a silicon nanowire ridge waveguide (SNRW) for optical biosensing. This structure is comprised of an array of silicon nanowires, with the envelope of a ridge, on an insulator substrate. The SNRW maximizes the overlap between the analyte and the incident light wave by introducing voids to the otherwise bulk structure, and strengthens the contribution of the material under test to the overall modal effective index will greatly augment the sensitivity. Additionally, the SNRW provides a fabrication convenience as it covers the entire substrate, ensuring that the etching process would not damage the substrate. FDTD simulations were conducted and showed that the percentage change in the effective index due to a 1% change in the surrounding environment was more than 170 times the amount of change perceived in an evanescent detection based bulk silicon ridge waveguide.

  7. Simple Implant Augmentation Rhinoplasty.

    Science.gov (United States)

    Nguyen, Anh H; Bartlett, Erica L; Kania, Katarzyna; Bae, Sang Mo

    2015-11-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placement. An implant prosthesis should be used on a case-by-case basis. Augmentation rhinoplasty requires the consideration of specific anatomical preoperative factors, including the external nose, nasal length, nasofrontal angle, humps, and facial proportions. It is equally important to consider several operative guidelines to appropriately shape implants to minimize the occurrence of adverse effects and postoperative complications. The most common postoperative complications include infection, nasal height change, movement of implant prosthesis, and silicone implant protrusion. In addition, the surgeon should consider the current standards of Asian beauty aesthetics to better understand the patient's desired outcome.

  8. Augmented reality in surgery.

    Science.gov (United States)

    Shuhaiber, Jeffrey H

    2004-02-01

    To evaluate the history and current knowledge of computer-augmented reality in the field of surgery and its potential goals in education, surgeon training, and patient treatment. National Library of Medicine's database and additional library searches. Only articles suited to surgical sciences with a well-defined aim of study, methodology, and precise description of outcome were included. Augmented reality is an effective tool in executing surgical procedures requiring low-performance surgical dexterity; it remains a science determined mainly by stereotactic registration and ergonomics. Strong evidence was found that it is an effective teaching tool for training residents. Weaker evidence was found to suggest a significant influence on surgical outcome, both morbidity and mortality. No evidence of cost-effectiveness was found. Augmented reality is a new approach in executing detailed surgical operations. Although its application is in a preliminary stage, further research is needed to evaluate its long-term clinical impact on patients, surgeons, and hospital administrators. Its widespread use and the universal transfer of such technology remains limited until there is a better understanding of registration and ergonomics.

  9. Augmented reality services

    Directory of Open Access Journals (Sweden)

    Tomáš Koubek

    2013-01-01

    Full Text Available We assume that one of the key reasons is in the difference between a standalone application and a web service. Both architectures have some advantages and disadvantages. The Standalone application (e.g. Nokia/OVI Maps provides the required functionality. From the user point of view, main asset of this “offline” approach is network connectivity independence. However, this kind of applications must be upgraded manually. Moreover, it is hard to get any data about the application usage because it requires additional actions from the user – data are usually acquired through conventional ways, such as email or web forms.The online service such as Google Maps (including its mobile application can offer the same functionality as the offline application. Nevertheless, a permanent connection to provider servers is necessary. This can be taken as a drawback. On the other hand, usage data collection is easier and can be done without the user intervention. The data collection provides a valuable analysis basis of the user habits and needs. This analysis is necessary for design of a complex “user” based solutions such as Google Now.Augmented reality applications are usually based on the first mentioned approach. In this article, we describe our model of augmented reality as a service and compare its features with standalone solutions. Further, other important key aspects for large emergence of augmented reality services in a mainstream market are discussed.

  10. Socket grafting with or without buccal augmentation with anorganic bovine bone at immediate post-extractive implants: 6-month after loading results from a multicenter randomised controlled clinical trial.

    Science.gov (United States)

    Zuffetti, Francesco; Esposito, Marco; Capelli, Matteo; Galli, Fabio; Testori, Tiziano; Del Fabbro, Massimo

    2013-01-01

    To evaluate whether grafting with additional anorganic bovine bone to augment horizontally the buccal plate (internal and external grafting [IEG]) at single post-extractive implants preserves the alveolar ridge, improving aesthetics, better than internal socket grafting alone (ISGA). A total of 78 patients, treated in four Italian private practices, requiring a single immediate post-extractive implant, having at least 1 mm of implant-to-buccal bone gap after implant insertion and a preserved buccal bone, had the residual bone-to-implant gap filled with anorganic bovine bone. Thirty-nine randomly allocated patients received additional buccal horizontal augmentation of about 2 mm thickness with the same bone substitute (IEG group) covered with collagen resorbable membranes. Implants were submerged for 4 months before being loaded with provisional acrylic crowns. Definitive crowns were delivered after 6 months. Outcome measures were crown/implant failures, complications and aesthetics recorded by blinded assessors 6 months after initial loading, at delivery of definitive crowns. Six months after initial loading, 8 patients dropped out, did not complete the treatment or were treated twice and therefore had to be excluded (4 from each group). There were no statistically significant differences for implant failures and complications between the two groups. Two implants failed in the IEG group versus 1 in the ISGA group. Four complications occurred, 2 in each group. The mean implant aesthetic score (IAS) was 7.8 at ISGA sites and 8.0 at IEG sites. There were no statistically significant differences between the two groups (P = 0.492; difference 0.2 mm; 95% CI -0.769, 0.369) for IAS score. There were no statistically significant differences in the outcomes between the centres. The use of adjunctive anorganic bovine bone placed buccally at preserved buccal sites of immediate post-extractive implants may not improve the aesthetic outcome, however additional research is needed

  11. Prevalence and location of the posterior superior alveolar artery using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tehranchi, Maryam; Taleghani, Ferial; Shahab, Shahriar [Faculty of Dentistry, Shahed University, Tehran (Iran, Islamic Republic of); Nouri, Arash [Nouri' s Dental Clinic, Tehran (Iran, Islamic Republic of)

    2017-03-15

    Insufficient knowledge of the anatomy of the maxillary sinuses prior to sinus graft surgery may lead to perioperative or postoperative complications. This study sought to characterize the position of the posterior superior alveolar artery (PSAA) within the maxillary sinuses using cone-beam computed tomography (CBCT). A total of 300 patients with edentulous posterior maxillae, including 138 females and 162 males with an age range of 33-86 years, who presented to a radiology clinic between 2013 and 2015 were enrolled in this retrospective cross-sectional study. The distance from the inferior border of the PSAA to the alveolar crest according to the residual ridge classification by Lekholm and Zarb, the distance from the PSAA to the nasal septum and zygomatic arch, and the diameter and position of the PSAA were all assessed on patients' CBCT scans. The data were analyzed using the Mann-Whitney test and the t-test. The PSAA was detected on the CBCT scans of 87% of the patients; it was located beneath the sinus membrane in 47% of cases and was intraosseous in 47% of cases. The diameter of the artery was between 1 and 2 mm in most patients (72%). The mean diameter of the artery was 1.29±0.39 mm, and the mean distances from the PSAA to the zygomatic arch, nasal septum, and alveolar crest were 22.59±4.89 mm, 26.51±3.52 mm, and 16.7±3.96 mm, respectively. The likelihood of detecting the PSAA on CBCT scans is high; its location is intraosseous or beneath the sinus membrane in most patients. Determining the exact location of the PSAA on CBCT scans preoperatively can help prevent it from being damaged during surgery.

  12. Alveolar socket preservation technique: Effect of biomaterial on bone regenerative pattern.

    Science.gov (United States)

    Canullo, Luigi; Pellegrini, Gaia; Canciani, Elena; Heinemann, Friedhelm; Galliera, Emanuela; Dellavia, Claudia

    2016-07-01

    There is a lack of evidence in the literature on the correlation between histomorphometric findings and gene/protein expression markers for bone metabolism. Evaluation of the histological features, changes in protein expression and gene activation for specific markers of bone metabolism following application of the alveolar ridge preservation technique with magnesium-enriched hydroxyapatite (MgHA). For each patient (n=15), bone samples were harvested after tooth extraction and processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar sockets were grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression were evaluated for: RANK, RANKL, OPG, IL-6, TNF-α. For all markers, gene expression increased, but not significantly, from T0 to T1. The mean RANKL/OPG ratio was 1.88±1.24. Protein expression increased significantly (ppreservation with MgHA, markers for bone catabolism were activated. No significant correlation was found between histomorphometrical features of the regenerated tissue and protein expression at baseline. Copyright © 2015 Elsevier GmbH. All rights reserved.

  13. Intranasal Fentanyl Intoxication Leading to Diffuse Alveolar Hemorrhage.

    Science.gov (United States)

    Ruzycki, Shannon; Yarema, Mark; Dunham, Michael; Sadrzadeh, Hossein; Tremblay, Alain

    2016-06-01

    Increasing rates of opioid abuse, particularly fentanyl, may lead to more presentations of unusual effects of opioid toxicity. Diffuse alveolar hemorrhage is a rare complication of fentanyl overdose. A 45-year-old male presented in hypoxic respiratory failure secondary to diffuse alveolar hemorrhage requiring intubation. Comprehensive drug screening detected fentanyl without exposure to cocaine. Further history upon the patient's recovery revealed exposure to snorted fentanyl powder immediately prior to presentation. Diffuse alveolar hemorrhage is a potential, though rare, presentation of opioid intoxication. Recognition of less common complications of opioid abuse such as diffuse alveolar hemorrhage is important in proper management of overdoses.

  14. Oak Ridge Leadership Computing Facility (OLCF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Oak Ridge Leadership Computing Facility (OLCF) was established at Oak Ridge National Laboratory in 2004 with the mission of standing up a supercomputer 100 times...

  15. Oak Ridge Geochemical Reconnaissance Program

    International Nuclear Information System (INIS)

    Arendt, J.W.

    1977-03-01

    The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed

  16. Ridge Regression for Interactive Models.

    Science.gov (United States)

    Tate, Richard L.

    1988-01-01

    An exploratory study of the value of ridge regression for interactive models is reported. Assuming that the linear terms in a simple interactive model are centered to eliminate non-essential multicollinearity, a variety of common models, representing both ordinal and disordinal interactions, are shown to have "orientations" that are…

  17. PERFORATION OF INFERIOR ALVEOLAR NERVE BY MAXILLARY ARTERY. LA PERFORACION DEL NERVIO ALVEOLAR INFERIOR POR LA ARTERIA MAXILAR

    OpenAIRE

    Vanishree S Nayak; Ramachandra Bhat K; Prakash Billakanti Babu

    2011-01-01

    Infratemporal fossa is clinically important anatomical area for the delivery of local anesthetic agents in dentistry and maxillofacial surgery. Variations in the anatomy of the inferior alveolar nerve and maxillary artery were studied in infratemporal dissection. During routine dissection of the head in an adult male cadaver an unusual variation in the origin of the inferior alveolar nerve and its relationship with the surrounding structures was observed. The inferior alveolar nerve originate...

  18. InRidge program: Preliminary results from the first cruise

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Murthy, K.S.R.; Iyer, S.D.; Rao, M.M.M.; Banerjee, R.; Subrahmanyam, A.S.; Shirodkar, P.V.; Ghose, I.

    The first cruise under India's own Ridge research initiative, InRidge collected new data on bathymetry, free-air gravity and magnetic anomalies across the ridge axis between the Vema and Zhivago transform faults in the Central Indian Ridge...

  19. Crustal structure along Gakkel Ridge

    Science.gov (United States)

    Schmidt-Aursch, M. C.; Jokat, W.

    2003-04-01

    Relationships between melt generation, crustal thicknesses and spreading rates are well-known for fast- and intermediate- to slow-spreading midoceanic ridges. But for very-slow-spreading ridges with full spreading rates smaller than 20 mm/yr only few data have been available yet. Therefore, the 1800 km long ultra-slow-spreading Gakkel Ridge with full spreading rates between 13 mm/yr near Greenland and 6 mm/yr in the Laptev Sea was investigated by the joint AMORE expedition in summer 2001. The two research icebreakers RV Polarstern and USCGC Healy conducted several petrological and geophysical programs. Seismic refraction experiments with receivers deployed on ice floes and a 24 l airgun array towed behind one ship were performed along the rift valley during the cruise. Gravity measurements onboard revealed additional information on the crustal structure. A helicopter-based magnetic survery gave evidence for long term focused magmatism along the ridge. Forward modelling of the wide-angle seismic data with raytracing yields an exceptional thin crust with thicknesses well below 3 km. Crustal seismic velocities not higher than 6.4 km/s indicate a missing or not resolvable oceanic layer 3. Refracted mantle waves with seismic velocities up to 7.8 km/s give constraints on the crustal thickness. First results of a 3D forward gravity modelling based on the 5-minute-grid of the Arctic Gravity Project and shipboard data will also be shown. They extend the knowledge of crustal thickness and upper mantle structure to areas off-axis Gakkel Ridge and the parts along the rift valley not covered by deep seismic data.

  20. Segment distraction to reduce a wide alveolar cleft before alveolar bone grafting.

    NARCIS (Netherlands)

    Binger, T.; Katsaros, C.; Rucker, M.; Spitzer, W.J.

    2003-01-01

    OBJECTIVE: To demonstrate a method for reduction of wide alveolar clefts prior to bone grafting. This method aims to facilitate bone grafting and achieve adequate soft tissue coverage of the graft with attached gingiva. CASE REPORT: Treatment of a patient with bilateral cleft lip and palate with a

  1. Alveolar soft part sarcoma: A rare diagnosis

    Directory of Open Access Journals (Sweden)

    Priyanka Sarkar

    2013-01-01

    Full Text Available Alveolar soft-part sarcoma (ASPS is an extremely rare disease arising from connective tissues with a propensity for recurrence and metastasis. Clinically, it can be confused with hemangioma or arterio-venous malformations. Thus, a high index of suspicion and histopathological examination are required to make a definitive diagnosis. We report a case of recurrent ASPS in a young female with multiple sites involvement without any features of metastasis who has been treated with excision of the symptomatic lesions followed by chemotherapy.

  2. The efficacy of hydrothermally obtained carbonated hydroxyapatite in healing alveolar bone defects in rats with or without corticosteroid treatment.

    Science.gov (United States)

    Marković, Dejan; Jokanović, Vukoman; Petrović, Bojan; Perić, Tamara; Vukomanović, Biserka

    2014-05-01

    Autogenous bone grafting has been the gold standard in clinical cases when bone grafts are required for bone defects in dentistry. The study was undertaken to evaluate multilevel designed carbonated hydroxyapatite (CHA) obtained by hydrothermal method, as a bone substitute in healing bone defects with or without corticosteroid treatment in rats as assessed by histopathologic methods. Bone defects were created in the alveolar bone by teeth extraction in 12 rats. The animals were initially divided into two groups. The experimental group was pretreated with corticosteroids: methylprednisolone and dexamethasone, intramuscularly, while the control group was without therapy. Posterior teeth extraction had been performed after the corticosteroid therapy. The extraction defects were fulfilled with hydroxyapatite with bimodal particle sizes in the range of 50-250 μm and the sample from postextocactional defect of the alveolar bone was analyzed pathohystologically. The histopatological investigations confirmed the biologic properties of the applied material. The evident growth of new bone in the alveolar ridge was clearly noticed in both groups of rats. Carbonated HA obtained by hydrothermal method promoted bone formation in the preformed defects, confirming its efficacy for usage in bone defects. Complete resorption of the material's particles took place after 25 weeks. Hydroxyapatite completely meets the clinical requirements for a bone substitute material. Due to its microstructure, complete resorption took place during the observation period of the study. Corticosteroid treatment did not significantly affect new bone formation in the region of postextractional defects.

  3. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  4. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student...... involvement. The AR-sci-project (Augmented Reality for SCIence education) addresses the issue of applying augmented reality in developing innovative science education and enhancing the quality of science teaching and learning....

  5. Alveolar bone loss in obese subjects.

    Science.gov (United States)

    Alabdulkarim, Maher; Bissada, Nabil; Al-Zahrani, Mohammad; Ficara, Anthony; Siegel, Burton

    2005-04-01

    Obesity was found to be significantly associated with periodontal disease prevalence as measured by probing depth and clinical attachment loss. The aim of this study was to examine if obesity correlates with chronic periodontitis as diagnosed by radiographic alveolar bone loss. Four hundred subjects > or =18 years old were included; 200 with body mass index (BMI) > or =30 kg/m2 (obese) and 200 with BMI periodontitis. Obesity was found to be significantly associated with periodontitis in the uni-variate regression analysis (OR = 2.37, 95% CI, 1.55-3.63). After adjusting for age, gender, smoking, employment, diabetes, marital status, and number of teeth present, obese subjects were found to be 1.86 times more likely to have periodontitis (95% CI, 0.99-3.51) than non-obese ones. When the sample was stratified based on age, the multivariate association was statistically significant among individuals or = 40 years of age the association was statistically insignificant (OR = 1.06, 95% CI, 0.57-1.95). Stratifying the sample based on gender and smoking status revealed a stronger association among females than males (OR = 3.14 vs. 1.95) and among non-smokers than smokers (OR = 3.36 vs. 2.22). Obesity is associated with increased prevalence of periodontitis as measured by radiographic alveolar bone loss, especially among younger individuals. Prevention and management of obesity may be considered to promote better systemic and periodontal health.

  6. Prevention of Alveolar Osteitis After Third Molar Surgery ...

    African Journals Online (AJOL)

    2017-05-16

    May 16, 2017 ... development of alveolar osteitis were obtained and analyzed. Comparative statistics were done using ... KEY WORDS: Alveolar osteitis, chlorhexidine, prevention, warm saline. Department of Dental. Surgery .... healing by inducing vasodilatation of the vasculature of oral cavity, and thus enhances migration ...

  7. Increased alveolar soluble Annexin V promotes lung inflammation and fibrosis

    OpenAIRE

    Buckley, S.; Shi, W.; Xu, W.; Frey, M.R.; Moats, R.; Pardo, A.; Selman, M.; Warburton, D.

    2015-01-01

    The causes underlying the self-perpetuating nature of idiopathic pulmonary fibrosis (IPF), a progressive and usually lethal disease, remain unknown. We hypothesized that alveolar soluble Annexin V contributes to lung fibrosis, based on the observation that human IPF BALF containing high Annexin V levels promoted fibroblast involvement in alveolar epithelial wound healing that was reduced when Annexin V was depleted from the BALF.

  8. Tongue-Palate Contact of Perceptually Acceptable Alveolar Stops

    Science.gov (United States)

    Lee, Alice; Gibbon, Fiona E.; O'Donovan, Cliona

    2013-01-01

    Increased tongue-palate contact for perceptually acceptable alveolar stops has been observed in children with speech sound disorders (SSD). This is a retrospective study that further investigated this issue by using quantitative measures to compare the target alveolar stops /t/, /d/ and /n/ produced in words by nine children with SSD (20 tokens of…

  9. Classification of alveolar bone destruction patterns on maxillary ...

    African Journals Online (AJOL)

    Objective: The defective diagnosis of alveolar structures is one of most serious handicaps when assessing available periodontal treatment options for the prevention of tooth loss. The aim of this research was to classify alveolar bone defects in the maxillary molar region which is a challenging area for dental implant ...

  10. Pulmonary alveolar proteinosis in a child from an informal settlement

    African Journals Online (AJOL)

    clinical, histopathological, biochemical and genetic data.[3]. Surfactant homeostasis is critical for lung function and is tightly regulated, in part by pulmonary granulocyte-macrophage colony- stimulating factor (GM-CSF), which is required for surfactant clearance by alveolar macrophages and alveolar macrophage maturation.

  11. Diffuse alveolar hemorrhage in a young woman with systemic lupus ...

    African Journals Online (AJOL)

    Diffuse Alveolar Hemorrhage (DAH) is rarely reported complication of Systemic Lupus Erythematosus (SLE). A young woman diagnosed SLE, with a previously normal plain chest radiograph, developed acute onset cough, dyspnoea and hemoptysis. The repeat urgent chest radiograph revealed alveolar opacities. The triad ...

  12. A Novel Procedure for the Immediate Reconstruction of Severely Resorbed Alveolar Sockets for Advanced Periodontal Disease

    Directory of Open Access Journals (Sweden)

    Mario Aimetti

    2017-01-01

    Full Text Available Background. Several clinical techniques and a variety of biomaterials have been introduced over the years in an effort to overcome bone remodeling and resorption after tooth extraction. However, the predictability of these procedures in sockets with severely resorbed buccal/lingual plate due to periodontal disease is still unknown. Case Description. A patient with advanced periodontitis underwent extraction of upper right lateral and central incisors. The central incisor exhibited complete buccal bone plate loss and a 9 mm vertical bone deficiency on its palatal side. The alveolar sockets were filled with collagen sponge and covered with a nonresorbable high-density PTFE membrane. Primary closure was not attained and any rigid scaffold material was not used. Histologic analysis provided evidence of new bone formation. At 12 months a cone-beam computed tomographic scan revealed enough bone volume to insert two conventional dental implants in conjunction with minor horizontal bone augmentation procedures. Clinical Implications. This case report would seem to support the potential of the proposed reconstructive approach in changing the morphology of severely resorbed alveolar sockets, minimizing the need for advanced bone regeneration procedures during implant placement.

  13. A Novel Procedure for the Immediate Reconstruction of Severely Resorbed Alveolar Sockets for Advanced Periodontal Disease.

    Science.gov (United States)

    Aimetti, Mario; Manavella, Valeria; Cricenti, Luca; Romano, Federica

    2017-01-01

    Background. Several clinical techniques and a variety of biomaterials have been introduced over the years in an effort to overcome bone remodeling and resorption after tooth extraction. However, the predictability of these procedures in sockets with severely resorbed buccal/lingual plate due to periodontal disease is still unknown. Case Description. A patient with advanced periodontitis underwent extraction of upper right lateral and central incisors. The central incisor exhibited complete buccal bone plate loss and a 9 mm vertical bone deficiency on its palatal side. The alveolar sockets were filled with collagen sponge and covered with a nonresorbable high-density PTFE membrane. Primary closure was not attained and any rigid scaffold material was not used. Histologic analysis provided evidence of new bone formation. At 12 months a cone-beam computed tomographic scan revealed enough bone volume to insert two conventional dental implants in conjunction with minor horizontal bone augmentation procedures. Clinical Implications. This case report would seem to support the potential of the proposed reconstructive approach in changing the morphology of severely resorbed alveolar sockets, minimizing the need for advanced bone regeneration procedures during implant placement.

  14. Arachidonate metabolism increases as rat alveolar type II cells differentiate in vitro

    International Nuclear Information System (INIS)

    Lipchik, R.J.; Chauncey, J.B.; Paine, R.; Simon, R.H.; Peters-Golden, M.

    1990-01-01

    Rat type II alveolar epithelial cells are known to undergo morphological and functional changes when maintained in culture for several days. Having previously demonstrated that these cells can deacylate free arachidonic acid (AA) and metabolize it to products of the cyclooxygenase pathway, the present study was undertaken to determine whether in vitro differentiation was accompanied by alterations in the availability and metabolism of AA. We assessed the constitutive and ionophore A23187-induced deacylation and metabolism of endogenous AA, as well as the metabolism of exogenously supplied AA, in primary cultures of rat type II cells at days 2, 4, and 7 after isolation. Levels of free endogenous AA were increased at day 4, whereas eicosanoid synthesis, predominantly prostaglandin E2 and prostacyclin, increased markedly only at day 7. A similar time course of augmentation of prostanoid release was seen in response to exogenous AA. Type II cells cultured on fibronectin, intended to hasten cell flattening and spreading, demonstrated accelerated increases in available free AA in response to A23187; cells cultured on basement membrane derived from Engelbreth-Holm-Swarm mouse sarcoma, known to maintain the type II phenotype, exhibited diminished levels of available free AA. From these findings, we conclude that alterations in arachidonate metabolism are linked to alterations in cellular phenotype. The potentiation of eicosanoid synthesis accompanying in vitro differentiation suggests a possible role for the alveolar epithelium in the modulation of inflammation and fibrosis in the distal lung

  15. Contemporary Approaches in the Repair of Alveolar Clefts

    Directory of Open Access Journals (Sweden)

    Ufuk Tatli

    2014-08-01

    Full Text Available Cleft lip and palate is one of the most common craniofacial anomalies. The repair of the alveolar clefts is an important part of the treatment for patients with cleft lip and palate. The treatment concepts of alveolar bone grafting are still controversial. The corresponding controversial issues are; timing of alveolar bone grafting, graft materials, and timing of the orthodontic expansion. In the present article, aforementioned controversial issues and contemporary treatment modalities of the maxillary alveolar clefts were reviewed in the light of current literature. In conclusion, the most suitable time for alveolar bone grafting is mixed dentition period. Grafting procedure may be performed in the early or late phases of this period depending on some clinical features. Adjunct orthodontic expansion procedures should be performed before and/or after grafting depending on the patient's current features. [Archives Medical Review Journal 2014; 23(4.000: 563-574

  16. Prosthodontic management of ridge deficiencies.

    Science.gov (United States)

    Malament, Kenneth A; Neeser, Stefan

    2004-07-01

    The treatment goals in prosthodontics and dental laboratory technology are to provide patients with long-term predictable and esthetic outcomes. The periodontal tissues define the framework that will maintain ridge height, thickness, color, texture, and gingival-tooth frame. The loss of teeth, residual ridge resorption and the loss of gingival tissues continue to affect long-term and esthetic treatment outcomes. Prosthodontic treatment requires consideration of the potential negative tissue effect that time and normal biologic change might have on the completed prosthetic design. This article describes alternative restorative solutions for clinical conditions that have traditionally been managed by surgery, removable prosthodontics, or esthetically compromised fixed restorations. Different clinical conditions for tooth-retained and implant-retained fixed partial dentures as well as the laboratory technology describing construction of these different restorations will be discussed.

  17. Approaching revisional surgery in augmentation and mastopexy/augmentation patients.

    Science.gov (United States)

    Dickinson, Brian P; Handel, Neal

    2012-01-01

    Breast augmentation and mastopexy augmentation procedures are becoming more common. The young plastic and reconstructive surgeon is often challenged revisional surgery operations in these patients. These cases are challenging, require significant operative time, and can be associated with a high revision rate. It is important for the young surgeon to have an approach to deal with these common and difficult scenarios. A retrospective chart review was conducted on all patients who underwent a revision augmentation or revision mastopexy augmentation procedure between 2008 and 2010 by the authors. The most commonly encountered mitigating circumstances in the revision augmentation or revision mastopexy augmentation populations were identified and an algorithm was created on how to address these difficult problems. Between July 1, 2008 and July 1, 2010, 264 patients underwent revision augmentation or revision mastopexy augmentation procedures. The most commonly encountered patient scenarios were recurrence of ptosis, recurrent capsular contracture, implant malposition, rippling, and desiring a reduction in implant size. We encountered many mitigating circumstances that complicated the revisions. We devised a stepwise algorithmic approach to address these problems based on the following factors: (1) blood supply to the nipple-areola complex, (2) need to change implant plane, (3) patient desire to reduce or increase in breast implant volume, (4) need for total en bloc capsulectomy or capsulorrhaphy, (5) incision approach used to perform the capsulectomy, and (6) patient-related factors that need to be medically optimized or treated before, during, and after surgery. By adhering to these steps, outcomes can be accomplished more reliably and safely. Specialized preoperative planning is necessary to consistently deliver safe and aesthetic revision augmentation and revision mastopexy augmentation results. It is important for the operative surgeon to carefully consider the

  18. NASA Communications Augmentation network

    Science.gov (United States)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-09-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  19. Augmented Virtual Reality Laboratory

    Science.gov (United States)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  20. Augmented fish health monitoring

    International Nuclear Information System (INIS)

    Michak, P.; Rogers, R.; Amos, K.

    1991-05-01

    The Bonneville Power Administration (BPA) initiated the Augmented Fish Health Monitoring project in 1986. This project was a five year interagency project involving fish rearing agencies in the Columbia Basin. Historically, all agencies involved with fish health in the Columbia Basin were conducting various levels of fish health monitoring, pathogen screening and collection. The goals of this project were; to identify, develop and implement a standardized level of fish health methodologies, develop a common data collection and reporting format in the area of artificial production, evaluate and monitor water quality, improve communications between agencies and provide annual evaluation of fish health information for production of healthier smolts. This completion report will contain a project evaluation, review of the goals of the project, evaluation of the specific fish health analyses, an overview of highlights of the project and concluding remarks. 8 refs., 1 fig., 4 tabs

  1. NASA Communications Augmentation network

    Science.gov (United States)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-01-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  2. Augmented reality system

    Science.gov (United States)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  3. NAESA Augmentation Pilot Project

    Science.gov (United States)

    Hoover, John J.

    1998-01-01

    This project was one project within the Native American Earth and Space Academy (NAESA). NAESA is a national initiative comprised of several organizations that support programs which focus on 1) enhancing the technological, scientific and pedagogical skills of K-14 teachers who instruct Native Americans, 2) enhancing the understanding and applications of science, technology, and engineering of college-bound Native Americans and teaching them general college "survival skills" (e.g., test taking, time management, study habits), 3) enhancing the scientific and pedagogical skills of the faculty of tribally-controllcd colleges and community colleges with large Native American enrollments, and 4) strengthening the critical relationships between students, their parents, tribal elders, and their communities. This Augmentation Pilot Project focused on the areas of community-school alliances and intemet technology use in teaching and learning and daily living addressing five major objectives.

  4. Oak Ridge National Laboratory Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.; Pearce, J.; Zucker, A. (eds.)

    1992-01-01

    This report presents brief descriptions of the following programs at Oak Ridge National Laboratory: The effects of pollution and climate change on forests; automation to improve the safety and efficiency of rearming battle tanks; new technologies for DNA sequencing; ORNL probes the human genome; ORNL as a supercomputer research center; paving the way to superconcrete made with polystyrene; a new look at supercritical water used in waste treatment; and small mammals as environmental monitors.

  5. Bose enhancement and the ridge

    Directory of Open Access Journals (Sweden)

    Tolga Altinoluk

    2015-12-01

    Full Text Available We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  6. Oak Ridge strategy accelerates cleanup

    International Nuclear Information System (INIS)

    Garland, S.B. II; Boston, H.L.

    1996-01-01

    The strategy of the Oak Ridge Reservation Environmental Restoration Program is to accelerate the transition from characterization to remediation by making decisions at the watershed scale based on recommended land uses and historical data. Since the primary means of contaminant transport is via shallow groundwater to surface water, grouping contaminated sites by watersheds for characterization, decision-making, and remediation allows consistency and appropriateness in remedy selection. It also results in cost and schedule savings

  7. Bose enhancement and the ridge

    Energy Technology Data Exchange (ETDEWEB)

    Altinoluk, Tolga [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Armesto, Néstor, E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Kovner, Alex [Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269-3046 (United States); Lublinsky, Michael [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

    2015-12-17

    We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  8. Maxillary sinus augmentation

    Directory of Open Access Journals (Sweden)

    A B Tarun Kumar

    2015-01-01

    Full Text Available Placing dental implants in the maxillary posterior region can be both challenging and un-nerving for a regular implant dentist who is not well versed with advanced surgical procedures. It is vital for a general dentist to understand the fundamentals of bone grafting the maxillary sinus if he/she is really committed to providing the best health care for their patients. The dental practice is seeing an increasing group of patients who are living longer, and this group of older baby boomers often has an edentulous posterior maxilla either unilateral or bilateral. When edentulous, the posterior maxilla more likely has diminished bone height, which does not allow for the placement of dental implants without creating additional bone. Through grafting the maxillary sinus, bone of ideal quality can be created (allowing for placement of dental implants, which offer many advantages over other tooth replacement modalities. The sinus graft offers the dental patient a predictable procedure of regenerating lost osseous structure in the posterior maxilla. This offers the patient many advantages for long-term success. If dentists understand these concepts, they can better educate their patients and guide them to have the procedure performed. This article outlines bone grafting of the maxillary sinus for the purpose of placing dental implants. This review will help the readers to understand the intricacies of sinus augmentation. They can relate their patient's condition with the available literature and chalk out the best treatment plan for the patient, especially by using indirect sinus augmentation procedures which are less invasive and highly successful if done using prescribed technique.

  9. Investigation of a Novel PLGA/CaP Scaffold in the Healing of Tooth Extraction Sockets to Alveolar Bone Preservation in Humans.

    Science.gov (United States)

    Araujo-Pires, Ana Claudia; Mendes, Vanessa Cristina; Ferreira-Junior, Osny; Carvalho, Paulo Sérgio Perri; Guan, Limin; Davies, John Edward

    2016-06-01

    It is expected that 40% to 60% of initial alveolar bone volume will be lost up to 6 months after tooth extraction. OsteoScaf(TM) (TRT, Toronto, ON, Canada) (poly (DL-lactide-co-glycololide/calcium phosphate [PLGA/CaP] scaffold) is a novel bone substitute material and represents a promising alternative for maintaining alveolar bone integrity in this clinical scenario. Here it was hypothesized that OsteoScaf would reduce alveolar bone lost after tooth extraction in patient, acting as a clot-retention device. A total of 10 patients (32 sockets) were included in the study, of which 16 sockets were grafted with OsteoScaf and 16 were used as control (coagulum alone). Cone beam computed tomography (CBCT) was performed both immediately following extraction and also at 120 days postoperatively, at which time biopsy samples were also harvested for histological analyses. Quantitative analysis of CBCT showed less bone resorption in the OsteoScaf groups, being 10.5% to 14.4% less bone lost in the center of the socket, 15.4% in the buccal region, and 12.6% in the palatal. Qualitative histological analysis showed new bone tissue in direct apposition to the scaffold - demonstrating its osteoconductive nature. OsteoScaf diminished the expected bone lost during the postextraction remodeling of the alveolar bone ridge at 120 days postextraction. © 2015 Wiley Periodicals, Inc.

  10. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-01-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  11. Surgical protocols for ridge preservation after tooth extraction. A systematic review.

    Science.gov (United States)

    Vignoletti, Fabio; Matesanz, Paula; Rodrigo, Daniel; Figuero, Elena; Martin, Conchita; Sanz, Mariano

    2012-02-01

    This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocols designed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration. A thorough search in MEDLINE-PubMed, Embase and the Cochrane Central Register of controlled trials (CENTRAL) was conducted up to February 2011. Randomized clinical trials and prospective cohort studies with a follow-up of at least 3 months reporting changes on both the hard and soft tissues (height and/or width) of the alveolar process (mm or %) after tooth extraction were considered for inclusion. The screening of titles and abstracts resulted in 14 publications meeting the eligibility criteria. Data from nine of these 14 studies could be grouped in the meta-analyses. Results from the meta-analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups (weighted mean differences, WMD = -1.47 mm; 95% CI [-1.982, -0.953]; P regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width (meta-regression; slope = 2.26; 95% IC [1.01; 3.51]; P = 0.003). The potential benefit of socket preservation therapies was demonstrated resulting in significantly less vertical and horizontal contraction of the alveolar bone crest. The scientific evidence does not provide clear guidelines in regards to the type of biomaterial, or surgical procedure, although a significant positive effect of the flapped surgery was observed. There are no data available to draw conclusions on the consequences of such benefits on the long-term outcomes of implant therapy. © 2011 John Wiley & Sons A/S.

  12. Spiess Ridge: An axial high on the slow spreading Southwest Indian Ridge

    Science.gov (United States)

    Mitchell, Neil C.; Livermore, Roy A.

    1998-07-01

    We report recent mapping of Spiess Ridge with the Hawaii-MR1 sidescan sonar. Spiess Ridge is an unusual elongate 90 by 50 km volcanic feature on the slow spreading Southwest Indian Ridge near the Bouvet hotspot. The northwest half of the ridge has a narrow ˜7-km neovolcanic zone in MR1 sonar images and a simple magnetic anomaly sequence including possible anomalies C1n and C2n. In contrast, the southeast half shows extrusive volcanism over >40 km with distributed eruption sites, a broadened central magnetic anomaly with no anomaly C2n, and a volcanic ridge radiating from the summit of Spiess Ridge, oblique to the spreading orthogonal trend. The images show no evidence for large-offset normal faults or an axial rift valley typical of slow spreading ridges. Overall, Spiess Ridge has an appearance very unlike that of either fast or slow spreading ridges and more transitional between a spreading ridge and a seamount. We compare the morphology of Spiess Ridge to other large volcanic structures in oceanic rifts. Spiess Ridge and Bouvet Island represent localized zones of excess melting along the Southwest Indian Ridge and we discuss their origin in the light of current ideas on ridge-hotspot interaction.

  13. PERFORATION OF INFERIOR ALVEOLAR NERVE BY MAXILLARY ARTERY. Perforation of inferior alveolar nerve by maxillary artery

    OpenAIRE

    Prakash B Billakanti

    2016-01-01

    La fosa infratemporal es un área anatómica clínicamente importante para la administración de agentes anestésicos locales en odontología y cirugía maxilofacial. Fueron estudiadas variaciones en la anatomía del nervio alveolar inferior y la arteria maxilar en la disección infratemporal. Durante la disección rutinaria de la cabeza en el cadáver de un varón adulto, fue observada una variación excepcional en el origen del nervio alveolar inferior y su relación con las estructuras circundantes. El ...

  14. Influence of balanced occlusion in complete dentures on the decrease in the reduction of an edentulous ridge.

    Science.gov (United States)

    Postić, Srdjan D

    2012-12-01

    Balanced occlusal arrangement of artificial teeth and balanced occlusion is a specific type of occlusion that preserves the stability of complete dentures. Balanced occlusion comprises realization of tooth contacts at the working side as well as at the balancing side, at the same time. The aim of this study was to assess the influence of balanced occlusal arrangement of artificial teeth on the decrease in reduction of edentulous alveolar ridge. A longitudinal study on 91 fully edentulous patients was conducted using their panoramic radiographs and parameters of vertical dimension of edentulous ridges. All the patients were clinically examined by the same and a qualified dental practitioner. Numerical values of parameters of vertical dimensions of edentulous ridges and lines were statistically processed and compared using the Student's t-test. Vertical dimensions and heights of edentulous ridges were different after comparison of parameters in complete denture wearers with balanced occlusion and complete denture wearers without bilaterally balanced occlusion, as well as between male and female edentulous patients. Statistically significant differences of heights were established in complete denture wearers' with a set of artificial teeth without balanced occlusion, at the baseline and 12 months after wearing of complete dentures. Balanced occlusion is a favored occlusal design in setting of artificial teeth in conventional complete dentures, which preserves edentulous ridge and influence the stability of dentures.

  15. Histologic Evaluation of Wound Healing After Ridge Preservation With Cortical, Cancellous, and Combined Cortico-Cancellous Freeze-Dried Bone Allograft: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Demetter, Randy S; Calahan, Blaine G; Mealey, Brian L

    2017-09-01

    Cortical and cancellous mineralized freeze-dried bone allografts (FDBA) are available for use in alveolar ridge preservation after tooth extraction. There are currently no data regarding use of a combination 50%/50% cortico-cancellous FDBA compared with a 100% cortical or 100% cancellous FDBA in ridge preservation. The primary objective of this study is to dimensionally and histologically evaluate healing after ridge preservation in non-molar sites using 50%/50% cortico-cancellous FDBA versus 100% cortical and 100% cancellous FDBA. Sixty-six patients requiring extraction of a non-molar tooth were enrolled and randomized into three groups to receive ridge preservation with the following: 1) 100% cortical FDBA; 2) 100% cancellous FDBA; or 3) 50%/50% cortico-cancellous FDBA. After 18 to 20 weeks of healing, a biopsy was harvested, and an implant was placed. The alveolar ridge was measured pre- and postoperatively to evaluate change in ridge height and width. Percentages of vital bone, residual graft, and connective tissue (CT)/other were determined via histomorphometric analysis. Histomorphometric analysis revealed no significant differences among groups regarding percentage of vital bone or CT/other. The 100% cortical FDBA group had significantly greater residual graft material (P = 0.04). Dimensional analysis revealed no significant between-group differences in any parameter measured. To the best knowledge of the authors, this study offers the first histologic evidence demonstrating no significant difference in vital bone formation or dimensional changes among 50%/50% cortico-cancellous FDBA, 100% cortical FDBA, and 100% cancellous FDBA when used in ridge preservation of non-molar tooth sites.

  16. Proteomic Analysis of Gingival Tissue and Alveolar Bone during Alveolar Bone Healing*

    OpenAIRE

    Yang, Hee-Young; Kwon, Joseph; Kook, Min-Suk; Kang, Seong Soo; Kim, Se Eun; Sohn, Sungoh; Jung, Seunggon; Kwon, Sang-Oh; Kim, Hyung-Seok; Lee, Jae Hyuk; Lee, Tae-Hoon

    2013-01-01

    Bone tissue regeneration is orchestrated by the surrounding supporting tissues and involves the build-up of osteogenic cells, which orchestrate remodeling/healing through the expression of numerous mediators and signaling molecules. Periodontal regeneration models have proven useful for studying the interaction and communication between alveolar bone and supporting soft tissue. We applied a quantitative proteomic approach to analyze and compare proteins with altered expression in gingival sof...

  17. Hemorragia alveolar associada a nefrite lúpica Alveolar hemorrhage associated with lupus nephritis

    Directory of Open Access Journals (Sweden)

    Ricardo Henrique de Oliveira Braga Teixeira

    2003-12-01

    Full Text Available Hemorragia alveolar, como causa de insuficiência respiratória, é pouco freqüente, com diversas etiologias possíveis. Entre elas, o lúpus eritematoso sistêmico, que se apresenta geralmente como síndrome pulmão-rim, possui alta morbimortalidade. Acredita-se que a patogênese da microangiopatia, tanto renal como pulmonar, esteja associada ao depósito de imunocomplexos, que ativariam as vias de apoptose celular. Relatam-se dois casos de pacientes com nefrite lúpica que evoluíram com hemorragia alveolar associada à insuficiência respiratória necessitando de ventilação mecânica com evoluções totalmente distintas frente às terapias farmacológicas. O achado de anticorpos antimembrana basal em um dos casos evidencia a multiplicidade de mecanismos fisiopatológicos possivelmente envolvidos, que poderiam justificar as respostas heterogêneas frente aos tratamentos disponíveis.Alveolar hemorrhage leading to respiratory failure is uncommon. Various etiologies have been reported, including systemic lupus erythematosus, which generally presents as pulmonary-renal syndrome. It is believed that the pathogenesis of microangiopathy is related to deposits of immune complexes that lead to activation of cellular apoptosis. The authors report two cases of alveolar hemorrhage and respiratory failure, both requiring mechanical ventilation. The two cases had opposite outcomes after pharmacological therapy. The presence of anti-glomerular basement membrane antibodies in one of the cases demonstrates the multiplicity of physiopathological mechanisms that may be involved. This multiplicity of mechanisms provides a possible explanation for the heterogeneous responses to the available treatments.

  18. Variational Ridging in Sea Ice Models

    Science.gov (United States)

    Roberts, A.; Hunke, E. C.; Lipscomb, W. H.; Maslowski, W.; Kamal, S.

    2017-12-01

    This work presents the results of a new development to make basin-scale sea ice models aware of the shape, porosity and extent of individual ridges within the pack. We have derived an analytic solution for the Euler-Lagrange equation of individual ridges that accounts for non-conservative forces, and therefore the compressive strength of individual ridges. Because a region of the pack is simply a collection of paths of individual ridges, we are able to solve the Euler-Lagrange equation for a large-scale sea ice field also, and therefore the compressive strength of a region of the pack that explicitly accounts for the macro-porosity of ridged debris. We make a number of assumptions that have simplified the problem, such as treating sea ice as a granular material in ridges, and assuming that bending moments associated with ridging are perturbations around an isostatic state. Regardless of these simplifications, the ridge model is remarkably predictive of macro-porosity and ridge shape, and, because our equations are analytic, they do not require costly computations to solve the Euler-Lagrange equation of ridges on the large scale. The new ridge model is therefore applicable to large-scale sea ice models. We present results from this theoretical development, as well as plans to apply it to the Regional Arctic System Model and a community sea ice code. Most importantly, the new ridging model is particularly useful for pinpointing gaps in our observational record of sea ice ridges, and points to the need for improved measurements of the evolution of porosity of deformed ice in the Arctic and Antarctic. Such knowledge is not only useful for improving models, but also for improving estimates of sea ice volume derived from altimetric measurements of sea ice freeboard.

  19. [Massive alveolar haemorrhage in Wegener's granulomatosis].

    Science.gov (United States)

    Valero-Roldán, J; Nuñez-Castillo, D; Fernández-Fígares, C; López-Leiva, I

    2014-01-01

    Wegener's granulomatosis is a systemic vasculitis with involvement of primary granulomatous upper and lower respiratory tract, glomerulonephritis and vasculitis of small vessels. The lung disease ranges from asymptomatic pulmonary nodules to pulmonary infiltrates and fulminant alveolar haemorrhage. The prognosis is poor due to kidney and respiratory failure, although the data are changing due to new treatments with glucocorticoids and cyclophosphamide. We report a case with severe lung disease, which after appropriate anamnesis, multiple tests, and optimal sequential action, the patient was diagnosed with Wegener's granulomatosis. This disease has a low incidence in the Emergency Department, where the patient history supported by the appropriate additional provides a diagnostic suspicion. It is important that the Emergency Department has the skills to manage the stability in these patients in order to resolve their symptoms. Copyright © 2013 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  20. Magnetohydrodynamic Augmented Propulsion Experiment

    Science.gov (United States)

    Litchford, Ron J.; Cole, John; Lineberry, John; Chapman, Jim; Schmidt, Harold; Cook, Stephen (Technical Monitor)

    2002-01-01

    A fundamental obstacle to routine space access is the specific energy limitations associated with chemical fuels. In the case of vertical take-off, the high thrust needed for vertical liftoff and acceleration to orbit translates into power levels in the 10 GW range. Furthermore, useful payload mass fractions are possible only if the exhaust particle energy (i.e., exhaust velocity) is much greater than that available with traditional chemical propulsion. The electronic binding energy released by the best chemical reactions (e.g., LOX/LH2 for example, is less than 2 eV per product molecule (approx. 1.8 eV per H2O molecule), which translates into particle velocities less than 5 km/s. Useful payload fractions, however, will require exhaust velocities exceeding 15 km/s (i.e., particle energies greater than 20 eV). As an added challenge, the envisioned hypothetical RLV (reusable launch vehicle) should accomplish these amazing performance feats while providing relatively low acceleration levels to orbit (2-3g maximum). From such fundamental considerations, it is painfully obvious that planned and current RLV solutions based on chemical fuels alone represent only a temporary solution and can only result in minor gains, at best. What is truly needed is a revolutionary approach that will dramatically reduce the amount of fuel and size of the launch vehicle. This implies the need for new compact high-power energy sources as well as advanced accelerator technologies for increasing engine exhaust velocity. Electromagnetic acceleration techniques are of immense interest since they can be used to circumvent the thermal limits associated with conventional propulsion systems. This paper describes the Magnetohydrodynamic Augmented Propulsion Experiment (MAPX) being undertaken at NASA Marshall Space Flight Center (MSFC). In this experiment, a 1-MW arc heater is being used as a feeder for a 1-MW magnetohydrodynamic (MHD) accelerator. The purpose of the experiment is to demonstrate

  1. Protocol for Bone Augmentation with Simultaneous Early Implant Placement: A Retrospective Multicenter Clinical Study

    Directory of Open Access Journals (Sweden)

    Peter Fairbairn

    2015-01-01

    Full Text Available Purpose. To present a novel protocol for alveolar bone regeneration in parallel to early implant placement. Methods. 497 patients in need of extraction and early implant placement with simultaneous bone augmentation were treated in a period of 10 years. In all patients the same specific method was followed and grafting was performed utilizing in situ hardening fully resorbable alloplastic grafting materials consisting of β-tricalcium phosphate and calcium sulfate. The protocol involved atraumatic extraction, implant placement after 4 weeks with simultaneous bone augmentation, and loading of the implant 12 weeks after placement and grafting. Follow-up periods ranged from 6 months to 10 years (mean of 4 years. Results. A total of 601 postextraction sites were rehabilitated in 497 patients utilizing the novel protocol. Three implants failed before loading and three implants failed one year after loading, leaving an overall survival rate of 99.0%. Conclusions. This standardized protocol allows successful long-term functional results regarding alveolar bone regeneration and implant rehabilitation. The concept of placing the implant 4 weeks after extraction, augmenting the bone around the implant utilizing fully resorbable, biomechanically stable, alloplastic materials, and loading the implant at 12 weeks seems to offer advantages when compared with traditional treatment modalities.

  2. Understanding augmented reality concepts and applications

    CERN Document Server

    Craig, Alan B

    2013-01-01

    Augmented reality is not a technology. Augmented reality is a medium. Likewise, a book on augmented reality that only addresses the technology that is required to support the medium of augmented reality falls far short of providing the background that is needed to produce, or critically consume augmented reality applications. One reads a book. One watches a movie. One experiences augmented reality. Understanding Augmented Reality addresses the elements that are required to create compelling augmented reality experiences. The technology that supports

  3. Pendeteksian Outlier dengan Metode Regresi Ridge

    OpenAIRE

    Sri Harini

    2009-01-01

    Dalam analisis regresi linier berganda adanya satu atau lebih pengamatan pencilan (outlier) akan menimbulkan dilema bagi para peneliti. Keputusan untuk menghilangkan pencilan tersebut harus dilandasi alasan yang kuat, karena kadang-kadang pencilan dapat memberikan informasi penting yang diperlukan. Masalah outlier ini dapat diatasi dengan berbagai metode, diantaranya metode regresi ridge (ridge regression). Untuk mengetahui kekekaran regresi ridge perlu melihat nilai-nilai R2, PRESS, serta le...

  4. Inverse regression for ridge recovery I: Theory

    OpenAIRE

    Glaws, Andrew T.; Constantine, Paul G.; Cook, R. Dennis

    2017-01-01

    We investigate the application of sufficient dimension reduction (SDR) to a deterministic function of several variables. In this context, SDR provides a framework for ridge recovery. A ridge function is a function of a few linear combinations of the variables---i.e., a composition of a nonlinear function with a low-dimensional linear transformation. We connect the key feature of SDR---the dimension reduction subspace---to ridge structure in functions, which provides a subspace-based perspecti...

  5. Augmented reality som wearable technology

    DEFF Research Database (Denmark)

    Rahn, Annette

    “How Augmented reality can facilitate learning in visualizing human anatomy “ At this station I demonstrate how Augmented reality can be used to visualize the human lungs in situ and as a wearable technology which establish connection between body, image and technology in education. I will show...... the potential of Augmented reality increasing students level of understanding, interaction and engagement with the object. I will demonstrate the technology and show you the human lungs in your body and the future perspectives of the technology. Organization: developed in collaboration with Mie Buhl, Professor...

  6. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  7. Partially Biodegradable Distraction Implant to Replace Conventional Implants in Alveolar Bone of Insufficient Height: A Preliminary Study in Dogs.

    Science.gov (United States)

    Li, Tao; Zhang, Yongqiang; Shao, Bo; Gao, Yuan; Zhang, Chen; Cao, Qiang; Kong, Liang

    2015-12-01

    Dental implants have been widely used in the last few decades. However, patients with insufficient bone height need reconstructive surgeries before implant insertion. The distraction implant (DI) has been invented to simplify the treatment procedure, but the shortcomings of DIs have limited their clinical use. We incorporated biodegradable polyester into a novel DI called the partially biodegradable distraction implant (PBDI). The purpose of this study was to assess the radiological, histological, and biomechanical properties of the PBDI in animal models. PBDIs were manufactured and inserted into the atrophied mandibles of nine dogs. Box-shaped alveolar bones were segmented and distracted. The dogs were randomly divided into three groups that were sacrificed 1, 2, and 3 months after the implant insertion. Actual augmentation height (AAH) of the bone segments was measured to evaluate the effect of distraction. X-ray examination and micro-CT reconstruction and analysis were used to evaluate the regenerated bone in the distraction gap and bone around the functional element. Histological sections were used to evaluate the osseointegration and absorption of the PBDI. Fatigue tests were used to evaluate the biomechanical properties of the PBDI. Little change was found in AAH among the three groups. X-ray examination and micro-CT reconstruction showed good growth of regenerated bone in the distraction gap. Alveolar bone volume around the functional element increased steadily. No obvious bone absorption occurred in the alveolar crest around PBDI. Three months after distraction, the functional element achieved osseointegration, and the support element began to be absorbed. All PBDIs survived the fatigue test. The PBDI is a novel and reliable dental implant. It becomes a conventional implant after the absorption of the support element and the removal of the distraction screw. It is a promising replacement for conventional implants in patients with insufficient alveolar bone

  8. Reduced Frizzled Receptor 4 Expression Prevents WNT/β-Catenin-driven Alveolar Lung Repair in Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Skronska-Wasek, Wioletta; Mutze, Kathrin; Baarsma, Hoeke A; Bracke, Ken R; Alsafadi, Hani N; Lehmann, Mareike; Costa, Rita; Stornaiuolo, Mariano; Novellino, Ettore; Brusselle, Guy G; Wagner, Darcy E; Yildirim, Ali Ö; Königshoff, Melanie

    2017-07-15

    Chronic obstructive pulmonary disease (COPD), in particular emphysema, is characterized by loss of parenchymal alveolar tissue and impaired tissue repair. Wingless and INT-1 (WNT)/β-catenin signaling is reduced in COPD; however, the mechanisms thereof, specifically the role of the frizzled (FZD) family of WNT receptors, remain unexplored. To identify and functionally characterize specific FZD receptors that control downstream WNT signaling in impaired lung repair in COPD. FZD expression was analyzed in lung homogenates and alveolar epithelial type II (ATII) cells of never-smokers, smokers, patients with COPD, and two experimental COPD models by quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and immunofluorescence. The functional effects of cigarette smoke on FZD4, WNT/β-catenin signaling, and elastogenic components were investigated in primary ATII cells in vitro and in three-dimensional lung tissue cultures ex vivo. Gain- and loss-of-function approaches were applied to determine the effects of FZD4 signaling on alveolar epithelial cell wound healing and repair, as well as on expression of elastogenic components. FZD4 expression was reduced in human and experimental COPD lung tissues as well as in primary human ATII cells from patients with COPD. Cigarette smoke exposure down-regulated FZD4 expression in vitro and in vivo, along with reduced WNT/β-catenin activity. Inhibition of FZD4 decreased WNT/β-catenin-driven epithelial cell proliferation and wound closure, and it interfered with ATII-to-ATI cell transdifferentiation and organoid formation, which were augmented by FZD4 overexpression. Moreover, FZD4 restoration by overexpression or pharmacological induction led to induction of WNT/β-catenin signaling and expression of elastogenic components in three-dimensional lung tissue cultures ex vivo. Reduced FZD4 expression in COPD contributes to impaired alveolar repair capacity.

  9. Augmented Mirror: Interactive Augmented Reality System Based on Kinect

    OpenAIRE

    Vera , Lucía; Gimeno , Jesús; Coma , Inmaculada; Fernández , Marcos

    2011-01-01

    Part 1: Long and Short Papers; International audience; In this paper we present a virtual character controlled by an actor in real time, who talks with an audience through an augmented mirror. The application, which integrates video images, the avatar and other virtual objects within an Augmented Reality system, has been implemented using a mixture of technologies: two kinect systems for motion capture, depth map and real images, a gyroscope to detect head movements, and control algorithms to...

  10. Mid-oceanic ridge system

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    , leading to the creation of new ocean floor. As two tectonic plates slowly separate, molten material rises up from within the mantle to fill the opening. Thus the rugged volcanic landscape of a mid-ocean ridge is created along the plate boundary... In order to understand how magnetic stripe anomalies support plate tectonics we need to understand (1) the basics of plate tectonic theory, especially the part about sea-floor spreading; (2) how the Earth’s magnetic field behaves, and (3) how magnetic...

  11. Ridge filter design for carbon radiotherapy

    International Nuclear Information System (INIS)

    Gata-Danil, G.; Parajpan, M.; Timoshenko, G.

    2008-01-01

    The design of a ridge filter intended for forming the uniform spread-out Bragg peak within a tumor at carbon radiotherapy is described. The computation of the ridge filter shape was carried out by an analytical algorithm and tested by MC simulation (GEANT4 code). Two kinds of the ridge filter were considered: stationary and movable. The influence on a ridge filter shape of the carbon beam energy and type of relative biological effectiveness dependence on the carbon ion linear energy transfer in tissue were examined

  12. Pendeteksian Outlier dengan Metode Regresi Ridge

    Directory of Open Access Journals (Sweden)

    Sri Harini

    2009-11-01

    Full Text Available Dalam analisis regresi linier berganda adanya satu atau lebih pengamatan pencilan (outlier akan menimbulkan dilema bagi para peneliti. Keputusan untuk menghilangkan pencilan tersebut harus dilandasi alasan yang kuat, karena kadang-kadang pencilan dapat memberikan informasi penting yang diperlukan. Masalah outlier ini dapat diatasi dengan berbagai metode, diantaranya metode regresi ridge (ridge regression. Untuk mengetahui kekekaran regresi ridge perlu melihat nilai-nilai R2, PRESS, serta leverage (hii, untuk metode regresi ridge dengan berbagai nilai tetapan bias k yang dipilih.

  13. Geo-Morphological Analyses of the Gakkel Ridge and the Southwest Indian Ridge

    Science.gov (United States)

    Dorschel, B.; Schlindwein, V. S. N.; Eagles, G.

    2014-12-01

    The Gakkel Ridge in the Arctic Ocean and the Southwest Indian Ridge in the Southwest Indian Ocean between Africa and Antarctica are ultraslow-spreading (<20 mm yr-1) mid ocean ridges. This type of mid ocean ridge has distinct geo-morphologies that are influenced by the slow rate of plate divergence and by mantle potential temperature, which control the processes (peridotite diapirism and intersticial melt migration) by which material rises to fill the space vacated by plate divergence. These ridges are characterised by non-orthogonal spreading. Transform faults, typical of faster spreading mid ocean ridges, are far less common at ultraslow spreading mid ocean ridges. Thus in return, detailed geo-statistical analyses of the geo-morphology of ultraslow-spreading mid ocean ridges can provide valuable information towards a better understanding of these slowest of spreading ridges. We have generated high resolution bathymetric grids for the Gakkel and Southwest Indian ridges based on high resolution multibeam echosounder data from various expeditions with RV Polarstern. On the basis of these grids, geo-statistical analyses allow for an assessment of the geo-morphological elements of the ridges on various scales. The results of these analyses show that, approximately 200 km long medium-scale sections of the ridges can be characterised by the lengths and orientations of the short-scale (hundreds of meters to tens of kilometres) ridges and troughs. The geomorphologies of short-scale ridges and troughs situated at the junctions between medium scale sections often exhibit a mixture of the geomorphological elements seen in the neighbouring sections. These geo-morphological patterns provide insights into the overall spreading-geometry along the Gakkel Ridge and the Southwest Indian Ridge.

  14. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    2010-01-01

    Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus......, physical damage: they are all readable and interpretable signs. As augmented reality the crime scene carries a narrative which at first is hidden and must be revealed. Due to the process of investigation and the detective's ability to reason and deduce, the crime scene as place is reconstructed as virtual...... to understand the concept of augmentet reality. The crime scene is an encoded place due to certain actions and events which have taken place and which have left various traces which in turn may be read and interpreted: blood, nails, hair are all (DNA) codes to be cracked as are traces of gun powder, shot holes...

  15. Mersiline mesh in premaxillary augmentation.

    Science.gov (United States)

    Foda, Hossam M T

    2005-01-01

    Premaxillary retrusion may distort the aesthetic appearance of the columella, lip, and nasal tip. This defect is characteristically seen in, but not limited to, patients with cleft lip nasal deformity. This study investigated 60 patients presenting with premaxillary deficiencies in which Mersiline mesh was used to augment the premaxilla. All the cases had surgery using the external rhinoplasty technique. Two methods of augmentation with Mersiline mesh were used: the Mersiline roll technique, for the cases with central symmetric deficiencies, and the Mersiline packing technique, for the cases with asymmetric deficiencies. Premaxillary augmentation with Mersiline mesh proved to be simple technically, easy to perform, and not associated with any complications. Periodic follow-up evaluation for a mean period of 32 months (range, 12-98 months) showed that an adequate degree of premaxillary augmentation was maintained with no clinically detectable resorption of the mesh implant.

  16. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student i...... involvement. The AR-sci-project (Augmented Reality for SCIence education) addresses the issue of applying augmented reality in developing innovative science education and enhancing the quality of science teaching and learning.......Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student...

  17. Alveolar cleft closure with iliac bone graft: A case report.

    Directory of Open Access Journals (Sweden)

    Tichvy Tammama

    2017-04-01

    Conclusion: The timing of alveolar bone grafting usually associated with the state of the developing of dentition. Post operative management is important to get a good result, and to prevent any complications.

  18. Radionuclide study of the action of cadmium on alveolar macrophages

    International Nuclear Information System (INIS)

    Reulet, Maryse.

    1976-01-01

    The experimental toxicity of cadmium was studied on the lung, using cadmium sulfate, cadmium acetate and the radioactive isotope cadmium 109 in chloride or acetate form. The results are given in the following order: part one is devoted to the results of investigations on chronic cadmium poisoning and the role of alveolar macrophages in this poisoning; in part two the uptake of cadmium on alveolar macrophages is studied with cadmium 109, administered intraperitoneally; in part three the action of cadmium on the phospholipid metabolism of alveolar macrophages is examined. The cadmium, as sulfate or acetate, is administered in several ways: by intraperitoneal injection; or by inhalation of cadmium dusts or aerosols. The effect of cadmium on the oxidative metabolism of alveolar macrophages is studied in part four. This work is carried out 'in vitro' and 'in vivo' after cadmium oxide dusting of the air [fr

  19. The Augmented REality Sandtable (ARES)

    Science.gov (United States)

    2015-10-01

    Introduction The US Army Research Laboratory (ARL) Human Sciences Campaign calls out the topic of Virtual /Mixed and Augmented Reality as one of the...type of virtual environment. In virtual reality (VR), the totality of the environment is computer generated. In AR, the real world is augmented by...tangible user interfaces; and the effectiveness of virtual sand tables and similar systems. A market survey was also done to discover the state of

  20. Horizontal alveolar bone loss: A periodontal orphan

    Directory of Open Access Journals (Sweden)

    Jayakumar A

    2010-01-01

    Full Text Available Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician′s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs (of patients diagnosed with chronic periodontitis and seeking periodontal care, which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36% OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2% teeth, and vertical defects were found only in 264 (7.8% of the teeth, which was statistically significant (P<.001. Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3% have addressed vertical bone loss, and 18 (3.7% have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment

  1. Use of a permanent soft denture liner in the retromylohyoid eminence and knife-edge ridge areas of the mandible to aid in retention and stability.

    Science.gov (United States)

    Mendez, Maritza; Lee, Christina

    2013-01-01

    Many edentulous patients who wear complete dentures have alveolar ridge resorption. While retention is a concern in both arches, the mandibular arch presents more of a challenge due to less available bone. Mini-implants may not be an option in a case with knife-edge ridges. Lingual undercuts in the posterior mandibular region of the retromylohyoid eminence can be used to increase retention. A permanent soft denture liner is ideal for this application. It is softer than the acrylic denture material that is typically utilized, thus there is less discomfort when the patient inserts or removes the denture. A literature search indicates underutilization or lack of knowledge of this technique. This article presents a case involving a patient who could not tolerate traditional dentures. A silicone-based permanent soft denture liner was placed over the knife-edge ridge and retromylohyoid areas of the mandible.

  2. Alveolar lymphangioma in infants: report of two cases.

    LENUS (Irish Health Repository)

    FitzGerald, Kirsten

    2012-02-01

    The alveolar lymphangioma is a benign but relatively rare condition found only in the oral cavities of black infants. Dentists practising in Ireland may be unaware of this condition due to its racial specificity. This paper presents two case reports of multiple alveolar lymphangiomas found in black infants in a children\\'s hospital in Ireland. The epidemiology, aetiology, clinical presentation, histology, and management options are discussed. The photographs should aid the practitioner in recognising these lesions.

  3. Soft tissue healing in alveolar socket preservation technique: histologic evaluations.

    Science.gov (United States)

    Pellegrini, Gaia; Rasperini, Giulio; Obot, Gregory; Farronato, Davide; Dellavia, Claudia

    2014-01-01

    After tooth extraction, 14 alveolar sockets were grafted with porous bovine bone mineral particles and covered with non-cross-linked collagen membrane (test group), and 14 alveolar sockets were left uncovered. At 5 and 12 weeks, microvascular density (MVD), collagen content, and amount of lymphocytes (Lym) T and B were analyzed in soft tissue. At 5 weeks, MVD was significantly lower and Lym T was significantly higher in tests than in controls (P healing process of the soft tissue.

  4. Dynamic thermal performance of alveolar brick construction system

    International Nuclear Information System (INIS)

    Gracia, A. de; Castell, A.; Medrano, M.; Cabeza, L.F.

    2011-01-01

    Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

  5. Alveolar lymphangioma in infants: report of two cases.

    LENUS (Irish Health Repository)

    FitzGerald, Kirsten

    2009-06-01

    The alveolar lymphangioma is a benign but relatively rare condition found only in the oral cavities of black infants. Dentists practising in Ireland may be unaware of this condition due to its racial specificity. This paper presents two case reports of multiple alveolar lymphangiomas found in black infants in a children\\'s hospital in Ireland. The epidemiology, aetiology, clinical presentation, histology, and management options are discussed. The photographs should aid the practitioner in recognising these lesions.

  6. Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Skipper, M.N.

    1990-03-01

    Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs

  7. Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Skipper, M.N.

    1990-03-01

    Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs.

  8. [Fatal alveolar haemorrhage following a "bang" of cannabis].

    Science.gov (United States)

    Grassin, F; André, M; Rallec, B; Combes, E; Vinsonneau, U; Paleiron, N

    2011-09-01

    The new methods of cannabis consumption (home made water pipe or "bang") may be responsible for fatal respiratory complications. We present a case, with fatal outcome, of a man of 19 years with no previous history other than an addiction to cannabis using "bang". He was admitted to intensive care with acute dyspnoea. A CT scan showed bilateral, diffuse alveolar shadowing. He was anaemic with an Hb of 9.3g/l. Bronchoalveolar lavage revealed massive alveolar haemorrhage. Investigations for infection and immunological disorder were negative and toxicology was negative except for cannabis. Antibiotic treatment was given and favourable progress allowed early discharge. Death occurred 15 days later due to alveolar haemorrhage following a further "bang" of cannabis. Autopsy showed toxic alveolar haemorrhage. The probable mechanism is pulmonary damage due to acid anhydrides released by the incomplete combustion of cannabis in contact with plastic. These acids have a double effect on the lungs: a direct toxicity with severe inflammation of the mucosa leading to alveolar haemorrhage and subsequently the acid anhydrides may lead to the syndrome of intra-alveolar haemorrhage and anaemia described in occupational lung diseases by Herbert in Oxford in 1979. It manifests itself by haemoptysis and intravascular haemolysis. We draw attention to the extremely serious potential consequences of new methods of using cannabis, particularly the use of "bang" in homemade plastic materials. Copyright © 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  9. Short implants compared to implants in vertically augmented bone: a systematic review.

    Science.gov (United States)

    Nisand, D; Picard, N; Rocchietta, I

    2015-09-01

    To assess relevant data comparing short implants or implants associated with vertical ridge augmentation derived from RCT's and CCT's. A PubMed and hand search was performed to identify all RCT's and CCT's published in English language comparing short implants to implants associated with vertical ridge augmentation. The initial search resulted in 3387 articles. A total of 17 articles were eligible for full-text analysis and four were finally included. This review tends to demonstrate similar implant survival rates between implants placed in vertically augmented bone and short implants (95.09% vs. 96.24%, respectively) with a follow-up ranging from 1 to 5 years. In terms of prosthetic survival rates, there were no differences between the treatments. More surgical complications were reported when using implants placed in vertically augmented bone compared to short implants (56 patients with surgical complications compared to 18 patients, respectively). This evidence should, however, be interpreted with caution as it is derived from four RCT's with limited sample size (ranging from 15 to 30 per group), limited follow-up and performed by the same research group. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Inferior alveolar canal course: a radiographic study.

    Science.gov (United States)

    Liu, Tie; Xia, Bing; Gu, Zhiyuan

    2009-11-01

    To describe the morphology and course of the inferior alveolar canal (IAC) as it appears in digital panoramic radiographs. Three hundred and eighty-six digital rotational panoramic radiographs (OPG) were studied using the Clinview Software (6.1.3.7 version, Instrumentarium). Among the 386 radiographs, 86 radiographs with 5-mm steel balls were used to calculate the magnification. The average magnification of radiographs in this study was 7.24+/-7.55%. The course of IAC as seen in the panoramic radiograph may be classified into four types: (1) linear curve, 12.75%, (2) spoon-shaped curve, 29.25%, (3) elliptic-arc curve, 48.5%, and (4) turning curve, 9.5%. On panoramic radiographs, the IAC appeared closest to the inferior border of the mandible in the region of the first molar. In relation to the teeth, on panoramic radiographs, the IAC appeared closest to the distal root tip of the third molar and furthest from the mesial root tip of the first molar. In the OPG, there are four types of IAC: linear, spoon shape, elliptic-arc, and turning curve. The data found in the study may be useful for dental implant, mandibule surgery, and dental anesthesia. The limitations of the panoramic radiograph in depicting the true three-dimensional (3D) morphology of the IAC are recognized, computed tomography (CT) and cone beam (CB)3D imaging being more precise.

  11. Populations at Risk for Alveolar Echinococcosis, France

    Science.gov (United States)

    Piarroux, Martine; Piarroux, Renaud; Knapp, Jenny; Bardonnet, Karine; Dumortier, Jérôme; Watelet, Jérôme; Gerard, Alain; Beytout, Jean; Abergel, Armand; Bresson-Hadni, Solange

    2013-01-01

    During 1982–2007, alveolar echinococcosis (AE) was diagnosed in 407 patients in France, a country previously known to register half of all European patients. To better define high-risk groups in France, we conducted a national registry-based study to identify areas where persons were at risk and spatial clusters of cases. We interviewed 180 AE patients about their way of life and compared responses to those of 517 controls. We found that almost all AE patients lived in 22 départements in eastern and central France (relative risk 78.63, 95% CI 52.84–117.02). Classification and regression tree analysis showed that the main risk factor was living in AE-endemic areas. There, most at-risk populations lived in rural settings (odds ratio [OR] 66.67, 95% CI 6.21–464.51 for farmers and OR 6.98, 95% CI 2.88–18.25 for other persons) or gardened in nonrural settings (OR 4.30, 95% CI 1.82–10.91). These findings can help sensitization campaigns focus on specific groups. PMID:23647623

  12. Computed tomography of the alveolar bone

    International Nuclear Information System (INIS)

    Schueller, H.

    1996-01-01

    In addition to the conventional radiological methods used in odontology, computed tomography (CT) provides superposition-free images of the mandible and maxilla. Its value has been proved not only in cases of malignancy but also in many other problems. If an examination is performed with a slice thickness of less than 1.5 mm, the form and position of retained teeth in the alveolar bone, as well as subsequent lesions of neighboring permanent teeth, can be visualized so that early treatment can be planned. If the parodontal space of a retained tooth is visible, orthodontic intervention is possible. Precise assessment of horizontal or vertical bone loss is essential in inflammatory dental diseases. The morphology and extent of benign cystic lesions are also shown by CT. With CT surgical strategy of an intended implant therapy can take into account the remaining bone substance and the exact position of nerves and foramina. If such therapy is possible, the location, form and number of implants are easily defined. (orig.) [de

  13. The origin and destruction of beach ridges

    NARCIS (Netherlands)

    Doeglas, D.J.

    1955-01-01

    During the Fall of 1945 the author measured daily the micro-topography of a beach profile at Zandvoort, the Netherlands. The daily changes and the movements of the beach ridges have been determined. Several beach ridges came into being and were destroyed during storms. The structure of the deposits

  14. Tectonics and magmatism of ultraslow spreading ridges

    Science.gov (United States)

    Dubinin, E. P.; Kokhan, A. V.; Sushchevskaya, N. M.

    2013-05-01

    The tectonics, structure-forming processes, and magmatism in rift zones of ultraslow spreading ridges are exemplified in the Reykjanes, Kolbeinsey, Mohns, Knipovich, Gakkel, and Southwest Indian ridges. The thermal state of the mantle, the thickness of the brittle lithospheric layer, and spreading obliquety are the most important factors that control the structural pattern of rift zones. For the Reykjanes and Kolbeinsey ridges, the following are crucial factors: variations in the crust thickness; relationships between the thicknesses of its brittle and ductile layers; width of the rift zone; increase in intensity of magma supply approaching the Iceland thermal anomaly; and spreading obliquety. For the Knipovich Ridge, these are its localization in the transitional zone between the Gakkel and Mohns ridges under conditions of shear and tensile stresses and multiple rearrangements of spreading; nonorthogonal spreading; and structural and compositional barrier of thick continental lithosphere at the Barents Sea shelf and Spitsbergen. The Mohns Ridge is characterized by oblique spreading under conditions of a thick cold lithosphere and narrow stable rift zone. The Gakkel and the Southwest Indian ridges are distinguished by the lowest spreading rate under the settings of the along-strike variations in heating of the mantle and of a variable spreading geometry. The intensity of endogenic structure-forming varies along the strike of the ridges. In addition to the prevalence of tectonic factors in the formation of the topography, magmatism and metamorphism locally play an important role.

  15. Petrology of tectonically segmented Central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Iyer, S.D.

    Distribution and mineralogy of various rock types along the 4200-km-long slow-spreading Central Indian Ridge, between Owen fracture zone in the north and Indian Ocean triple junction in the south, is studied in the light of ridge segmentation...

  16. Sex Determination from Fingerprint Ridge Density | Gungadin ...

    African Journals Online (AJOL)

    This study was conducted with an aim to establish a relationship between sex and fingerprint ridge density. The fingerprints were taken from 500 subjects (250 males and 250 females) in the age group of 18-60 years. After taking fingerprints, the ridges were counted in the upper portion of the radial border of each print for all ...

  17. An Interactive Approach to Ridge Regression

    Science.gov (United States)

    Marquette, J. F.; Dufala, M. M.

    1978-01-01

    Ridge regression is an approach to ameliorating the problem of large standard errors of regression estimates when predictor variables are highly intercorrelated. An interactive computer program is presented which allows for investigation of the effects of using various ridge regression adjustment values. (JKS)

  18. An Identity for Kernel Ridge Regression

    OpenAIRE

    Zhdanov, Fedor; Kalnishkan, Yuri

    2011-01-01

    This paper derives an identity connecting the square loss of ridge regression in on-line mode with the loss of the retrospectively best regressor. Some corollaries about the properties of the cumulative loss of on-line ridge regression are also obtained.

  19. Ridges and tidal stress on Io

    Science.gov (United States)

    Bart, G.D.; Turtle, E.P.; Jaeger, W.L.; Keszthelyi, L.P.; Greenberg, R.

    2004-01-01

    Sets of ridges of uncertain origin are seen in twenty-nine high-resolution Galileo images, which sample seven locales on Io. These ridges are on the order of a few kilometers in length with a spacing of about a kilometer. Within each locale, the ridges have a consistent orientation, but the orientations vary from place to place. We investigate whether these ridges could be a result of tidal flexing of Io by comparing their orientations with the peak tidal stress orientations at the same locations. We find that ridges grouped near the equator are aligned either north-south or east-west, as are the predicted principal stress orientations there. It is not clear why particular groups run north-south and others east-west. The one set of ridges observed far from the equator (52?? S) has an oblique azimuth, as do the tidal stresses at those latitudes. Therefore, all observed ridges have similar orientations to the tidal stress in their region. This correlation is consistent with the hypothesis that tidal flexing of Io plays an important role in ridge formation. ?? 2004 Elsevier Inc. All rights reserved.

  20. Oak Ridge Reservation environmental report for 1991

    International Nuclear Information System (INIS)

    Mucke, P.C.

    1992-10-01

    The Oak Ridge Reservation Environmental Report for 1991 is the 21st in a series that began in 1971. The report documents the annual results of a comprehensive program to estimate the impact of the US Department of Energy (DOE) Oak Ridge operations upon human health and the environment. The report is organized into ten sections that address various aspects of effluent monitoring, environmental surveillance, dose assessment, waste management, and quality assurance. A compliance summary gives a synopsis of the status of each facility relative to applicable state and federal regulations. Data are included for the following: Oak Ridge Y-12 Plant; Oak Ridge National Laboratory (ORNL); and Oak Ridge K-25 Site. Effluent monitoring and environmental surveillance programs are intended to serve as effective indicators of contaminant releases and ambient contaminant concentrations that have the potential to result in adverse impacts to human health and the environment

  1. Nitrate augmented myocardial viability assessment

    International Nuclear Information System (INIS)

    Wadhwa, S.; Mansberb, R.; Fernandes, V.B.

    1997-01-01

    Full text: 24 hour 201 TI reinjection imaging improves myocardial viability detection when compared to standard 3-4 hour redistribution imaging, however, it is a time-consuming approach and some images do not provide adequate quality due to high background activity on the delayed scan. We tested whether sensitivity of redistribution and same day reinjection imaging could be improved by giving short-acting nitrates immediately prior to redistribution and reinjection imaging. Eighteen patients underwent a stress test (exercise or pharmacological) and 4 hour redistribution 201 TI SPECT study. Immediately after redistribution imaging, each patient was given 600 μg of sublingual glyceryl trinitrate and reimaged 15-20 minutes later (nitrate augmented image). Immediately following nitrate augmentation imaging, each patient was reinjected with 30 MBq of 201 TI and reimaged 20 minutes later (nitrate augmented reinjection images). Each patient returned 24 hours later and was reinjected with 40 MBq of 201 TI and imaged 20 minutes later (24 hour reinjection images). In all, each patient had five SPECT images as follows: stress/redistribution/ nitrate augmented redistribution/nitrate augmented same day reinjection/ 24 hour reinjection. The myocardium was divided into 11 segments and perfusion to each segment was scored by consensus method (2 blinded assessors) on a 4 point graded scale (0 = no perfusion, 1 = minimal perfusion, 2 = moderate perfusion, 3 = normal perfusion). Perfusion scores were analysed on a segment by segment basis; as well, each patient was given an overall perfusion score equal to the sum of the perfusion score for each segment. 150 segments with reduced perfusion were identified, of these 23 (15.3%) showed improvement in the redistribution images, 60 (40%) segments improved in the nitrate augmented images, 49 (32.7%) improved in the nitrate augmented reinjection images and 52 (34.7%) improved in the 24 hour reinjection images. To assess overall cardiac

  2. Modeling Alveolar Epithelial Cell Behavior In Spatially Designed Hydrogel Microenvironments

    Science.gov (United States)

    Lewis, Katherine Jean Reeder

    The alveolar epithelium consists of two cell phenotypes, elongated alveolar type I cells (AT1) and rounded alveolar type II cells (ATII), and exists in a complex three-dimensional environment as a polarized cell layer attached to a thin basement membrane and enclosing a roughly spherical lumen. Closely surrounding the alveolar cysts are capillary endothelial cells as well as interstitial pulmonary fibroblasts. Many factors are thought to influence alveolar epithelial cell differentiation during lung development and wound repair, including physical and biochemical signals from the extracellular matrix (ECM), and paracrine signals from the surrounding mesenchyme. In particular, disrupted signaling between the alveolar epithelium and local fibroblasts has been implicated in the progression of several pulmonary diseases. However, given the complexity of alveolar tissue architecture and the multitude of signaling pathways involved, designing appropriate experimental platforms for this biological system has been difficult. In order to isolate key factors regulating cellular behavior, the researcher ideally should have control over biophysical properties of the ECM, as well as the ability to organize multiple cell types within the scaffold. This thesis aimed to develop a 3D synthetic hydrogel platform to control alveolar epithelial cyst formation, which could then be used to explore how extracellular cues influence cell behavior in a tissue-relevant cellular arrangement. To accomplish this, a poly(ethylene glycol) (PEG) hydrogel network containing enzymatically-degradable crosslinks and bioadhesive pendant peptides was employed as a base material for encapsulating primary alveolar epithelial cells. First, an array of microwells of various cross-sectional shapes was photopatterned into a PEG gel containing photo-labile crosslinks, and primary ATII cells were seeded into the wells to examine the role of geometric confinement on differentiation and multicellular arrangement

  3. Advances in bone augmentation to enable dental implant placement: Consensus Report of the Sixth European Workshop on Periodontology.

    Science.gov (United States)

    Tonetti, Maurizio S; Hämmerle, Christoph H F

    2008-09-01

    Bone augmentation procedures to enable dental implant placement are frequently performed in practice. In this session the European Workshop on Periodontology discussed the evidence in support of the procedures and examined both adverse events and implant performance in the augmented bone. While the available evidence improved both in quantity and quality since previous workshops the conclusions that could be drawn were limited by elements of design and/or reporting that are amenable to improvement. With regards to lateral bone augmentation, a sizable body of evidence supports its use to enable dental implant placement. The group recognized the potential for vertical ridge augmentation procedures to allow implant placement in clinical practice but questioned the applicability of these data to a wider array of operators and clinical settings. With regards to sinus floor augmentation, perforation of the sinus membrane, graft infection and graft loss resulting in inability of implant placement were the major reported adverse events. In cases with dental implants placed in pristine sites. The consensus emphasized the research need to answer questions on: (i) long-term performance of dental implants placed in augmented bone; (ii) the clinical performance of dental implants placed in augmented or pristine sites; and (iii) the clinical benefits of bone augmentation with respect to alternative treatments.

  4. Esthetic consideration for alveolar socket preservation prior to implant placement: description of a technique and 80-case series report.

    Science.gov (United States)

    Kutkut, Ahmad; Andreana, Sebastiano; Monaco, Edward

    2012-01-01

    An esthetic restoration supported by dental implant rehabilitation is a major challenge to restorative dentists. The ultimate goal of a dental implant is to restore missing or extracted teeth by placing implants in anatomically, esthetically, and long-term functional restorations. Alveolar ridge preservation and site enhancement following tooth extraction has a major impact on the hard and soft tissue volume. Extraction socket preservation is technique sensitive, not 100% successful, and at times unpredictable. Current techniques may delay surgical implant placement for a few months, and the quality of new bone regeneration is questionable. The aim of this report was to describe a minimally traumatic extraction socket preservation technique using different types of bone graft as a preserver prior to implant placement applied for 80 consecutive cases.

  5. The Knipovich Ridge segmentation and the comparison with other ultraslow spreading ridges

    Science.gov (United States)

    Okino, K.; Curewitz, D.; Asada, M.; Tamaki, K.

    2003-04-01

    The ultraslow-spreading Knipovich Ridge is an ~550 km long, transform-free ridge segment linking the Molloy transform fault and the Mohns Ridge in the Arctic Ocean. Discrete volcanic centers marked by large volcanic constructions and accompanying short wavelength mantle Bouguer anomaly (MBA) lows generally resemble those of the Gakkel Ridge and the easternmost Southwest Indian Ridge. These magmatically robust segment centers are regularly spaced about 85-100 km apart along the ridge, and are characterized by accumulated hummocky terrain, high relief, off-axis seamount chains and significant MBA lows. We suggest that these eruptive centers correspond to areas of enhanced magma flux, and that their spacing reflects the geometry of underlying mantle upwelling cells. The large-scale thermal structure of the mantle primarily controls discrete and focused magmatism, and the relatively wide spacing of these segments may reflect cool mantle beneath the ridge. Segment centers along the southern Knipovich Ridge are characterized by lower relief and smaller MBA anomalies than along the northern section of the ridge. This suggests that ridge obliquity is a secondary control on ridge construction on the Knipovich Ridge, as the obliquity changes from 35 to 49 deg. from north to south, respectively, while spreading rate and axial depth remain approximately constant. A comparison of along-axis depths, MBA anomalies and other fundamental parameters of ultraslow spreading ridges based on previous studies shows that the scale of volcanic edifices tends to decrease as obliquity increases. High relief and large MBA characterize the non-oblique segment of the SWIR, while low relief and small MBA characterize the southern Knipovich Ridge (obliquity 49deg.) and the oblique segment of the SWIR (obliquity 45deg.). The increased obliquity may contribute to decreased effective spreading rates, lower upwelling magma velocity and melt formation, and limited horizontal dike propagation near the

  6. The influence of Aloe vera and xenograft XCB toward of bone morpho protein 2 BMP2 expression and amount of osteoblast of alveolar bone induced into tooth extraction sockets Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2014-12-01

    Full Text Available Tooth extraction can cause inflammation leading to alveolar ridge resorption. In addition, prominent ridge has crucial role for making denture su-ccessfully. Thus, socket preservation is needed to prevent greater alveolar ridge resorption. An innovative material, a combination of Aloe vera and xe-nograft (XCB, is then considered as a biogenic stimulator that can reduce inflammation, as a result, the growth of alveolar bone is expected to be impro-ved. This research is aimed to prove whether the mixture of Aloe vera and xenograft can stimulate BMP2 and increase osteoblasts. Forty-eight Cavia co-baya animals were divided into eight groups each of which consisted of six animals. The mandibular incisors of those Cavia cobaya animals were then extracted and filled with PEG as Group Control, XCB as Group XCB, Aloe vera as Group Aloe vera, and a combination of Aloe vera +XCB as Group Aloe vera +XCB. Next, the first four groups were sacrificed seven days after extraction, and the second four groups were sacrificed 30 days after extrac-tion. And then, immunohistochemical and histopathology examinations were conducted to examine BMP2 expression and osteoblasts. Based on the re-sult known that the mixture of Aloe vera and xenograft can increase BMP2 expression and amount of osteoblasts. It can be concluded that the mixture of Aloe vera and xenograft can increase BMP2 expression and amount of osteoblast cel . It can be used as an alternative material to increase the growth of alveolar bone after extraction.

  7. Bayesian Alternation During Tactile Augmentation

    Directory of Open Access Journals (Sweden)

    Caspar Mathias Goeke

    2016-10-01

    Full Text Available A large number of studies suggest that the integration of multisensory signals by humans is well described by Bayesian principles. However, there are very few reports about cue combination between a native and an augmented sense. In particular, we asked the question whether adult participants are able to integrate an augmented sensory cue with existing native sensory information. Hence for the purpose of this study we build a tactile augmentation device. Consequently, we compared different hypotheses of how untrained adult participants combine information from a native and an augmented sense. In a two-interval forced choice (2 IFC task, while subjects were blindfolded and seated on a rotating platform, our sensory augmentation device translated information on whole body yaw rotation to tactile stimulation. Three conditions were realized: tactile stimulation only (augmented condition, rotation only (native condition, and both augmented and native information (bimodal condition. Participants had to choose one out of two consecutive rotations with higher angular rotation. For the analysis, we fitted the participants’ responses with a probit model and calculated the just notable difference (JND. Then we compared several models for predicting bimodal from unimodal responses. An objective Bayesian alternation model yielded a better prediction (χred2 = 1.67 than the Bayesian integration model (χred2= 4.34. Slightly higher accuracy showed a non-Bayesian winner takes all model (χred2= 1.64, which either used only native or only augmented values per subject for prediction. However the performance of the Bayesian alternation model could be substantially improved (χred2= 1.09 utilizing subjective weights obtained by a questionnaire. As a result, the subjective Bayesian alternation model predicted bimodal performance most accurately among all tested models. These results suggest that information from augmented and existing sensory modalities in

  8. Radiographic follow-up evaluation of sinus augmentation with deproteinized bovine bone and implant installation after loading

    Directory of Open Access Journals (Sweden)

    Park Jun-Beom

    2010-01-01

    Full Text Available Computed tomography (CT has been used in diagnosis and implant treatment, and CT can be used to assess the dimensional stability of graft materials after maxillary sinus augmentation. A 50-year-old male patient was treated for the simultaneous placement of implants with sinus augmentation and two post-operative CT scans were performed after the delivery of the prosthesis at 9 months and 15 months after the operation. There were no significant changes in alveolar bone height and the buccal window seemed to show remodeling over time. The continuity of the defect and the cortication were apparent in the 15-month post-operative CT scan. Implants installed simultaneously with sinus augmentation were well in function and the graft material seemed to be stable in maintaining tissue dimensions after the loading of the implants. The presented results need to be validated in further large case series or case-controlled studies.

  9. Proteinose alveolar pulmonar: série de quatro casos Pulmonary alveolar proteinosis: four cases

    Directory of Open Access Journals (Sweden)

    João Carlos Thompson

    2006-06-01

    Full Text Available OBJETIVO: Apresentar a evolução de quatro casos de proteinose alveolar pulmonar atendidos na Faculdade de Medicina da Universidade Estadual de Londrina, enfocando a importância da lavagem pulmonar total como tratamento de escolha. MÉTODOS: Trata-se de um estudo retrospectivo de quatro pacientes, sendo três do gênero feminino, com idades de 22 a 34 anos, e histórias semelhantes de dispnéia progressiva e tosse seca. O diagnóstico final foi realizado por biópsia pulmonar a céu aberto. A lavagem pulmonar total foi realizada em três pacientes em centro cirúrgico, com anestesia geral e sonda de duplo lúme. RESULTADOS: Um paciente apresentou regressão espontânea da proteinose alveolar pulmonar, não sendo necessária a lavagem pulmonar. Nos outros três casos, o número de lavagens variou: uma única lavagem unilateral com remissão completa do quadro bilateralmente, três lavagens sem melhora significativa e quatro procedimentos intercalados com períodos de melhora. CONCLUSÃO: Constatamos em nossa casuística que a lavagem pulmonar se mostrou eficiente, apesar de alguns pacientes apresentarem certa resistência ao procedimento, enquanto que outros podem ter remissão completa da doença.OBJECTIVE: The aim of this study was to present the evolution of four patients presenting pulmonary alveolar proteinosis and treated at the State University of Londrina School of Medicine. We focus on the importance of whole-lung lavage as the treatment of choice. METHODS: A retrospective study of four patients, three females and one male, 22 to 34 years old, presenting similar histories of progressive dyspnea and dry cough. The final diagnosis was established through open-lung biopsy. Three of the patients underwent whole-lung lavage in the Department of Surgery. The procedures were performed under general anesthesia and using a double-lumen endotracheal tube. RESULTS: One patient presented spontaneous regression of the pulmonary alveolar proteinosis

  10. Augmented reality for breast imaging.

    Science.gov (United States)

    Rancati, Alberto; Angrigiani, Claudio; Nava, Maurizio B; Catanuto, Giuseppe; Rocco, Nicola; Ventrice, Fernando; Dorr, Julio

    2018-02-21

    Augmented reality (AR) enables the superimposition of virtual reality reconstructions onto clinical images of a real patient, in real time. This allows visualization of internal structures through overlying tissues, thereby providing a virtual transparency vision of surgical anatomy. AR has been applied to neurosurgery, which utilizes a relatively fixed space, frames, and bony references; the application of AR facilitates the relationship between virtual and real data. Augmented Breast imaging (ABI) is described. Breast MRI studies for breast implant patients with seroma were performed using a Siemens 3T system with a body coil and a four-channel bilateral phased-array breast coil as the transmitter and receiver, respectively. The contrast agent used was (CA) gadolinium (Gd) injection (0.1 mmol/kg at 2 ml/s) by a programmable power injector. Dicom formated images data from 10 MRI cases of breast implant seroma and 10 MRI cases with T1-2 N0 M0 breast cancer, were imported and transformed into Augmented reality images. Augmented breast imaging (ABI) demonstrated stereoscopic depth perception, focal point convergence, 3D cursor use, and joystick fly-through. Augmented breast imaging (ABI) to the breast can improve clinical outcomes, giving an enhanced view of the structures to work on. It should be further studied to determine its utility in clinical practice.

  11. Optical biosensor based on a silicon nanowire ridge waveguide for lab on chip applications

    Science.gov (United States)

    Gamal, Rania; Ismail, Yehea; Swillam, Mohamed A.

    2015-04-01

    We propose a novel sensor using a silicon nanowire ridge waveguide (SNRW). This waveguide is comprised of an array of silicon nanowires on an insulator substrate that has the envelope of a ridge waveguide. The SNRW inherently maximizes the overlap between the material-under-test and the incident light wave by introducing voids to the otherwise bulk structure. When a sensing sample is injected, the voids within the SNRW adopt the refractive index of the material-under-test. Hence, the strong contribution of the material-under-test to the overall modal effective index will greatly augment the sensitivity. Additionally, the ridge structure provides a fabrication convenience as it covers the entire substrate, ensuring that the etching process would not damage the substrate. Finite-difference time-domain simulations are conducted and showed that the percentage change in the effective index due to a 1% change in the surrounding environment is more than 170 times the change perceived in an evanescent-detection based bulk silicon ridge waveguide. Moreover, the SNRW proves to be more sensitive than recent other, non-evanescent sensors. In addition, the detection limit for this structure was revealed to be as small as 10-8. A compact bimodal waveguide based on SNRW is designed and tested. It delivers high sensitivity values that offer comparable performance to similar low-index light-guiding sensing configurations; however, our proposed structure has much smaller footprints and allows high dense integration for lab-on-chip applications.

  12. Partial pulmonary embolization disrupts alveolarization in fetal sheep

    Directory of Open Access Journals (Sweden)

    Hooper Stuart B

    2010-04-01

    Full Text Available Abstract Background Although bronchopulmonary dysplasia is closely associated with an arrest of alveolar development and pulmonary capillary dysplasia, it is unknown whether these two features are causally related. To investigate the relationship between pulmonary capillaries and alveolar formation, we partially embolized the pulmonary capillary bed. Methods Partial pulmonary embolization (PPE was induced in chronically catheterized fetal sheep by injection of microspheres into the left pulmonary artery for 1 day (1d PPE; 115d gestational age; GA or 5 days (5d PPE; 110-115d GA. Control fetuses received vehicle injections. Lung morphology, secondary septal crests, elastin, collagen, myofibroblast, PECAM1 and HIF1α abundance and localization were determined histologically. VEGF-A, Flk-1, PDGF-A and PDGF-Rα mRNA levels were measured using real-time PCR. Results At 130d GA (term ~147d, in embolized regions of the lung the percentage of lung occupied by tissue was increased from 29 ± 1% in controls to 35 ± 1% in 1d PPE and 44 ± 1% in 5d PPE fetuses (p VEGF and Flk-1, although a small increase in PDGF-Rα expression at 116d GA, from 1.00 ± 0.12 in control fetuses to 1.61 ± 0.18 in 5d PPE fetuses may account for impaired differentiation of alveolar myofibroblasts and alveolar development. Conclusions PPE impairs alveolarization without adverse systemic effects and is a novel model for investigating the role of pulmonary capillaries and alveolar myofibroblasts in alveolar formation.

  13. Asymmetric [14C]albumin transport across bullfrog alveolar epithelium

    International Nuclear Information System (INIS)

    Kim, K.J.; LeBon, T.R.; Shinbane, J.S.; Crandall, E.D.

    1985-01-01

    Bullfrog lungs were prepared as planar sheets and bathed with Ringer solution in Ussing chambers. In the presence of a constant electrical gradient (20, 0, or -20 mV) across the tissue, 14 C-labeled bovine serum albumin or inulin was instilled into the upstream reservoir and the rate of appearance of the tracer in the downstream reservoir was monitored. Two lungs from the same animal were used to determine any directional difference in tracer fluxes. An apparent permeability coefficient was estimated from a relationship between normalized downstream radioactivities and time. Results showed that the apparent permeability of albumin in the alveolar to pleural direction across the alveolar epithelial barrier is 2.3 X 10(-7) cm/s, significantly greater (P less than 0.0005) than that in the pleural to alveolar direction (5.3 X 10(-8) cm/s) when the tissue was short circuited. Permeability of inulin, on the other hand, did not show any directional dependence and averaged 3.1 X 10(-8) cm/s in both directions. There was no effect on radiotracer fluxes permeabilities of different electrical gradients across the tissue. Gel electrophoretograms and corresponding radiochromatograms suggest that the large and asymmetric isotope fluxes are not primarily due to digestion or degradation of labeled molecules. Inulin appears to traverse the alveolar epithelial barrier by simple diffusion through hydrated paracellular pathways. On the other hand, [ 14 C]albumin crosses the alveolar epithelium more rapidly than would be expected by simple diffusion. These asymmetric and large tracer fluxes suggest that a specialized mechanism is present in alveolar epithelium that may be capable of helping to remove albumin from the alveolar space

  14. NFκB signaling in alveolar rhabdomyosarcoma

    Directory of Open Access Journals (Sweden)

    Megan M. Cleary

    2017-09-01

    Full Text Available Alveolar rhabdomyosarcoma (aRMS is a pediatric soft tissue cancer commonly associated with a chromosomal translocation that leads to the expression of a Pax3:Foxo1 or Pax7:Foxo1 fusion protein, the developmental underpinnings of which may give clues to its therapeutic approaches. In aRMS, the NFκB–YY1–miR-29 regulatory circuit is dysregulated, resulting in repression of miR-29 and loss of the associated tumor suppressor activity. To further elucidate the role of NFκB in aRMS, we first tested 55 unique sarcoma cell lines and primary cell cultures in a large-scale chemical screen targeting diverse molecular pathways. We found that pharmacological inhibition of NFκB activity resulted in decreased cell proliferation of many of the aRMS tumor cultures. Surprisingly, mice that were orthotopically allografted with aRMS tumor cells exhibited no difference in tumor growth when administered an NFκB inhibitor, compared to control. Furthermore, inhibition of NFκB by genetically ablating its activating kinase inhibitor, IKKβ, by conditional deletion in a mouse model harboring the Pax3:Foxo1 chimeric oncogene failed to abrogate spontaneous tumor growth. Genetically engineered mice with conditionally deleted IKKβ exhibited a paradoxical decrease in tumor latency compared with those with active NFκB. However, using a synthetic-lethal approach, primary cell cultures derived from tumors with inactivated NFκB showed sensitivity to the BCL-2 inhibitor navitoclax. When used in combination with an NFκB inhibitor, navitoclax was synergistic in decreasing the growth of both human and IKKβ wild-type mouse aRMS cells, indicating that inactivation of NFκB alone may not be sufficient for reducing tumor growth, but, when combined with another targeted therapeutic, may be clinically beneficial.

  15. The efficacy of hydrothermally obtained carbonated hydroxyapatite in healing alveolar bone defects in rats with or without corticosteroid treatment

    Directory of Open Access Journals (Sweden)

    Marković Dejan

    2014-01-01

    Full Text Available Background/Aim. Autogenous bone grafting has been the gold standard in clinical cases when bone grafts are required for bone defects in dentistry. The study was undertaken to evaluate multilevel designed carbonated hydroxyapatite (CHA obtained by hydrothermal method, as a bone substitute in healing bone defects with or without corticosteroid treatment in rats as assessed by histopathologic methods. Methods. Bone defects were created in the alveolar bone by teeth extraction in 12 rats. The animals were initially divided into two groups. The experimental group was pretreated with corticosteroids: methylprednisolone and dexamethasone, intramuscularly, while the control group was without therapy. Posterior teeth extraction had been performed after the corticosteroid therapy. The extraction defects were fulfilled with hydroxyapatite with bimodal particle sizes in the range of 50-250 μm and the sample from postextocactional defect of the alveolar bone was analyzed pathohystologically. Results. The histopatological investigations confirmed the biologic properties of the applied material. The evident growth of new bone in the alveolar ridge was clearly noticed in both groups of rats. Carbonated HA obtained by hydrothermal method promoted bone formation in the preformed defects, confirming its efficacy for usage in bone defects. Complete resorption of the material’s particles took place after 25 weeks. Conclusion. Hydroxyapatite completely meets the clinical requirements for a bone substitute material. Due to its microstructure, complete resorption took place during the observation period of the study. Corticosteroid treatment did not significantly affect new bone formation in the region of postextractional defects. [Projekat Ministarstva nauke Republike Srbije, br. 172026

  16. Augmented Reality Tower Technology Assessment

    Science.gov (United States)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  17. Therapeutic options for lip augmentation.

    Science.gov (United States)

    Segall, Lorne; Ellis, David A F

    2007-11-01

    Aesthetic ideals vary with emerging fashion trends and within different cultures. However, over the past few decades, fuller lips have been considered a desirable trait. Many younger patients are presenting for lip augmentation to achieve the sought-after look commonly seen in many fashion magazines. In addition, as individuals age, they lose lip volume, with a thinning of the red lip, some effacement of the vermillion border, and elongation and flattening of the white portion of the lip. Rejuvenation of the lips plays a key role in restoring a more youthful appearance. As a result, lip augmentation appeals to a wide spectrum of patients who present with various different aesthetic goals and expectations. Numerous therapeutic options exist for aesthetic lip augmentation, ranging from temporary and permanent injectable fillers to implants and other surgical techniques.

  18. Ridge alterations following tooth extraction with and without flap elevation: an experimental study in the dog.

    Science.gov (United States)

    Araújo, Mauricio G; Lindhe, Jan

    2009-06-01

    Different approaches were advocated to preserve or improve the dimension and contour of the ridge following tooth extraction. In some of studies, socket 'flapless extraction' apparently had a successful outcome. The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps. Five mongrel dogs were used. The two second mandibular premolars ((2)P(2)) were hemi-sected. The mesial roots were retained. By random selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side, root extraction was performed in a flapless procedure. The soft tissue wound was closed with interrupted sutures. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections - two from the mesial root and two from the healed socket - were prepared, stained and examined in the microscope. The data showed that the removal of a single tooth (root) during healing caused a marked change in the edentulous ridge. In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial. Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was, i.e. flapless or following flap elevation. Tooth loss (extraction) resulted in marked alterations of the ridge. The size of the alveolar process was reduced. The procedure used for tooth extraction - flapless or following flap elevation - apparently did not influence the more long-term outcome of healing.

  19. Vertical Osseodistraction with a New Intraosseous Alveolar Distractor Prototype for Dental Implant Rehabilitation: A Pilot Study in Dogs.

    Science.gov (United States)

    Esposito, Marco; Trullenque-Eriksson, Anna; Vila, Carlos Navarro; Peñarrocha, Miguel; García, Abel; Sánchez, Arturo; Muñoz-Guzón, Fernando; Martínez Martín, José Manuel

    To evaluate in dogs a newly developed intraosseous alveolar distractor (Mozo-Grau Alveolar Distractor) for vertical bone augmentation to allow placement of dental implants. Four dogs had their posterior teeth removed, and sockets were left to heal for 20 weeks. The right and left sides of the posterior mandibles were randomly allocated, according to a split-mouth design, to receive either two distractors, distracting a 32-mm-long bone segment, or two distractors supporting one bony segment 20 mm long and one 8 mm long. Each side of the jaw was treated by a different operator. Eight days after placement, distractors were activated with one complete turn (corresponding to 0.75 mm of vertical distraction) per day for 8 days, followed by a latency period of 10 weeks. Distractors were removed, and seven dental implants of two randomly allocated designs were placed in each dog. Implants were submerged for 2 months, and the dogs were sacrificed. Outcome measures were: success of the augmentation procedure (defined as a vertical gain of at least 5 mm of bone), any complications, implant failure, bone-to-implant contact (BIC), and peri-implant marginal bone level changes. One dog was withdrawn because of a mandible fracture. Eight complications occurred, and six osseodistractors were lost, but no implant failed. Only two segments in one dog achieved a vertical bone gain of at least 5 mm. The mean radiographic vertical bone gain was 2.28 mm, whereas the mean histologic vertical bone gain was 3.16 mm. Histologically, all the implants were osseointegrated. The mean BIC for implants placed in new distracted bone was 34.78% ± 11.60% and 35.66% ± 8.84% for those placed in native bone. The mean peri-implant marginal bone level loss was 0.56 ± 0.54 mm. It is possible to achieve vertical augmentation using intraosseous alveolar distractors to allow successful implantation of dental implants; however, the technique still requires surgical refinements and a dedicated training of

  20. AUGMENTATION-RELATED BRAIN PLASTICITY

    Directory of Open Access Journals (Sweden)

    Giovanni eDi Pino

    2014-06-01

    Full Text Available Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyzes the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain.Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools.Augmentation modifies function and structure of a number of areas, i.e. primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the

  1. Augmentation-related brain plasticity

    Science.gov (United States)

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  2. Augmented reality for anatomical education.

    Science.gov (United States)

    Thomas, Rhys Gethin; John, Nigel William; Delieu, John Michael

    2010-03-01

    The use of Virtual Environments has been widely reported as a method of teaching anatomy. Generally such environments only convey the shape of the anatomy to the student. We present the Bangor Augmented Reality Education Tool for Anatomy (BARETA), a system that combines Augmented Reality (AR) technology with models produced using Rapid Prototyping (RP) technology, to provide the student with stimulation for touch as well as sight. The principal aims of this work were to provide an interface more intuitive than a mouse and keyboard, and to evaluate such a system as a viable supplement to traditional cadaver based education.

  3. Superconducting augmented rail gun (SARG)

    International Nuclear Information System (INIS)

    Homan, C.G.; Cummings, C.E.; Fowler, C.M.

    1986-01-01

    Superconducting augmentation consists of a superconducting coil operating in the persistent mode closely coupled magnetically with a normally conducting rail gun. A theoretical investigation of the effect of this system on a rail gun has shown that two benefits occur. Projectile velocities and launch efficiencies increase significantly depending on the magnetic coupling between the rail and augmentation circuits. Previous work evaluated an idealized system by neglecting energy dissipation effects. In this paper, the authors extend the analysis to include the neglected terms and show improved actual launch efficiencies for the SARG configuration. In this paper, the authors discuss details of projectile design in depth and present preliminary results of rail gun performance

  4. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. (Royal Free Hospital, London (England))

    1990-04-01

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  5. Hypocapnic but Not Metabolic Alkalosis Impairs Alveolar Fluid Reabsorption

    Science.gov (United States)

    Myrianthefs, Pavlos M.; Briva, Arturo; Lecuona, Emilia; Dumasius, Vidas; Rutschman, David H.; Ridge, Karen M.; Baltopoulos, George J.; Sznajder, Jacob Iasha

    2005-01-01

    Acid-base disturbances, such as metabolic or respiratory alkalosis, are relatively common in critically ill patients. We examined the effects of alkalosis (hypocapnic or metabolic alkalosis) on alveolar fluid reabsorption in the isolated and continuously perfused rat lung model. We found that alveolar fluid reabsorption after 1 hour was impaired by low levels of CO2 partial pressure (PCO2; 10 and 20 mm Hg) independent of pH levels (7.7 or 7.4). In addition, PCO2 higher than 30 mm Hg or metabolic alkalosis did not have an effect on this process. The hypocapnia-mediated decrease of alveolar fluid reabsorption was associated with decreased Na,K-ATPase activity and protein abundance at the basolateral membranes of distal airspaces. The effect of low PCO2 on alveolar fluid reabsorption was reversible because clearance normalized after correcting the PCO2 back to normal levels. These data suggest that hypocapnic but not metabolic alkalosis impairs alveolar fluid reabsorption. Conceivably, correction of hypocapnic alkalosis in critically ill patients may contribute to the normalization of lung ability to clear edema. PMID:15764729

  6. Is alveolar cleft reconstruction still controversial? (Review of literature

    Directory of Open Access Journals (Sweden)

    Sameh A. Seifeldin

    2016-01-01

    Full Text Available Cleft lip and palate (CL/P is a frequent congenital malformation that manifests in several varieties including unilateral or bilateral and complete or incomplete. Alveolar cleft reconstruction remains controversial with regard to timing, graft materials, surgical techniques, and methods of evaluation. Many studies have been conducted addressing these points to develop an acceptable universal protocol for managing CL/P. The primary goal of alveolar cleft reconstruction in CL/P patients is to provide a bony bridge at the cleft site that allows maxillary arch continuity, oronasal fistula repair, eruption of the permanent dentition into the newly formed bone, enhances nasal symmetry through providing alar base support, orthodontic movement and placement of osseointegrated implants when indicated. Other goals include improving speech, improvement of periodontal conditions, establishing better oral hygiene, and limiting growth disturbances. In order to rehabilitate oral function in CL/P patients alveolar bone grafting is necessary. Secondary bone grafting is the most widely accepted method for treating alveolar clefts. Autogenous bone graft is the primary source for reconstructing alveolar cleft defects and is currently the preferred grafting material.

  7. Maxillary Sinus Floor Augmentation: a Review of Selected Treatment Modalities

    Directory of Open Access Journals (Sweden)

    Thomas Starch-Jensen

    2017-09-01

    Full Text Available Objectives: The objective of the present study is to present the current best evidence for enhancement of the vertical alveolar bone height and oral rehabilitation of the atrophic posterior maxilla with dental implants and propose some evidence-based treatment guidelines. Material and Methods: A comprehensive review of the English literature including MEDLINE (PubMed, Embase and Cochrane Library search was conducted assessing the final implant treatment outcome after oral rehabilitation of the atrophic posterior maxilla with dental implants. No year of publication restriction was applied. The clinical, radiological and histomorphometric outcome as well as complications are presented after maxillary sinus floor augmentation applying the lateral window technique with a graft material, maxillary sinus membrane elevation without a graft material and osteotome-mediated sinus floor elevation with or without the use of a graft material. Results: High implant survival rate and new bone formation was reported with the three treatment modalities. Perforation of the Schneiderian membrane was the most common complication, but the final implant treatment outcome was not influenced by a Schneiderian membrane perforation. Conclusions: The different surgical techniques for enhancement of the vertical alveolar bone height in the posterior part of the maxilla revealed high implant survival with a low incidence of complications. However, the indication for the various surgical techniques is not strictly equivalent and the treatment choice should be based on a careful evaluation of the individual case. Moreover, further high evidence-based and well reported long-term studies are needed before one treatment modality might be considered superior to another.

  8. Magnetic Anomaly Amplitudes on the Gakkel Ridge: Indicators of Ridge Variability

    Science.gov (United States)

    Childers, V. A.; Lawver, L. A.; Brozena, J. M.

    2002-12-01

    For most of its length, the Gakkel Ridge in the Arctic Ocean's Eurasia Basin is characterized by a discontinuous magnetic signature with regions of missing or low-amplitude central anomalies punctuated by short, high-amplitude segments. The ridge segment in between the Morris Jesup Rise and the Yermak Plateau has an unusually large amplitude central magnetic anomaly that is more than four times the amplitude of the flanking anomalies. This ridge segment is straight, without large offsets, for about 150 km. The difference in character between the central anomaly in this segment and the rest of Gakkel Ridge is striking. The western half of the Gakkel Ridge and the Eurasia Basin were surveyed in 1998-99 by a Naval Research Laboratory aerogeophysical campaign that measured magnetics, gravity, and sea-surface topography. The new magnetic data densify the historical US Navy aeromagnetic data and improve the resolution of the magnetic anomaly field in this region. This new field highlights the variability of the Gakkel Ridge over time, showing regions of strong anomalies that are continuous along strike and anomalies that fade away or become discontinuous. In particular, anomalies 15y to 21o show regions of high amplitudes on both sides of the ridge for varying distances along strike. We suggest that these high-amplitude segments were formed at times when the Gakkel Ridge at this location had a high-amplitude central magnetic anomaly like the present day high-amplitude segment or the shorter ones distributed along the ridge. The higher central anomaly amplitudes may be associated with variations in geochemistry and/or melt delivery along the ridge. Recent dredging of zero-aged crust along the Gakkel Ridge showed a good but not perfect correlation of high-amplitude central anomalies and basalt recovery (P. Michael, personal communication). This magnetic data set in conjunction with future dredging provides an opportunity to constrain past ridge variability.

  9. Optimization of ridge parameters in multivariate generalized ridge regression by plug-in methods

    OpenAIRE

    Nagai, Isamu; Yanagihara, Hirokazu; Satoh, Kenichi

    2012-01-01

    Generalized ridge (GR) regression for an univariate linear model was proposed simultaneously with ridge regression by Hoerl and Kennard (1970). In this paper, we deal with a GR regression for a multivariate linear model, referred to as a multivariate GR (MGR) regression. From the viewpoint of reducing the mean squared error (MSE) of a predicted value, many authors have proposed several GR estimators consisting of ridge parameters optimized by non-iterative methods. By expanding...

  10. Frenotomy and keratinized tissue augmentation.

    Science.gov (United States)

    Peacock, M E

    1998-01-01

    Aberrant frenula can be an important etiological factor in progressive gingival recession. When separating or removing frenula, augmentation with keratinized tissue is the treatment of choice in most circumstances. A case is described as a mandibular labial frenotomy in combination with a free gingival graft.

  11. Indeterminacy and labor augmenting externalities

    DEFF Research Database (Denmark)

    Poulsen, Odile; Goenka, Aditya

    2002-01-01

    In this two-sector discrete time model of endogenous economic growth intersectoral effects are assumed to be "labor augmenting" We derive necessary and sufficient conditions for local indeterminacy and multiplicity of the balanced growth path in terms of factor intensities in both sectors...

  12. Aplikasi Web Augmented Reality Villa

    Directory of Open Access Journals (Sweden)

    Gede Yudha Prema Pangestu

    2017-07-01

    Full Text Available Bali is one of the highly developed tourist destination in Indonesia. The arrival of tourists having holiday in Bali led to increase residential needs with complete amenities. The occupancy rate of hotel and villa in Bali is increase significantlly during the long vacation. The emergence of new villa and hotel occupancy raises the level of competition in business, so it needs a correct use good marketing communication strategy in marketing the product in order to attract the attention of consumers. Web Application Augmented Reality Villa can help visualize the residential villa in three-dimensional shapes that look more attractive and practical. The use of brochures as written information and the application of augmented reality technology on the Web Application Augmented Reality Villa aims to develop an application that can provide information about the villa to visitors. Web Application uses Augmented Reality Villa designed by FlarToolkit library. Based on the test results show the application can display 3-dimensional objects by scanning marker villa in a brochure which already contain marker.

  13. Data Augmentation for Plant Classification

    NARCIS (Netherlands)

    Pawara, Pornntiwa; Okafor, Emmanuel; Schomaker, Lambertus; Wiering, Marco

    2017-01-01

    Data augmentation plays a crucial role in increasing the number of training images, which often aids to improve classification performances of deep learning techniques for computer vision problems. In this paper, we employ the deep learning framework and determine the effects of several

  14. Diffuse bronchiolo-alveolar carcinoma in a dog.

    Science.gov (United States)

    Bertazzolo, W; Zuliani, D; Pogliani, E; Caniatti, M; Bussadori, C

    2002-06-01

    An eight-year-old female German wirehaired pointer was presented with signs of respiratory distress. Clinical examination, laboratory results, thoracic radiography and echocardiography indicated the presence of a diffuse interstitial lung disease with secondary appropriate erythrocytosis, pulmonary hypertension and cor pulmonale. Transthoracic fine needle aspiration biopsy of the lung suggested malignant epithelial neoplasia. A primary lung cancer with an unusually diffuse distribution of miliary/micronodular lesions was found at postmortem examination. Histological diagnosis was bronchiolo-alveolar carcinoma. Bronchiolo-alveolar carcinoma can occasionally occur in a diffuse fashion involving most or all of the lung parenchyma. In man, diffuse bronchiolo-alveolar carcinoma is considered a great imitator of other, more common diffuse interstitial forms of lung disease. This case report indicates that it is also a differential diagnosis to consider in dogs.

  15. The beach ridges of India: A review

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Wagle, B.G.

    are distinguished into 4 genetic classes. Finally the utilization of beach ridges in the reconstruction of sea level curve, palaeo-climate and sediment budget histories has been highlighted and scope for future study is discussed...

  16. KINERJA JACKKNIFE RIDGE REGRESSION DALAM MENGATASI MULTIKOLINEARITAS

    Directory of Open Access Journals (Sweden)

    HANY DEVITA

    2015-02-01

    Full Text Available Ordinary least square is a parameter estimations for minimizing residual sum of squares. If the multicollinearity was found in the data, unbias estimator with minimum variance could not be reached. Multicollinearity is a linear correlation between independent variabels in model. Jackknife Ridge Regression(JRR as an extension of Generalized Ridge Regression (GRR for solving multicollinearity.  Generalized Ridge Regression is used to overcome the bias of estimators caused of presents multicollinearity by adding different bias parameter for each independent variabel in least square equation after transforming the data into an orthoghonal form. Beside that, JRR can  reduce the bias of the ridge estimator. The result showed that JRR model out performs GRR model.

  17. Ridge Preservation with Modified “Socket-Shield” Technique: A Methodological Case Series

    Directory of Open Access Journals (Sweden)

    Markus Glocker

    2014-01-01

    Full Text Available After tooth extraction, the alveolar bone undergoes a remodeling process, which leads to horizontal and vertical bone loss. These resorption processes complicate dental rehabilitation, particularly in connection with implants. Various methods of guided bone regeneration (GBR have been described to retain the original dimension of the bone after extraction. Most procedures use filler materials and membranes to support the buccal plate and soft tissue, to stabilize the coagulum and to prevent epithelial ingrowth. It has also been suggested that resorption of the buccal bundle bone can be avoided by leaving a buccal root segment (socket shield technique in place, because the biological integrity of the buccal periodontium (bundle bone remains untouched. This method has also been described in connection with immediate implant placement. The present case report describes three consecutive cases in which a modified method was applied as part of a delayed implantation. The latter was carried out after six months, and during re-entry the new bone formation in the alveolar bone and the residual ridge was clinically evaluated as proof of principle. It was demonstrated that the bone was clinically preserved with this method. Possibilities and limitations are discussed and directions for future research are disclosed.

  18. Phase 2 Sampling Plan for Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1992-08-01

    CDM Federal Programs Corporation (CDM Federal) was contracted by Martin Marietta Energy Systems, Inc. to prepare a Phase H Sampling Plan to describe field investigation work necessary to address regulatory agency review comments on the Remedial Investigation of Filled Coal Ash Pond (FCAP)/Upper McCoy Branch, Chestnut Ridge Operable Unit 2 at the Y-12 Plant, conducted by CH2M Hill in 1990. The scope and approach of the field investigation described in this plan specifically focus on deficiencies noted by the regulators in discussions at the comment resolution meeting of May 8, 1992, in Oak Ridge, Tennessee. This Phase II Sampling Plan includes a field sampling plan, a field and laboratory quality assurance project plan, a health and safety plan, a waste management plan, and appendixes providing an update to applicable or relevant and appropriate requirements for this site and field and laboratory testing methods and procedures. To address deficiencies noted by the regulators, the following activities will be conducted: Background surface soil and surface water/sediment samples will be collected based on statistical considerations for comparison to site data. Existing and new data to be collected will be used to support a human health risk assessment that includes the future homesteader scenario. Biological surveys, samples, and measurements will be collected/conducted to augment existing data and support an ecological risk assessment. Another round of groundwater sampling will be conducted, including on-site wells and the wells on Chestnut Ridge downgradient of the Security Pits. Borings will be completed in the FCAP to collect samples from below the surface depth to describe the chemical characteristics and volume of the ash. The volume of ash associated with sluice channel on Chestnut Ridge will be determined. Soil samples will be corrected below the coal ash in the FCAP and adjacent to sluice channel to evaluate soil contamination and migration of contaminants

  19. New Seismic Monitoring Station at Mohawk Ridge, Valles Caldera

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Peter Morse [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-20

    Two new broadband digital seismic stations were installed in the Valles Caldera in 2011 and 2012. The first is located on the summit of Cerros del Abrigo (station code CDAB) and the second is located on the flanks of San Antonio Mountain (station code SAMT). Seismic monitoring stations in the caldera serve multiple purposes. These stations augment and expand the current coverage of the Los Alamos Seismic Network (LASN), which is operated to support seismic and volcanic hazards studies for LANL and northern New Mexico (Figure 1). They also provide unique continuous seismic data within the caldera that can be used for scientific studies of the caldera’s substructure and detection of very small seismic signals that may indicate changes in the current and evolving state of remnant magma that is known to exist beneath the caldera. Since the installation of CDAB and SAMT, several very small earthquakes have already been detected near San Antonio Mountain just west of SAMT (Figure 2). These are the first events to be seen in that area. Caldera stations also improve the detection and epicenter determination quality for larger local earthquakes on the Pajarito Fault System east of the Preserve and the Nacimiento Uplift to the west. These larger earthquakes are a concern to LANL Seismic Hazards assessments and seismic monitoring of the Los Alamos region, including the VCNP, is a DOE requirement. Currently the next closest seismic stations to the caldera are on Pipeline Road (PPR) just west of Los Alamos, and Peralta Ridge (PER) south of the caldera. There is no station coverage near the resurgent dome, Redondo Peak, in the center of the caldera. Filling this “hole” is the highest priority for the next new LASN station. We propose to install this station in 2018 on Mohawk Ridge just east of Redondito, in the same area already occupied by other scientific installations, such as the MCON flux tower operated by UNM.

  20. Inverse regression for ridge recovery II: Numerics

    OpenAIRE

    Glaws, Andrew; Constantine, Paul G.; Cook, R. Dennis

    2018-01-01

    We investigate the application of sufficient dimension reduction (SDR) to a noiseless data set derived from a deterministic function of several variables. In this context, SDR provides a framework for ridge recovery. In this second part, we explore the numerical subtleties associated with using two inverse regression methods---sliced inverse regression (SIR) and sliced average variance estimation (SAVE)---for ridge recovery. This includes a detailed numerical analysis of the eigenvalues of th...

  1. Proximal alveolar bone loss in a longitudinal radiographic investigation

    International Nuclear Information System (INIS)

    Bolin, A.; Lavstedt, S.; Henrikson, C.O.; Frithiof, L.

    1986-01-01

    The difference in proximal alveolar bone height between 1970 and 1980, the ''ABD index'', has been measured longitudinally in radiographs from an unselected material. The group constitutes 406 individuals born in 1904 - 1952 in the county of Stockholm. 13 of 18 predictors determined in 1970 were significantly related to the ABD index in the simple correlation analyses. The predictor ''the alveolar bone loss 1970'' (ABL index 1970) had the strongest correlation to the ABD index. In the stepwise multiple regression analysis the predictor ABL index 1970 and three other predictors reached significant levels. These were age, number of lost teeth and Russell's Periodontal Index

  2. Repopulation of denuded tracheal grafts with alveolar type II cells

    International Nuclear Information System (INIS)

    Johnson, N.F.

    1988-01-01

    Repopulation of denuded heterotopic tracheal grafts with populations of specific epithelial cell types is one approach to study the differentiation potential of various cell types. This technique has been adopted to delineate the differentiation pathways of alveolar type II cells isolated from rat lungs. Under the conditions of this experiment, the reestablished epithelial lining was alveolar-like, however, ultrastructural analysis of the cells showed them to be like Clara cells. These preliminary results suggest that the secretary cells of the lung parenchyma and terminal airways may share a common ancestry. (author)

  3. New data of the Gakkel Ridge seismicity

    Science.gov (United States)

    Antonovskaya, Galina; Basakina, Irina; Kremenetskaya, Elena

    2016-04-01

    250 earthquakes were recorded in the Gakkel Ridge during the period 2012-2014 by Arkhangelsk seismic network. The magnitude Ml of these earthquakes is 1.5 - 5.7, 70% of them have Ml up to 3.0. Seismic events are arranged along to a narrow center line of the Mid-Arctic Ridge, most of the earthquakes are confined to the southern board of the Ridge. Presumably it's connected with the reflection of spreading processes. The high seismic activity zones, which we associate with the volcano-tectonic processes, have been identified. Have been recorded 13 events per day in the Western Volcanic Zone. The largest number of events (75%) is confined to the Sparsely Magmatic Zone. About 30% of all recorded earthquakes with magnitudes above 2.9 have a T-phase. We divided the Gakkel Ridge's earthquakes into two groups by using spectral-time analysis. The first group: maximum energy of the earthquake is observed from 1.5 to 10 Hz, values of magnitudes Ml 2.50-5.29. Earthquakes are distributed along the Gakkel Ridge. The second group: maximum energy of the earthquake is observed from 1.5 to 20 Hz, clearly expressed a high-frequency component, values of magnitudes Ml 2.3-3.4. Earthquakes 2 groups focused only in the Sparsely Magmatic Zone. The new seismic data shows an unique information about geodynamic processes of the Gakkel Ridge.

  4. Oak Ridge Reservation environmental report for 1989

    International Nuclear Information System (INIS)

    Jacobs, V.A.; Wilson, A.R.

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a ''stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1

  5. Oak Ridge Reservation environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, V.A.; Wilson, A.R. (eds.)

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1.

  6. Lateral trap-door window approach with maxillary sinus membrane lifting for dental implant placement in atrophied edentulous alveolar ridge

    Directory of Open Access Journals (Sweden)

    Shou-Yen Kao

    2015-02-01

    Full Text Available One of the most challenging and technically sensitive surgical procedures in conjunction with dental implant rehabilitation is sinus membrane lifting to increase the bone height or volume from the maxillary sinus floor. This important preprosthetic surgical technique has been available for >15 years, making possible the creation of bone volume in the edentulous posterior maxilla for the placement of dental implants in surgically compromised cases. Substantial literature exists regarding the most efficacious way to increase the predictability of this surgical procedure, and reduce its associated complications. In this article, we describe the regional anatomy of the maxillary sinus, the evolution of the sinus membrane lifting procedure, the current surgical technique, its survival rate and associated complications, the need for bone graft or bone substitutes, and current advances in the lateral approach through a trap-door window for sinus membrane lifting for dental implants.

  7. Methodological approach for the evaluation of homologous bone graft use in post-extractive atrophic alveolar ridges

    Directory of Open Access Journals (Sweden)

    B. Musante

    2013-01-01

    Full Text Available The aim of this study is to investigate the in vivo efficacy of Puros® cancellous particulate allograft bone in the regeneration of post-extractive sites. Twelve molar or premolar sites were selected. Seven days after minimally invasive tooth extraction, Puros® cancellous particulate allografts were inserted into the elected sites. TC Cone-Beam investigation and at 4 months from surgery; bone height and width were evaluated. Five months after surgery, biopsy samples of the regenerated sites were taken and histologically analyzed to qualitatively evaluate bone regeneration. TC analysis showed, a mean bone gain of 4.1 mm in height and 2.02 mm in width. The histological analysis of the samples showed intense bone metabolic activity with active osteoblasts on the implant surface, at the level of the native bone-graft interface and in the grafted area. The radiographic and histological analyses demonstrate an optimal bonen regeneration, both in terms of quality and quantity using Puros®.

  8. Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients

    DEFF Research Database (Denmark)

    Andersen, Kristian

    2012-01-01

    Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients......Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients...

  9. Secondary bone grafting for alveolar cleft in children with cleft lip or cleft lip and palate

    NARCIS (Netherlands)

    Guo, J.; Li, C.; Zhang, Q.; Wu, G.; Deacon, S.A.; Chen, J.; Hu, H.; Zou, S.; Ye, Q.

    2011-01-01

    BACKGROUND: Secondary alveolar bone grafting has been widely used to reconstruct alveolar cleft. However, there is still some controversy. OBJECTIVES: To compare the effectiveness and safety of different secondary bone grafting methods. SEARCH STRATEGY: The final electronic and handsearches were

  10. Implant-supported versus implant-retained distal extension mandibular partial overdentures and residual ridge resorption: a 5-year retrospective radiographic study in men.

    Science.gov (United States)

    Elsyad, Moustafa Abdou; Habib, Ahmed Ali

    2011-01-01

    This retrospective study sought to examine posterior mandibular ridge resorption under implant-supported and implant-retained distal extension partial overdentures in men at the end of a 5-year observation period. Class I mandibular partial edentulism was managed in 34 patients with removable partial overdentures that were adjunctively supported (n = 18) or retained (n = 16) via resilient attachments placed bilaterally on single implants (n = 68) in the first molar areas. Posterior Area Indices (PAI) were calculated for each patient by digitizing the traced rotational tomograms taken immediately before and after 5 years of treatment. Proportional rather than actual measurements were used in an effort to minimize errors related to magnification and distortion. Residual ridge resorption associated with the implant-supported partial overdentures was recorded as PAI =0.012 ± 0.022; it was PAI = 0.073 ± 0.044 for the implant-retained group. Estimated average reductions in ridge heights were 0.15 and 1.03 mm for implant-supported and implant-retained partial overdentures, respectively. Multiple linear regression models demonstrated that prosthesis type, initial mandibular ridge height, and relining frequency were significantly correlated with PAI. Implant-supported partial overdentures appear to be associated with reduced posterior mandibular alveolar ridge resorption when compared to implant-retained ones. Int J Prosthodont 2011;24:306-313.

  11. Augmented assessment as a means to augmented reality.

    Science.gov (United States)

    Bergeron, Bryan

    2006-01-01

    Rigorous scientific assessment of educational technologies typically lags behind the availability of the technologies by years because of the lack of validated instruments and benchmarks. Even when the appropriate assessment instruments are available, they may not be applied because of time and monetary constraints. Work in augmented reality, instrumented mannequins, serious gaming, and similar promising educational technologies that haven't undergone timely, rigorous evaluation, highlights the need for assessment methodologies that address the limitations of traditional approaches. The most promising augmented assessment solutions incorporate elements of rapid prototyping used in the software industry, simulation-based assessment techniques modeled after methods used in bioinformatics, and object-oriented analysis methods borrowed from object oriented programming.

  12. Augmenting Locomotion in an Anthropomorphic System

    OpenAIRE

    Derek Wight; Eric Kubica; David Wang

    2005-01-01

    A powered orthosis has applications ranging from assisting the elderly to augmenting astronauts. An assistive control scheme is developed that uses the force from a slave actuator to augment the force of a master actuator. This can be used to augment a closed-loop control scheme applied to the master actuator. Initially, actuator augmentation is explored both theoretically and experimentally using a simple mechanical system. The control scheme is then applied to a scale model of human lower l...

  13. Use of Augmented Reality in Education

    OpenAIRE

    Jeřábek, Tomáš

    2014-01-01

    This thesis deals with phenomena of augmented reality in context of didactics. The thesis aims to define augmented reality in conceptual and content area and focuses on augmented reality in the structure of educational tools and identification of its functions and use from the didactical standpoint. The thesis characterizes augmented reality as a specific technological-perceptual concept and establishes a system of perceptual, technological and resulting aspects that reflect important paramet...

  14. Opening of the Aden Gulf Ridge Derived from GPS Constraints and Plate Tectonic Models

    Science.gov (United States)

    Fernandes, R. M.; Rolandone, F.; Leroy, S.; Alothman, A.; Al-Aydrus, A.; Khalil, H.; Ahmed, A.; Khanbari, K.; Bos, M. S.; Nicolon, P.; Heydel, L.

    2012-12-01

    The Aden Gulf Ridge forms, together with the Red Sea and the Ethiopian Rift, the only emerged RRR-type (Ridge/Ridge/Ridge) triple junction in the globe: the Afar Triple Junction. The Aden Gulf Ridge defines the boundary between two major tectonic blocks: Arabia and Somalia, being Nubia the third unit in the triple junction (bordering Arabia along the Red Sea and Somalia along the Ethiopian Rift). Although the extensional behaviour of these structures are well known, the present-day magnitudes of their opening rates are still under evaluation, in particular for the opening rate between the Arabia and Somalia plates. This work uses GPS observations acquired in campaign and continuous mode in order to better constrain the opening rates of the three plate boundaries. For the Nubia-Arabia and Nubia-Somalia boundary plates, we use solely the velocity predictions given by our computed angular velocity models using the available continuous stations in Nubia, Somalia and Arabia. The available data set is augmented here with several stations in Saudi Arabia, which allow us to better constrain the angular velocity for the stable part of the Arabia plate. We estimate the angular velocity model with respect to ITRF2008 (the latest realization of the International Terrestrial Reference System) using the value of 2.5 years (although most of the stations have already a significantly longer time-series) as threshold data span for the processed time-series. Temporal correlations are used to properly estimate the uncertainty of the time-series and derived angular velocity model. In addition, to study the near-field in the Aden Gulf, data acquired in denser campaign networks in Yemen and Oman are used to also directly compute the extension rate in the Red Sea. We show that most of the Arabian Peninsula is stable (within the uncertainties) but the southwest part (Yemen) is influenced by the proximity with the Afar Triple Junction.

  15. Nanolithography using nanoscale ridge apertures

    Science.gov (United States)

    Wang, Liang

    There is a continuous effort to develop techniques for nanoscale feature definition below the diffraction limit. Nanolithography has been a key technique because of its precision and cost effective. A sub-wavelength hole in an opaque screen can be used to provide a small light source with the optical resolution beyond the diffraction limit in the near field. However, a nanometer-sized hole in circular or square shapes is plagued by low transmission and poor contrast. This drawback limits the nanoscale apertures from being employed in nanolithography applications. Ridge apertures in C, H and bowtie shapes, on the other hand, have been numerically and experimentally demonstrated to show the ability of achieving both enhanced light transmission and sub-wavelength optical resolution down to nanometer domain benefiting from the existence of waveguide propagation mode confined in the gap between the ridges. In this report, the detailed field distributions in contact nanolithography are analyzed using finite difference time domain (FDTD) simulations. It was found that the high imaging contrast, which is necessary for successful lithography, is achieved close to the mask exit plane and decays quickly with the increase of the distance from the mask exit plane. Simulations are also performed for comparable regular shaped apertures and different shape bowtie apertures. Design rules are proposed to optimize the bowtie aperture for producing a sub-wavelength, high transmission field with high imaging contrast. High resolution contact nanolithography was carried on a home constructed lithography setup. It has been experimentally demonstrated that nanoscale bowtie and C apertures can be used for contact lithography to achieve nanometer scale resolution due to its intrinsic advantages of achieving enhanced optical transmission and concentrating light far beyond the diffraction limit. It also has shown the advantages of bowtie and C apertures over conventional apertures in both

  16. New Augmented Reality Taxonomy: Technologies and Features of Augmented Environment.

    OpenAIRE

    Hugues , Olivier; Fuchs , Philippe; Nannipieri , Olivier

    2011-01-01

    978-1-4614-0063-9; This article has a dual aim: firstly to define augmented reality (AR) en- vironments and secondly, based on our definition, a new taxonomy enabling these environments to be classified. After briefly reviewing existing classifica- tions, we define AR by its purpose, ie. to enable someone to create sensory- motor and cognitive activities in a new space combining the real environment and a virtual environment. Below we present our functional taxonomy of AR environments. We div...

  17. Augmented Reality for Multi-disciplinary Collaboration

    OpenAIRE

    Wang, Xiangyu; Rui,

    2010-01-01

    This chapter presents a framework for multi-disciplinary collaboration. Tangible Augmented Reality has been raised as one of suitable systems for design collaboration. Furthermore, it emphasizes the advantages of Tangible Augmented Reality to illustrate the needs for integrating the Tangible User Interfaces and Augmented Reality Systems.

  18. Ridge preservation comparing socket allograft alone to socket allograft plus facial overlay xenograft: a clinical and histologic study in humans.

    Science.gov (United States)

    Poulias, Evmenios; Greenwell, Henry; Hill, Margaret; Morton, Dean; Vidal, Ricardo; Shumway, Brian; Peterson, Thomas L

    2013-11-01

    Previous studies of ridge preservation showed a loss of ≈18% or 1.5 mm of crestal ridge width in spite of treatment. The primary aim of this randomized, controlled, masked clinical trial is to compare a socket graft to the same treatment plus a buccal overlay graft, both with a polylactide membrane, to determine if loss of ridge width can be prevented by use of an overlay graft. Twelve patients who served as positive controls received an intrasocket mineralized cancellous allograft (socket group), and 12 patients received the same socket graft procedure plus buccal overlay cancellous xenograft (overlay group). Horizontal ridge dimensions were measured with a digital caliper, and vertical ridge changes were measured from a stent. Before implant placement, at 4 months, a trephine core was obtained for histologic analysis. The mean horizontal ridge width at the crest for the socket group decreased from 8.7 ± 1.0 to 7.1 ± 1.5 mm for a mean loss of 1.6 ± 0.8 mm (P overlay group decreased from 8.4 ± 1.4 to 8.1 ± 1.4 mm for a mean loss of 0.3 ± 0.9 mm (P >0.05). The overlay group was significantly different from the socket group (P overlay group had 40% ± 16% (P >0.05). The overlay treatment significantly prevented loss of ridge width and preserved or augmented the buccal contour. The socket and overlay groups healed with a high percentage of vital bone.

  19. A novel semi-automatic segmentation protocol for volumetric assessment of alveolar cleft grafting procedures

    NARCIS (Netherlands)

    Janssen, Nard G.; Schreurs, Ruud; Bittermann, Gerhard K.P.; Borstlap, Wilfred A.; Koole, Ronald; Meijer, Gert J.; Maal, Thomas J.J.

    2017-01-01

    A novel protocol for volumetric assessment of alveolar cleft grafting procedures is presented. Eleven cone-beam computed tomography (CBCT) datasets of patients who underwent secondary alveolar cleft reconstructive surgery for a unilateral alveolar cleft were evaluated by two investigators. Residual

  20. A novel semi-automatic segmentation protocol for volumetric assessment of alveolar cleft grafting procedures.

    NARCIS (Netherlands)

    Janssen, N.G.; Schreurs, R.; Bittermann, G.K.P.; Borstlap, W.A.; Koole, R.A.; Meijer, G.J.; Maal, T.J.J.

    2017-01-01

    A novel protocol for volumetric assessment of alveolar cleft grafting procedures is presented. Eleven cone-beam computed tomography (CBCT) datasets of patients who underwent secondary alveolar cleft reconstructive surgery for a unilateral alveolar cleft were evaluated by two investigators. Residual