WorldWideScience

Sample records for replacement tooth formation

  1. Replacing a Missing Tooth

    Science.gov (United States)

    ... vessels in the tooth pulps are rather large. Drilling down these teeth for crowns may expose the ... porcelain replacement tooth is held in place by metal extensions cemented to the backs of the adjacent ...

  2. Evolution of high tooth replacement rates in sauropod dinosaurs.

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    Michael D D'Emic

    Full Text Available BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days. Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size, and derived titanosaurs and

  3. Autogenous tooth transplantation: an alternative to replace extracted tooth

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    David B. Kamadjaja

    2015-09-01

    Full Text Available Background: The gold standard treatment to replace missing tooth is dental implants, however, in certain cases, such as in young patients its placement is contraindicated. Autogenous tooth transplantation, which has been widely done in Scandinavian countries for many years, may become a good alternative to overcome this problem. Purpose: This article attempted to provide information about the indication, treatment planning, surgical technique and the successful result of autogenous tooth transplantation. Case: A fifteen year old male patient presented with large caries and periapical disease of his lower left first molar, which was partially erupted and the roots was not fully formed in radiograph. Case management: Autogenous tooth transplantation procedure was performed consisting of extraction of #36, odontectomy of #38 followed by its implantation to socket #36 and fixation of the transplanted tooth to the adjacent teeth. Post operative evaluation was done on regular basis within 18 months period. There was no complaint, the tooth was clinically stable and no evidence of periodontal problem. Serial radiographs showed healing of alveolar bone and periodontal tissue, and the complete root formation was evident by 18 months post operatively. Conclusion: Autogenous tooth transplantation is a potential alternative to replace extracted tooth. Provided that the case be properly planned and operation carefully performed, successful result of this treatment can be achieved.

  4. Autogenous tooth transplantation for replacing a lost tooth: case reports

    OpenAIRE

    Kang, Ji-Youn; Chang, Hoon-Sang; Hwang,Yun-Chan; Hwang, In-Nam; Oh, Won-Mann; LEE, Bin-Na

    2013-01-01

    The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

  5. Biology of tooth replacement in amniotes

    Institute of Scientific and Technical Information of China (English)

    John A Whitlock; Joy M Richman

    2013-01-01

    Tooth replacement is a common trait to most vertebrates, including mammals. Mammals, however, have lost the capacity for continuous tooth renewal seen in most other vertebrates, and typically have only 1–2 generations of teeth. Here, we review the mechanisms of tooth replacement in reptiles and mammals, and discuss in detail the current and historical theories on control of timing and pattern of tooth replacement and development.

  6. Autogenous Transplantation for Replacing a Hopeless Tooth

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    Zakershahrak, Mehrsa; Moshari, Amirabbas; Vatanpour, Mehdi; Khalilak, Zohreh; Jalali Ara, Afsoon

    2017-01-01

    Autogenous tooth transplantation (ATT) is a simple and reasonable choice for replacing the missing teeth when a proper donor tooth is available. This report presents a case of successful ATT of a maxillary right third molar for replacement of mandibular right second molar with a concomitant endodontic-periodontal disease. The mandibular second molar was believed to be hopeless due to a severe damage to coronal tooth structure, inappropriate root canal treatment and apical radiolucency. After extraction of mandibular second molar and maxillary third molar (the donor), the tooth was re-implanted into the extracted socket of second molar site. Root canal therapy was then performed. After 3 years, clinical and radiographic examinations revealed satisfying results, with no signs and symptoms. The patient is asymptomatic and the transplanted tooth is still functional with no signs of marginal periodontal pathosis. Radiographies showed bone regeneration in the site of previous extensive periapical lesion, normal periodontal ligament with no signs of root resorption. PMID:28179939

  7. Functional tooth regenerative therapy: tooth tissue regeneration and whole-tooth replacement.

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    Oshima, Masamitsu; Tsuji, Takashi

    2014-07-01

    Oral and general health is compromised by irreversible dental problems, including dental caries, periodontal disease and tooth injury. Regenerative therapy for tooth tissue repair and whole-tooth replacement is currently considered a novel therapeutic concept with the potential for the full recovery of tooth function. Several types of stem cells and cell-activating cytokines have been identified in oral tissues. These cells are thought to be candidate cell sources for tooth tissue regenerative therapies because they have the ability to differentiate into tooth tissues in vitro and in vivo. Whole-tooth replacement therapy is regarded as an important model for the development of an organ regenerative concept. A novel three-dimensional cell-manipulation method, designated the organ germ method, has been developed to recapitulate organogenesis. This method involves compartmentalisation of epithelial and mesenchymal cells at a high cell density to mimic multicellular assembly conditions and epithelial-mesenchymal interactions. A bioengineered tooth germ can generate a structurally correct tooth in vitro and erupt successfully with the correct tooth structure when transplanted into the oral cavity. We have ectopically generated a bioengineered tooth unit composed of a mature tooth, periodontal ligament and alveolar bone, and that tooth unit was successfully engrafted into an adult jawbone through bone integration. Such bioengineered teeth were able to perform normal physiological tooth functions, such as developing a masticatory potential in response to mechanical stress and a perceptive potential for noxious stimuli. In this review, we describe recent findings and technologies underpinning tooth regenerative therapy.

  8. Exceptionally prolonged tooth formation in elasmosaurid plesiosaurians

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    Kear, Benjamin P.; Larsson, Dennis; Lindgren, Johan; Kundrát, Martin

    2017-01-01

    Elasmosaurid plesiosaurians were globally prolific marine reptiles that dominated the Mesozoic seas for over 70 million years. Their iconic body-plan incorporated an exceedingly long neck and small skull equipped with prominent intermeshing ‘fangs’. How this bizarre dental apparatus was employed in feeding is uncertain, but fossilized gut contents indicate a diverse diet of small pelagic vertebrates, cephalopods and epifaunal benthos. Here we report the first plesiosaurian tooth formation rates as a mechanism for servicing the functional dentition. Multiple dentine thin sections were taken through isolated elasmosaurid teeth from the Upper Cretaceous of Sweden. These specimens revealed an average of 950 daily incremental lines of von Ebner, and infer a remarkably protracted tooth formation cycle of about 2–3 years–other polyphyodont amniotes normally take ~1–2 years to form their teeth. Such delayed odontogenesis might reflect differences in crown length and function within an originally uneven tooth array. Indeed, slower replacement periodicity has been found to distinguish larger caniniform teeth in macrophagous pliosaurid plesiosaurians. However, the archetypal sauropterygian dental replacement system likely also imposed constraints via segregation of the developing tooth germs within discrete bony crypts; these partly resorbed to allow maturation of the replacement teeth within the primary alveoli after displacement of the functional crowns. Prolonged dental formation has otherwise been linked to tooth robustness and adaption for vigorous food processing. Conversely, elasmosaurids possessed narrow crowns with an elongate profile that denotes structural fragility. Their apparent predilection for easily subdued prey could thus have minimized this potential for damage, and was perhaps coupled with selective feeding strategies that ecologically optimized elasmosaurids towards more delicate middle trophic level aquatic predation. PMID:28241059

  9. Wnt signaling during tooth replacement in zebrafish (Danio rerio: pitfalls and perspectives

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    Ann eHuysseune

    2014-10-01

    Full Text Available The canonical (β-catenin dependent Wnt signaling pathway has emerged as a likely candidate for regulating tooth replacement in continuously renewing dentitions. So far, the involvement of canonical Wnt signaling has been experimentally demonstrated predominantly in amniotes. These studies tend to show stimulation of tooth formation by activation of the Wnt pathway, and inhibition of tooth formation when blocking the pathway. Here, we report a strong and dynamic expression of the soluble Wnt inhibitor dickkopf1 (dkk1 in developing zebrafish (Danio rerio tooth germs, suggesting an active repression of Wnt signaling during morphogenesis and cytodifferentiation of a tooth, and derepression of Wnt signaling during start of replacement tooth formation. To further analyse the role of Wnt signaling, we used different gain-of-function approaches. These yielded disjunct results, yet none of them indicating enhanced tooth replacement. Thus, masterblind (mbl mutants, defective in axin1, mimic overexpression of Wnt, but display a normally patterned dentition in which teeth are replaced at the appropriate times and positions. Activating the pathway with LiCl had variable outcomes, either resulting in the absence, or the delayed formation, of first-generation teeth, or yielding a regular dentition with normal replacement, but no supernumerary teeth or accelerated tooth replacement.The failure so far to influence tooth replacement in the zebrafish by perturbing Wnt signaling is discussed in the light of (i potential technical pitfalls related to dose- or time-dependency, (ii the complexity of the canonical Wnt pathway, and (iii species-specific differences in the nature and activity of pathway components. Finally, we emphasize the importance of in-depth knowledge of the wild-type pattern for reliable interpretations. It is hoped that our analysis can be inspiring to critically assess and elucidate the role of Wnt signaling in tooth development in polyphyodonts.

  10. Tooth replacement and putative odontogenic stem cell niches in pharyngeal dentition of medaka (Oryzias latipes).

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    Abduweli, Dawud; Baba, Otto; Tabata, Makoto J; Higuchi, Kazunori; Mitani, Hiroshi; Takano, Yoshiro

    2014-04-01

    The small-sized teleost fish medaka, Oryzias latipes, has as many as 1000 pharyngeal teeth undergoing continuous replacement. In this study, we sought to identify the tooth-forming units and determine its replacement cycles, and further localize odontogenic stem cell niches in the pharyngeal dentition of medaka to gain insights into the mechanisms whereby continuous tooth replacement is maintained. Three-dimensional reconstruction of pharyngeal epithelium and sequential fluorochrome labeling of pharyngeal bones and teeth indicated that the individual functional teeth and their successional teeth were organized in families, each comprising up to five generations of teeth and successional tooth germs, and that the replacement cycle of functional teeth was approximately 4 weeks. BrdU label/chase experiments confirmed the existence of clusters of label-retaining epithelial cells at the posterior end of each tooth family where the expression of pluripotency marker Sox2 was confirmed by in situ hybridization. Label-retaining cells were also identified in the mesoderm immediately adjacent to the posterior end of each tooth family. These data suggest the importance of existence of slow-cycling dental epithelial cells and Sox2 expressions at the posterior end of each tooth family to maintain continuous tooth formation and replacement in the pharyngeal dentition of medaka.

  11. An evolutionary view on tooth development and replacement in wild Atlantic salmon (Salmo salar L.).

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    Huysseune, A; Witten, P E

    2008-01-01

    To gain an insight into the evolution of tooth replacement mechanisms, we studied the development of first-generation and replacement teeth on the dentary of wild Atlantic salmon (Salmo salar L.), a protacanthopterygian teleost, using serially sectioned heads of early posthatching stages as well as adults. First-generation teeth develop within the oral epithelium. The anlage of the replacement tooth is first seen as a placode-like thickening of the outer dental epithelium of the predecessor, at its lingual and caudal side. Ongoing development of the replacement tooth germ is characterized by the elaboration of a population of epithelial cells, termed here the middle dental epithelium, apposed to the inner dental epithelium on the lingual side of the tooth germ. Before the formation of the new successor, a single-layered outer dental epithelium segregates from the middle dental epithelium. The dental organs of the predecessor and the successor remain broadly interconnected. The absence of a discrete successional dental lamina in salmon stands in sharp contrast to what is observed in other teleosts, even those that share with salmon the extraosseous formation of replacement teeth. The mode of tooth replacement in Atlantic salmon displays several characters similar to those observed in the shark Squalus acanthias. To interpret similarities in tooth replacement between Atlantic salmon and chondrichthyans as a case of convergence, or to see them as a result of a heterochronic shift, requires knowledge on the replacement process in more basal actinopterygian lineages. The possibility that the middle dental epithelium functionally substitutes for a successional lamina, and could be a source of stem cells, whose descendants subsequently contribute to the placode of the new replacement tooth, needs to be explored.

  12. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    OpenAIRE

    Banerjee Nandini; Singh Sushma

    2013-01-01

    A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness a...

  13. Signaling Pathways Critical for Tooth Root Formation.

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    Wang, J; Feng, J Q

    2017-10-01

    Tooth is made of an enamel-covered crown and a cementum-covered root. Studies on crown dentin formation have been a major focus in tooth development for several decades. Interestingly, the population prevalence for genetic short root anomaly (SRA) with no apparent defects in crown is close to 1.3%. Furthermore, people with SRA itself are predisposed to root resorption during orthodontic treatment. The discovery of the unique role of Nfic (nuclear factor I C; a transcriptional factor) in controlling root but not crown dentin formation points to a new concept: tooth crown and root have different control mechanisms. Further genetic mechanism studies have identified more key molecules (including Osterix, β-catenin, and sonic hedgehog) that play a critical role in root formation. Extensive studies have also revealed the critical role of Hertwig's epithelial root sheath in tooth root formation. In addition, Wnt10a has recently been found to be linked to multirooted tooth furcation formation. These exciting findings not only fill the critical gaps in our understanding about tooth root formation but will aid future research regarding the identifying factors controlling tooth root size and the generation of a whole "bio-tooth" for therapeutic purposes. This review starts with human SRA and mainly focuses on recent progress on the roles of NFIC-dependent and NFIC-independent signaling pathways in tooth root formation. Finally, this review includes a list of the various Cre transgenic mouse lines used to achieve tooth root formation-related gene deletion or overexpression, as well as strengths and limitations of each line.

  14. Autocrine and paracrine Shh signaling are necessary for tooth morphogenesis, but not tooth replacement in snakes and lizards (Squamata).

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    Handrigan, Gregory R; Richman, Joy M

    2010-01-01

    Here we study the role of Shh signaling in tooth morphogenesis and successional tooth initiation in snakes and lizards (Squamata). By characterizing the expression of Shh pathway receptor Ptc1 in the developing dentitions of three species (Eublepharis macularius, Python regius, and Pogona vitticeps) and by performing gain- and loss-of-function experiments, we demonstrate that Shh signaling is active in the squamate tooth bud and is required for its normal morphogenesis. Shh apparently mediates tooth morphogenesis by separate paracrine- and autocrine-mediated functions. According to this model, paracrine Shh signaling induces cell proliferation in the cervical loop, outer enamel epithelium, and dental papilla. Autocrine signaling within the stellate reticulum instead appears to regulate cell survival. By treating squamate dental explants with Hh antagonist cyclopamine, we induced tooth phenotypes that closely resemble the morphological and differentiation defects of vestigial, first-generation teeth in the bearded dragon P. vitticeps. Our finding that these vestigial teeth are deficient in epithelial Shh signaling further corroborates that Shh is needed for the normal development of teeth in snakes and lizards. Finally, in this study, we definitively refute a role for Shh signaling in successional dental lamina formation and conclude that other pathways regulate tooth replacement in squamates.

  15. Functional tooth regeneration using a bioengineered tooth unit as a mature organ replacement regenerative therapy.

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    Oshima, Masamitsu; Mizuno, Mitsumasa; Imamura, Aya; Ogawa, Miho; Yasukawa, Masato; Yamazaki, Hiromichi; Morita, Ritsuko; Ikeda, Etsuko; Nakao, Kazuhisa; Takano-Yamamoto, Teruko; Kasugai, Shohei; Saito, Masahiro; Tsuji, Takashi

    2011-01-01

    Donor organ transplantation is currently an essential therapeutic approach to the replacement of a dysfunctional organ as a result of disease, injury or aging in vivo. Recent progress in the area of regenerative therapy has the potential to lead to bioengineered mature organ replacement in the future. In this proof of concept study, we here report a further development in this regard in which a bioengineered tooth unit comprising mature tooth, periodontal ligament and alveolar bone, was successfully transplanted into a properly-sized bony hole in the alveolar bone through bone integration by recipient bone remodeling in a murine transplantation model system. The bioengineered tooth unit restored enough the alveolar bone in a vertical direction into an extensive bone defect of murine lower jaw. Engrafted bioengineered tooth displayed physiological tooth functions such as mastication, periodontal ligament function for bone remodeling and responsiveness to noxious stimulations. This study thus represents a substantial advance and demonstrates the real potential for bioengineered mature organ replacement as a next generation regenerative therapy.

  16. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

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    Banerjee Nandini

    2013-08-01

    Full Text Available A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness and predictability of endosseous implants. Implant placement is a viable option in the treatment of partial and full edentulism and has become an integral facet of periodontal therapy. The available implants are remarkably successful. This review discusses the different aspects of dental implant including its advantages over the contemporary removable implants, its procedure in detail and the financial outlook of the same. The review also has a small consideration on minidental implant.

  17. Single-tooth replacement: factors affecting different prosthetic treatment modalities

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    Al-Quran Firas A

    2011-12-01

    Full Text Available Abstract Background The choice between several treatment options for replacing a single missing tooth is influenced by clinical, dentist- and patient-immanent factors. This study aimed to determine the patient factors that would affect the treatment decision to replace a single missing tooth and to assess the satisfaction with several options. Method 200 volunteers involved (121 females and 79 males divided into four groups, Group A: consisted of patients with conventional fixed partial dentures or patients with resin bonded fixed partial dentures. Group B: consisted of patients who received removable partial dentures while Group C: consisted of patients who received a single implant supported crown, and a control group D: consisted of patients who received no treatment. Data were collected using a questionnaire. Results The highest percentage of males within groups (58% was within the removable prostheses category. The majority of the subjects in the study reported that the main reason for replacing a missing tooth was for esthetic and function. Most important factor affecting the choice between treatment modalities was damaging the neighboring teeth. Pain, post operative sensitivity and dental phobia were important factors in choosing the prosthesis type and affected the control group patients not to have any treatment. The highest satisfaction percentage among groups studied was recorded for dental implants then FPD groups, while the least percentage were in both the control and RPD groups, for all aspects of function, esthetic and speech efficiency. Conclusions The final choice between FPD, RPD and implant depended on several factors which affected the decision making; among these is cost and patients' awareness of the different treatment options.

  18. Tooth regeneration: implications for the use of bioengineered organs in first-wave organ replacement.

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    Nakahara, Taka; Ide, Yoshiaki

    2007-08-01

    Experiments with animal models have shown that the tooth crown structure can be regenerated using tissue engineering techniques that combine tooth bud cells and biodegradable materials, or by using embryonic tissue and adult stem cells. Moreover, tooth roots and periodontal tissues have been reconstructed by grafting dental stem cells, which leads to the recovery of tooth function, suggesting that tooth regeneration will become possible in humans in the near future. The present article reviews current research on tooth regeneration, discusses a model of tooth replacement that could be used clinically, and proposes a new tooth regeneration approach that overcomes the difficulties associated with the tooth replacement model. Tooth regeneration is an important stepping stone in the establishment of engineered organ transplantation, which is one of the ultimate goals of regenerative therapies.

  19. An Innovative Rigid Tray Technique for Replacement and Reattachment of the Anterior Composite Tooth Pontic

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    Saied Mostafa Moazzami

    2014-06-01

    Full Text Available Replacement and reattachment of a newly detached composite tooth pontic is sometimes justified because of shape, color, function and patient satisfaction. The aim of this case report is to describe a new method using Rigid Tray Technique for exact replacement and reattachment of acceptable detached composite tooth pontic

  20. Epithelial topography for repetitive tooth formation

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    Marcia Gaete

    2015-12-01

    Full Text Available During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2+ cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial topography involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2+/Sox9+ cells.

  1. Complex patterns of tooth replacement revealed in the fruit bat (Eidolon helvum).

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    Popa, Elena M; Anthwal, Neal; Tucker, Abigail S

    2016-12-01

    How teeth are replaced during normal growth and development has long been an important question for comparative and developmental anatomy. Non-standard model animals have become increasingly popular in this field due to the fact that the canonical model laboratory mammal, the mouse, develops only one generation of teeth (monophyodonty), whereas the majority of mammals possess two generations of teeth (diphyodonty). Here we used the straw-coloured fruit bat (Eidolon helvum), an Old World megabat, which has two generations of teeth, in order to observe the development and replacement of tooth germs from initiation up to mineralization stages. Our morphological study uses 3D reconstruction of histological sections to uncover differing arrangements of the first and second-generation tooth germs during the process of tooth replacement. We show that both tooth germ generations develop as part of the dental lamina, with the first generation detaching from the lamina, leaving the free edge to give rise to a second generation. This separation was particularly marked at the third premolar locus, where the primary and replacement teeth become positioned side by side, unconnected by a lamina. The position of the replacement tooth, with respect to the primary tooth, varied within the mouth, with replacements forming posterior to or directly lingual to the primary tooth. Development of replacement teeth was arrested at some tooth positions and this appeared to be linked to the timing of tooth initiation and the subsequent rate of development. This study adds an additional species to the growing body of non-model species used in the study of tooth replacement, and offers a new insight into the development of the diphyodont condition. © 2016 Anatomical Society.

  2. Massive clot formation after tooth extraction

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    Santosh Hunasgi

    2015-01-01

    Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.

  3. Tooth replacement of tigerfish Hydrocynus vittatus from the Kruger National Park

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    C.L. Gagiano

    1996-01-01

    Full Text Available Evidence of tooth replacement was observed in 14 tigerfish which had been caught during the period 1991 - 1993 in the Olifants and Letaba rivers in the Kruger National Park. Replacement of teeth is a quick process (3-5 days and first replacement of adult coni- cal dentition takes place at six to seven months post hatch, at a body length of 100 mm (FL. Swollen gums are evident prior to tooth replacement and newly erupted teeth are loosely embedded in the gums. Tooth replacement occurs in both the upper and lower jaws simultaneously. It was observed in the laboratory that the feeding behaviour was affected when adult conical dentition was replaced in @ 287 mm (FL specimens.

  4. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala O; Bardow, Allan; Hertz, Jens Michael;

    2007-01-01

    is the first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heterozygous females, enabling an earlier diagnosis, and therefore, better treatment and genetic...

  5. Tooth development in a scincid lizard, Chalcides viridanus (Squamata), with particular attention to enamel formation.

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    Delgado, Sidney; Davit-Béal, Tiphaine; Allizard, Françoise; Sire, Jean-Yves

    2005-01-01

    Comparative analysis of tooth development in the main vertebrate lineages is needed to determine the various evolutionary routes leading to current dentition in living vertebrates. We have used light, scanning and transmission electron microscopy to study tooth morphology and the main stages of tooth development in the scincid lizard, Chalcides viridanus, viz., from late embryos to 6-year-old specimens of a laboratory-bred colony, and from early initiation stages to complete differentiation and attachment, including resorption and enamel formation. In C. viridanus, all teeth of a jaw have a similar morphology but tooth shape, size and orientation change during ontogeny, with a constant number of tooth positions. Tooth morphology changes from a simple smooth cone in the late embryo to the typical adult aspect of two cusps and several ridges via successive tooth replacement at every position. First-generation teeth are initiated by interaction between the oral epithelium and subjacent mesenchyme. The dental lamina of these teeth directly branches from the basal layer of the oral epithelium. On replacement-tooth initiation, the dental lamina spreads from the enamel organ of the previous tooth. The epithelial cell population, at the dental lamina extremity and near the bone support surface, proliferates and differentiates into the enamel organ, the inner (IDE) and outer dental epithelium being separated by stellate reticulum. IDE differentiates into ameloblasts, which produce enamel matrix components. In the region facing differentiating IDE, mesenchymal cells differentiate into dental papilla and give rise to odontoblasts, which first deposit a layer of predentin matrix. The first elements of the enamel matrix are then synthesised by ameloblasts. Matrix mineralisation starts in the upper region of the tooth (dentin then enamel). Enamel maturation begins once the enamel matrix layer is complete. Concomitantly, dental matrices are deposited towards the base of the

  6. Beta-Catenin and Plakoglobin Expression during Zebrafish Tooth Development and Replacement.

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    Barbara Verstraeten

    Full Text Available We analyzed the protein distribution of two cadherin-associated molecules, plakoglobin and β-catenin, during the different stages of tooth development and tooth replacement in zebrafish. Plakoglobin was detected at the plasma membrane already at the onset of tooth development in the epithelial cells of the tooth. This pattern remained unaltered during further tooth development. The mesenchymal cells only showed plakoglobin from cytodifferentiation onwards. Plakoglobin 1a morpholino-injected embryos showed normal tooth development with proper initiation and differentiation. Although plakoglobin is clearly present during normal odontogenesis, the loss of plakoglobin 1a does not influence tooth development. β-catenin was found at the cell borders of all cells of the successional lamina but also in the nuclei of surrounding mesenchymal cells. Only membranous, not nuclear, β-catenin, was found during morphogenesis stage. However, during cytodifferentiation stage, both nuclear and membrane-bound β-catenin was detected in the layers of the enamel organ as well as in the differentiating odontoblasts. Nuclear β-catenin is an indication of an activated Wnt pathway, therefore suggesting a possible role for Wnt signalling during zebrafish tooth development and replacement.

  7. Beta-Catenin and Plakoglobin Expression during Zebrafish Tooth Development and Replacement.

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    Verstraeten, Barbara; van Hengel, Jolanda; Huysseune, Ann

    2016-01-01

    We analyzed the protein distribution of two cadherin-associated molecules, plakoglobin and β-catenin, during the different stages of tooth development and tooth replacement in zebrafish. Plakoglobin was detected at the plasma membrane already at the onset of tooth development in the epithelial cells of the tooth. This pattern remained unaltered during further tooth development. The mesenchymal cells only showed plakoglobin from cytodifferentiation onwards. Plakoglobin 1a morpholino-injected embryos showed normal tooth development with proper initiation and differentiation. Although plakoglobin is clearly present during normal odontogenesis, the loss of plakoglobin 1a does not influence tooth development. β-catenin was found at the cell borders of all cells of the successional lamina but also in the nuclei of surrounding mesenchymal cells. Only membranous, not nuclear, β-catenin, was found during morphogenesis stage. However, during cytodifferentiation stage, both nuclear and membrane-bound β-catenin was detected in the layers of the enamel organ as well as in the differentiating odontoblasts. Nuclear β-catenin is an indication of an activated Wnt pathway, therefore suggesting a possible role for Wnt signalling during zebrafish tooth development and replacement.

  8. A short report on tooth replacement in an older suburban population in Nigeria.

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    Ibiyemi, Olushola; Lawal, Folake B

    2017-09-20

    To determine: the knowledge of the participants about removable dentures, importance of tooth replacement; prevalence of tooth loss and denture use; and factors associated with its non-use among an elderly population in Nigeria. Tooth loss without replacement can impact negatively on the quality of life of the elders, thus making use of denture a basic requirement for those with partial or complete edentulous arches in developed countries. It is, however, not known if this is the case among elders in suburban Nigeria. A cross-section of 392 consenting elderly participants aged ≥65 years residing at Idikan, Ibadan, Nigeria, were interviewed on their biodata, knowledge of removable denture and importance of tooth replacement, history of use of denture and reasons for non-use where applicable. Oral examinations for the presence of missing teeth and denture were conducted by an examiner. Data were analysed with SPSS and P value set at ˂.05. The mean age of the participants was 73 (SD = 9.2) years. About 39% of the participants believed that it was important to replace missing teeth, 56.0% had poor knowledge about tooth replacement options, and 47.7% had at least a missing tooth. Only 7.1% of those with missing teeth had them replaced and all were using removable acrylic partial dentures. Financial constraint was the main reason for non-replacement of missing teeth (80.1%). Age, gender, occupation before retirement, income, level of education and presence of physical impairment were associated with non-use of denture (P ˂ .05). Many elderly individuals had poor knowledge about removable dentures and the importance of tooth replacement. About half of the participants had full complement of teeth and only 7.1% of those with tooth loss reported denture wear. Major reasons for non-use of dentures were due to economic reasons. © 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  9. Roles of Bmp4 during tooth morphogenesis and sequential tooth formation

    Science.gov (United States)

    Jia, Shihai; Zhou, Jing; Gao, Yang; Baek, Jin-A; Martin, James F.; Lan, Yu; Jiang, Rulang

    2013-01-01

    Previous studies have suggested that Bmp4 is a key Msx1-dependent mesenchymal odontogenic signal for driving tooth morphogenesis through the bud-to-cap transition. Whereas all tooth germs were arrested at the bud stage in Msx1–/– mice, we show that depleting functional Bmp4 mRNAs in the tooth mesenchyme, through neural crest-specific gene inactivation in Bmp4f/f;Wnt1Cre mice, caused mandibular molar developmental arrest at the bud stage but allowed maxillary molars and incisors to develop to mineralized teeth. We found that expression of Osr2, which encodes a zinc finger protein that antagonizes Msx1-mediated activation of odontogenic mesenchyme, was significantly upregulated in the molar tooth mesenchyme in Bmp4f/f;Wnt1Cre embryos. Msx1 heterozygosity enhanced maxillary molar developmental defects whereas Osr2 heterozygosity partially rescued mandibular first molar morphogenesis in Bmp4f/f;Wnt1Cre mice. Moreover, in contrast to complete lack of supernumerary tooth initiation in Msx1–/–Osr2–/– mice, Osr2–/–Bmp4f/f;Wnt1Cre compound mutant mice exhibited formation and subsequent arrest of supernumerary tooth germs that correlated with downregulation of Msx1 expression in the tooth mesenchyme. In addition, we found that the Wnt inhibitors Dkk2 and Wif1 were much more abundantly expressed in the mandibular than maxillary molar mesenchyme in wild-type embryos and that Dkk2 expression was significantly upregulated in the molar mesenchyme in Bmp4f/f;Wnt1Cre embryos, which correlated with the dramatic differences in maxillary and mandibular molar phenotypes in Bmp4f/f;Wnt1Cre mice. Together, these data indicate that Bmp4 signaling suppresses tooth developmental inhibitors in the tooth mesenchyme, including Dkk2 and Osr2, and synergizes with Msx1 to activate mesenchymal odontogenic potential for tooth morphogenesis and sequential tooth formation. PMID:23250216

  10. A multidisciplinary esthetic approach to single-tooth replacement and diastema closure.

    Science.gov (United States)

    Lyssova, Valentina; Estafan, Denise; Cunnigham, Ralph P

    2008-05-01

    Anterior tooth replacement has always posed an esthetic challenge for dentists. A multidisciplinary approach makes it possible to provide patients with esthetics and function. Treatment planning should involve other specialists when clinicians are faced with the additional esthetic concerns of the patient (such as anterior spatial anomalies and esthetically unpleasant existing restorations). Metal-ceramic fixed partial dentures have been used to allow the replacement of missing teeth for many years, providing both strength and esthetics. Several other options also are available, including implant placement. Dental implants in the esthetic zone are well-documented in the literature; numerous controlled clinical trials have shown overall implant survival and success rates. This article illustrates a step-by-step analysis and treatment option for a single-tooth replacement and maxillary anterior spatial dilemma using Captek crowns.

  11. Multiple essential MT1-MMP functions in tooth root formation, dentinogenesis, and tooth eruption.

    Science.gov (United States)

    Xu, H; Snider, T N; Wimer, H F; Yamada, S S; Yang, T; Holmbeck, K; Foster, B L

    2016-01-01

    Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a transmembrane zinc-endopeptidase that breaks down extracellular matrix components, including several collagens, during tissue development and physiological remodeling. MT1-MMP-deficient mice (MT1-MMP(-/-)) feature severe defects in connective tissues, such as impaired growth, osteopenia, fibrosis, and conspicuous loss of molar tooth eruption and root formation. In order to define the functions of MT1-MMP during root formation and tooth eruption, we analyzed the development of teeth and surrounding tissues in the absence of MT1-MMP. In situ hybridization showed that MT1-MMP was widely expressed in cells associated with teeth and surrounding connective tissues during development. Multiple defects in dentoalveolar tissues were associated with loss of MT1-MMP. Root formation was inhibited by defective structure and function of Hertwig's epithelial root sheath (HERS). However, no defect was found in creation of the eruption pathway, suggesting that tooth eruption was hampered by lack of alveolar bone modeling/remodeling coincident with reduced periodontal ligament (PDL) formation and integration with the alveolar bone. Additionally, we identified a significant defect in dentin formation and mineralization associated with the loss of MT1-MMP. To segregate these multiple defects and trace their cellular origin, conditional ablation of MT1-MMP was performed in epithelia and mesenchyme. Mice featuring selective loss of MT1-MMP activity in the epithelium were indistinguishable from wild type mice, and importantly, featured a normal HERS structure and molar eruption. In contrast, selective knock-out of MT1-MMP in Osterix-expressing mesenchymal cells, including osteoblasts and odontoblasts, recapitulated major defects from the global knock-out including altered HERS structure, short roots, defective dentin formation and mineralization, and reduced alveolar bone formation, although molars were able to erupt. These data

  12. Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

    Science.gov (United States)

    Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

    2014-01-01

    This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

  13. Single Tooth Replacement Using InCeram Resin Bonded Fixed Partial Denture: A Clinical Report.

    Directory of Open Access Journals (Sweden)

    Elnaz Moslehifard

    2014-02-01

    Full Text Available This clinical report describes a treatment option for replacement of a missing mandibular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD. The conventional approach for replacing mandibular incisors dictates the placement of either a conventional porcelain-fused-to-metal (PFM bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure.

  14. Dental implant as an option for tooth replacement: The awareness of patients at a tertiary hospital in a developing country

    Directory of Open Access Journals (Sweden)

    Olaide Shakeerah Gbadebo

    2014-01-01

    Full Text Available Aim: A survey was set out to evaluate the knowledge of patients about tooth replacement as a whole, and assess their awareness of implant-retained prosthesis as an option of tooth replacement. Materials and Methods: Information on sociodemographic characteristics, knowledge about implant-retained tooth as an option for missing tooth replacement, cost implication, source of information and knowledge about other options of tooth replacement were obtained from patients attending the dental clinics of the University College Hospital, Ibadan, using structured self-administered questionnaires. Data were analyzed using SPSS version 20. Result: A total of 220 patients aged 18-84 years with a mean age of 37.6 (±16.5 years participated in the study, with a male to female ratio of 1:1.1. The majority (92.5% knew that missing teeth can be replaced, while a significantly lower proportion (28.9% knew about dental implants as an option (P < 0.01. Dentists were the major source of information on dental implants (68%. Only 21 (36.8% of those who had heard about dental implant had knowledge about the cost (P < 0.000. Conclusion: A low level of awareness about dental implant as tooth replacement option exist in this environment, although most of the study participants were aware that missing teeth can be replaced.

  15. A comparison of tooth retention and replacement across 15 countries in the over-50s.

    Science.gov (United States)

    Stock, Christian; Jürges, Hendrik; Shen, Jing; Bozorgmehr, Kayvan; Listl, Stefan

    2016-06-01

    Oral diseases are still among the most common chronic diseases globally with substantial detrimental impact especially on elderly people's health and well-being. However, limited evidence exists on international variation in the oral health status of the older population. We aimed to examine international variation in tooth loss and tooth replacement in the general population aged between 50 and 90 years. A cross-sectional analysis of data from the fifth wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) was conducted. The data cover 14 European countries (Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Luxembourg, the Netherlands, Slovenia, Spain, Sweden, and Switzerland) and Israel, and they were collected during the year 2013. Age-specific percentages of the population having all natural teeth, the age-specific numbers of natural (and artificial) teeth, and the age-specific percentages of full, partial, or no replacement of missing teeth were assessed with stratification by country. It was further evaluated to which extent proposed oral health goals concerning tooth loss at higher ages had been achieved. In total, 62,763 individuals were included in the study. Age-standardized mean numbers of natural teeth exhibited substantial variation, ranging from 14.3 (Estonia) to 24.5 (Sweden). The oral health goal of retaining at least 20 teeth at age 80 years was achieved by 25% of the population or less in most countries. A target concerning edentulism (≤15% in population aged 65-74 years) was reached in Sweden, Switzerland, Denmark, France, and Germany. Tooth replacement practices varied especially for a number of up to five missing teeth which were more likely to be replaced in Austria, Germany, Luxembourg, and Switzerland than in Israel, Denmark, Estonia, Spain, and Sweden. This study suggests that the age-specific number of natural teeth and the practice of tooth replacement in the over 50s differ substantially among

  16. Expression analysis of candidate genes regulating successional tooth formation in the human embryo

    Directory of Open Access Journals (Sweden)

    Ryan eOlley

    2014-11-01

    Full Text Available Human dental development is characterized by formation of the primary teeth, which are subsequently replaced by the secondary dentition. The secondary dentition consists of incisors, canines and premolars derived from the successional dental lamina of the corresponding primary tooth germs; and molar teeth, which develop as a continuation of the dental lamina. Currently, very little is known about the molecular regulation of human successional tooth formation. Here, we have investigated expression of three candidate regulators for human successional tooth formation; the Fibroblast Growth Factor-antagonist SPROUTY2, the Hedgehog co-receptor GAS1 and the RUNT-related transcription factor RUNX2. At around 8 weeks of development, only SPROUTY2 showed strong expression in both epithelium and mesenchyme of the early bud. During the cap stage between 12-14 weeks, SPROUTY2 predominated in the dental papilla and inner enamel epithelium of the developing tooth. No specific expression was seen in the successional dental lamina. GAS1 was expressed in the dental papilla and follicle, and associated with mesenchyme adjacent to the primary dental lamina during the late cap stage. In addition, GAS1 transcripts were identifiable in mesenchyme adjacent to the successional lamina, particularly in the developing primary first molar. For RUNX2, expression predominated in the dental papilla and follicle. Localized expression was seen in mesenchyme adjacent to the primary dental lamina at the late cap stage; but surprisingly, not in the early successional lamina at these stages. These findings confirm that SPROUTY2, GAS1 and RUNX2 are all expressed during early human tooth development. The domains of GAS1 and RUNX2 are consistent with a role influencing function of the primary dental lamina but only GAS1 transcripts were identifiable in the successional lamina at these early stages of development.

  17. Unique method of tooth replacement in durophagous placodont marine reptiles, with new data on the dentition of Chinese taxa.

    Science.gov (United States)

    Neenan, James M; Li, Chun; Rieppel, Olivier; Bernardini, Federico; Tuniz, Claudio; Muscio, Giuseppe; Scheyer, Torsten M

    2014-05-01

    The placodonts of the Triassic period (~252-201 mya) represent one of the earliest and most extreme specialisations to a durophagous diet of any known reptile group. Exceptionally enlarged crushing tooth plates on the maxilla, dentary and palatine cooperated to form functional crushing areas in the buccal cavity. However, the extreme size of these teeth, combined with the unusual way they occluded, constrained how replacement occurred. Using an extensive micro-computed tomographic dataset of 11 specimens that span all geographic regions and placodont morphotypes, tooth replacement patterns were investigated. In addition, the previously undescribed dental morphologies and formulae of Chinese taxa are described for the first time and incorporated into the analysis. Placodonts have a unique tooth replacement pattern and results follow a phylogenetic trend. The plesiomorphic Placodus species show many replacement teeth at various stages of growth, with little or no discernible pattern. On the other hand, the more derived cyamodontoids tend to have fewer replacement teeth growing at any one time, replacing teeth unilaterally and/or in functional units, thus maintaining at least one functional crushing area at all times. The highly derived placochelyids have fewer teeth and, as a result, only have one or two replacement teeth in the upper jaw. This supports previous suggestions that these taxa had an alternative diet to other placodonts. Importantly, all specimens show at least one replacement tooth growing at the most posterior palatine tooth plates, indicating increased wear at this point and thus the most efficient functional crushing area.

  18. A 5-year prospective study of single-tooth replacements supported by the Astra Tech implant: a pilot study

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2004-01-01

    BACKGROUND: Implant-supported single-tooth replacements are an increasingly used method to replace teeth, especially in young patients. Therefore, long-term validation of different treatment modalities with different implant systems is of great importance. PURPOSE: The aim of the present study wa...

  19. A 5-year prospective study of single-tooth replacements supported by the Astra Tech implant: a pilot study

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2004-01-01

    BACKGROUND: Implant-supported single-tooth replacements are an increasingly used method to replace teeth, especially in young patients. Therefore, long-term validation of different treatment modalities with different implant systems is of great importance. PURPOSE: The aim of the present study...

  20. Unicuspid and bicuspid tooth crown formation in squamates.

    Science.gov (United States)

    Handrigan, Gregory R; Richman, Joy M

    2011-12-15

    The molecular and developmental factors that regulate tooth morphogenesis in nonmammalian species, such as snakes and lizards, have received relatively little attention compared to mammals. Here we describe the development of unicuspid and bicuspid teeth in squamate species. The simple, cone-shaped tooth crown of the bearded dragon and ball python is established at cap stage and fixed in shape by the differentiation of cells and the secretion of dental matrices. Enamel production, as demonstrated by amelogenin expression, occurs relatively earlier in squamate teeth than in mouse molars. We suggest that the early differentiation in squamate unicuspid teeth at cap stage correlates with a more rudimentary tooth crown shape. The leopard gecko can form a bicuspid tooth crown despite the early onset of differentiation. Cusp formation in the gecko does not occur by the folding of the inner enamel epithelium, as in the mouse molar, but by the differential secretion of enamel. Ameloblasts forming the enamel epithelial bulge, a central swelling of cells in the inner enamel epithelium, secrete amelogenin at cap stage, but cease to do so by bell stage. Meanwhile, other ameloblasts in the inner enamel epithelium continue to secrete enamel, forming cusp tips on either side of the bulge. Bulge cells specifically express the gene Bmp2, which we suggest serves as a pro-differentiation signal for cells of the gecko enamel organ. In this regard, the enamel epithelial bulge of the gecko may be more functionally analogous to the secondary enamel knot of mammals than the primary enamel knot. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  1. Outcome of bonded vs all-ceramic and metal- ceramic fixed prostheses for single tooth replacement.

    Science.gov (United States)

    Karl, Matthias

    2016-01-01

    The conventional treatment of a single missing tooth is most frequently based on the provision of a fixed dental prosthesis (FDPs). A variety of designs and restorative materials are available which have an impact on the treatment outcome. Consequently, it was the aim of this review to compare resin-bonded, all-ceramic and metal-ceramic FDPs based on existing evidence. An electronic literature search using "metal-ceramic" AND "fixed dental prosthesis" AND "clinical, all-ceramic" AND "fixed dental prosthesis" AND "clinical, resin-bonded" AND "fixed dental prosthesis" AND "clinical, fiber reinforced composite" AND "clinical, monolithic" AND "zirconia" AND "clinical" was conducted and supplemented by the manual searching of bibliographies from articles already included. A total of 258 relevant articles were identified. Metal-ceramic FDPs still show the highest survival rates of all tooth-supported restorations. Depending on the ceramic system used, all-ceramic restorations may reach comparable survival rates while the technical complications, i.e. chipping fractures of veneering materials in particular, are more frequent. Resin-bonded FDPs can be seen as long-term provisional restorations with the survival rate being higher in anterior locations and when a cantilever design is applied. Inlay-retained FDPs and the use of fiber-reinforced composites overall results in a compromised long-term prognosis. Recently advocated monolithic zirconia restorations bear the risk of low temperature degradation. Several variables affect treatment planning for a given patient situation, with survival and success rates of different restorative options representing only one factor. The broad variety of designs and materials available for conventional tooth-supported restorations should still be considered as a viable treatment option for single tooth replacement.

  2. Digital reconstruction of the mandible of an adult Lesothosaurus diagnosticus with insight into the tooth replacement process and diet

    Science.gov (United States)

    Knoll, Fabien; Bordy, Emese M.; de Kock, Michiel O.; Redelstorff, Ragna

    2017-01-01

    Fragmentary caudal ends of the left and right mandible assigned to Lesothosaurus diagnosticus, an early ornithischian, was recently discovered in the continental red bed succession of the upper Elliot Formation (Lower Jurassic) at Likhoele Mountain (Mafeteng District) in Lesotho. Using micro-CT scanning, this mandible could be digitally reconstructed in 3D. The replacement teeth within the better preserved (left) dentary were visualised. The computed tomography dataset suggests asynchronous tooth replacement in an individual identified as an adult on the basis of bone histology. Clear evidence for systematic wear facets created by attrition is lacking. The two most heavily worn teeth are only apically truncated. Our observations of this specimen as well as others do not support the high level of dental wear expected from the semi-arid palaeoenvironment in which Lesothosaurus diagnosticus lived. Accordingly, a facultative omnivorous lifestyle, where seasonality determined the availability, quality, and abundance of food is suggested. This would have allowed for adaptability to episodes of increased environmental stress. PMID:28265518

  3. Tooth replacement related to number of natural teeth in a dentate adult population in Bulgaria: a cross-sectional study

    NARCIS (Netherlands)

    Damyanov, N.D.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2013-01-01

    PURPOSE: This study aimed to explore the relationships among tooth replacement, number of present natural teeth, and sociodemographic and behavioral factors in an adult population in Bulgaria. MATERIALS AND METHODS: Quota sampling was used to recruit 2,531 dentate subjects aged 20 years and over fro

  4. Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

    DEFF Research Database (Denmark)

    Karlsson, U; Gotfredsen, K; Olsson, C

    1998-01-01

    This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been...

  5. Telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement.

    Science.gov (United States)

    Mladenović, Dragan; Tosić, Goran; Zivković, Dusan; Djindjić, Natasa; Mladenović, Lidija; Mladenović, Sanja; Marković, Ivana

    2013-09-01

    In the management of edentulous spaces, there is a permanent need of a dentist-prosthetician in charge to consult other specialists. Modern telemedicine, based on powerful computer and telecomunication systems, offers an adequate answer to these challenges, being able to transfer and obtain clinical data and consultation information over large distances. Using smartphone or a computer, the teleconsultant acces the system, downloads and review the data and photographs and gave suggestions. The system then enables direct, real time contact with the consultant, chat, or directs them to contact each other by phone. We presented telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement in 3 cases with different teleconsultation requirements: the first case for prosthetic rehabilitation of his upper teeth, the second one for prosthetic management of his partial edentulousness and "a growth on his gums" in the vestibular region of the frontal teeth and the third one for prosthetic management of total edentulousness of her upper jaw. We used the system of telemedicine in dentistry, established at the Faculty of Medicine in Kosovska Mitrovica. The operation was based on the computer application system XPA3 Online, computer networking and mobile smartphone network. All consultations were succefull with no need for further procedures in regional center. The use of a mobile smartphone has brought about the mobility and availability of teleconsultant specialists in an extent never seen before. Prostheticians are thus able to offer better service to their patients and improve the quality of management of partially or totally edentulous patients, especially in rural areas.

  6. Telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement

    Directory of Open Access Journals (Sweden)

    Mladenović Dragan

    2013-01-01

    Full Text Available Introduction. In the management of edentulous spaces, there is a permanent need of a dentist-prosthetician in charge to consult other specialists. Modern telemedicine, based on powerful computer and telecomunication systems, offers an adequate answer to these challenges, being able to transfer and obtain clinical data and consultation information over large distances. Using smartphone or a computer, the teleconsultant acces the system, downloads and review the data and photographs and gave suggestions. The system then enables direct, real time contact with the consultant, chat, or directs them to contact each other by phone. Case report. We presented telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement in 3 cases with different teleconsultation requirements: the first case for prosthetic rehabilitation of his upper teeth, the second one for prosthetic management of his partial edentulousness and “a growth on his gums” in the vestibular region of the frontal teeth and the third one for prosthetic management of total edentulousness of her upper jaw. We used the system of telemedicine in dentistry, established at the Faculty of Medicine in Kosovska Mitrovica. The operation was based on the computer application system XPA3 Online, computer networking and mobile smartphone network. All consultations were succefull with no need for further procedures in regional center. Conclusion. The use of a mobile smartphone has brought about the mobility and availability of teleconsultant specialists in an extent never seen before. Prostheticians are thus able to offer better service to their patients and improve the quality of management of partially or totally edentulous patients, especially in rural areas.

  7. Aesthetic Alternative Using Composite Resin to Replace a Missing Tooth. A Case Report

    Directory of Open Access Journals (Sweden)

    Yuritza Hernández Núñez

    2014-06-01

    Full Text Available Patients who experience dental trauma resulting in permanent tooth loss are often prosthetically rehabilitated through any of its variants. However, it is uncommon to rehabilitate a patient using composite resin when a tooth is lost. The case of a patient who had lost a maxillary central incisor years ago and its space had been occupied by the lateral incisor is presented. The missing tooth was built up through the enlargement of the lateral incisor using the layering technique or stratification with Brilliant New Line resin. This paper aims at demonstrating a more economical and simpler alternative for restoring the aesthetics of a patient with unfavorable prognosis.

  8. The endodontically involved tooth: treat, or extract, and replace?%牙髓病患牙:治疗,拔除,种植?

    Institute of Scientific and Technical Information of China (English)

    Roger J.Smales

    2010-01-01

    @@ Introduction In recent years there has been increasing discussion and controversy regarding endodontic therapy and restoration versus tooth extraction and replacement with an osseointegrated dental implant-supported single crown[1-10].

  9. Peptide-induced de novo bone formation after tooth extraction prevents alveolar bone loss in a murine tooth extraction model.

    Science.gov (United States)

    Arai, Yuki; Aoki, Kazuhiro; Shimizu, Yasuhiro; Tabata, Yasuhiko; Ono, Takashi; Murali, Ramachandran; Mise-Omata, Setsuko; Wakabayashi, Noriyuki

    2016-07-05

    Tooth extraction causes bone resorption of the alveolar bone volume. Although recombinant human bone morphogenetic protein 2 (rhBMP-2) markedly promotes de novo bone formation after tooth extraction, the application of high-dose rhBMP-2 may induce side effects, such as swelling, seroma, and an increased cancer risk. Therefore, reduction of the necessary dose of rhBMP-2 which can still obtain sufficient bone mass is necessary by developing a new osteogenic reagent. Recently, we showed that the systemic administration of OP3-4 peptide, which was originally designed as a bone resorption inhibitor, had osteogenic ability both in vitro and in vivo. This study evaluated the ability of the local application of OP3-4 peptide to promote bone formation in a murine tooth extraction model with a very low-dose of BMP. The mandibular incisor was extracted from 10-week-old C57BL6/J male mice and a gelatin hydrogel containing rhBMP-2 with or without OP3-4 peptide (BMP/OP3-4) was applied to the socket of the incisor. Bone formation inside the socket was examined radiologically and histologically at 21 days after the extraction. The BMP/OP3-4-group showed significant bone formation inside the mandibular extraction socket compared to the gelatin-hydrogel-carrier-control group or rhBMP-2-applied group. The BMP/OP3-4-applied mice showed a lower reduction of alveolar bone and fewer osteoclast numbers, suggesting that the newly formed bone inside the socket may prevent resorption of the cortical bone around the extraction socket. Our data revealed that OP3-4 peptide promotes BMP-mediated bone formation inside the extraction socket of mandibular bone, resulting in preservation from the loss of alveolar bone.

  10. 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 Sinus membrane abnormalities were most frequent in P2. Periodontal status and sinus membrane abnormality increased the odds of RH 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.

  11. Bio-Root and Implant-Based Restoration as a Tooth Replacement Alternative.

    Science.gov (United States)

    Gao, Z H; Hu, L; Liu, G L; Wei, F L; Liu, Y; Liu, Z H; Fan, Z P; Zhang, C M; Wang, J S; Wang, S L

    2016-06-01

    We previously reported that dental stem cell-mediated bioengineered tooth root (bio-root) regeneration could restore tooth loss in a miniature pig model. As a potential new method for tooth restoration, it is essential to compare this method with the widely used commercial dental implant-based method of tooth restoration. Tooth loss models were created by extracting mandibular incisors from miniature pigs. Allogeneic periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) were isolated and cultured. A PDLSC sheet was prepared by adding 20.0 µg/mL vitamin C to the culture medium; in addition, a hydroxyapatite tricalcium phosphate (HA/TCP)/DPSC graft was fabricated and cultured in a 3-dimensional culture system. A total of 46 bio-root implantations and 9 dental implants were inserted, and crown restorations were performed 6 mo after implantation. Histological, radiological, biomechanical, and elemental analyses were used to evaluate and compare tissue-engineered bio-roots and dental implants to the natural tooth roots. After 6 mo, both computed tomography scans and histological examinations showed that root-like structures and dentin-like tissues had formed. Three months after crown restoration, clinical assessments revealed that tooth function was equivalent in the regenerated bio-root and the dental implant. Biomechanical testing showed that the bio-roots were similar to natural tooth roots in compressive strength, modulus of elasticity, and torsional force; however, these properties were significantly higher in the dental implants. Elemental analysis revealed a higher similarity in elemental composition between bio-roots and natural tooth roots than between bio-roots and dental implants. However, the dental implant success rate was 100% (9 of 9) and the bio-root success rate was only 22% (10 of 46). Taken together, we showed that an allogeneic HA/TCP/DPSC/PDLSC sheet could successfully build a bio-root with structure and function similar to

  12. Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    R. Ebru Tirali

    2013-01-01

    Full Text Available Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

  13. Randomized controlled trial to evaluate tooth stain reduction with nicotine replacement gum during a smoking cessation program

    LENUS (Irish Health Repository)

    Whelton, Helen

    2012-06-13

    AbstractBackgroundIn addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette® Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers.MethodsAn evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette® Freshmint Gum or Nicorette® Microtab (tablet). Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita® Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA), using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat) was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test.ResultsAt week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p = 0.005, ANCOVA). The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p = 0.015), 6 (p = 0

  14. Site-specific function and regulation of Osterix in tooth root formation

    Science.gov (United States)

    He, Y. D.; Sui, B. D.; Li, M.; Huang, J.; Chen, S.; Wu, L. A.

    2016-01-01

    Congenital diseases of tooth roots, in terms of developmental abnormalities of short and thin root phenotypes, can lead to loss of teeth. A more complete understanding of the genetic molecular pathways and biological processes controlling tooth root formation is required. Recent studies have revealed that Osterix (Osx), a key mesenchymal transcriptional factor participating in both the processes of osteogenesis and odontogenesis, plays a vital role underlying the mechanisms of developmental differences between root and crown. During tooth development, Osx expression has been identified from late embryonic to postnatal stages when the tooth root develops, particularly in odontoblasts and cementoblasts to promote their differentiation and mineralization. Furthermore, the site-specific function of Osx in tooth root formation has been confirmed, because odontoblastic Osx-conditional knockout mice demonstrate primarily short and thin root phenotypes with no apparent abnormalities in the crown (Journal of Bone and Mineral Research 30, 2014 and 742, Journal of Dental Research 94, 2015 and 430). These findings suggest that Osx functions to promote odontoblast and cementoblast differentiation and root elongation only in root, but not in crown formation. Mechanistic research shows regulatory networks of Osx expression, which can be controlled through manipulating the epithelial BMP signalling, mesenchymal Runx2 expression and cellular phosphorylation levels, indicating feasible routes of promoting Osx expression postnatally (Journal of Cellular Biochemistry 114, 2013 and 975). In this regard, a promising approach might be available to regenerate the congenitally diseased root and that regenerative therapy would be the best choice for patients with developmental tooth diseases. PMID:26599722

  15. Squalicorax Chips a Tooth: A Consequence of Feeding-Related Behavior from the Lowermost Navesink Formation (Late Cretaceous: Campanian-Maastrichtian of Monmouth County, New Jersey, USA

    Directory of Open Access Journals (Sweden)

    John A. Chamberlain

    2012-05-01

    Full Text Available Chipped and broken functional teeth are common in modern sharks with serrated tooth shape. Tooth damage consists of splintering, cracking, and flaking near the cusp apex where the enameloid is broken and exposes the osteodentine and orthodentine. Such damage is generally viewed as the result of forces applied during feeding as the cusp apex impacts the skeletal anatomy of prey. Damage seen in serrated functional teeth from sharks Squalicorax kaupi [1] and Squalicorax pristodontus [1] from the late Cretaceous lowermost Navesink Formation of New Jersey resembles that occurring in modern sharks and suggests similar feeding behavior. Tumbling experiments using serrated modern and fossil functional shark teeth, including those of Squalicorax, show that teeth are polished, not cracked or broken, by post-mortem abrasion in lowermost Navesink sediment. This provides further evidence that chipped and broken Squalicorax teeth are feeding-related and not taphonomic in origin. Evolution of rapid tooth replacement in large sharks such as Squalicorax ensured maximum functionality after feeding-related tooth damage occurred. Serrated teeth and rapid tooth replacement in the large sharks of the Mesozoic and Cenozoic afforded them competitive advantages that helped them to achieve their place as apex predators in today’s ocean.

  16. Malnutrition has no effect on the timing of human tooth formation.

    Directory of Open Access Journals (Sweden)

    Fadil Elamin

    Full Text Available The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤-2 (cut-off were used to identify the malnourished group (N = 474 while the normal was defined by Z-scores of ≥0 (N = 799. Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05. This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems.

  17. Malnutrition has no effect on the timing of human tooth formation.

    Science.gov (United States)

    Elamin, Fadil; Liversidge, Helen M

    2013-01-01

    The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females) consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤-2 (cut-off) were used to identify the malnourished group (N = 474) while the normal was defined by Z-scores of ≥0 (N = 799). Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05). This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems.

  18. Functional tooth restoration by next-generation bio-hybrid implant as a bio-hybrid artificial organ replacement therapy.

    Science.gov (United States)

    Oshima, Masamitsu; Inoue, Kaoru; Nakajima, Kei; Tachikawa, Tetsuhiko; Yamazaki, Hiromichi; Isobe, Tomohide; Sugawara, Ayaka; Ogawa, Miho; Tanaka, Chie; Saito, Masahiro; Kasugai, Shohei; Takano-Yamamoto, Teruko; Inoue, Takashi; Tezuka, Katsunari; Kuboki, Takuo; Yamaguchi, Akira; Tsuji, Takashi

    2014-01-01

    Bio-hybrid artificial organs are an attractive concept to restore organ function through precise biological cooperation with surrounding tissues in vivo. However, in bio-hybrid artificial organs, an artificial organ with fibrous connective tissues, including muscles, tendons and ligaments, has not been developed. Here, we have enveloped with embryonic dental follicle tissue around a HA-coated dental implant, and transplanted into the lower first molar region of a murine tooth-loss model. We successfully developed a novel fibrous connected tooth implant using a HA-coated dental implant and dental follicle stem cells as a bio-hybrid organ. This bio-hybrid implant restored physiological functions, including bone remodelling, regeneration of severe bone-defect and responsiveness to noxious stimuli, through regeneration with periodontal tissues, such as periodontal ligament and cementum. Thus, this study represents the potential for a next-generation bio-hybrid implant for tooth loss as a future bio-hybrid artificial organ replacement therapy.

  19. Continued Root Formation after Delayed Replantation of an Avulsed Immature Permanent Tooth

    Directory of Open Access Journals (Sweden)

    Nima Moradi Majd

    2014-01-01

    Full Text Available Introduction. Tooth avulsion in the young permanent dentition is a frequent finding, and its prognosis depends on the treatment of the avulsed tooth before replantation, the extra-alveolar time, the storage medium, and the patient’s general health. The present report describes management of an immature avulsed lower central incisor 90 minutes after the accident. Methods. A right lower central incisor of a 7-year-old girl was avulsed, and it was soaked in a glass of milk. 90 minutes after avulsion, replantation was performed, and the tooth was splinted; but after two weeks the replanted tooth’s pulp was necrotic. Thus, endodontic treatment was performed and root canal was filled using a calcium hydroxide and iodoform paste (Metapex. Three months later, the intracanal medication was washed out and the canal was sealed using an apical plug of calcium enriched mixture (CEM cement. Results. 20 months after replantation the tooth was completely asymptomatic, with physiologic mobility. Also, continued root formation including an apical segment beyond the artificial apical plug was observed. Conclusion. Creation of an appropriate apical barrier following the disinfection of root canal system promoted continued root-end growth in a replanted immature permanent tooth.

  20. A rotated palatal flap ridge preservation technique to enhance restorative and hard and soft tissue esthetics for tooth replacement in the anterior maxilla.

    Science.gov (United States)

    Bitter, Robert N

    2010-04-01

    Hard and soft tissue alveolar ridge deformities occur following the extraction of teeth, creating functional and esthetic tooth replacement challenges, especially in the maxillary anterior smile zone. A surgical technique using a rotated palatal flap for ridge preservation is discussed that, whether combined with conventional fixed dentures or implant treatment for tooth replacement, provides the possibility for greatly improved esthetics. This technique, used in combination with or in preparation for implant treatment, allows for preservation of the alveolar bone height and width for improved implant size and placement options. In addition, preservation and enhancement of the soft tissue at the extraction site provides for soft tissue contours adjacent to the definitive restoration that vary little from those of the original natural tooth. Combined with conventional fixed dentures, use of this technique creates a template of the labial and interproximal sulcus of the extracted tooth, allowing for the molding of an ovate pontic replacement tooth. This results in vastly improved restorative emergence profiles with minimal or no change in the height of the labial gingival margin and the form and height of the interproximal papillae with adjacent teeth.

  1. Numerical modelling of tooth enamel subsurface lesion formation induced by dental plaque.

    Science.gov (United States)

    Ilie, O; van Turnhout, A G; van Loosdrecht, M C M; Picioreanu, C

    2014-01-01

    Using a one-dimensional mathematical model that couples tooth demineralisation and remineralisation with metabolic processes occurring in the dental plaque, two mechanisms for subsurface lesion formation were evaluated. It was found that a subsurface lesion can develop only as the result of alternating periods of demineralisation (acid attack during sugar consumption) and remineralisation (resting period) in tooth enamel with uniform mineral composition. It was also shown that a minimum plaque thickness that can induce an enamel lesion exists. The subsurface lesion formation can also be explained by assuming the existence of a fluoride-containing layer at the tooth surface that decreases enamel solubility. A nearly constant thickness of the surface layer was obtained with both proposed mechanisms. Sensitivity analysis showed that surface layer formation is strongly dependent on the length of remineralisation and demineralisation cycles. The restoration period is very important and the numerical simulations support the observation that often consumption of sugars is a key factor in caries formation. The calculated profiles of mineral content in enamel are similar to those observed experimentally. Most probably, both studied mechanisms interact in vivo in the process of caries development, but the simplest explanation for subsurface lesion formation remains the alternation between demineralisation and remineralisation cycles without any pre-imposed gradients.

  2. Test Tube Tooth: The Next Big Thing

    Science.gov (United States)

    Tahir, Mohammed; Yadav, Harsh; Sureka, Rakshit; Garg, Aarti

    2016-01-01

    Unlike some vertebrates and fishes, humans do not have the capacity for tooth regeneration after the loss of permanent teeth. Although artificial replacement with removable dentures, fixed prosthesis and implants is possible through advances in the field of prosthetic dentistry, it would be ideal to recreate a third set of natural teeth to replace lost dentition. For many years now, researchers in the field of tissue engineering have been trying to bioengineer dental tissues as well as whole teeth. In order to attain a whole tooth through dental engineering, that has the same or nearly same biological, mechanical and physical properties of a natural tooth, it’s necessary to deal with all the cells and tissues which are concerned with the formation, maintenance and repair of the tooth. In this article we review the steps involved in odontogenesis or organogenesis of a tooth and progress in the bioengineering of a whole tooth. PMID:27504430

  3. Parathyroid hormone receptor signalling in osterix-expressing mesenchymal progenitors is essential for tooth root formation.

    Science.gov (United States)

    Ono, Wanida; Sakagami, Naoko; Nishimori, Shigeki; Ono, Noriaki; Kronenberg, Henry M

    2016-04-12

    Dental root formation is a dynamic process in which mesenchymal cells migrate toward the site of the future root, differentiate and secrete dentin and cementum. However, the identities of dental mesenchymal progenitors are largely unknown. Here we show that cells expressing osterix are mesenchymal progenitors contributing to all relevant cell types during morphogenesis. The majority of cells expressing parathyroid hormone-related peptide (PTHrP) are in the dental follicle and on the root surface, and deletion of its receptor (PPR) in these progenitors leads to failure of eruption and significantly truncated roots lacking periodontal ligaments. The PPR-deficient progenitors exhibit accelerated cementoblast differentiation with upregulation of nuclear factor I/C (Nfic). Deletion of histone deacetylase-4 (HDAC4) partially recapitulates the PPR deletion root phenotype. These findings indicate that PPR signalling in dental mesenchymal progenitors is essential for tooth root formation, underscoring importance of the PTHrP-PPR system during root morphogenesis and tooth eruption.

  4. Zeolites replacing plant fossils in the Denver formation, Lakewood, Colorado.

    Science.gov (United States)

    Modreski, P.J.; Verbeek, E.R.; Grout, M.A.

    1984-01-01

    Well-developed crystals of heulandite and stilbite, within fossil wood, occur in sedimentary rocks in Lakewood, Jefferson County. The rocks belong to the Denver formation, a locally fossiliferous deposit of fluvial claystone, siltstone, sandstone and conglomerate, containing some volcanic mudflows (andesitic) of late Cretaceous to Palaeocene age. Altered volcanic glass released Na and Ca into the ground-water and subsequently zeolites were crystallized in the open spaces between grains and within fossil plant structures. Minor pyrite, quartz (jasper), calcite and apatite also occur as replacements of fossil wood. Similar zeolite occurrences in other areas are reviewed.-R.S.M.

  5. The Role of Microbial Iron Reduction in the Formation of Proterozoic Molar Tooth Structures

    Science.gov (United States)

    Hodgskiss, M. S. W.; Kunzmann, M.; Halverson, G. P.; Poirier, A.

    2016-12-01

    Molar tooth structures are poorly understood early diagenetic, microspar-filled voids in clay-rich carbonate sediments. They are a common structure in sedimentary successions dating from 2600-720 Ma, but do not occur in rocks older or younger. Despite being volumetrically significant in carbonate rocks of this age, their formation and disappearance are poorly understood. Here, we present iron isotope data, supported by carbon and oxygen isotopes, major and minor element concentrations, and total organic carbon and pyrite contents for samples from ten regions spanning 1870-635 Ma. The iron isotopic composition of molar tooth structures is almost always lighter (modal depletion of 2‰) than the carbonate or siliciclastic components in the host sediment, whereas carbon isotopes are indistinguishable. We interpret the isotopically light iron in molar tooth structures to have been produced by microbial iron reduction utilising Fe-oxyhydroxides and smectites. The microbial conversion of smectite to illite results in a volume reduction of clay minerals ( 30%), while locally increasing pore water alkalinity. Therefore, this biogeochemical process is a viable mechanism to produce voids and subsequently precipitate carbonate minerals. The disappearance of molar tooth structures is likely linked to a combination of a decrease in smectite abundance, a decline in the marine DIC reservoir, and increase in the concentration of O2 in shallow seawater in the mid-Neoproterozoic.

  6. 3-D analysis of tooth formation and eruption in patients with craniofacial anomalies

    DEFF Research Database (Denmark)

    Kreiborg, Sven; Larsen, Per; Bro-Nielsen, Morten

    1996-01-01

    A number of craniofacial anomalies or syndromes involve severe disturbances of tooth formation and eruption (e.g. Apert syndrome, Crouzon syndrome, tricho-dento-osseous syndrome, cleidocranial dysplasia, and cleft lip and palate). So far, studies of these dental problems have been limited to two......-dimensional analysis from orthopantomograms, intra-oral X-rays or cephalometric radiographs. A method for visualization of the developing tooth crowns in three dimensions based on CT-scans of the jaws has been developed (Bro-Nielsen et al., 1996). The purpose of the present study was to apply this new visualization...... method to the analysis of the complex dental problems found in some of the syndromes listed above....

  7. Alveolar Ridge Conservation by Early Bone Formation After Tooth Extraction in Rabbits. A Histomorphological Study

    Science.gov (United States)

    Cantín, Mario; Olate, Sergio; Fuentes, Ramón; Vásquez, Bélgica

    2016-01-01

    SUMMARY Alveolar ridge volume loss is an irreversible process. To prevent this physiological event, which typically result in significant local anatomical changes in both the horizontal and the vertical dimension, some strategies are indicated to minimize the loss of ridge volume that typically follows tooth extraction. The purpose of this study was to evaluate if three different bone grafts could promote new bone formation in the alveolar socket following tooth extraction for the alveolar ridge conservation. First mandibular molars of male adults rabbits were extracted and the extraction sockets were randomly treated with three different bone grafts, one xenograft and two alloplastic grafts, and a group that received no treatment (blood clot). The extraction sockets of selected rabbits from each group were evaluated at 4, 6, or 8-week post-extraction. The results indicated that the extraction sockets treated with alloplastic graft (biphasic calcium phosphate) exhibited lamellar bone formation (6.5%) as early as four weeks after the extraction was performed. Moreover, the degree of new bone formation was significantly higher (P<0.05) in the extraction sockets treated with biphasic calcium phosphate at 8-week post-extraction than that in the other study groups. In this study, we demonstrated that the proposed animal model is useful to evaluate the bone formation after tooth extraction and the alveolar ridge conservation is feasible. The new bone formation and alveolar ridge preservation with bone graft after extraction of molar teeth, could result in the maintenance of sufficient bone volume to place an implant in an ideal restorative position without the need for ancillary implant site development procedures. PMID:27840551

  8. Bone morphogenetic protein-2 gene controls tooth root development in coordination with formation of the periodontium

    Institute of Scientific and Technical Information of China (English)

    Audrey Rakian; Wu-Chen Yang; Jelica Gluhak-Heinrich; Yong Cui; Marie A Harris; Demitri Villarreal; Jerry Q Feng; Mary MacDougall; Stephen E Harris

    2013-01-01

    Formation of the periodontium begins following onset of tooth-root formation in a coordinated manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone and Sharpey’s fibers of the periodontal ligament (PDL). However, little is known about the regulatory morphogens that control differentiation and function of these progenitor cells, as well as the progenitor cells involved in crown and root formation. We investigated the role of bone morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar, with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age. When the Bmp2 gene is removed from Sp71 (Osterix1) cells, major defects are noted in root, cellular cementum and periodontium formation. First, there are major cell autonomous defects in root-odontoblast terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular cementum, correlated with decreased nuclear factor IC (Nfic), periostin and a-SMA1 cells. Third, there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and the pulp leading to decreased formation of the microvascular and associated candidate stem cells in the Bmp2-cKOSp7-Cre-EGFP. Fourth, ameloblast function and enamel formation are indirectly altered in the Bmp2-cKOSp7-Cre-EGFP. These data demonstrate that the Bmp2 gene has complex roles in postnatal tooth development and periodontium formation.

  9. NFI-C2 temporal-spatial expression and cellular localization pattern during tooth formation.

    Science.gov (United States)

    Lamani, Ejvis; Gluhak-Heinrich, Jelica; MacDougall, Mary

    2015-12-01

    Currently, little is known regarding critical signaling pathways during later stages of tooth development, especially those associated with root formation. Nfi-c null mice, lacking molar roots, have implicated the transcription factor NFI-C as having an essential role in root development. Previously, we identified three NFI-C isoforms expressed in dental tissues with NFI-C2 being the major transcript. However, the expression pattern of the NFI-C2 protein is not characterized. In this study we performed in situ hybridization and immunohistochemistry using isoform specific probes. We show the production of a NFI-C2 peptide antibody, its characterization, the temporal-spatial expression pattern of the NFI-C2 protein during odontogenesis and sub-cellular localization in dental cells. Moderate NFI-C2 staining, as early as bud stage, was detected mostly in the condensing dental ectomesenchyme. This staining intensified within the dental pulp at later stages culminating in high expression in the dentin producing odontoblasts. The dental epithelium showed slight staining until cytodifferentiation of enamel organ into ameloblasts and stratum intermedium. During root formation NFI-C2 expression was high in the Hertwig's epithelial root sheath and later was found in the fully developed root and its supporting tissues. NFI-C2 cellular staining was cytosolic, associated with the Golgi, and nuclear. These data suggest a broader role for NFI-C during tooth formation than limited to root and periodontal ligament development. © 2015 Japanese Society of Developmental Biologists.

  10. Effect of Alendronate on Bone Formation during Tooth Extraction Wound Healing.

    Science.gov (United States)

    Tanoue, R; Koi, K; Yamashita, J

    2015-09-01

    Alendronate (ALN) is an antiresorptive agent widely used for the treatment of osteoporosis. Its suppressive effect on osteoclasts has been extensively studied. However, the effect of ALN on bone formation is not as clear as its effect on resorption. The objective was to determine the effect of short-term ALN on bone formation and tooth extraction wound healing. Molar tooth extractions were performed in mice. ALN, parathyroid hormone (PTH), or saline (vehicle control) was administered. PTH was used as the bone anabolic control. Mice were euthanized at 3, 5, 7, 10, and 21 d after extractions. Hard tissue healing was determined histomorphometrically. Neutrophils and lymphatic and blood vessels were quantified to evaluate soft tissue healing. Gene expression in the wounds was assessed at the RNA level. Furthermore, the vossicle bone transplant system was used to verify findings from extraction wound analysis. Alkaline phosphatase (ALP) was visualized in the vossicles to assess osteoblast activity. ALN exhibited no negative effect on bone formation. In intact tibiae, ALN increased bone mass significantly more than PTH did. Consistently, significantly elevated osteoblast numbers were noted. In the extraction sockets, bone fill in the ALN-treated mice was equivalent to the control. Genes associated with bone morphogenetic protein signaling, such as bmp2, nog, and dlx5, were activated in the extraction wounds of the ALN-treated animals. Bone formation in vossicles was significantly enhanced in the ALN versus PTH group. In agreement with this, ALN upregulated ALP activity considerably in vossicles. Neutrophil aggregation and suppressed lymphangiogenesis were evident in the soft tissue at 21 d after extraction, although gross healing of extraction wounds was uneventful. Bone formation was not impeded by short-term ALN treatment. Rather, short-term ALN treatment enhanced bone formation. ALN did not alter bone fill in extraction sockets.

  11. Decellularized Tooth Bud Scaffolds for Tooth Regeneration.

    Science.gov (United States)

    Zhang, W; Vazquez, B; Oreadi, D; Yelick, P C

    2017-01-01

    Whole tooth regeneration approaches currently are limited by our inability to bioengineer full-sized, living replacement teeth. Recently, decellularized organ scaffolds have shown promise for applications in regenerative medicine by providing a natural extracellular matrix environment that promotes cell attachment and tissue-specific differentiation leading to full-sized organ regeneration. We hypothesize that decellularized tooth buds (dTBs) created from unerupted porcine tooth buds (TBs) can be used to guide reseeded dental cell differentiation to form whole bioengineered teeth, thereby providing a potential off-the-shelf scaffold for whole tooth regeneration. Porcine TBs were harvested from discarded 6-mo-old pig jaws, and decellularized by successive sodium dodecyl sulfate/Triton-X cycles. Four types of replicate implants were used in this study: 1) acellular dTBs; 2) recellularized dTBs seeded with porcine dental epithelial cells, human dental pulp cells, and human umbilical vein endothelial cells (recell-dTBs); 3) dTBs seeded with bone morphogenetic protein (BMP)-2 (dTB-BMPs); and 4) freshly isolated nondecellularized natural TBs (nTBs). Replicate samples were implanted into the mandibles of host Yucatan mini-pigs and grown for 3 or 6 mo. Harvested mandibles with implanted TB constructs were fixed in formalin, decalcified, embedded in paraffin, sectioned, and analyzed via histological methods. Micro-computed tomography (CT) analysis was performed on harvested 6-mo samples prior to decalcification. All harvested constructs exhibited a high degree of cellularity. Significant production of organized dentin and enamel-like tissues was observed in dTB-recell and nTB implants, but not in dTB or dTB-BMP implants. Micro-CT analyses of 6-mo implants showed the formation of organized, bioengineered teeth of comparable size to natural teeth. To our knowledge, these results are the first to describe the potential use of dTBs for functional whole tooth regeneration.

  12. Spatial signalling mediated by the transforming growth factor-β signalling pathway during tooth formation.

    Science.gov (United States)

    He, Xin-Yu; Sun, Ke; Xu, Ruo-Shi; Tan, Jia-Li; Pi, Cai-Xia; Wan, Mian; Peng, Yi-Ran; Ye, Ling; Zheng, Li-Wei; Zhou, Xue-Dong

    2016-12-16

    Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day (E) 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factor-β signalling pathway might play a role in this process.

  13. Comparing the three color pounehh tooth paste with the conventional one in preventing the formation of the microbial plaque

    Directory of Open Access Journals (Sweden)

    Ebadifar A.

    2008-11-01

    Full Text Available "nBackground and Aim: Plaque control has always been important in preventive dentistry. Various methods and materials have been introduced for this purpose. Recently a three-colored tooth paste has been introduced which claims to prevent plaque formation. The aim of this study was to compare three-colored pouneh tooth paste containing triclosan with the conventional one in preventing plaque formation. "nMaterials and Methods: This was a randomized double blind cross over clinical trial which was carried out on 40 dental students of Tehran azad university in 2005. Before beginning the trial, the index of plaque was evaluated, registered and reduced to null. The subjects were randomly divided into two groups, the case group (three color tooth paste and the control group (conventional tooth paste. The participants were asked to apply the specified tooth paste with an oral B Advantage Artica toothbrush for two weeks. After two weeks, the amount of plaque was re-registered and again reduced to null. The type of tooth paste was changed among two groups and the plaque was registered for the third time at the end of two weeks. Then the patients and assessors were not aware of the type of tooth paste in the tubes (double blind. McNamar and ManWhitney test were used. "nResults: From the 40 subjects, 4 cases were omitted due to the different reasons. The amount of initial plaque index was 88.3 12.1 which was reduced to 78.2 16.9 in the control and 74.1 19.3 in the case group. The difference between primary plaque and secondary plaque (after applying tooth paste was significant in both case and control groups, however there was not any significant difference between two groups. "nConclusion: Based on the results of this study, there was not any significant difference between conventional and three-colored tooth paste in reducing the plaque index.

  14. Hedgehog signaling regulates dental papilla formation and tooth size during zebrafish odontogenesis

    National Research Council Canada - National Science Library

    Yu, Jeffrey C; Fox, Zachary D; Crimp, James L; Littleford, Hana E; Jowdry, Andrea L; Jackman, William R

    2015-01-01

    ... cell behavior at different stages of odontogenesis. To address this issue, we have manipulated hedgehog activity during zebrafish tooth development and visualized the results using confocal microscopy. Results...

  15. Replacement

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2014-03-01

    Full Text Available The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E, enzymatic antioxidants (superoxide dismutase (SOD and catalase (CAT and lipid peroxidation (LPx were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05 improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

  16. 牙仙女%The Tooth Fairy

    Institute of Scientific and Technical Information of China (English)

    李世荣

    2009-01-01

    @@ The American children’s ritual of hiding a lost tooth under a pillow stems from an old German tradition of placing a lost tooth in a mouse or rat hole SO that when a new tooth grew in,it would possess the strong dental qualities of a rodent’S tooth.In America the “tooth rat”was replaced by the“tooth fairy”,who would compensate the child with money for surrendering a tooth to her.

  17. Augmented BMPRIA-mediated BMP signaling in cranial neural crest lineage leads to cleft palate formation and delayed tooth differentiation.

    Directory of Open Access Journals (Sweden)

    Lu Li

    Full Text Available The importance of BMP receptor Ia (BMPRIa mediated signaling in the development of craniofacial organs, including the tooth and palate, has been well illuminated in several mouse models of loss of function, and by its mutations associated with juvenile polyposis syndrome and facial defects in humans. In this study, we took a gain-of-function approach to further address the role of BMPR-IA-mediated signaling in the mesenchymal compartment during tooth and palate development. We generated transgenic mice expressing a constitutively active form of BmprIa (caBmprIa in cranial neural crest (CNC cells that contributes to the dental and palatal mesenchyme. Mice bearing enhanced BMPRIa-mediated signaling in CNC cells exhibit complete cleft palate and delayed odontogenic differentiation. We showed that the cleft palate defect in the transgenic animals is attributed to an altered cell proliferation rate in the anterior palatal mesenchyme and to the delayed palatal elevation in the posterior portion associated with ectopic cartilage formation. Despite enhanced activity of BMP signaling in the dental mesenchyme, tooth development and patterning in transgenic mice appeared normal except delayed odontogenic differentiation. These data support the hypothesis that a finely tuned level of BMPRIa-mediated signaling is essential for normal palate and tooth development.

  18. Socket seal surgery: Clinical uses in implant dentistry and guided bone regeneration procedures for single tooth replacement in the esthetic zone.

    Science.gov (United States)

    Negri, Bruno; Zuhr, Otto; Fickl, Stefan; Ciurana, Xavier Rodríguez; Navarro Martínez, José Manuel; Blanco, Víctor Méndez

    2016-02-01

    Restoring failing anterior teeth with a dental implant is considered a complex treatment even with thorough biologic knowledge of the situation. The goal is to produce a result in which the labial soft tissues and the papillae remain stable over time. Treatment of the fresh extraction socket in the alveolar ridge presents a challenge in everyday clinical practice. Regardless of the subsequent treatment, maintenance of the ridge contour will frequently facilitate all further therapeutic steps. Socket seal surgery and socket preservation in combination with immediate, early, or delayed implant placement can be valuable procedures for single tooth replacement. However, their potential as ridge preservation techniques in these different situations still needs to be demonstrated. The use of these procedures is illustrated in three consecutive cases.

  19. Hedgehog signaling regulates dental papilla formation and tooth size during zebrafish odontogenesis

    Science.gov (United States)

    Yu, Jeffrey C.; Fox, Zachary D.B.; Crimp, James L.; Littleford, Hana E.; Jowdry, Andrea L.; Jackman, William R.

    2015-01-01

    Background Intercellular communication by the hedgehog cell signaling pathway is necessary for tooth development throughout the vertebrates, but it remains unclear which specific developmental signals control cell behavior at different stages of odontogenesis. To address this issue, we have manipulated hedgehog activity during zebrafish tooth development and visualized the results using confocal microscopy. Results We first established that reporter lines for dlx2b, fli1, NF-κB, and prdm1a are markers for specific subsets of tooth germ tissues. We then blocked hedgehog signaling with cyclopamine and observed a reduction or elimination of the cranial neural crest derived dental papilla, which normally contains the cells that later give rise to dentin-producing odontoblasts. Upon further investigation we observed that the dental papilla begins to form and then regresses in the absence of hedgehog signaling, through a mechanism unrelated to cell proliferation or apoptosis. We also found evidence of an isometric reduction in tooth size that correlates with the time of earliest hedgehog inhibition. Conclusions We hypothesize that these results reveal a previously uncharacterized function of hedgehog signaling during tooth morphogenesis, regulating the number of cells in the dental papilla and thereby controlling tooth size. PMID:25645398

  20. Hedgehog signaling regulates dental papilla formation and tooth size during zebrafish odontogenesis.

    Science.gov (United States)

    Yu, Jeffrey C; Fox, Zachary D; Crimp, James L; Littleford, Hana E; Jowdry, Andrea L; Jackman, William R

    2015-04-01

    Intercellular communication by the hedgehog cell signaling pathway is necessary for tooth development throughout the vertebrates, but it remains unclear which specific developmental signals control cell behavior at different stages of odontogenesis. To address this issue, we have manipulated hedgehog activity during zebrafish tooth development and visualized the results using confocal microscopy. We first established that reporter lines for dlx2b, fli1, NF-κB, and prdm1a are markers for specific subsets of tooth germ tissues. We then blocked hedgehog signaling with cyclopamine and observed a reduction or elimination of the cranial neural crest derived dental papilla, which normally contains the cells that later give rise to dentin-producing odontoblasts. Upon further investigation, we observed that the dental papilla begins to form and then regresses in the absence of hedgehog signaling, through a mechanism unrelated to cell proliferation or apoptosis. We also found evidence of an isometric reduction in tooth size that correlates with the time of earliest hedgehog inhibition. We hypothesize that these results reveal a previously uncharacterized function of hedgehog signaling during tooth morphogenesis, regulating the number of cells in the dental papilla and thereby controlling tooth size. © 2015 Wiley Periodicals, Inc.

  1. Non-Metallic Biomaterials for Tooth Repair and Replacement. By Pekka Vallittu, Woodhead Publishing, 2013; 406 pages. Price £145.00/US$245.00/€175.00 ISBN 978-0-85709-244-1

    Directory of Open Access Journals (Sweden)

    Shu-Kun Lin

    2013-01-01

    Full Text Available 1. Discusses the properties of enamel and dentin and their role in adhesive dental restoration;2. Chapters also examine the wear properties of dental ceramics, glasses and bioactive glass ceramics for tooth repair and replacement;3. Dental composites and antibacterial restorative materials are also considered;4. Provides a concise overview of non-metallic biomaterials for dental clinicians, materials scientists and academic researchers alike.As the demand for healthy, attractive teeth increases, the methods and materials employed in restorative dentistry have become progressively more advanced. Non-metallic biomaterials for tooth repair and replacement focuses on the use of biomaterials for a range of applications in tooth repair and, in particular, dental restoration.

  2. Impact of Ellagic Acid in Bone Formation after Tooth Extraction: An Experimental Study on Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mazen M. Jamil Al-Obaidi

    2014-01-01

    Full Text Available Objectives. To estimate the impact of ellagic acid (EA towards healing tooth socket in diabetic animals, after tooth extraction. Methods. Twenty-four Sprague Dawley male rats weighing 250–300 g were selected for this study. All animals were intraperitoneally injected with 45 mg/kg (b.w. of freshly prepared streptozotocin (STZ, to induce diabetic mellitus. Then, the animals were anesthetized, and the upper left central incisor was extracted and the whole extracted sockets were filled with Rosuvastatin (RSV. The rats were separated into three groups, comprising 8 rats each. The first group was considered as normal control group and orally treated with normal saline. The second group was regarded as diabetic control group and orally treated with normal saline, whereas the third group comprised diabetic rats, administrated with EA (50 mg/kg orally. The maxilla tissue stained by eosin and hematoxylin (H&E was used for histological examinations and immunohistochemical technique. Fibroblast growth factor (FGF-2 and alkaline phosphatase (ALP were used to evaluate the healing process in the extracted tooth socket by immunohistochemistry test. Results. The reactions of immunohistochemistry for FGF-2 and ALP presented stronger expression, predominantly in EA treated diabetic rat, than the untreated diabetic rat. Conclusion. These findings suggest that the administration of EA combined with RSV may have accelerated the healing process of the tooth socket of diabetic rats, after tooth extraction.

  3. Fragment reattachment associated with pulpotomy in a posterior tooth with incomplete root formation.

    Science.gov (United States)

    Alcântara, Carlos Eduardo Pinto; Corrêa-Faria, Patrícia; Tavano, Karine Taís Aguiar; Botelho, Adriana Maria

    2011-12-01

    This article reports a case of preserving pulp vitality combined with aesthetics and functional reconstruction of an immature permanent molar extensively destroyed because of a carious lesion. After a pulpotomy using calcium hydroxide, the tooth crown was restored by bonding a dental fragment obtained from an extracted tooth from another individual. Aspects of diagnosis and treatment that directly affect the prognosis of the techniques are discussed. Radiographic and clinical follow-up for two years showed complete root development and a very satisfactory restoration with regard to aesthetics and function.

  4. The adsorption of peptides and purified salivary proteins onto tooth enamel. A study on pellicle formation

    NARCIS (Netherlands)

    Juriaanse, Adriaan Cornelis

    1980-01-01

    The most common diseases that occur in the oral cavity are dental decay (caries) and inflammation of the soft tissues surrounding the teeth (periodontal disease). Both caries and periodontal disease are caused by bacterial metabolites in the plaque, an organic layer on the tooth surface, which consi

  5. The adsorption of peptides and purified salivary proteins onto tooth enamel. A study on pellicle formation

    NARCIS (Netherlands)

    Juriaanse, Adriaan Cornelis

    1980-01-01

    The most common diseases that occur in the oral cavity are dental decay (caries) and inflammation of the soft tissues surrounding the teeth (periodontal disease). Both caries and periodontal disease are caused by bacterial metabolites in the plaque, an organic layer on the tooth surface, which

  6. Tooth Problems

    Science.gov (United States)

    ... that knocked out a tooth?YesNoDo you have pain that is specific to one tooth?YesNoHave you broken or chipped a tooth, or ... room. The tooth may be saved.Start OverDiagnosisYour pain may be from a FRACTURED, CRACKED or LOOSE TOOTH.Self CareSave any pieces of the tooth, wrap ...

  7. Metallosis with pseudotumour formation: Long-term complication following cementless total hip replacement in a dog

    Science.gov (United States)

    Volstad, Nicola J.; Schaefer, Susan L.; Snyder, Laura A.; Meinen, Jeffrey B.; Sample, Susannah J.

    2017-01-01

    Summary Case description A 10-year-old female Belgian Teruven dog was presented to our clinic for total hip revision following a diagnosis of implant (cup) failure with metallosis and abdominal pseudotumour formation. The patient had a cementless metal-on-polyethylene total hip replacement performed nine years prior to presentation. Clinical findings The clinical findings, including pseudotumour formation locally and at sites distant from the implant and pain associated with the joint replacement, were similar to those described in human patients with this condition. Histopathological, surgical, and radiographic findings additionally supported the diagnosis of metallosis and pseudotumour formation. Treatment and outcome Distant site pseudo tumours were surgically removed and the total hip replacement was explanted due to poor bone quality. The patient recovered uneventfully and has since resumed normal activity. Conclusion In veterinary patients with metal-on-polyethylene total hip implants, cup failure leading to metallosis and pseudotumour formation should be considered as a potential cause of ipsilateral hindlimb lameness, intra-pelvic abdominal tumours, or a combination of both. These clinical findings may occur years after total hip replacement surgery. PMID:27189390

  8. 3-D analysis of tooth formation and eruption in patients with craniofacial anomalies

    DEFF Research Database (Denmark)

    Kreiborg, Sven; Larsen, Per; Bro-Nielsen, Morten

    1996-01-01

    -dimensional analysis from orthopantomograms, intra-oral X-rays or cephalometric radiographs. A method for visualization of the developing tooth crowns in three dimensions based on CT-scans of the jaws has been developed (Bro-Nielsen et al., 1996). The purpose of the present study was to apply this new visualization...... method to the analysis of the complex dental problems found in some of the syndromes listed above....

  9. New material of Longipteryx (Aves: Enantiornithes) from the Lower Cretaceous Yixian Formation of China with the first recognized avian tooth crenulations.

    Science.gov (United States)

    Wang, Xuri; Shen, Caizhi; Liu, Sizhao; Gao, Chunling; Cheng, Xiaodong; Zhang, Fengjiao

    2015-04-02

    We report on a new specimen of Longipteryx chaoyangensis from the Lower Cretaceous Yixian Formation in Chaoyang, Liaoning Province, China. The new material preserves previously unknown tooth crenulations. This is the first recognized tooth crenulations within Aves. It not only provides new information regarding the anatomy of the Longipteryx, but also sheds new light on the trophic specialization of this genus and even this family. It was discovered from the Yixian Formation, which is older than the Longipteryx chaoyangensis bearing-Jiufotang Formation. This new discovery also expands the known stratigraphic range of Longipteryx.

  10. Impacted tooth

    Science.gov (United States)

    ... is not causing any problems. Over-the-counter pain relievers may help if the impacted tooth causes discomfort. Warm saltwater (one-half teaspoon or ... tooth (or partially emerged tooth) and you have pain in the gums or other symptoms. Alternative Names ... tooth; Dental impaction; Unerupted tooth References ...

  11. Tooth extraction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007630.htm Tooth extraction To use the sharing features on this page, please enable JavaScript. A tooth extraction is a procedure to remove a tooth from ...

  12. Tooth development in Ambystoma mexicanum: phosphatase activities, calcium accumulation and cell proliferation in the tooth-forming tissues.

    Science.gov (United States)

    Wistuba, Joachim; Ehmcke, Jens; Clemen, Günter

    2003-06-01

    Prerequisites of tooth formation, cell proliferation in the tooth-forming tissues, calcium accumulation and the enzymatic activities of alkaline (ALP) and acid phosphatases (ACP) were investigated by immunohistochemical and histochemical methods in various developmental stages of the Mexican Axolotl, Ambystoma mexicanum. During the growth of replacement teeth, the tooth-forming tissues continually recruit cells from the surrounding regions. The basal layer of the oral epithelium, the dental lamina and sometimes even the outer enamel epithelium provide cells for the differentiated inner enamel epithelium, in which the active ameloblasts are localized. The differentiating odontoblasts are derived from proliferating cells situated basally to the replacement teeth in the mesenchymal tissue. When differentiation has started and the cells have become functional, proliferative activity can no longer be observed. Calcium is accumulated close to the site of mineralization in the inner enamel epithelium and in the odontoblasts as it is in mammals, elasmobranchii and teleostei. The activities of ACP and ALP related to the mineralization of the replacement teeth are separated spatially and not sequentially as they are in mammals. However, the results indicate a similar function of these enzymatic components in relation to tooth formation and maturation of mineral deposition. Most of the substantial processes related to tooth formation reported from other vertebrates occur in a manner similar to that in Ambystoma mexicanum, but there also seem to be basic mechanisms present that are realised in a unique way in this urodele.

  13. Endodontic therapy or single tooth implant? A systematic review.

    Science.gov (United States)

    Torabinejad, Mahmoud; Lozada, Jaime; Puterman, Israel; White, Shane N

    2008-06-01

    Should a tooth with pulpal involvement be saved through endodontic therapy, or extracted and replaced with a single tooth implant? Within the limitations of the existing literature, this systematic review of treatment outcomes found that initial endodontic treatment had a high long-term survival rate, equivalent to replacement of a missing tooth with an implant-supported restoration. Single tooth implants should be considered as the first treatment option for patients requiring extraction and tooth replacement.

  14. Developing a biomimetic tooth bud model.

    Science.gov (United States)

    Smith, Elizabeth E; Zhang, Weibo; Schiele, Nathan R; Khademhosseini, Ali; Kuo, Catherine K; Yelick, Pamela C

    2017-01-08

    A long-term goal is to bioengineer, fully functional, living teeth for regenerative medicine and dentistry applications. Biologically based replacement teeth would avoid insufficiencies of the currently used dental implants. Using natural tooth development as a guide, a model was fabricated using post-natal porcine dental epithelial (pDE), porcine dental mesenchymal (pDM) progenitor cells, and human umbilical vein endothelial cells (HUVEC) encapsulated within gelatin methacrylate (GelMA) hydrogels. Previous publications have shown that post-natal DE and DM cells seeded onto synthetic scaffolds exhibited mineralized tooth crowns composed of dentin and enamel. However, these tooth structures were small and formed within the pores of the scaffolds. The present study shows that dental cell-encapsulated GelMA constructs can support mineralized dental tissue formation of predictable size and shape. Individually encapsulated pDE or pDM cell GelMA constructs were analysed to identify formulas that supported pDE and pDM cell attachment, spreading, metabolic activity, and neo-vasculature formation with co-seeded endothelial cells (HUVECs). GelMa constructs consisting of pDE-HUVECS in 3% GelMA and pDM-HUVECs within 5% GelMA supported dental cell differentiation and vascular mineralized dental tissue formation in vivo. These studies are the first to demonstrate the use of GelMA hydrogels to support the formation of post-natal dental progenitor cell-derived mineralized and functionally vascularized tissues of specified size and shape. These results introduce a novel three-dimensional biomimetic tooth bud model for eventual bioengineered tooth replacement teeth in humans. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Replacive sulfide formation in anhydrite chimneys from the Pacmanus hydrothermal field, Papua New Guinea

    Science.gov (United States)

    Los, Catharina; Bach, Wolfgang; Plümper, Oliver

    2016-04-01

    Hydrothermal flow within the oceanic crust is an important process for the exchange of energy and mass between the lithosphere, hydrosphere and biosphere. Infiltrated seawater heats up and interacts with wall rock, causing mineral replacement reactions. These play a large role in the formation of ore deposits; at the discharge zone, a hot, acidic and metal-rich potential ore fluid exits the crust. It mixes with seawater and forms chimneys, built up of sulfate minerals such as anhydrite (CaSO4), which are subsequently replaced by sulfide minerals. Sulfide formation is related to fluid pathways, defined by cracks and pores in the sulfate chimney. Over time, these systems might develop into massive sulfide deposits. The big question is then: how is sulfate-sulfide replacement related to the evolution of rock porosity? To address this question, sulfide-bearing anhydrite chimneys from the Pacmanus hydrothermal field (Manus Basin, Papua New Guinea) were studied using X-ray tomography, EMPA, FIB-SEM and -TEM. The apparently massive anhydrite turns out highly porous on the micro scale, with sulfide minerals in anhydrite cleavage planes and along grain boundaries. The size of the sulfide grains relates to the pores they grew into, suggesting a tight coupling between dissolution (porosity generation) and growth of replacive minerals. Some of the sulfide grains are hollow and apparently used the dissolving anhydrite as a substrate to start growth in a pore. Another mode of sulfide development is aggregates of euhedral pyrite cores surrounded by colloform chalcopyrite. This occurrence implies that fluid pathways have remained open for some time to allow several stages of precipitation during fluid evolution. To start the replacement and to keep it going, porosity generation is crucial. Our samples show that dissolution of anhydrite occurred along pathways where fluid could enter, such as cleavage planes and grain boundaries. It appears that fluids ascending within the inner

  16. Successful autotransplantation of a mature mesiodens to replace a traumatized maxillary central incisor.

    Science.gov (United States)

    Dharmani, U; Rajput, A; Kamal, C; Talwar, S; Verma, M

    2015-06-01

    This case describes the successful transplantation of a mature mesiodens tooth to replace a traumatized maxillary central incisor. A 17-year-old male attended 1 week after a traumatic injury to his left maxillary central incisor (tooth 21). Radiographs revealed a horizontal root fracture and a poor prognosis. The tooth was atraumatically removed and replaced with a mesiodens lying in the same region. After stabilization, root canal treatment was performed and aesthetics were restored with a tooth coloured restoration. A 2-year follow-up revealed the tooth had good aesthetics and function. A supernumerary nonfunctional tooth such as a mesiodens can be successfully used to replace a missing permanent tooth by autotransplantation. Autotransplantation has a high success rate if case selection is good, appropriate surgery is carried out and excellent hygiene is maintained. Autotransplantation should be considered as one of the most biologic techniques for replacing a missing tooth with minimal cost. Autotransplantation can be carried out even after complete root formation in the donor tooth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. Evolution and developmental diversity of tooth regeneration.

    Science.gov (United States)

    Tucker, Abigail S; Fraser, Gareth J

    2014-01-01

    This review considers the diversity observed during both the development and evolution of tooth replacement throughout the vertebrates in a phylogenetic framework from basal extant chondrichthyan fish and more derived teleost fish to mammals. We illustrate the conservation of the tooth regeneration process among vertebrate clades, where tooth regeneration refers to multiple tooth successors formed de novo for each tooth position in the jaws from a common set of retained dental progenitor cells. We discuss the conserved genetic mechanisms that might be modified to promote morphological diversity in replacement dentitions. We review current research and recent progress in this field during the last decade that have promoted our understanding of tooth diversity in an evolutionary developmental context, and show how tooth replacement and dental regeneration have impacted the evolution of the tooth-jaw module in vertebrates.

  18. Tooth anatomy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002214.htm Tooth anatomy To use the sharing features on this page, ... upper jawbone is called the maxilla. Images Tooth anatomy References Lingen MW. Head and neck. In: Kumar ...

  19. Hydration of Biodentine, Theracal LC, and a prototype tricalcium silicate-based dentin replacement material after pulp capping in entire tooth cultures.

    Science.gov (United States)

    Camilleri, Josette; Laurent, Patrick; About, Imad

    2014-11-01

    The calcium-releasing ability of pulp-capping materials induces pulp tissue regeneration. Tricalcium silicate-based materials produce calcium hydroxide as a by-product of hydration. Assessment of hydration and calcium ion leaching is usually performed on samples that have been aged in physiological solution for a predetermined period of time. The hydration and activity of the materials in vivo may not be similar to those displayed in vitro because of insufficient fluid available in contact with dentin. The aim of this research was the assessment of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate-based material after pulp capping and to compare it with direct hydration in an aqueous solution. The extent of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate-based material with a similar composition to Biodentine but not incorporating the additives was assessed by scanning electron microscopy and energy dispersive spectroscopy of polished specimens after being allowed to hydrate in Hank's balanced salt solution for 14 days. The extent of hydration was compared with material hydration when used as direct pulp capping materials by using a tooth culture model. Material activity was also assessed by x-ray diffraction analysis to investigate the deposition of calcium hydroxide by the materials, and calcium ion leaching in Hank's balanced salt solution was assessed by ion chromatography. Biodentine and the prototype tricalcium silicate cement hydrated and reaction by-products were deposited in the cement matrix both after pulp capping and when incubated in an aqueous solution. Calcium hydroxide was formed, and calcium ions were leached in solution. Theracal LC hydration was incomplete because of the limited moisture diffusion within the material. Thus, no calcium hydroxide was produced, and a lower calcium ion leaching was recorded. Theracal LC had a heterogeneous structure with large unhydrated

  20. An intramembranous ossification model for the in silico analysis of bone tissue formation in tooth extraction sites.

    Science.gov (United States)

    Corredor-Gómez, Jennifer Paola; Rueda-Ramírez, Andrés Mauricio; Gamboa-Márquez, Miguel Alejandro; Torres-Rodríguez, Carolina; Cortés-Rodríguez, Carlos Julio

    2016-07-21

    The accurate modeling of biological processes allows us to predict the spatiotemporal behavior of living tissues by computer-aided (in silico) testing, a useful tool for the development of medical strategies, avoiding the expenses and potential ethical implications of in vivo experimentation. A model for bone healing in mouth would be useful for selecting proper surgical techniques in dental procedures. In this paper, the formulation and implementation of a model for Intramembranous Ossification is presented aiming to describe the complex process of bone tissue formation in tooth extraction sites. The model consists in a mathematical description of the mechanisms in which different types of cells interact, synthesize and degrade extracellular matrices under the influence of biochemical factors. Special attention is given to angiogenesis, oxygen-dependent effects and growth factor-induced apoptosis of fibroblasts. Furthermore, considering the depth-dependent vascularization of mandibular bone and its influence on bone healing, a functional description of the cell distribution on the severed periodontal ligament (PDL) is proposed. The developed model was implemented using the finite element method (FEM) and successfully validated by simulating an animal in vivo experiment on dogs reported in the literature. A good fit between model outcome and experimental data was obtained with a mean absolute error of 3.04%. The mathematical framework presented here may represent an important tool for the design of future in vitro and in vivo tests, as well as a precedent for future in silico studies on osseointegration and mechanobiology.

  1. Using dental enamel wrinkling to define sauropod tooth morphotypes from the Canadon Asfalto Formation, Patagonia, Argentina.

    Directory of Open Access Journals (Sweden)

    Femke M Holwerda

    Full Text Available The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic-early Middle Jurassic in Central Patagonia (Argentina, which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.

  2. Origin of Molar-Tooth Structure Based on Sequence-Stratigraphic Position and Macroscopic Features:Example from Mesoproterozoic Gaoyuzhuang Formation at Jixian Section, Tianjin, North China

    Institute of Scientific and Technical Information of China (English)

    Mei Mingxiang

    2006-01-01

    Both the macroscopic feature and the sequence-stratigraphic position of the molar-tooth structure developed in the third member of the Gaoyuzhuang (高于庄) Formation at the Jixian (蓟县)Section in Tianjin (天津) can provide some useful information about its origin and can reveal some problems to be further researched in the future. The Mesoproterozoic Gaoyuzhuang Formation is a set of ~ 1 600 m thick carbonate strata. This formation can be divided into four members. The first member is mainly made up of stromatolitic dolomites; the second is marked by a set of manganese dolomites; the third is mainly composed of lamina limestones with the development of molar-tooth strcutures; the fourth is a set of stromatolitic-lithoherm dolomites. According to lithofacies and its succession, several types of meter-scale cycles can be discerned in the Gaoyuzhuang Formation: the L-M type, the subtidal type and the peritidal type. There is a regularly vertical stacking pattern for meter-scale cycles in the third-order sequence. Therefore, the Mesoproterozoic Gaoyuzhuang Formation can be divided into 13 third-order sequences (SQ1 to SQ13 ) and can further be grouped into 4 second-order sequences. The third member is marked by lamina limestones and can be grouped into three third-order sequences (SQ9 to SQ11 ). The molar-tooth structure is developed in the middle part of the third sequence, I.e. SQ11, in the third member. Several features of this kind of molar-tooth structure reflect some features of carbonate sedimentation in the Precambrian, such as the particular configuration, abundant organic matter, and easy silication. Stromatolites are chiefly formed in a shallow tidal-flat environment; lamina are mainly formed in the shallow ramp and molar-tooth structures are mainly generated in a relatively more deep-water environment from the middle to the deep ramp. Therefore, similar to stromatolite and lamina, the molartooth structure might also be a kind of bio

  3. The functional and palaeoecological implications of tooth morphology and wear for the megaherbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada.

    Science.gov (United States)

    Mallon, Jordan C; Anderson, Jason S

    2014-01-01

    Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche

  4. Practical whole-tooth restoration utilizing autologous bioengineered tooth germ transplantation in a postnatal canine model

    Science.gov (United States)

    Ono, Mitsuaki; Oshima, Masamitsu; Ogawa, Miho; Sonoyama, Wataru; Hara, Emilio Satoshi; Oida, Yasutaka; Shinkawa, Shigehiko; Nakajima, Ryu; Mine, Atsushi; Hayano, Satoru; Fukumoto, Satoshi; Kasugai, Shohei; Yamaguchi, Akira; Tsuji, Takashi; Kuboki, Takuo

    2017-01-01

    Whole-organ regeneration has great potential for the replacement of dysfunctional organs through the reconstruction of a fully functional bioengineered organ using three-dimensional cell manipulation in vitro. Recently, many basic studies of whole-tooth replacement using three-dimensional cell manipulation have been conducted in a mouse model. Further evidence of the practical application to human medicine is required to demonstrate tooth restoration by reconstructing bioengineered tooth germ using a postnatal large-animal model. Herein, we demonstrate functional tooth restoration through the autologous transplantation of bioengineered tooth germ in a postnatal canine model. The bioengineered tooth, which was reconstructed using permanent tooth germ cells, erupted into the jawbone after autologous transplantation and achieved physiological function equivalent to that of a natural tooth. This study represents a substantial advancement in whole-organ replacement therapy through the transplantation of bioengineered organ germ as a practical model for future clinical regenerative medicine. PMID:28300208

  5. Use of postoperative irradiation for the prevention of heterotopic bone formation after total hip replacement

    Energy Technology Data Exchange (ETDEWEB)

    Sylvester, J.E.; Greenberg, P.; Selch, M.T.; Thomas, B.J.; Amstutz, H.

    1988-03-01

    Formation of heterotopic bone (HTB) following total hip replacement may partially or completely ankylose the joint space, causing pain and/or limiting the range of motion. Patients at high risk for formation of HTB postoperatively include those with previous HTB formation, heterotopic osteoarthritis, and active rheumatoid spondylitis. Patients in these high risk groups have a 63-69% incidence of post-operative HTB formation, usually seen radiographically by 2 months post-operation. From 1980-1986 twenty-nine hips in 28 consecutively treated patients were irradiated post-operatively at the UCLA Center for the Health Sciences. The indication for irradiation was documented HTB formation previously in 26 of the 27 hips presented below. From 1980-1982 patients received 20 Gray (Gy) in 2 Gy fractions; from 1982-1986 the dose was reduced to 10 Gy in 2 Gy fractions. Twenty-seven hips in 26 patients completed therapy and were available for evaluation, with a minimum of 2 month follow-up, and a median follow-up of 12 months. Three of 27 hips developed significant HTB (Brooker grade III or IV) post-operatively, whereas 5 of 27 hips developed minor, nonsymptomatic HTB (Brooker grade I). When irradiation was begun by postoperative day 4, 0 of 17 hips formed significant HTB. If irradiation began after post-operative day 4, 3 of 10 hips formed significant HTB (Brooker grade III or IV). These 3 hips received doses of 10 Gy in one hip and 20 Gy in the other 2 hips. There were no differences in the incidence or severity of side effects in the 10 Gy vs. the 20 Gy treatment groups. Eighteen hips received 10 Gy, 8 hips 20 Gy and, 1 hip 12 Gy. In conclusion, 10 Gy in 5 fractions appears as effective as 20 Gy in 10 fractions at preventing post-operative formation of HTB. For optimal results, treatment should begin as early as possible prior to post-operative day 4.

  6. Effect of mangosteen peel extract combined with demineralized freezed-dried bovine bone xenograft on osteoblast and osteoclast formation in post tooth extraction socket

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    Utari Kresnoadi

    2016-12-01

    Full Text Available Background: Tooth extraction, a common procedure in dentistry, can cause bone resorption during socket healing. Therefore, it is important to perform socket preservation procedure to maintain alveolar bone. Providing a combination of mangosteen peel extract with demineralized freezed-dried bovine bone xenograft (DFDBBX in tooth extraction socket was expected to accelerate alveol bone formation. Purpose: This study aims to determine the effect of mangosteen peel extract combined with DFDBBX introduced into the socket of post tooth extraction on the formation of osteoblasts and osteoclasts. Method: Twenty-eight (28 Cavia cobayas were divided into four groups. Extraction to the lower left incisor of Cavia cobaya was performed. The extraction socket was filled with 25 gram of PEG (group I as a control, active materials consisted of mangosteen peel extract and DFDBBX 0.5% (group II, active materials consisted of mangosteen peel extract and DFDBBX 1% (group III, and active materials consisted of mangosteen peel extract and DFDBBX 2% (group IV. After thirty days, those Cavia cobayas were sacrificed. By using HE on Histopatological examination, the number of osteoblasts and osteoclasts were measured by light microscope with 400 times of magnification. The statistical analysis was then performed using oneway Anova & TukeyHSD test. Result: The component active materials consisted of mangosteen peel extract and DFDBBX 2% had the most significant results related to the formation of osteoblasts and osteoclasts. Conclusion: Mangosteen peel extract combined with DFDBBX can increase osteoblasts and decrease osteoclasts in the socket of tooth extraction in Cavia cobaya. The combination of mangosteen peel extract and DFDBBX 2% is the most effective material in increasing osteoblast and decreasing osteoclast.

  7. Extent of tooth decay in the mouth and increased need for replacement of dental restorations: the New England Children's Amalgam Trial.

    Science.gov (United States)

    Trachtenberg, Felicia; Maserejian, Nancy Nairi; Tavares, Mary; Soncini, Jennifer Ann; Hayes, Catherine

    2008-01-01

    The purpose of this study was to assess the relationship between baseline caries experience and the restoration replacement rate in children. The 5-year New England Children's Amalgam Trial recruited 534 6- to 10-year-old children with 2 or more carious posterior teeth. The association between decoy and longevity of restorations was assessed. Restorations with no follow-up (N = 391) were excluded from analysis. The average follow-up was 3.0 +/- 1.6 years in 489 children. Restorations with follow-up (N = 3,604) were placed in mouths with a median of 15 dfs/DFS and 8 dft/DFT. The need for replacement increased significantly (P or = 14 dfs/DFS needed replacement, compared to 9% for 2 to 5 dfs/DFS. Comparing dft/DFT after 5 years of follow-up, there was a 23% replacement rate for > or = 12 dft/DFT compared to 10% for 2 to 3 dft/DFT. Decoy in the mouth had a greater association with the need for replacement due to new caries compared to replacement due to recurrent caries. Children with more decoy at the time of restoration placement were at higher risk for replacement of restorations.

  8. How does domain replacement affect fibril formation of the rabbit/human prion proteins.

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    Xu Yan

    Full Text Available It is known that in vivo human prion protein (PrP have the tendency to form fibril deposits and are associated with infectious fatal prion diseases, while the rabbit PrP does not readily form fibrils and is unlikely to cause prion diseases. Although we have previously demonstrated that amyloid fibrils formed by the rabbit PrP and the human PrP have different secondary structures and macromolecular crowding has different effects on fibril formation of the rabbit/human PrPs, we do not know which domains of PrPs cause such differences. In this study, we have constructed two PrP chimeras, rabbit chimera and human chimera, and investigated how domain replacement affects fibril formation of the rabbit/human PrPs.As revealed by thioflavin T binding assays and Sarkosyl-soluble SDS-PAGE, the presence of a strong crowding agent dramatically promotes fibril formation of both chimeras. As evidenced by circular dichroism, Fourier transform infrared spectroscopy, and proteinase K digestion assays, amyloid fibrils formed by human chimera have secondary structures and proteinase K-resistant features similar to those formed by the human PrP. However, amyloid fibrils formed by rabbit chimera have proteinase K-resistant features and secondary structures in crowded physiological environments different from those formed by the rabbit PrP, and secondary structures in dilute solutions similar to the rabbit PrP. The results from transmission electron microscopy show that macromolecular crowding caused human chimera but not rabbit chimera to form short fibrils and non-fibrillar particles.We demonstrate for the first time that the domains beyond PrP-H2H3 (β-strand 1, α-helix 1, and β-strand 2 have a remarkable effect on fibrillization of the rabbit PrP but almost no effect on the human PrP. Our findings can help to explain why amyloid fibrils formed by the rabbit PrP and the human PrP have different secondary structures and why macromolecular crowding has different

  9. Placement of replace select Ti-Unite-coated type implants using a combination of immediate and submerge techniques after tooth extraction

    Directory of Open Access Journals (Sweden)

    Coen Pramono D

    2006-06-01

    Full Text Available The high success rate of immediate implant placement both in the anterior and posterior regions were reported by many authors, therefore applying this techniques can be considered as a safe surgical procedure and minimizing the dental office visit for patient satisfaction. This paper reports the outcome of immediate placement of implants following extraction of anterior maxillary teeth. Combination technique of immediate and submerge implant placements including bone grafting procedure were used. Four implants with TiUnite surface type were placed immediately in two patients with the short-term result indicated that this technique may serve as a simple and safe procedure for immediate implant placement. It was concluded that immediate implant placement technique combined with TiUnite implant surface was successful in treating region directly after tooth extraction therefore this technique can be use as an alternative surgical method for dental implant rehabilitation.

  10. Pulpal regeneration following allogenic tooth transplantation into mouse maxilla.

    Science.gov (United States)

    Unno, Hideki; Suzuki, Hironobu; Nakakura-Ohshima, Kuniko; Jung, Han-Sung; Ohshima, Hayato

    2009-04-01

    Autogenic tooth transplantation is now a common procedure in dentistry for replacing a missing tooth. However, there are many difficulties in clinical application of allogenic tooth transplantation because of immunological rejection. This study aims to clarify pulpal regeneration following allogenic tooth transplantation into the mouse maxilla by immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU) and nestin, and by the histochemistry for tartrate-resistant acid phosphatase (TRAP). The upper right first molar (M1) of 2-week-old mice was extracted and allografted in the original socket in both the littermate and non-littermate after the extraction of M1. Tooth transplantation weakened the nestin-positive reactions in the pulp tissue that had shown immunoreactivity for nestin before operation. On postoperative Days 5-7, tertiary dentin formation commenced next to the preexisting dentin where nestin-positive odontoblast-like cells were arranged in all cases of the littermate group until Day 14, except for one case showing immunological rejection in the pulp chamber. In the non-littermate group, bone-like tissue formation occurred in the pulp chamber in addition to tertiary dentin formation until Day 14. The rate of tertiary dentin was 38%, and the rate of the mixed form of dentin and bone-like tissue formation was 23% (the remainder was immunological rejection). Interestingly, the periodontal tissue recovered even in the case of immunological rejection in which the pulp chamber was replaced by sparse connective tissue. These results suggest that the selection of littermate or non-littermate is decisive for the survival of odontoblast-lineage cells and that the immunological rejection does not influence the periodontal regeneration.

  11. Estimating ages of white-tailed deer: Age and sex patterns of error using tooth wear-and-replacement and consistency of cementum annuli

    Science.gov (United States)

    Samuel, Michael D.; Storm, Daniel J.; Rolley, Robert E.; Beissel, Thomas; Richards, Bryan J.; Van Deelen, Timothy R.

    2014-01-01

    The age structure of harvested animals provides the basis for many demographic analyses. Ages of harvested white-tailed deer (Odocoileus virginianus) and other ungulates often are estimated by evaluating replacement and wear patterns of teeth, which is subjective and error-prone. Few previous studies however, examined age- and sex-specific error rates. Counting cementum annuli of incisors is an alternative, more accurate method of estimating age, but factors that influence consistency of cementum annuli counts are poorly known. We estimated age of 1,261 adult (≥1.5 yr old) white-tailed deer harvested in Wisconsin and Illinois (USA; 2005–2008) using both wear-and-replacement and cementum annuli. We compared cementum annuli with wear-and-replacement estimates to assess misclassification rates by sex and age. Wear-and-replacement for estimating ages of white-tailed deer resulted in substantial misclassification compared with cementum annuli. Age classes of females were consistently underestimated, while those of males were underestimated for younger age classes but overestimated for older age classes. Misclassification resulted in an impression of a younger age-structure than actually was the case. Additionally, we obtained paired age-estimates from cementum annuli for 295 deer. Consistency of paired cementum annuli age-estimates decreased with age, was lower in females than males, and decreased as age estimates became less certain. Our results indicated that errors in the wear-and-replacement techniques are substantial and could impact demographic analyses that use age-structure information. 

  12. Tooth abscess

    Science.gov (United States)

    ... tissue swelling within the tooth. This causes a toothache . The toothache may stop if pressure is relieved. But the ... tissue. Symptoms The main symptom is a severe toothache. The pain is continuous. It does not stop. ...

  13. The Effects of Irradiation and Calcium-deficient Diet on the Expression of Interleukin-1 during Tooth Formation of Rat Molar

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Joong; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    2000-09-15

    To elucidate the effects of the irradiation and calcium-deficient diet on expression of interleukin (IL)-1 during tooth formation of rat molar. The pregnant three-week-old Spague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group, and the experimental groups were irradiation/normal diet group and irradiation/calcium-diet group. The abdomen of the rats on the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae tooth germs were taken. The specimen were prepared to make sections for light microscopy, and some of tissue sections were stained immunohistochemically with anti-IL-1 antibody. In the irradiation/normal diet group, dental follicle showed fewer blood vessels, mononuclear cells, and fusions of mononuclear cells than in non-irradiation/normal diet group. Alveolar bone showed a few osteoblasts and osteoclasts. Periodontal ligament showed collagen fibers and fibroblasts with irregularity. Weak immunoreactivity for IL-1 was shown in dental follicle, alveolar bone, and periodontal ligament. In the irradiation/calcium-deficient diet group, dental follicle showed sparse cellularity. Alveolar bone showed diminished number of osteoblasts. Periodontal ligament showed irregular collagen fibers and atrophy of cementoblasts and fibroblasts. No immunoreactivity for IL-1 was shown in dental follicle, alveolar bone, and periodontal ligament. Irradiation and calcium-deficient diet seems to cause disturbance of the expression of interleukin-1 during tooth formation of rat molar.

  14. The dam replacing gene product enhances Neisseria gonorrhoeae FA1090 viability and biofilm formation.

    Science.gov (United States)

    Kwiatek, Agnieszka; Bacal, Pawel; Wasiluk, Adrian; Trybunko, Anastasiya; Adamczyk-Poplawska, Monika

    2014-01-01

    Many Neisseriaceae do not exhibit Dam methyltransferase activity and, instead of the dam gene, possess drg (dam replacing gene) inserted in the leuS/dam locus. The drg locus in Neisseria gonorrhoeae FA1090 has a lower GC-pairs content (40.5%) compared to the whole genome of N. gonorrhoeae FA1090 (52%). The gonococcal drg gene encodes a DNA endonuclease Drg, with GmeATC specificity. Disruption of drg or insertion of the dam gene in gonococcal genome changes the level of expression of genes as shown by transcriptome analysis. For the drg-deficient N. gonorrhoeae mutant, a total of 195 (8.94% of the total gene pool) genes exhibited an altered expression compared to the wt strain by at least 1.5 fold. In dam-expressing N. gonorrhoeae mutant, the expression of 240 genes (11% of total genes) was deregulated. Most of these deregulated genes were involved in translation, DNA repair, membrane biogenesis and energy production as shown by cluster of orthologous group analysis. In vivo, the inactivation of drg gene causes the decrease of the number of live neisserial cells and long lag phase of growth. The insertion of dam gene instead of drg locus restores cell viability. We have also shown that presence of the drg gene product is important for N. gonorrhoeae FA1090 in adhesion, including human epithelial cells, and biofilm formation. Biofilm produced by drg-deficient strain is formed by more dispersed cells, compared to this one formed by parental strain as shown by scanning electron and confocal microscopy. Also adherence assays show a significantly smaller biomass of formed biofilm (OD570 = 0.242 ± 0.038) for drg-deficient strain, compared to wild-type strain (OD570 = 0.378 ± 0.057). Dam-expressing gonococcal cells produce slightly weaker biofilm with cells embedded in an extracellular matrix. This strain has also a five times reduced ability for adhesion to human epithelial cells. In this context, the presence of Drg is more advantageous for N. gonorrhoeae biology than

  15. Transplantation of premolars as an approach for replacing avulsed teeth.

    Science.gov (United States)

    Andreasen, Jens Ove; Schwartz, Ole; Kofoed, Thomas; Daugaard-Jensen, Jette

    2009-01-01

    Autotransplantation of premolars to the anterior region subsequent to tooth loss represent a unique treatment method that has a number of advantages in comparison with other tooth substitution methods. A tooth transplant has a bone inducing capacity implying that lost labial bone is regenerated. Secondly the tooth precipitates growth of the alveolar procces and allows treatment to be performed at an early age (10-12 years) where the trauma incidence is at its maximum. Finally transplanted teeth can be moved orthodontically. These characteristics make implant solutions appealing in a number of situations. The procedure consist in selecting a premolar in a optimal root development stage which is approximately three fourths root formation where optimal pulp and periodontal ligament healing can be achieved in more than 90 percent of the cases. The tooth is later after slight crown remodeling restored with composite or a porcelain laminate. Four recent long-term studies have shown survival rates between 90-98 percent and a single long term study (33 years) showed a survival rate of 90 percent, a survival rate not surpassed by any other type of tooth replacement (fixed or removable prostetics, implants). In conclusion premolar transplantation should be considered in cases of early loss of a permanent tooth.

  16. Structure, attachment, replacement and growth of teeth in bluefish, Pomatomus saltatrix (Linnaeus, 1776), a teleost with deeply socketed teeth.

    Science.gov (United States)

    Bemis, William E; Giuliano, Anne; McGuire, Betty

    2005-01-01

    Tooth replacement poses many questions about development, pattern formation, tooth attachment mechanisms, functional morphology and the evolution of vertebrate dentitions. Although most vertebrate species have polyphyodont dentitions, detailed knowledge of tooth structure and replacement is poor for most groups, particularly actinopterygians. We examined the oral dentition of the bluefish, Pomatomus saltatrix, a pelagic and coastal marine predator, using a sample of 50 individuals. The oral teeth are located on the dentary and premaxillary bones, and we scored each tooth locus in the dentary and premaxillary bones using a four-part functional classification: absent (A), incoming (I), functional (F=fully ankylosed) or eroding (E). The homodont oral teeth of Pomatomus are sharp, deeply socketed and firmly ankylosed to the bone of attachment. Replacement is intraosseus and occurs in alternate tooth loci with long waves of replacement passing from rear to front. The much higher percentage of functional as opposed to eroding teeth suggests that replacement rates are low but that individual teeth are quickly lost once erosion begins. Tooth number increases ontogenetically, ranging from 15-31 dentary teeth and 15-39 premaxillary teeth in the sample studied. Teeth increase in size with every replacement cycle. Remodeling of the attachment bone occurs continuously to accommodate growth. New tooth germs originate from a discontinuous dental lamina and migrate from the lingual (dentary) or labial (premaxillary) epithelium through pores in the bone of attachment into the resorption spaces beneath the existing teeth. Pomatomus shares unique aspects of tooth replacement with barracudas and other scombroids and this supports the interpretation that Pomatomus is more closely related to scombroids than to carangoids.

  17. Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

    Science.gov (United States)

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2014-09-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis.

  18. Estradiol replacement enhances fear memory formation, impairs extinction and reduces COMT expression levels in the hippocampus of ovariectomized female mice.

    Science.gov (United States)

    McDermott, Carmel M; Liu, Dan; Ade, Catherine; Schrader, Laura A

    2015-02-01

    Females experience depression, posttraumatic stress disorder (PTSD), and anxiety disorders at approximately twice the rate of males, but the mechanisms underlying this difference remain undefined. The effect of sex hormones on neural substrates presents a possible mechanism. We investigated the effect of ovariectomy at two ages, before puberty and in adulthood, and 17β-estradiol (E2) replacement administered chronically in drinking water on anxiety level, fear memory formation, and extinction. Based on previous studies, we hypothesized that estradiol replacement would impair fear memory formation and enhance extinction rate. Females, age 4 weeks and 10 weeks, were divided randomly into 4 groups; sham surgery, OVX, OVX+low E2 (200nM), and OVX+high E2 (1000nM). Chronic treatment with high levels of E2 significantly increased anxiety levels measured in the elevated plus maze. In both age groups, high levels of E2 significantly increased contextual fear memory but had no effect on cued fear memory. In addition, high E2 decreased the rate of extinction in both ages. Finally, catechol-O-methyltransferase (COMT) is important for regulation of catecholamine levels, which play a role in fear memory formation and extinction. COMT expression in the hippocampus was significantly reduced by high E2 replacement, implying increased catecholamine levels in the hippocampus of high E2 mice. These results suggest that estradiol enhanced fear memory formation, and inhibited fear memory extinction, possibly stabilizing the fear memory in female mice. This study has implications for a neurobiological mechanism for PTSD and anxiety disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Communicating effectiveness of intervention for chronic diseases: what single format can replace comprehensive information?

    Directory of Open Access Journals (Sweden)

    Kristiansen Ivar S

    2008-06-01

    Full Text Available Abstract Background There is uncertainty about how GPs should convey information about treatment effectiveness to their patients in the context of cardiovascular disease. Hence we study the concordance of decisions based on one of four single information formats for treatment effectiveness with subsequent decisions based on all four formats combined with a pictorial representation. Methods A randomized study comprising 1,169 subjects aged 40–59 in Odense, Denmark. Subjects were randomized to receive information in terms of absolute risk reduction (ARR, relative risk reduction (RRR, number needed to treat (NNT, or prolongation of life (POL without heart attack, and were asked whether they would consent to treatment. Subsequently the same information was conveyed with all four formats jointly accompanied by a pictorial presentation of treatment effectiveness. Again, subjects should consider consent to treatment. Results After being informed about all four formats, 52%–79% of the respondents consented to treatment, depending on level of effectiveness and initial information format. Overall, ARR gave highest concordance, 94% (95% confidence interval (91%; 97% between initial and final decision, but ARR was not statistically superior to the other formats. Conclusion Decisions based on ARR had the best concordance with decisions based on all four formats and pictorial representation, but the difference in concordance between the four formats was small, and it is unclear whether respondents fully understood the information they received.

  20. Tooth wear

    Directory of Open Access Journals (Sweden)

    Tušek Ivan

    2014-01-01

    Full Text Available Tooth wear is the loss of dental hard tissue that was not caused by decay and represents a common clinical problem of modern man. In the etiology of dental hard tissue lesions there are three dominant mechanisms that may act synergistically or separately:friction (friction, which is caused by abrasion of exogenous, or attrition of endogenous origin, chemical dissolution of dental hard tissues caused by erosion, occlusal stress created by compression and flexion and tension that leads to tooth abfraction and microfracture. Wear of tooth surfaces due to the presence of microscopic imperfections of tooth surfaces is clinically manifested as sanding veneers. Tribology, as an interdisciplinary study of the mechanisms of friction, wear and lubrication at the ultrastructural level, has defined a universal model according to which the etiopathogenesis of tooth wear is caused by the following factors: health and diseases of the digestive tract, oral hygiene, eating habits, poor oral habits, bruxism, temporomandibular disorders and iatrogenic factors. Attrition and dental erosion are much more common in children with special needs (Down syndrome. Erosion of teeth usually results from diseases of the digestive tract that lead to gastroesophageal reflux (GER of gastric juice (HCl. There are two basic approaches to the assessment of the degree of wear and dental erosion. Depending on the type of wear (erosion, attrition, abfraction, the amount of calcium that was realised during the erosive attack could be determined qualitatively and quantitatively, or changes in optical properties and hardness of enamel could be recorded, too. Abrasion of teeth (abrasio dentium is the loss of dental hard tissue caused by friction between the teeth and exogenous foreign substance. It is most commonly provoked by prosthetic dentures and bad habits, while its effect depends on the size of abrasive particles and their amount, abrasive particle hardness and hardness of tooth

  1. Left ventricular outflow tract pseudoaneurysm formation following three aortic valve replacement surgeries

    Directory of Open Access Journals (Sweden)

    Nasrien E Ibrahim

    2015-01-01

    Full Text Available We present a case of a pseudoaneurysm arising from the left ventricular outflow tract/aortic root as a complication of aortic valve surgery. A 45-year-old Nigerian female presented to our institution′s emergency department with chest discomfort. She had three bioprosthetic aortic valve replacements in the preceding year at an outside institution for aortic regurgitation and wanted a second opinion on remaining surgical options. The learning points relevant to this case are as follows: (1 Recognizing potential complications postmultiple valve surgeries, (2 screening patients for chronic infections and rheumatologic conditions that can contribute to failed valve surgeries.

  2. Communicating effectiveness of intervention for chronic diseases: what single format can replace comprehensive information?

    DEFF Research Database (Denmark)

    Stovring, Henrik; Gyrd-Hansen, Dorte; Kristiansen, Ivar S

    2008-01-01

    BACKGROUND: There is uncertainty about how GPs should convey information about treatment effectiveness to their patients in the context of cardiovascular disease. Hence we study the concordance of decisions based on one of four single information formats for treatment effectiveness with subsequent...... (NNT), or prolongation of life (POL) without heart attack, and were asked whether they would consent to treatment. Subsequently the same information was conveyed with all four formats jointly accompanied by a pictorial presentation of treatment effectiveness. Again, subjects should consider consent...... to treatment. RESULTS: After being informed about all four formats, 52%-79% of the respondents consented to treatment, depending on level of effectiveness and initial information format. Overall, ARR gave highest concordance, 94% (95% confidence interval (91%; 97%)) between initial and final decision, but ARR...

  3. Mesenchymal Stem Cells and Tooth Engineering

    Institute of Scientific and Technical Information of China (English)

    Li Peng; Ling Ye; Xue-dong Zhou

    2009-01-01

    Tooth loss compromises human oral health. Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss problems, they are thought to have safety and usage time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells (MSCs) are multipotent stem cells which can differentiate into a variety of cell types. The potential MSCs for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth (SHEDs), adult dental pulp stem cells (DPSCs), stem cells from the apical part of the papilla (SCAPs), stem cells from the dental follicle (DFSCs), periodontal ligament stem cells (PDLSCs) and bone marrow derived mesenchymal stem cells (BMSCs). This review outlines the recent progress in the mesenchymal stem cells used in tooth regeneration.

  4. Common developmental pathways link tooth shape to regeneration.

    Science.gov (United States)

    Fraser, Gareth J; Bloomquist, Ryan F; Streelman, J Todd

    2013-05-15

    In many non-mammalian vertebrates, adult dentitions result from cyclical rounds of tooth regeneration wherein simple unicuspid teeth are replaced by more complex forms. Therefore and by contrast to mammalian models, the numerical majority of vertebrate teeth develop shape during the process of replacement. Here, we exploit the dental diversity of Lake Malawi cichlid fishes to ask how vertebrates generally replace their dentition and in turn how this process acts to influence resulting tooth morphologies. First, we used immunohistochemistry to chart organogenesis of continually replacing cichlid teeth and discovered an epithelial down-growth that initiates the replacement cycle via a labial proliferation bias. Next, we identified sets of co-expressed genes from common pathways active during de novo, lifelong tooth replacement and tooth morphogenesis. Of note, we found two distinct epithelial cell populations, expressing markers of dental competence and cell potency, which may be responsible for tooth regeneration. Related gene sets were simultaneously active in putative signaling centers associated with the differentiation of replacement teeth with complex shapes. Finally, we manipulated targeted pathways (BMP, FGF, Hh, Notch, Wnt/β-catenin) in vivo with small molecules and demonstrated dose-dependent effects on both tooth replacement and tooth shape. Our data suggest that the processes of tooth regeneration and tooth shape morphogenesis are integrated via a common set of molecular signals. This linkage has subsequently been lost or decoupled in mammalian dentitions where complex tooth shapes develop in first generation dentitions that lack the capacity for lifelong replacement. Our dissection of the molecular mechanics of vertebrate tooth replacement coupled to complex shape pinpoints aspects of odontogenesis that might be re-evolved in the lab to solve problems in regenerative dentistry.

  5. Common developmental pathways link tooth shape to regeneration

    Science.gov (United States)

    Fraser, Gareth J.; Bloomquist, Ryan F.; Streelman, J. Todd

    2013-01-01

    In many non-mammalian vertebrates, adult dentitions result from cyclical rounds of tooth regeneration wherein simple unicuspid teeth are replaced by more complex forms. Therefore and by contrast to mammalian models, the numerical majority of vertebrate teeth develop shape during the process of replacement. Here, we exploit the dental diversity of Lake Malawi cichlid fishes to ask how vertebrates generally replace their dentition and in turn how this process acts to influence resulting tooth morphologies. First, we used immunohistochemistry to chart organogenesis of continually replacing cichlid teeth and discovered an epithelial down-growth that initiates the replacement cycle via a labial proliferation bias. Next, we identified sets of co-expressed genes from common pathways active during de novo, lifelong tooth replacement and tooth morphogenesis. Of note, we found two distinct epithelial cell populations, expressing markers of dental competence and cell potency, which may be responsible for tooth regeneration. Related gene sets were simultaneously active in putative signaling centers associated with the differentiation of replacement teeth with complex shapes. Finally, we manipulated targeted pathways (BMP, FGF, Hh, Notch, Wnt/β-catenin) in vivo with small molecules and demonstrated dose-dependent effects on both tooth replacement and tooth shape. Our data suggest that the processes of tooth regeneration and tooth shape morphogenesis are integrated via a common set of molecular signals. This linkage has subsequently been lost or decoupled in mammalian dentitions where complex tooth shapes develop in first generation dentitions that lack the capacity for lifelong replacement. Our dissection of the molecular mechanics of vertebrate tooth replacement coupled to complex shape pinpoints aspects of odontogenesis that might be re-evolved in the lab to solve problems in regenerative dentistry. PMID:23422830

  6. Whole Tooth Regeneration as a Future Dental Treatment.

    Science.gov (United States)

    Oshima, Masamitsu; Tsuji, Takashi

    2015-01-01

    Dental problems caused by dental caries, periodontal disease and tooth injury compromise the oral and general health issues. Current advances for the development of regenerative therapy have been influenced by our understanding of embryonic development, stem cell biology, and tissue engineering technology. Tooth regenerative therapy for tooth tissue repair and whole tooth replacement is currently expected a novel therapeutic concept with the full recovery of tooth physiological functions. Dental stem cells and cell-activating cytokines are thought to be candidate approach for tooth tissue regeneration because they have the potential to differentiate into tooth tissues in vitro and in vivo. Whole tooth replacement therapy is considered to be an attractive concept for next generation regenerative therapy as a form of bioengineered organ replacement. For realization of whole tooth regeneration, we have developed a novel three-dimensional cell manipulation method designated the "organ germ method". This method involves compartmentalisation of epithelial and mesenchymal cells at a high cell density to mimic multicellular assembly conditions and epithelial-mesenchymal interactions in organogenesis. The bioengineered tooth germ generates a structurally correct tooth in vitro, and erupted successfully with correct tooth structure when transplanted into the oral cavity. We have ectopically generated a bioengineered tooth unit composed of a mature tooth, periodontal ligament and alveolar bone, and that tooth unit was engrafted into an adult jawbone through bone integration. Bioengineered teeth were also able to perform physiological tooth functions such as mastication, periodontal ligament function and response to noxious stimuli. In this review, we describe recent findings and technologies underpinning whole tooth regenerative therapy.

  7. Tooth engineering: searching for dental mesenchymal cells sources.

    Directory of Open Access Journals (Sweden)

    Laetitia eKeller

    2011-03-01

    Full Text Available The implantation of cultured re-associations between embryonic dental mesenchymal cells and epithelial cells from mouse molars at ED14 allowed making full teeth with crown, root, periodontal ligament fibers and bone. Although representing valuable tools to set up methodologies embryonic cells are not easily available. This work thus aimed to replace the embryonic cells by dental mesenchymal cell lines or cultured expanded embryonic cells, and to test their ability to mediate tooth development in vitro when re-associated with a competent dental epithelium. Histology, immunostaining and RT-PCR allowed getting complementary sets of results. Two different immortalized cell lines from ED18 dental mesenchyme failed in mediating tooth formation. The potentialities of embryonic dental mesenchymal cells decreased from ED14 to ED16 and were lost at ED18. This is likely related to a change in the mesenchymal cell phenotype and/or populations during development. Attempts to cultivate ED14 or ED16 embryonic dental mesenchymal cells prior to re-association led to the loss of their ability to support tooth development. This was accompanied by a down-regulation of Fgf3 transcription. Supplementation of the culture medium with FGF2 allowed restoring Fgf3 expression, but not the ability of mesenchymal cells to engage in tooth formation. Altogether, these observations suggest that a competent cell population exists in the dental mesenchyme at ED14, progressively decreases during development, and cannot as such be maintained in vitro. This study evidenced the need for specific conditions to maintain the ability of dental mesenchymal cells to initiate whole tooth formation, when re-associated with an odontogenic epithelium. Efforts to improve the culture conditions will have to be combined with attempts to characterize the competent cells within the dental mesenchyme.

  8. Dental patterning in the earliest sharks: Implications for tooth evolution.

    Science.gov (United States)

    Maisey, John G; Turner, Susan; Naylor, Gavin J P; Miller, Randall F

    2014-05-01

    Doliodus problematicus is the oldest known fossil shark-like fish with an almost intact dentition (Emsian, Lower Devonian, c. 397Ma). We provide a detailed description of the teeth and dentition in D. problematicus, based on tomographic analysis of NBMG 10127 (New Brunswick Museum, Canada). Comparisons with modern shark dentitions suggest that Doliodus was a ram-feeding predator with a dentition adapted to seizing and disabling prey. Doliodus provides several clues about the early evolution of the "shark-like" dentition in chondrichthyans and also raises new questions about the evolution of oral teeth in jawed vertebrates. As in modern sharks, teeth in Doliodus were replaced in a linguo-labial sequence within tooth families at fixed positions along the jaws (12-14 tooth families per jaw quadrant in NBMG 10127). Doliodus teeth were replaced much more slowly than in modern sharks. Nevertheless, its tooth formation was apparently as highly organized as in modern elasmobranchs, in which future tooth positions are indicated by synchronized expression of shh at fixed loci within the dental epithelium. Comparable dental arrays are absent in osteichthyans, placoderms, and many "acanthodians"; a "shark-like" dentition, therefore, may be a synapomorphy of chondrichthyans and gnathostomes such as Ptomacanthus. The upper anterior teeth in Doliodus were not attached to the palatoquadrates, but were instead supported by the ethmoid region of the prechordal basicranium, as in some other Paleozoic taxa (e.g., Triodus, Ptomacanthus). This suggests that the chondrichthyan dental lamina was originally associated with prechordal basicranial cartilage as well as jaw cartilage, and that the modern elasmobranch condition (in which the oral dentition is confined to the jaws) is phylogenetically advanced. Thus, oral tooth development in modern elasmobranchs does not provide a complete developmental model for chondrichthyans or gnathostomes.

  9. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Find Data by Topic > Dental Caries (Tooth Decay) Dental Caries (Tooth Decay) Main Content Dental caries (tooth decay) remains the most prevalent chronic ... important source of information on oral health and dental care in the United States since the early ...

  10. Seal Out Tooth Decay

    Science.gov (United States)

    ... Decay (Caries) > Seal Out Tooth Decay Seal Out Tooth Decay Main Content What are dental sealants? How are ... fix decayed teeth. Back to Top What causes tooth decay? Germs in the mouth use the sugar in ...

  11. Influence of Different PBL Schemes on Secondary Eyewall Formation and Eyewall Replacement Cycle in Simulated Typhoon Sinlaku (2008)

    Science.gov (United States)

    Zhang, Yutao

    2017-04-01

    The effects of the different planetary boundary layer (PBL) processes on the secondary eyewall formation (SEF) and eyewall replacement cycle (ERC) in Typhoon Sinlaku (2008) are investigated by using the Weather Research and Forecasting Model (WRF) with six different PBL schemes. The SEF and ERC have been successfully simulated with all the six PBL schemes and the mechanism of the SEF and ERC proposed in our previous study has been reconfirmed: It is demonstrated that both the intensification of the storm and the inward-moving outer spiral rainband contribute to the SEF. After the SEF, the associated diabatic heating enhances the secondary eyewall further and transfer of the moist air from outer region to the primary eyewall is cut off by the secondary eyewall. In such a way the primary eyewall dies and an ERC completes. It is found that some simulated features of the SEF and ERC, such as the time and location of the SEF and duration of the ERC, do vary from one simulation to another. In order to describe the feature of the SEF and ERC quantitatively, a concentric eyewall index (CEI) is defined and a threshold of the CEI is suggested to determine the onset of the secondary eyewall. The differences of the simulated SEF and ERC are discussed and some possible causes are suggested. In addition, based on the threshold of the CEI and the conservation law of the angular momentum a formula to predict the location of the SEF is also suggested and applied to all the six simulations. The success and failure of the formula are also discussed. Key words: eye-wall replacement cycle, secondary eye-wall formation, PBL scheme, CEI

  12. Analysis of gap formation at tooth-composite resin interface: effect of C-factor and light-curing protocol

    Directory of Open Access Journals (Sweden)

    Gustavo Oliveira dos Santos

    2007-08-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effect of C-factor and light-curing protocol on gap formation in composite resin restorations. Material and METHODS: Cylindrical cavities with 5.0 mm diameter and three different depths (A=1.0, B=2.0 and C=3.0 mm were prepared on the occlusal surface of 30 human molars and restored in a single increment with P 60. The composite resin was light-cured according to two protocols: standard - 850 mW/cm² / 20 s and gradual - 100 up to 1000 mW/cm² / 10 s + 1000 mW/cm² / 10 s. After storage in distilled water (37°C/7 days, the restorations were cut into three slices in a buccolingual direction and the gap widths were analyzed using a 3D-scanning system. The data were submitted to ANOVA and Student-Newman-Keuls test (alpha=0.05. RESULTS: ANOVA detected a significant influence for the C-factor and light-curing protocol as independent factors, and for the double interaction C-factor vs. light-curing protocol. Cavities with higher C-factor presented the highest gap formation. The gradual light-curing protocol led to smaller gap formation at cavity interfaces. CONCLUSIONS: The findings of this study suggest that the C-factor played an essential role in gap formation. The gradual light-curing protocol may allow relaxation of composite resin restoration during polymerization reaction.

  13. Expression of a dynamin 2 mutant associated with Charcot-Marie-Tooth disease leads to aberrant actin dynamics and lamellipodia formation.

    Science.gov (United States)

    Yamada, Hiroshi; Kobayashi, Kinue; Zhang, Yubai; Takeda, Tetsuya; Takei, Kohji

    2016-08-15

    Specific mutations in dynamin 2 are linked to Charcot-Marie-Tooth disease (CMT), an inherited peripheral neuropathy. However, the effects of these mutations on dynamin function, particularly in relation to the regulation of the actin cytoskeleton remain unclear. Here, selected CMT-associated dynamin mutants were expressed to examine their role in the pathogenesis of CMT in U2OS cells. Ectopic expression of the dynamin CMT mutants 555Δ3 and K562E caused an approximately 50% decrease in serum stimulation-dependent lamellipodia formation; however, only K562E caused aberrations in the actin cytoskeleton. Immunofluorescence analysis showed that the K562E mutation resulted in the disappearance of radially aligned actin bundles and the simultaneous appearance of F-actin clusters. Live-cell imaging analyses showed F-actin polymers of decreased length assembled into immobile clusters in K562E-expressing cells. The K562E dynamin mutant colocalized with the F-actin clusters, whereas its colocalization with clathrin-coated pit marker proteins was decreased. Essentially the same results were obtained using another cell line, HeLa and NG108-15 cells. The present study is the first to show the association of dynamin CMT mutations with aberrant actin dynamics and lamellipodia, which may contribute to defective endocytosis and myelination in Schwann cells in CMT. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  14. Probable biofilm formation in the cheek as a complication of soft tissue filler resulting from improper endodontic treatment of tooth 16

    Directory of Open Access Journals (Sweden)

    Marusza W

    2012-03-01

    Full Text Available Wojciech Marusza1, Grazyna Mlynarczyk2, Romuald Olszanski3, Irina Netsvyetayeva2, Michael Obrowski1, Tommaso Iannitti4, Beniamino Palmieri51Academy of Face Sculpturing, 2Department of Microbiology, Medical University of Warsaw, 3Military Institute of Health Services, Warsaw, Poland; 4Department of Physiology, School of Medicine, University of Kentucky Medical Center, KY, USA; 5Department of General Surgery and Surgical Specialties, University of Modena and Reggio Emilia Medical School, Surgical Clinic, Modena, ItalyAbstract: Injectable filling agents offer the promise of a better appearance without surgery and, among them, hyaluronic acid is the most commonly used. Although complications are rare, it is necessary to know the possible side effects and complications in order to be prepared for their management. That is why many researchers have been focusing on the interactions between hyaluronic acid and pathogens, inflammatory mediators, the immune system, and markers of oxidative stress to achieve efficient drug delivery, given that hyaluronic acid has widening applications in the field of nanomedicine. Here we report the case of a 37-year-old female patient who returned to our clinic with an abscess in her left cheek 3 months after a deep injection of 1 mL of stabilized hyaluronic acid in both cheeks. Steroid and antibiotic therapy was initiated without success, and abscess drainage was performed. Extraction of tooth 16 was performed 11 days after insertion of drains into the abscess. Laboratory blood tests showed acute inflammation of presumed bacterial etiology. Microbiological examination of pus was negative. Bacterial cultures were found in the extracted tooth. After antibiotic therapy, a complete reversal of the pathological process was observed. The present report highlights the need to assess periodontal problems prior to any aesthetic facial treatment. Analyses of further case reports and clinical studies are necessary to understand

  15. Detection of impaired IgG antibody formation facilitates the decision on early immunoglobulin replacement in hypogammaglobulinemic patients

    Directory of Open Access Journals (Sweden)

    Hermann Maximilian Wolf

    2015-02-01

    Full Text Available Hypogammaglobulinemia (serum IgG lower than 2SD below the age-matched mean and clinical symptoms such as increased susceptibility to infection, autoimmune manifestations, granulomatous disease, unexplained polyclonal lymphoproliferation are considered to be diagnostic hallmarks in patients with common variable immunodeficiency (CVID, the most frequent clinically severe primary immunodeficiency syndrome. In the present study we investigated patients with hypogammaglobulinemia and no clinical or immunological signs of defective cell-mediated immunity and differentiated two groups on the basis of their IgG antibody formation capacity against a variety of different antigens (bacterial toxins, polysaccharide antigens, viral antigens. Patients with hypogammaglobulinemia and intact antibody production (HIAP displayed no or only mild susceptibility to infections, while CVID patients showed marked susceptibility to bacterial infections that normalized following initiation of IVIG or SCIG replacement therapy. There was a substantial overlap in IgG serum levels between the asymptomatic HIAP group and the CVID patients examined before immunoglobulin treatment. HIAP patients showed normal levels of switched B memory cells (CD19+CD27+IgD-, while both decreased and normal levels of switched B memory cells could be found in CVID patients. IgG antibody response to a primary antigen, tick borne encephalitis virus (TBEV, was defective in CVID patients, thus confirming their substantial defect in IgG antibody production. Defective IgG antibody production against multiple antigens could also be demonstrated in an adult patient with recurrent infections but normal IgG levels. To facilitate early treatment before recurrent infections may lead to organ damage the antibody formation capacity should be examined in hypogammaglobulinemic patients and the decision to treat should be based on the finding of impaired IgG antibody production.

  16. Tooth polishing: The current status.

    Science.gov (United States)

    Sawai, Madhuri Alankar; Bhardwaj, Ashu; Jafri, Zeba; Sultan, Nishat; Daing, Anika

    2015-01-01

    Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients' need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

  17. Tooth polishing: The current status

    Directory of Open Access Journals (Sweden)

    Madhuri Alankar Sawai

    2015-01-01

    Full Text Available Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients′ need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

  18. Tooth formation - delayed or absent

    Science.gov (United States)

    ... 2016 Updated by: Michael Kapner, DDS, general and aesthetic dentistry, Norwalk Medical Center, Norwalk, CT. Review provided ... for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department ...

  19. Tooth crown heights, tooth wear, sexual dimorphism and jaw growth in hominoids.

    Science.gov (United States)

    Dean, M C; Beynon, A D

    1991-01-01

    The aim of this review is to bring together data that link tooth morphology with tooth function and tooth growth: We aim to show how the microanatomy of hominoid teeth is providing evidence about rates of tooth growth that are likely to be a consequence of both masticatory strategy and social behaviour. First, we present data about incisor and molar tooth wear in wild short chimpanzees that demonstrate how crown heights are likely to be related to relative tooth use in a broad sense. Following this we review recent studies that describe the microanatomy of hominoid tooth enamel and show how these studies are providing evidence about tooth crown formation times in hominoids, as well as improving estimates for the age at death of certain juvenile fossil hominids. Next, we outline what is known about the mechanisms of tooth growth in the sexually dimorphic canine teeth of chimpanzees and compare these patterns of growth with tooth growth patterns in the canines of three fossil hominids from Laetoli, Tanzania. Finally, we discuss how selection pressures that operate to increase or reduce the size of anterior teeth interact with jaw size. We argue that the space available to grow developing teeth in the mandibles of juvenile hominoids is determined by the growth patterns of the mandibles, which in turn reflect masticatory strategy. The consequences of selection pressure to grow large or small anterior teeth are likely to be reflected in the times at which these teeth are able to emerge into occlusion.

  20. The effect of factor VIII deficiencies and replacement and bypass therapies on thrombus formation under venous flow conditions in microfluidic and computational models.

    Directory of Open Access Journals (Sweden)

    Abimbola A Onasoga-Jarvis

    Full Text Available Clinical evidence suggests that individuals with factor VIII (FVIII deficiency (hemophilia A are protected against venous thrombosis, but treatment with recombinant proteins can increase their risk for thrombosis. In this study we examined the dynamics of thrombus formation in individuals with hemophilia A and their response to replacement and bypass therapies under venous flow conditions. Fibrin and platelet accumulation were measured in microfluidic flow assays on a TF-rich surface at a shear rate of 100 s⁻¹. Thrombin generation was calculated with a computational spatial-temporal model of thrombus formation. Mild FVIII deficiencies (5-30% normal levels could support fibrin fiber formation, while severe (1 nM, but too low to support fibrin formation (<10 nM. In the absence of platelets, fibrin formation was not supported even at normal FVIII levels, suggesting platelet adhesion is necessary for fibrin formation. Individuals treated by replacement therapy, recombinant FVIII, showed normalized fibrin formation. Individuals treated with bypass therapy, recombinant FVIIa, had a reduced lag time in fibrin formation, as well as elevated fibrin accumulation compared to healthy controls. Treatment of rFVIIa, but not rFVIII, resulted in significant changes in fibrin dynamics that could lead to a prothrombotic state.

  1. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic

    Directory of Open Access Journals (Sweden)

    K. Pavan Kumar

    2016-01-01

    Full Text Available For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge was intact with good esthetics and no problem was reported.

  2. Cavities/Tooth Decay

    Science.gov (United States)

    Cavities/tooth decay Overview By Mayo Clinic Staff Cavities are permanently damaged areas in the hard surface of your teeth ... into tiny openings or holes. Cavities, also called tooth decay or caries, are caused by a combination of ...

  3. Space maintenance in autogenous fresh demineralized tooth blocks with platelet-rich plasma for maxillary sinus bone formation: a prospective study.

    Science.gov (United States)

    Kim, Eun-Suk; Kang, Ji-Yeon; Kim, Jae-Jin; Kim, Kyoung-Won; Lee, Eun-Young

    2016-01-01

    This prospective study evaluated the effectiveness of autogenous fresh demineralized tooth block (Auto-FDT block) with platelet-rich plasma (PRP) for maxillary sinus augmentation with simultaneous implant installation. Auto-FDT block with PRP was used in Group 1 (n = 15) and combined graft (allograft and xenograft) powder with PRP was used in Group 2 (n = 15). For up to 2 years after the final prosthesis was installed, clinical and radiographic examinations were performed to evaluate the amount of graft materials, residual alveolar height (RAH), sinus height (SH) after grafting, augmented graft height (AGH) and resorption height (RH). In ten cases, biopsies were harvested for histological and histomorphometric analyses. A total of 59 implants were placed in a severe atrophic posterior maxilla with less than 5 mm of RAH and sinus augmentation. None of the patients developed sinusitis or other complications, such as implant loss. The graft material extracted included one molar (or 2 premolars) in Group 1 and 1.8 cc in Group 2. The radiologic examination revealed the following average between-group difference SH (Group 1, 14.12 ± 1.63 mm vs Group 2, 16.51 ± 1.29 mm) and AGH (Group 1, 11.62 ± 2.22 mm vs Group 2, 13.65 ± 1.35 mm). However, sufficient SH and AGH were observed for the implants in the Auto-FDT block group. Two years after final prosthesis was installed, no between-group difference in the RH was observed (Group 1, 1.23 ± 0.73 mm vs Group 2, 1.77 ± 0.54 mm, P = 0.021). The histomorphometric analysis revealed no between-group difference in the new bone volume (Group 1, 23.13 ± 1.42 % vs Group 2, 24.18 ± 2.19 %, P = 0.548). The results showed that Auto-FDT block with PRP can be used in grafted sinuses for implants with only one extracted molar (or two premolars). Auto-FDT block with PRP promotes new bone formation that is comparable with combined grafts. Auto-FDT block with PRP is as an alternative to bone grafting

  4. Intracranial supernumerary tooth

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, S.; Loerinc, P.

    1984-12-01

    Case report of an accidentally diagnosed supernumerary tooth in the superior orbital fissure. Computed tomography (CT) contributed with a more precise localization of the tooth being situated between the orbit and the brain. CT also showed that there was no cyst or other pathological process around the supernumerary tooth, which is plausible and frequently reported in the literature.

  5. Tooth sensitivity and whitening.

    Science.gov (United States)

    Swift, Edward J

    2005-09-01

    This article presents a review of the basic concepts of tooth sensitivity and how those concepts apply to cervical dentin hypersensitivity and the sensitivity frequently associated with tooth whitening. The etiology and treatment of cervical dentin hypersensitivity are described. The clinical presentation, incidence, and predisposing factors for sensitivity associated with tooth whitening also are discussed.

  6. Tissue Interactions Regulating Tooth Development and Renewal.

    Science.gov (United States)

    Balic, Anamaria; Thesleff, Irma

    2015-01-01

    Reciprocal interactions between epithelial and mesenchymal tissues play a fundamental role in the morphogenesis of teeth and regulate all aspects of tooth development. Extensive studies on mouse tooth development over the past 25 years have uncovered the molecular details of the signaling networks mediating these interactions (reviewed by Jussila & Thesleff, 2012; Lan, Jia, & Jiang, 2014). Five conserved signaling pathways, namely, the Wnt, BMP, FGF, Shh, and Eda, are involved in the mediation of the successive reciprocal epithelial-mesenchymal cross talk which follows the general principle of morphogenetic interactions (Davidson, 1993). The pathways regulate the expression of transcription factors which confer the identity of dental epithelium and mesenchyme. The signals and transcription factors are integrated in complex signaling networks whose fine-tuning allows the generation of the variation in tooth morphologies. In this review, we describe the principles and molecular mechanisms of the epithelial-mesenchymal interactions regulating successive stages of tooth formation: (i) the initiation of tooth development, with special reference to the shift of tooth-forming potential from epithelium to mesenchyme; (ii) the morphogenesis of the tooth crown, focusing on the roles of epithelial signaling centers; (iii) the differentiation of odontoblasts and ameloblasts, which produce dentin and enamel, respectively; and (iv) the maintenance of dental stem cells, which support the continuous growth of teeth. © 2015 Elsevier Inc. All rights reserved.

  7. Effect of the partial replacement of sodium chloride by other salts on the formation of volatile compounds during ripening of dry-cured ham.

    Science.gov (United States)

    Armenteros, Mónica; Toldrá, Fidel; Aristoy, M-Concepción; Ventanas, Jesús; Estévez, Mario

    2012-08-01

    The effect of the partial NaCl replacement by other salts (potassium, calcium, and magnesium chloride) on the formation of volatile compounds through the processing of dry-cured ham was studied using solid-phase microextraction (SPME). Three salt formulations were considered, namely, I (100% NaCl), II (50% NaCl and 50% KCl), and III (55% NaCl, 25% KCl, 15% CaCl(2), and 5% MgCl(2)). There was an intense formation of volatile compounds throughout the processing of dry-cured hams, particularly during the "hot-cellar" stage. The differences between treatments were found to be more remarkable at the end of the curing process. Hams from formulations I and II had significantly higher amounts of lipid-derived volatiles such as hexanal than hams from formulation III, whereas the latter had significantly higher amounts of Strecker aldehydes and alcohols. Plausible mechanisms by which salt replacement may affect the generation of volatile compounds include the influence of such replacement on lipid oxidation and proteolysis phenomena. The potential influence of the volatiles profile on the aroma of the products is also addressed in the present paper.

  8. A theropod tooth from the Late Triassic of southern Africa

    Indian Academy of Sciences (India)

    Sanghamitra Ray; Anusuya Chinsamy

    2002-06-01

    An isolated, large recurved and finely serrated tooth found associated with the prosauropod Euskelosaurus from the Late Triassic part of the Elliot Formation is described here. It is compared to the Triassic thecodonts and carnivorous dinosaurs and its possible affinity is discussed. The tooth possibly belongs to a basal theropod and shows some features similar to the allosauroids. This tooth is of significance, as dinosaur remains except for some footprints and trackways, are poorly known in the Late Triassic horizons of southern Africa.

  9. Nasal tooth: case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Si Hyun; Kim, Ji Hye; Hwang, Hee Young; Yang, Dal Mo; Kim, Hyung Sik; Park, Chol Heui [Gachon Medical School, Inchon (Korea, Republic of)

    2002-12-01

    Ectopic tooth is not uncommon and usually occurs in the palate and maxillary sinus. We report a case of ectopic tooth located in the nasal cavity, a rare site. The mass depicted by CT was highly attenuated, and central lucency was observed.

  10. To Tell the Tooth

    Science.gov (United States)

    ... To Tell the Tooth Print and Take a Quiz + Watch Videos Dudley and Friends Sesame Street + For Preteens Healthy Habits Nutrition Be a Dentist + For Educators Career Resources Presentations and Resources Smile Smarts Dental Health Curriculum MouthHealthy Kids > Games and Quizzes > To Tell the Tooth To Tell ...

  11. Analysis of the soluble human tooth proteome and its ability to induce dentin/tooth regeneration.

    Science.gov (United States)

    Chun, So Young; Lee, Hyo Jung; Choi, Young Ae; Kim, Kyung Min; Baek, Sang Heum; Park, Hyo Sang; Kim, Jae-Young; Ahn, Jung-Mo; Cho, Je-Yeol; Cho, Dong-Woo; Shin, Hong-In; Park, Eui Kyun

    2011-01-01

    While the soluble proteins of human teeth consist of various extracellular matrix and bioactive proteins, they have not yet been characterized fully. Moreover, the role they play in tooth regeneration is not clear. Analysis of the soluble proteins in human teeth by liquid chromatography-mass spectrometry revealed 147 different ethylenediaminetetraacetic acid-soluble tooth proteins (ESTPs). Of these, 29 had not been shown previously to be present in human teeth. To determine their effect on the in vitro responses of dental pulp stem cells (DPSCs), DPSCs were cultured in ESTP-coated culture plates and three-dimensional scaffolds. The ESTPs significantly enhanced DPSC odontoblast differentiation and mineralization in vitro, but had only partial effect on bone marrow stem cells or adipose tissue stem cells. To test the effect of ESTPs on in vivo dentin and tooth formation, mouse embryonic tooth-forming primordia and xenogenic murine apical bud epithelium/human DPSC composites were treated with ESTPs before implantation under the renal capsule of ICR mice. ESTP treatment promoted the formation of morphologically normal teeth by the tooth-forming primordium regions and enhanced the development of a regular and large dentin structure by the composites. These observations suggest that human ESTPs contain dentinogenic proteins and can promote dentin and tooth formation.

  12. Tooth reorientation affects tooth function during prey processing and tooth ontogeny in the lesser electric ray, Narcine brasiliensis.

    Science.gov (United States)

    Dean, Mason N; Ramsay, Jason B; Schaefer, Justin T

    2008-01-01

    The dental anatomy of elasmobranch fishes (sharks, rays and relatives) creates a functional system that is more dynamic than that of mammalian dentition. Continuous dental replacement (where new teeth are moved rostrally to replace older ones) and indirect fibrous attachment of the dentition to the jaw allow teeth to reorient relative to the jaw over both long- and short-term scales, respectively. In this study, we examine the processing behavior and dental anatomy of the lesser electric ray Narcine brasiliensis (Olfers, 1831) to illustrate that the freedom of movement of elasmobranch dentition allows a functional flexibility that can be important for complex prey processing behaviors. From static manipulations of dissected jaws and observations of feeding events in live animals, we show that the teeth rotate during jaw protrusion, resulting in a secondary grasping mechanism that likely serves to hold prey while the buccal cavity is flushed free of sediment. The function of teeth is not always readily apparent from morphology; in addition to short-term reorientation, the long-term dental reorientation during replacement allows a given tooth to serve multiple functions during tooth ontogeny. Unlike teeth inside the mouth, the cusps of external teeth (on the portion of the tooth pad that extends past the occlusal plane) lay flat, such that the labial faces act as a functional battering surface, protecting the jaws during prey excavation.

  13. Tooth whitening today.

    Science.gov (United States)

    Sarrett, David C

    2002-11-01

    Methods to improve the esthetics of the dentition by tooth whitening are of interest to dentists, their patients and the public. In the past 20 years, research on bleaching and other methods of removing tooth discolorations has dramatically increased. Dentist-supervised and over-the-counter products now are available to solve a variety of tooth discoloration problems without restorative intervention. The indications for appropriate use of tooth-whitening methods and products are dependent on correct diagnosis of the discoloration. Tooth-whitening methods include the use of peroxide bleaching agents to remove internal discolorations or abrasive products to remove external stains. Peroxide bleaching procedures are completed by the dentist in single or multiple appointments, or by the patient over a period of weeks to months using custom trays loaded with a bleaching agent. Both methods are safe and effective when supervised by the dentist. Microabrasion is indicated for the removal of isolated discolorations that often are associated with fluorosis. Whitening toothpastes remove surface stains only through the polishing effect of the abrasives they contain. Tooth whitening is a form of dental treatment and should be completed as part of a comprehensive treatment plan developed by a dentist after an oral examination. When used appropriately, tooth-whitening methods are safe and effective.

  14. Gingival Papillae Contour after Implant-supported Single-Tooth Replacements%单枚后牙种植修复体龈乳头形态及其变化的临床分析

    Institute of Scientific and Technical Information of China (English)

    王国世; 李韶伟; 蔡露

    2011-01-01

    Objective: To observe the gingival papillae contour and its variation after posterior single-tooth implantsupported restoration. Methods: 20 single-tooth implant-supported restorations which were followed-up for more than 3 months were retrospectively evaluated. Data related with the height of gingival papillae, the papilla index score (PIS),and questionnaire of the patient's satisfaction were obtained. Analysis of data were performed with SAS 9.13 software. P< 0.01 was considered high significant. Results: 19 implants showed osseointegration. In the 35 observed gingival papillae, the mesial and distal papillae index score was at levels 3 in 11, at levels 2 in 19, at levels 1 in 5.Questionnaire of the patient' s satisfaction degree was 89.47%. The heights of gingival papillae measured immediately after restoration, at the end of 1-month and 3-month respectively revealed significant differences (P<0.01). Conclusion: The heights of gingival papillae supported by a single implant restoration grows to the top at the end of three months when final crown prosthesos were done.%目的:通过分析单枚后牙种植修复体龈乳头形态及变化,探讨其与种植修复体牙龈美学有关的相关因素.方法:选择20枚后牙种植修复体,通过修复后不同时期的临床检查、根尖片、研究模型、患者满意度调查等方法.得到种植修复体龈乳头高度、牙龈乳头指数(papilla index score,PIS)和患者满意度数据,并进行统计分析.结果:随访到的19枚种植体均形成良好的骨结合,所观察的35个龈乳头中,根据Jemt的PIS分级,11个龈乳头为Ⅲ级,19个龈乳头为Ⅱ级,5个龈乳头为I级.龈乳头高度在修复完成后即刻、修复后1个月、修复后3个月的3次测量中逐次增大.使用SAS 9.13软件进行统计分析,其差异有高度统计学意义(P<0.01).在患者满意度问卷调查中.满意率达89.47%.结论:单枚后牙种植修复体的龈乳头高度在冠修复完成后的3

  15. Accurate Modeling of the Spiral Bevel and Hypoid Gear with a New Tooth Profile

    Institute of Scientific and Technical Information of China (English)

    LI Yun-song; ADAYI Xieeryazidan; DING Han

    2014-01-01

    Distinguishing with traditional tooth profile of spiral bevel and hypoid gear, it proposed a new tooth profile namely the spherical involute. Firstly, a new theory of forming the spherical involute tooth profile was proposed. Then, this theory was applied to complete parametric derivation of each part of its tooth profile. For enhancing the precision, the SWEEP method used for formation of each part of tooth surface and G1 stitching schema for obtaining a unified tooth surface are put forward and made the application in the accurate modeling. Lastly, owing to the higher accuracy of tooth surface of outputted model, it gave some optimization approaches. Given numerical example about the model can show that this designed gear with spherical involute tooth profile can achieve fast and accurate parametric modeling and provide a foundation for tooth contact analysis (TCA) in digitized design and manufacture.

  16. Ankle replacement

    Science.gov (United States)

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... You may not be able to have a total ankle replacement if you have had ankle joint infections in ...

  17. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  18. In vitro differentiation and attachment of human embryonic stem cells on periodontal tooth root surfaces.

    Science.gov (United States)

    Inanç, Bülend; Elçin, A Eser; Elçin, Y Murat

    2009-11-01

    Periodontal tissue engineering based on cell replacement therapies is a promising field for improved regeneration of tooth supporting structures lost as a result of destructive periodontal diseases. Human embryonic stem cells (hESCs) could become adequate cell source for tissue engineering because of their unlimited proliferative potential and ability to differentiate to all somatic cell types. The aim of this study was to analyze the differentiation capacity of hESCs toward periodontal compartment cells and their relationship with tooth root surfaces in vitro. Periodontal ligament fibroblastic cell (PDLF) cultures were established and characterized; hESCs (HUES-9 line) were expanded in undifferentiated state and characterized for pluripotency morphologically and immunohistochemically. Extracted tooth root slices (RS) of 300 microm thickness, prepared with both periodontal and endodontic instrumentation, were used. Three different experimental groups were established: (i) undifferentiated hESC colonies cultured on and around the RS; (ii) undifferentiated hESC colonies cultured on and around RS with PDLF coculture, and (iii) undifferentiated hESC colonies cultured on and around RS with PDLF coculture in osteoinductive medium for 3 weeks. The fibrogenic and osteogenic marker expression was assessed with immunohistochemistry; histological staining and scanning electron microscopy were utilized to determine the relationship between differentiating hESCs and mineralized tooth root structures. Results demonstrate that hESC differentiation is influenced by tooth structures, PDLFs, and osteogenic medium, resulting with increased propensity toward mesenchymal lineage commitment, and formation of soft-hard tissue relationship in close contact areas. The proposed experimental system may facilitate further understanding in development of periodontal structures and contribute to realization of hESCs as a cell source in periodontal tissue engineering applications.

  19. Overview of Tooth Disorders

    Science.gov (United States)

    ... Abbreviations Weights & Measures ENGLISH View Professional English Deutsch Japanese Espaniol Find information on medical topics, symptoms, drugs, ... Abnormal tooth enamel may be due to a diet containing insufficient vitamin D, as in rickets . Abnormal ...

  20. Tooth in oropharynx

    Directory of Open Access Journals (Sweden)

    D Nagarajappa

    2011-01-01

    Full Text Available The incidence of ectopic teeth has increased. In many cases, the etiology of ectopic teeth cannot be identified. Ectopic tooth in deciduous dentition period is very rare and information is limited about its causes and characteristics. The conditions commonly associated with an increased prevalence of ectopic teeth include cleft lip and palate, cleidocranial dysplasia, and Gardner syndrome. The diagnosis is made by the clinical and radiological examinations. The indication for extraction in ectopic teeth cases is in general determined by the presence of symptomatology, or by the need for preventing future complications. We present a case of an ectopic maxillary tooth in a 4 year-old boy. In addition, this report also addresses a young patient with a tooth in the oropharynx with the objective of non traumatic etiology, and such a clinical presentation is extremely rare. The authors believe the case presented here is the first documented case of an ectopic supernumerary tooth seen in the oropharynx.

  1. Tooth in oropharynx.

    Science.gov (United States)

    Nagarajappa, D; Manjunatha, Bs

    2011-09-01

    The incidence of ectopic teeth has increased. In many cases, the etiology of ectopic teeth cannot be identified. Ectopic tooth in deciduous dentition period is very rare and information is limited about its causes and characteristics. The conditions commonly associated with an increased prevalence of ectopic teeth include cleft lip and palate, cleidocranial dysplasia, and Gardner syndrome. The diagnosis is made by the clinical and radiological examinations. The indication for extraction in ectopic teeth cases is in general determined by the presence of symptomatology, or by the need for preventing future complications. We present a case of an ectopic maxillary tooth in a 4 year-old boy. In addition, this report also addresses a young patient with a tooth in the oropharynx with the objective of non traumatic etiology, and such a clinical presentation is extremely rare. The authors believe the case presented here is the first documented case of an ectopic supernumerary tooth seen in the oropharynx.

  2. An inductive signalling network regulates mammalian tooth morphogenesis with implications for tooth regeneration.

    Science.gov (United States)

    Li, Z; Yu, M; Tian, W

    2013-10-01

    Sequential and reciprocal epithelial-mesenchymal interactions, essential throughout such aspects of tooth morphogenesis as patterning, size and number of teeth, involves a well-ordered series of inductive and permissive signals that exert global control over cell proliferation, differentiation and organogenesis. In particular, growth factors, transcription factors and their corresponding receptors, as well as other soluble morphogens, make up a regulatory network at the molecular level that synergistically or antagonistically controls intra-/inter-cellular signal transduction during odontogenesis. This review summarizes recent advances in the study of crucial signalling pathways, for example of BMPs, Wnt, Notch, Shh and FGF, with emphasis on the potential integrated signalling network responsible for tooth formation. Our work probes into the complexity of these inductive signalling pathways to promote the understanding of tooth regeneration. Additionally, our study provides further insights into therapeutic strategies for various dental abnormalities in patterning and number, such as tooth agenesis and supernumerary teeth.

  3. Evaluation of scaffold materials for tooth tissue engineering.

    Science.gov (United States)

    Ohara, Takayuki; Itaya, Toshimitsu; Usami, Kazutada; Ando, Yusuke; Sakurai, Hiroya; Honda, Masaki J; Ueda, Minoru; Kagami, Hideaki

    2010-09-01

    Recently, the possibility of tooth tissue engineering has been reported. Although there are a number of available materials, information about scaffolds for tooth tissue engineering is still limited. To improve the manageability of tooth tissue engineering, the effect of scaffolds on in vivo tooth regeneration was evaluated. Collagen and fibrin were selected for this study based on the biocompatibility to dental papilla-derived cells and the results were compared with those of polyglycolic acid (PGA) fiber and beta-tricalcium phosphate (beta-TCP) porous block, which are commonly used for tooth, dentin and bone tissue engineering. Isolated porcine tooth germ-derived cells were seeded onto one of those scaffolds and transplanted to the back of nude mice. Tooth bud-like structures were observed more frequently in collagen and fibrin gels than on PGA or beta-TCP, while the amount of hard tissue formation was less. The results showed that collagen and fibrin gel support the initial regeneration process of tooth buds possibly due to their ability to support the growth of epithelial and mesenchymal cells. On the other hand, maturation of tooth buds was difficult in fibrin and collagen gels, which may require other factors.

  4. Autogenous wisdom tooth transplantation: A case series with 6-9 months follow-up

    Directory of Open Access Journals (Sweden)

    Tatjana Nimcenko

    2014-01-01

    Full Text Available Tooth transplantation can be considered a valid and predictable treatment option for rehabilitating young patients with permanent teeth loss. This study presents several cases of successful autogenous tooth transplantation with a 6-9 months follow-up. Tooth auto-transplantation can be considered a reasonable option for replacing missing teeth when a donor tooth is available. The auto-transplantation of a right mandibular third molar with compromised function and esthetics to replace the residual roots resulting from coronal destruction due to extensive carious lesion of the second molar in the same quadrant as shown in the presented cases can result a viable treatment alternative especially in a young patient that cannot undergo dental implant therapy. Transplantation of mature third molar seems to be a promising method for replacing a lost permanent molar tooth and restoring esthetics and function. This clinical procedure showed excellent functional and esthetical long-term results in the analyzed cases.

  5. Autogenous wisdom tooth transplantation: A case series with 6-9 months follow-up

    Science.gov (United States)

    Nimčenko, Tatjana; Omerca, Gražvydas; Bramanti, Ennio; Cervino, Gabriele; Laino, Luigi; Cicciù, Marco

    2014-01-01

    Tooth transplantation can be considered a valid and predictable treatment option for rehabilitating young patients with permanent teeth loss. This study presents several cases of successful autogenous tooth transplantation with a 6-9 months follow-up. Tooth auto-transplantation can be considered a reasonable option for replacing missing teeth when a donor tooth is available. The auto-transplantation of a right mandibular third molar with compromised function and esthetics to replace the residual roots resulting from coronal destruction due to extensive carious lesion of the second molar in the same quadrant as shown in the presented cases can result a viable treatment alternative especially in a young patient that cannot undergo dental implant therapy. Transplantation of mature third molar seems to be a promising method for replacing a lost permanent molar tooth and restoring esthetics and function. This clinical procedure showed excellent functional and esthetical long-term results in the analyzed cases. PMID:25540668

  6. Morphological and Functional Parameters in Patients with Tooth Wear before and after Treatment

    OpenAIRE

    Sierpinska, Teresa; Kuc, Joanna; Golebiewska, Maria

    2013-01-01

    Advanced tooth wear often results in lost vertical dimension and impacts facial aesthetics. Complex restorative treatment can replace the lost tooth structure and improve functional occlusal and facial skeleton parameters. Purpose: The aim of the study is to assess changes in the morphological and functional occlusal parameters of the facial skeleton after prosthetic rehabilitation that increased lost occlusal vertical dimension. Material and Methodology: 50 patients with advanced tooth wear ...

  7. Replacement of missing teeth in a southern region of Vietnam--a descriptive dental laboratory study.

    NARCIS (Netherlands)

    Chau, T.N.; Witter, D.J.; Kreulen, C.M.; Creugers, N.H.J.; Tu, H.H.

    2009-01-01

    AIM: To explore whether tooth replacement in a southern region of Vietnam is in line with the primary health care approach, aiming at health services for all people at affordable costs. METHODS: Tooth replacement was investigated by means of prostheses as delivered by four dental laboratories of whi

  8. Contribution of donor and host mesenchyme to the transplanted tooth germs.

    Science.gov (United States)

    Nakaki, T; Saito, K; Ida-Yonemochi, H; Nakagawa, E; Kenmotsu, S; Ohshima, H

    2015-01-01

    Autologous tooth germ transplantation of immature teeth is an alternative method of tooth replacement that could be used instead of dental implants in younger patients. However, it is paramount that the dental pulp remain vital and that root formation continue in the transplanted location. The goal of this study is to characterize the healing of allogenic tooth grafts in an animal model using GFP-labeled donor or host postnatal mice. In addition, the putative stem cells were labeled before transplantation with a pulse-chase paradigm. Transplanted molars formed cusps and roots and erupted into occlusion by 2 wk postoperatively. Host label-retaining cells (LRCs) were maintained in the center of pulp tissue associating with blood vessels. Dual labeling showed that a proportion of LRCs were incorporated into the odontoblast layer. Host cells, including putative dendritic cells and the endothelium, also immigrated into the pulp tissue but did not contribute to the odontoblast layer. Therefore, LRCs or putative mesenchymal stem cells are retained in the transplanted pulps. Hertwig's epithelial root sheath remains vital, and epithelial LRCs are present in the donor cervical loops. Thus, the dynamic donor-host interaction occurred in the developing transplant, suggesting that these changes affect the characteristics of the dental pulp.

  9. Biomaterial selection for tooth regeneration.

    Science.gov (United States)

    Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y; Zhou, Hong; Chen, Lili; Mao, Jeremy J

    2011-10-01

    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or synthetic polymers, three-dimensional scaffold fabrication, stem cell transplantation, and stem cell homing. A tooth is a complex biological organ. Tooth loss represents the most common organ failure. Tooth regeneration encompasses not only regrowth of an entire tooth as an organ, but also biological restoration of individual components of the tooth including enamel, dentin, cementum, or dental pulp. Regeneration of tooth root represents perhaps more near-term opportunities than the regeneration of the whole tooth. In the adult, a tooth owes its biological vitality, arguably more, to the root than the crown. Biomaterials are indispensible for the regeneration of tooth root, tooth crown, dental pulp, or an entire tooth.

  10. Review of molar tooth structure research

    Directory of Open Access Journals (Sweden)

    Hong-Wei Kuang

    2014-10-01

    Full Text Available For more than a century, molar tooth structure (MTS has been studied. The study developed in three stages. During the first stage (before 1980, researchers described three basic morphologies of MTS, mainly from the Belt Supergroup in North America, and they provided several hypotheses for the origin of MTS. During the second stage (1980–1999, the frequent discoveries of MTS on all continents resulted in many detailed descriptions of their shape and in several hypotheses concerning the origin of MTS. Notably, hypotheses of MTS’s origin such as seismic activity and biological activity were developed. Since 2000, research has progressed into a new stage (the third stage. This is due to discoveries of MTS in the Meso–Neoproterozoic of China and elsewhere, and the ongoing debate on the seismic or biological origin is replaced by a hypothesis that involves gas expansion and chemically-controlled carbonate precipitation (both of them possibly affected by biological activities. This latter idea has gradually been commonly recognized as the mainstream theory. Despite continued disagreements, researchers now agree that microsparry calcite played a controlling role regarding the development and the global distribution of MTS in time and space during the Proterozoic, the morphological diversity, and the impact on the sedimentary environment. The present contribution analyses the three major hypotheses regarding the origin of MTS; it also discusses the shortcomings of the hypotheses regarding a seismic or biologic origin, and it details the modern hypothesis that links formation of cracks to the precipitation of sparry calcite. It is deduced that important questions dealing with the Precambrian can be answered, among other aspects regarding the depositional palaeogeography and stratigraphic correlations.

  11. Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur

    Directory of Open Access Journals (Sweden)

    Min eLiu

    2016-05-01

    Full Text Available Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids versus snakes: (i the orientation of replacement teeth compared to the major tooth axis, (ii the occurrence of resorption pits, and (iii the mode of tooth implantation/attachment to the tooth bearing element. The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as

  12. Tooth regeneration: Current status

    Directory of Open Access Journals (Sweden)

    Dadu Shifali

    2009-01-01

    Full Text Available Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  13. Tooth regeneration: current status.

    Science.gov (United States)

    Dadu, Shifali S

    2009-01-01

    Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  14. Directed Replacement

    CERN Document Server

    Karttunen, L

    1996-01-01

    This paper introduces to the finite-state calculus a family of directed replace operators. In contrast to the simple replace expression, UPPER -> LOWER, defined in Karttunen (ACL-95), the new directed version, UPPER @-> LOWER, yields an unambiguous transducer if the lower language consists of a single string. It transduces the input string from left to right, making only the longest possible replacement at each point. A new type of replacement expression, UPPER @-> PREFIX ... SUFFIX, yields a transducer that inserts text around strings that are instances of UPPER. The symbol ... denotes the matching part of the input which itself remains unchanged. PREFIX and SUFFIX are regular expressions describing the insertions. Expressions of the type UPPER @-> PREFIX ... SUFFIX may be used to compose a deterministic parser for a ``local grammar'' in the sense of Gross (1989). Other useful applications of directed replacement include tokenization and filtering of text streams.

  15. Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2012-01-01

    Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

  16. Atypical Odontalgia (Phantom Tooth Pain)

    Science.gov (United States)

    ... Odontalgia Atypical odontalgia, also known as atypical facial pain, phantom tooth pain, or neuropathic orofacial pain, is characterized by chronic pain in a tooth or teeth, or in a site where teeth ...

  17. Fluorescent intercalator displacement replacement (FIDR) assay: determination of relative thermodynamic and kinetic parameters in triplex formation--a case study using triplex-forming LNAs.

    Science.gov (United States)

    Sau, Sujay P; Kumar, Pawan; Sharma, Pawan K; Hrdlicka, Patrick J

    2012-11-01

    Triplex forming oligonucleotides (TFOs) are the most commonly used approach for site-specific targeting of double stranded DNA (dsDNA). Important parameters describing triplex formation include equilibrium binding constants (K(eq)) and association/dissociation rate constants (k(on) and k(off)). The 'fluorescent intercalator displacement replacement' (FIDR) assay is introduced herein as an operationally simple approach toward determination of these parameters for triplexes involving TC-motif TFOs. Briefly described, relative rate constants are determined from fluorescence intensity changes upon: (i) TFO-mediated displacement of pre-intercalated and fluorescent ethidium from dsDNA targets (triplex association) and (ii) Watson-Crick complement-mediated displacement of the TFO and replacement with ethidium (triplex dissociation). The assay is used to characterize triplexes between purine-rich dsDNA targets and TC-motif TFOs modified with six different locked nucleic acid (LNA) monomers, i.e. conventional and C5-alkynyl-functionalized LNA and α-L-LNA pyrimidine monomers. All of the studied monomers increase triplex stability by decreasing the triplex dissociation rate. LNA-modified TFOs form more stable triplexes than α-L-LNA-modified counterparts owing to slower triplex dissociation. Triplexes modified with C5-(3-aminopropyn-1-yl)-LNA-U monomer Z are particularly stable. The study demonstrates that three affinity-enhancing features can be combined into one high-affinity TFO monomer: conformational restriction of the sugar ring, expansion of the pyrimidine π-stacking surface and introduction of an exocyclic amine.

  18. Effect of acemannan, an extracted polysaccharide from Aloe vera, on BMSCs proliferation, differentiation, extracellular matrix synthesis, mineralization, and bone formation in a tooth extraction model.

    Science.gov (United States)

    Boonyagul, Sani; Banlunara, Wijit; Sangvanich, Polkit; Thunyakitpisal, Pasutha

    2014-07-01

    Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide extracted from Aloe vera gel, could affect bone formation. Primary rat bone marrow stromal cells (BMSCs) were treated with various concentrations of acemannan. New DNA synthesis, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein, osteopontin expression, and mineralization were determined by [(3)H] thymidine incorporation assay, ELISA, biochemical assay, western blotting, and Alizarin Red staining, respectively. In an animal study, mandibular right incisors of male Sprague-Dawley rats were extracted and an acemannan treated sponge was placed in the socket. After 1, 2, and 4 weeks, the mandibles were dissected. Bone formation was evaluated by dual-energy X-ray absorptiometry and histopathological examination. The in vitro results revealed acemannan significantly increased BMSC proliferation, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein and osteopontin expression, and mineralization. In-vivo results showed acemannan-treated groups had higher bone mineral density and faster bone healing compared with untreated controls. A substantial ingrowth of bone trabeculae was observed in acemannan-treated groups. These data suggest acemannan could function as a bioactive molecule inducing bone formation by stimulating BMSCs proliferation, differentiation into osteoblasts, and extracellular matrix synthesis. Acemannan could be a candidate natural biomaterial for bone regeneration.

  19. The Rachitic Tooth

    Science.gov (United States)

    Nociti, Francisco H.; Somerman, Martha J.

    2014-01-01

    Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed. PMID:23939820

  20. Pneumomediastinum after Tooth Extraction

    OpenAIRE

    Ilhan Ocakcioglu; Serhat Koyuncu; Mustafa Kupeli; Oguzhan Bol

    2016-01-01

    Pneumomediastinum is defined as the presence of air in mediastinum. Pneumomediastinum can sometimes occur after surgery. Pneumomediastinum seen after dental procedures is rare. We presented the case of subcutaneous emphysema developed in the neck and upper chest after tooth extraction and discussed the possible mechanisms of pneumomediastinum.

  1. A 10-Year Prospective Study of Single Tooth Implants Placed in the Anterior Maxilla

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2012-01-01

    in this study. Ten implants were placed with an early placement protocol, that is, 4 weeks after tooth extraction, whereas the other 10 implants were placed with a conventional delayed placement protocol, for example, 12 weeks after tooth extraction. At the baseline and at the annual re-examinations, pain from......Purpose: The aim of the study was to evaluate the biological and technical outcomes of early and delayed placed single tooth implants after 10 years of follow-up. Materials and Methods: Twenty consecutive patients who needed a single tooth replacement in the anterior maxilla were included...

  2. Using dental enamel wrinkling to define sauropod tooth morphotypes from the Cañadón Asfalto Formation, Patagonia, Argentina.

    Science.gov (United States)

    Holwerda, Femke M; Pol, Diego; Rauhut, Oliver W M

    2015-01-01

    The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic-early Middle Jurassic) in Central Patagonia (Argentina), which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina) is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.

  3. Knee Replacement

    Science.gov (United States)

    ... need knee replacement surgery usually have problems walking, climbing stairs, and getting in and out of chairs. Some ... a total living space on one floor since climbing stairs can be difficult. Install safety bars or a ...

  4. Replacing penalties

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.24The subject. The article deals with the problem of the use of "substitute" penalties.The purpose of the article is to identify criminal and legal criteria for: selecting the replacement punishment; proportionality replacement leave punishment to others (the formalization of replacement; actually increasing the punishment (worsening of legal situation of the convicted.Methodology.The author uses the method of analysis and synthesis, formal legal method.Results. Replacing the punishment more severe as a result of malicious evasion from serving accused designated penalty requires the optimization of the following areas: 1 the selection of a substitute punishment; 2 replacement of proportionality is serving a sentence other (formalization of replacement; 3 ensuring the actual toughening penalties (deterioration of the legal status of the convict. It is important that the first two requirements pro-vide savings of repression in the implementation of the replacement of one form of punishment to others.Replacement of punishment on their own do not have any specifics. However, it is necessary to compare them with the contents of the punishment, which the convict from serving maliciously evaded. First, substitute the punishment should assume a more significant range of restrictions and deprivation of certain rights of the convict. Second, the perfor-mance characteristics of order substitute the punishment should assume guarantee imple-mentation of the new measures.With regard to replacing all forms of punishment are set significant limitations in the application that, in some cases, eliminates the possibility of replacement of the sentence, from serving where there has been willful evasion, a stricter measure of state coercion. It is important in the context of the topic and the possibility of a sentence of imprisonment as a substitute punishment in cases where the original purpose of the strict measures excluded. It is noteworthy that the

  5. Single-tooth replacement in the anterior arch with a cantilevered IPS e.max press fixed-partial dentures for aged patients: 6 years follow-up%e.Max全瓷贴面单端翼板桥在老年患者前牙弓单颗牙缺失中的6年应用效果评价

    Institute of Scientific and Technical Information of China (English)

    孙强; 王冠超; 何天鹏; 李婧

    2012-01-01

    Objective:To evaluated the clinical outcomes of cantilevered veneer-retained fixed partial dentures (VRFPDs) fabricated with IPS e.max Press for single-tooth replacement in the anterior arch for the aged patients.Methods:A total of 13 patients were treated with VRFPDs,including 4 cases in the maxilla and 9 in the mandible.The patients were evaluated at baseline and annually from October 2005 to Sep 2012 for the integrity of the VRFPDs,proximal contacts,occulsal relationships,pulp vitality,and tooth mobility.The degree of satisfaction was indicated with a visual analog scale.Results:During a mean observation time of 60.5 months,13 VRFPDs on vital abutment teeth did not exhibit postoperative sensitivity or secondary caries.No fractures or chipping of the restorations occurred within the course of the evaluation.No patient complained of food impaction.One cantilevered pontic needed adjustment on the incisal edge due to premature contacts after the 3-year recall examination.Conclusion:Cantilevered IPS e.max Press VRFPDs should be considered as minimally invasive,single-tooth restorative strategy in the anterior arch for the aged patients.Longer observation periods are necessary before this type of restorative design can be recommended as a general conservative procedure.%目的:通过e.Max单端全瓷翼板桥修复老年患者单颗前牙缺失,并对其中短期临床应用效果进行评价,为其临床应用提供参考依据.方法:选择于2005年10月-2012年9月之间就诊于中日友好医院口腔医学中心.共入组13人,其中男性8人,平均62.2岁;女性5人,平均64.3岁.恢复上颌侧切牙3例,上颌第一前磨牙1例;恢复下颌中切牙5例,下颌侧切牙4例;应用Variolink Ⅱ作为树脂粘接剂,常规进行粘接.针对修复体的完整性、邻接关系、咬合关系和基牙牙髓活力以及患者的满意度进行每年一次的随访.结果:平均观察期为60.5个月,所有修复体无1例表现术后敏感和继发龋,

  6. Inhibition of apoptosis in early tooth development alters tooth shape and size.

    Science.gov (United States)

    Kim, J-Y; Cha, Y-G; Cho, S-W; Kim, E-J; Lee, M-J; Lee, J-M; Cai, J; Ohshima, H; Jung, H-S

    2006-06-01

    Apoptosis plays important roles in various stages of organogenesis. In this study, we hypothesized that apoptosis would play an important role in tooth morphogenesis. We examined the role of apoptosis in early tooth development by using a caspase inhibitor, z-VAD-fmk, concomitant with in vitro organ culture and tooth germ transplantation into the kidney capsule. Inhibition of apoptosis at the early cap stage did not disrupt the cell proliferation level when compared with controls. However, the macroscopic morphology of mice molar teeth exhibited dramatic alterations after the inhibition of apoptosis. Crown height was reduced, and mesiodistal diameter was increased in a concentration-dependent manner with z-VAD-fmk treatment. Overall, apoptosis in the enamel knot would be necessary for the proper formation of molar teeth, including appropriate shape and size.

  7. Ultrastructure of basement membranes in developing shark tooth.

    Science.gov (United States)

    Sawada, T; Inoue, S

    2003-01-01

    Based on studies of the tooth of largely mammalian species, the dental basement membranes are shown to be specialized for various roles significant in the development and maintenance of the tooth. Comparative studies with the nonmammalian tooth will facilitate further clarification of the mechanisms of mammalian tooth formation. In this study, basement membranes of the shark tooth in successive developmental stages was ultrastructurally examined for elucidation of their roles in odontogenesis. Teeth of a shark, Cephaloscyllium umbratile, were processed for thin section electron microscopy. Throughout the developmental stages the lamina densa of the basement membrane was made up of a fine network of "cords," irregular anastomosing strands known to be the major component of mammalian basement membranes. In the presecretory stage of the shark tooth, dental papilla cells were immobilized for their differentiation into odontoblasts by means of the binding of their processes to numerous narrow extensions of the lamina densa of the inner dental epithelium. In the secretory stage, a number of cords of the widened lamina densa were extended towards and bound to tubular vesicles of the forming enameloid. During the mineralization stage, fragments of the degrading enameloid matrix appeared to be moving through the lamina densa to the epithelial cells for processing. In the maturation stage, half of the lamina densa facing the enameloid was mineralized forming an advancing edge of mineralization of the enameloid. It provided strong binding and smooth transition of organic to mineral phase which may allow transportation of substances across the phases for enameloid maturation in a way similar to that reported in the mammalian tooth. These observations indicate that basement membranes of the developing shark tooth, as those in the mammalian tooth, play various roles, including anchoring, firm binding, and possible mediation of the transport of substances that are known to be

  8. Odontogenic differentiation of adipose-derived stem cells for tooth regeneration: necessity, possibility, and strategy.

    Science.gov (United States)

    Jing, Wei; Wu, Ling; Lin, Yunfeng; Liu, Lei; Tang, Wei; Tian, Weidong

    2008-01-01

    Tooth regeneration using tissue engineering concepts is a promising biological approach to solving problems of tooth loss in elderly patients. The seeding cells, however, for tooth regeneration such as odontoblasts from dental germ, stem cells from dental pulp and deciduous teeth, and ectomesenchymal cells from the first branchial arch are difficult, even impossible to harvest in clinic. Bone marrow mesenchymal stem cells have odontogenic capacity, but their differentiation abilities significantly decrease with the increasing age of the donors. Therefore, the cells mentioned above are not practical in the clinical application of tooth regeneration in the old. Adipose derived stem cells have many clinical advantages over bone marrow mesenchymal stem cells, and their differentiation potential can be maintained with aging. Here we propose the hypothesis that adipose derived stem cells could be induced into odontogenic lineage and might be used as suitable seeding cells for tooth regeneration to replace the lost tooth of elderly patients.

  9. Saw-tooth cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Karatza Ageliki A

    2009-12-01

    Full Text Available Abstract We present an unusual case of cardiomyopathy in a two month old male infant with a grade-I systolic murmur. Echocardiographic examination disclosed left ventricular (LV, dysplasia with saw-tooth like inwards myocardial projections extending from the lateral walls towards the LV cavity. There was mild LV systolic dysfunction with apical hypokinesia. Cardiovascular magnetic resonance demonstrated in detail these cross bridging muscular projections originating from the inferior interventricular septum and lateral LV wall, along with areas of hypokinesis at the LV septum and apex in a noncoronary distribution, without any late gadolinium enhancement. We have termed this condition saw-tooth cardiomyopathy because of the very characteristic appearance.

  10. Tooth in oropharynx

    OpenAIRE

    Nagarajappa, D; B S Manjunatha

    2011-01-01

    The incidence of ectopic teeth has increased. In many cases, the etiology of ectopic teeth cannot be identified. Ectopic tooth in deciduous dentition period is very rare and information is limited about its causes and characteristics. The conditions commonly associated with an increased prevalence of ectopic teeth include cleft lip and palate, cleidocranial dysplasia, and Gardner syndrome. The diagnosis is made by the clinical and radiological examinations. The indication for extraction in ec...

  11. Solving tooth sensitivity.

    Science.gov (United States)

    Miller, Michael B

    2010-01-01

    Solving tooth sensitivity requires both you and the patients to be resilient and to understand that if one approach doesn't work, you can try another one that is non-invasive or, at worst, minimally invasive. Much like the clinician who posted the original question, I strongly believe that it is our responsibility to convince patients that jumping to a radical solution could be totally unnecessary--and expensive-- and still might not solve the problem.

  12. Esophageal replacement.

    Science.gov (United States)

    Kunisaki, Shaun M; Coran, Arnold G

    2017-04-01

    This article focuses on esophageal replacement as a surgical option for pediatric patients with end-stage esophageal disease. While it is obvious that the patient׳s own esophagus is the best esophagus, persisting with attempts to retain a native esophagus with no function and at all costs are futile and usually detrimental to the overall well-being of the child. In such cases, the esophagus should be abandoned, and the appropriate esophageal replacement is chosen for definitive reconstruction. We review the various types of conduits used for esophageal replacement and discuss the unique advantages and disadvantages that are relevant for clinical decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Endodontic Treatment of an Anomalous Anterior Tooth with the Aid of a 3-dimensional Printed Physical Tooth Model.

    Science.gov (United States)

    Byun, Chanhee; Kim, Changhwan; Cho, Seungryong; Baek, Seung Hoon; Kim, Gyutae; Kim, Sahng G; Kim, Sun-Young

    2015-06-01

    Endodontic treatment of tooth formation anomalies is a challenge to clinicians and as such requires a complete understanding of the aberrant root canal anatomy followed by careful root canal disinfection and obturation. Here, we report the use of a 3-dimensional (3D) printed physical tooth model including internal root canal structures for the endodontic treatment of a challenging tooth anomaly. A 12-year-old boy was referred for endodontic treatment of tooth #8. The tooth showed class II mobility with swelling and a sinus tract in the buccal mucosa and periapical radiolucency. The tooth presented a very narrow structure between the crown and root by distal concavity and a severely dilacerated root. Moreover, a perforation site with bleeding and another ditching site were identified around the cervical area in the access cavity. A translucent physical tooth model carrying the information on internal root canal structures was built through a 3-step process: data acquisition by cone-beam computed tomographic scanning, virtual modeling by image processing, and manufacturing by 3D printing. A custom-made guide jig was then fabricated to achieve a safe and precise working path to the root canal. Endodontic procedures including access cavity preparation were performed using the physical tooth model and the guide jig. At the 7-month follow-up, the endodontically treated tooth showed complete periapical healing with no clinical signs and symptoms. This case report describes a novel method of endodontic treatment of an anomalous maxillary central incisor with the aid of a physical tooth model and a custom-made guide jig via 3D printing technique.

  14. Decoronation for the management of an ankylosed young permanent tooth.

    Science.gov (United States)

    Sapir, Shabtai; Shapira, Joseph

    2008-02-01

    Replacement resorption rate is a variable process, and is dependent on age, basal metabolic rate, extra-alveolar time, treatment prior to replantation, amount of root dentin, severity of trauma, and extent of periodontal ligament necrosis. In patients 7-16 years old a tooth is lost 3-7 years after the onset of root resorption. The complications that may develop as a consequence of ankylosis of a permanent incisor in children are due to the inevitable early loss of the traumatized tooth and local arrest of alveolar bone development. An ankylosed tooth should be removed before the changes become so pronounced that they compromise future prosthetic treatment. The treatment options may involve: interceptive regenerative treatment, early extraction of the ankylosed tooth, orthodontic space closure, intentional replantation, extraction of the ankylosed tooth followed with immediate ridge augmentation/preservation, auto-transplantation, single tooth dento-osseous osteotomy, and decoronation. The purpose of this article was to review the considerations involved in the decision-making concerning the use of the decoronation technique for the treatment of a permanent incisor diagnosed as ankylosed.

  15. Postoperative radiation therapy after hip replacement in high-risk patients for development of heterotopic bone formation; Role de la radiotherapie dans la prevention de l'ossification heterotopique

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, R.; Rene, N.; Souhami, L. [Department of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Tanzer, M. [Department of Orthopaedic Surgery, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Evans, M. [Department of Medical Physics, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

    2011-07-15

    Purpose. - To report the results of postoperative radiation therapy in preventing the development of heterotopic bone formation after hip replacement surgery in high-risk patients. Patients and methods. - Between 1991 and 2007, 44 patients were preventively treated with postoperative RT after total hip replacement. In total, 47 hips were treated. All patients were considered at high risk for developing heterotopic bone formation. Most patients (63.5%) were treated because of a history of severe osteoarthritis or ankylosing spondylitis. All patients were treated with shaped parallel-opposed fields with a single fraction of 7 Gy using 6 or 18 MV photons. Most patients (94%) received radiation therapy within 72 hours postoperative and in only three patients radiation therapy was delivered after 72 hours post-surgery (5-8 days). Results. - Minimum follow-up was 1 year. There were 18 females and 26 males. Median age was 63 years (range: 18-80). Treatments were well tolerated and no acute toxicity was seen post-radiation therapy. Only one of the 47 hips (2%) developed heterotopic bone formation. This patient received postoperative radiation therapy to both hips but only developed heterotopic bone formation in one of them. None of the three patients treated beyond 72 hours failed. To date no late toxicity has been observed. Conclusion. - The use of postoperative radiation therapy was an effective and safe treatment in the prevention of heterotopic bone formation in a high-risk group of patients undergoing total hip replacement. (authors)

  16. Fate of HERS during Tooth Root Development

    OpenAIRE

    HUANG, XIAOFENG; BRINGAS, PABLO; Slavkin, Harold C.; Chai, Yang

    2009-01-01

    Tooth root development begins after the completion of crown formation in mammals. Previous studies have shown that Hertwig's epithelial root sheath (HERS) plays an important role in root development, but the fate of HERS has remained unknown. In order to investigate the morphological fate and analyze the dynamic movement of HERS cells in vivo, we generated K14-Cre;R26R mice. HERS cells are detectable on the surface of the root throughout root formation and do not disappear. Most of the HERS c...

  17. Making a tooth: growth factors, transcription factors, and stem cells

    Institute of Scientific and Technical Information of China (English)

    Yah Ding ZHANG; Zhi CHEN; Yi Qiang SONG; Chao LIU; Yi Ping CHEN

    2005-01-01

    Mammalian tooth development is largely dependent on sequential and reciprocal epithelial-mesenchymal interactions.These processes involve a series of inductive and permissive interactions that result in the determination, differentiation,and organization of odontogenic tissues. Multiple signaling molecules, including BMPs, FGFs, Shh, and Wnt proteins,have been implicated in mediating these tissue interactions. Transcription factors participate in epithelial-mesenchymal interactions via linking the signaling loops between tissue layers by responding to inductive signals and regulating the expression of other signaling molecules. Adult stem cells are highly plastic and multipotent. These cells including dental pulp stem cells and bone marrow stromal cells could be reprogrammed into odontogenic fate and participated in tooth formation. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.

  18. Influence of tooth profile on the noncircular gear tooth contact

    Science.gov (United States)

    Cristescu, A.; Andrei, L.; Cristescu, B.

    2017-02-01

    With noncircular gears, the continuous modification of the tooth meshing, in terms of variation of the tooth profiles and the line of action position and inclination, makes difficult the implementation of a general standard procedure for the analysis of the noncircular gears tooth contact. In this paper, the authors present a graphical approach that enables the tooth contact static pattern to be produced and evaluated in case of a noncircular gear with complex geometry of the pitch curve. The study is virtually developed, in AutoCAD environment, by animating and investigating the gear solid models in mesh. The tooth static contact analysis enables the path of contact area and distribution to be evaluated in correlation with the following variable initial data: gear pitch curve geometry, tooth profile geometry, as a consequence of different generating procedures, and the gear pressure angle. It was found out that the noncircular gear tooth contact could be improved by choosing different procedures for the tooth flank generation in concave and convex zones and by increasing the gear pressure angle.

  19. Stem cell-based biological tooth repair and regeneration.

    Science.gov (United States)

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T

    2010-12-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regeneration of periodontal ligament lost in periodontal disease, and for generation of complete or partial tooth structures to form biological implants. As dental stem cells share properties with mesenchymal stem cells, there is also considerable interest in their wider potential to treat disorders involving mesenchymal (or indeed non-mesenchymal) cell derivatives, such as in Parkinson's disease.

  20. Oral pain due to severe pre-eruptive intracoronal resorption in permanent tooth.

    Science.gov (United States)

    Brunet-Llobet, Ll; Lahor-Soler, E; Miranda-Rius, J

    2014-09-01

    Pre-eruptive intracoronal resorption is a dental lesion located within the dentin. This defect is usually discovered incidentally on routine dental radiographs. Occasionally this process may be associated with oral pain in advanced lesions. This case report describes a 12-year-old boy whose chief complaint was a diffuse oral pain due to a severe pre-eruptive intracoronal resorption in a permanent second molar. The previous radiographs, taken at the age of nine years, showed no evidence of the lesion. After surgical exposure, a pulp-like tissue under the crown was removed and analyzed; subsequently the tooth was extracted due to extensive resorption. A follow-up of the unerupted third molar, still in formation process, allowed to see that it was favourably positioned for replacing the extracted molar.

  1. Strain partitioning into dry and wet zones and the formation of Ca-rich myrmekite in syntectonic syenites: A case for melt-assisted dissolution-replacement creep under granulite facies conditions

    Science.gov (United States)

    De Toni, G. B.; Bitencourt, M. F.; Nardi, L. V. S.

    2016-10-01

    The formation of Ca-rich myrmekites is described in syntectonic syenites crystallized and progressively deformed under granulite facies conditions. The syenites are found in high- and low-strain zones where microstructure and mineral composition are compared. Heterogeneously distributed water-rich, late-magmatic liquids were responsible for strain partitioning into dry and wet high-strain zones at outcrop scale, where contrasting deformation mechanisms are reported. In dry high-strain zones K-feldspar and clinopyroxene are recrystallized under high-T conditions. In wet high-strain zones, the de-stabilization of clinopyroxene and pervasive replacement of relatively undeformed K-feldspar porphyroclasts by myrmekite and subordinate micrographic intergrowths indicate dissolution-replacement creep as the main deformation mechanism. The reworking of these intergrowths is observed and is considered to contribute significantly to the development of the mylonitic foliation and banding. A model is proposed for strain partitioning relating a positive feedback between myrmekite-forming reaction, continuous inflow of late-magmatic liquids and dissolution-replacement creep in the wet zone at the expenses of original mineralogy preserved in the dry zones. Melt-assisted dissolution-replacement creep in syntectonic environments under granulite-facies conditions may extend the field of operation of dissolution-replacement creep, changing significantly the rheology of the lower continental crust.

  2. The junctional epithelium originates from the odontogenic epithelium of an erupted tooth.

    Science.gov (United States)

    Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

    2014-05-02

    The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period.

  3. Tooth loss caused by displaced elastic during simple preprosthetic orthodontic treatment

    Science.gov (United States)

    Dianiskova, Simona; Calzolari, Chiara; Migliorati, Marco; Silvestrini-Biavati, Armando; Isola, Gaetano; Savoldi, Fabio; Dalessandri, Domenico; Paganelli, Corrado

    2016-01-01

    The use of elastics to close a diastema or correct tooth malpositions can create unintended consequences if not properly controlled. The American Association of Orthodontists recently issued a consumer alert, warning of “a substantial risk for irreparable damage” from a new trend called “do-it-yourself” orthodontics, consisting of patients autonomously using elastics to correct tooth position. The elastics can work their way below the gums and around the roots of the teeth, causing damage to the periodontium and even resulting in tooth loss. The cost of implants to replace these teeth would well exceed the cost of proper orthodontic care. This damage could also occur in a dental office, when a general dentist tries to perform a simplified orthodontic correction of a minor tooth malposition. The present case report describes a case of tooth loss caused by a displaced intraoral elastic, which occurred during a simple preprosthetic orthodontic treatment. PMID:27672645

  4. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  5. Abiotic tooth enamel

    Science.gov (United States)

    Yeom, Bongjun; Sain, Trisha; Lacevic, Naida; Bukharina, Daria; Cha, Sang-Ho; Waas, Anthony M.; Arruda, Ellen M.; Kotov, Nicholas A.

    2017-03-01

    Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix. This structural motif is unusually consistent across all species from all geological eras. Such invariability—especially when juxtaposed with the diversity of other tissues—suggests the existence of a functional basis. Here we performed ex vivo replication of enamel-inspired columnar nanocomposites by sequential growth of zinc oxide nanowire carpets followed by layer-by-layer deposition of a polymeric matrix around these. We show that the mechanical properties of these nanocomposites, including hardness, are comparable to those of enamel despite the nanocomposites having a smaller hard-phase content. Our abiotic enamels have viscoelastic figures of merit (VFOM) and weight-adjusted VFOM that are similar to, or higher than, those of natural tooth enamels—we achieve values that exceed the traditional materials limits of 0.6 and 0.8, respectively. VFOM values describe resistance to vibrational damage, and our columnar composites demonstrate that light-weight materials of unusually high resistance to structural damage from shocks, environmental vibrations and oscillatory stress can be made using biomimetic design. The previously inaccessible combinations of high stiffness, damping and light weight that we achieve in these layer-by-layer composites are attributed to efficient energy dissipation in the interfacial portion of the organic phase. The in vivo contribution of this interfacial portion to macroscale deformations along the tooth’s normal is maximized when the architecture is columnar, suggesting an evolutionary advantage of the columnar motif in the enamel of living species. We expect our findings to apply to all columnar composites and to lead to the development of high-performance load-bearing materials.

  6. Tooth tissue engineering: optimal dental stem cell harvest based on tooth development.

    Science.gov (United States)

    Duailibi, Monica Talarico; Duailibi, Silvio Eduardo; Duailibi Neto, Eduardo Felippe; Negreiros, Renata Matalon; Jorge, Waldyr Antonio; Ferreira, Lydia Masako; Vacanti, Joseph Phillip; Yelick, Pamela Crotty

    2011-07-01

    Our long-term objective is to devise reliable methods to generate biological replacement teeth exhibiting the physical properties and functions of naturally formed human teeth. Previously, we demonstrated the successful use of tissue engineering approaches to generate small, bioengineered tooth crowns from harvested pig and rat postnatal dental stem cells (DSCs). To facilitate characterizations of human DSCs, we have developed a novel radiographic staging system to accurately correlate human third molar tooth developmental stage with anticipated harvested DSC yield. Our results demonstrated that DSC yields were higher in less developed teeth (Stages 1 and 2), and lower in more developed teeth (Stages 3, 4, and 5). The greatest cell yields and colony-forming units (CFUs) capability was obtained from Stages 1 and 2 tooth dental pulp. We conclude that radiographic developmental staging can be used to accurately assess the utility of harvested human teeth for future dental tissue engineering applications. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  7. Dental-derived Stem Cells and whole Tooth Regeneration: an Overview

    OpenAIRE

    2009-01-01

    The need for new dental tissue-replacement therapies is evident in recent reports which reveal startling statistics regarding the high incidence of tooth decay and tooth loss. Recent advances in the identification and characterization of dental stem cells, and in dental tissue-engineering strategies, suggest that bioengineering approaches may successfully be used to regenerate dental tissues and whole teeth. Interest in dental tissue-regeneration applications continues to increase as clinical...

  8. Coordination of tooth morphogenesis and neuronal development through tissue interactions: lessons from mouse models.

    Science.gov (United States)

    Luukko, Keijo; Kettunen, Päivi

    2014-07-15

    In addition to being an advantageous model to investigate general molecular mechanisms of organ formation, the tooth is a distinct target organ for peripheral nerve innervation. These nerves are required for the function and protection of the teeth and, as shown in fish, also for their regeneration. This review focuses on recent findings of the local tissue interactions and molecular signaling mechanisms that regulate the early nerve arrival and patterning of mouse mandibular molar tooth sensory innervation. Dental sensory nerve growth and patterning is a stepwise process that is intimately linked to advancing tooth morphogenesis. In particular, nerve growth factor and semaphorin 3A serve as essential functions during and are iteratively used at different stages of tooth innervation. The tooth germ controls development of its own nerve supply, and similar to the development of the tooth organ proper, tissue interactions between dental epithelial and mesenchymal tissues control the establishment of tooth innervation. Tgf-β, Wnt, and Fgf signaling, which regulate tooth formation, are implicated to mediate these interactions. Therefore, tissue interactions mediated by conserved signal families may constitute key mechanism for the integration of tooth organogenesis and development of its peripheral nerve supply. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Tooth root regeneration using dental follicle cell sheets in combination with a dentin matrix - based scaffold.

    Science.gov (United States)

    Yang, Bo; Chen, Gang; Li, Jie; Zou, Qing; Xie, Dan; Chen, Yali; Wang, Hang; Zheng, Xiaohui; Long, Jie; Tang, Wei; Guo, Weihua; Tian, Weidong

    2012-03-01

    Stem cell mediated tissue engineering has been acknowledged as a prospective strategy for repairing and replacing damaged and lost tissues. However, the low survival rate of implanted stem cells proves to be a major challenge in the management of transplantation failures. While previous studies have indicated the effectiveness of tissue engineered cell sheets in improving the survival rate of implanted cells, we have recently demonstrated the use of treated dentin matrix (TDM) as a biological scaffold and dental follicle cells (DFCs) as the seeding cells for dentinogenesis and tooth root construction. This study proposes a strategy utilizing TDM with human dental follicle cell sheets (DFCSs) for root regeneration. The biological characteristics and changes of human DFCSs under the effect of TDM were studied with scanning electron microscopy, transmission electron microscopy, immunofluorescence microscopy, immunohistochemistry and quantitative real-time PCR. DFCSs combined with TDM were implanted subcutaneously into the dorsum of mice. Histological examination of the harvested grafts revealed a whirlpool-like alignment of the DFCs in multiple layers that were positive for COLI, integrinβ1, fibronectin and alkaline phosphatase (ALP), suggestive of the formation of a rich extracellular matrix. DFCSs, under the effect of TDM, highly expressed DMP-1 and bone sialoprotein (BSP), indicating their potential for odontogenesis and osteogenesis. Importantly, in vivo, TDM could induce and support DFCSs to develop new dentin-pulp like tissues and cementum-periodontal complexes that were positive for markers such as DSP, nestin and VIII factors, COLI and cementum attachment protein (CAP), implying successful root regeneration. Therefore, DFCSs combined with TDM may prove to be a better strategy for the construction of tooth root, and is a prospective approach that could be utilized for the treatment of root or tooth defect or loss in future.

  10. Natural Tooth Pontic: An Instant Esthetic Option for Periodontally Compromised Teeth—A Case Series

    Science.gov (United States)

    Raj, Rishi; Narayan, Ipshita; Gowda, Triveni Mavinakote; Mehta, D. S.

    2016-01-01

    Sudden tooth loss in the esthetic zone of the maxillary or mandibular anterior region can be due to trauma, periodontal disease, or endodontic failure. The treatment options for replacing the missing tooth can vary between removable prosthesis, tooth-supported prosthesis, and implant-supported prosthesis. Irrespective of the final treatment, the first line of management would be to provisionally restore the patient's esthetic appearance at the earliest, while functionally stabilizing the compromised arch. Using the patient's own natural tooth as a pontic offers the benefits of being the right size, shape, and color and provides exact repositioning in its original intraoral three-dimensional position. Additionally, using the patient's platelet concentrate (platelet rich fibrin) facilitates early wound healing and preservation of alveolar ridge shape following tooth extraction. The abutment teeth can also be preserved with minimal or no preparation, thus keeping the technique reversible, and can be completed at the chair side thereby avoiding laboratory costs. This helps the patient better tolerate the effect of tooth loss psychologically. The article describes a successful, immediate, and viable technique for rehabilitation of three different patients requiring replacement of a single periodontally compromised tooth in an esthetic region. PMID:27994892

  11. [Estrogen replacement].

    Science.gov (United States)

    Søgaard, A J; Berntsen, G K; Magnus, J H; Tollan, A

    1998-02-10

    Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

  12. Managing congenitally missing lateral incisors. Part II: tooth-supported restorations.

    Science.gov (United States)

    Kinzer, Greggory A; Kokich, Vincent O

    2005-01-01

    Three treatment options exist for the replacement of congenitally missing lateral incisors: canine substitution, a tooth-supported restoration, or a single-tooth implant. Selecting the appropriate treatment option depends on the malocclusion, the anterior relationship, specific space requirements, and the condition of the adjacent teeth. The ideal treatment is the most conservative alternative that satisfies individual esthetic and functional requirements. This article closely examines the three options when replacing a missing lateral incisor with a tooth-supported restoration. These options are a resin-bonded fixed partial denture, a cantilevered fixed partial denture, and a conventional full-coverage fixed partial denture. The specific criteria that must be evaluated for each option is addressed to illustrate the importance of interdisciplinary treatment planning to achieve optimal esthetics and long-term predictability. This article is the second of a three-part series discussing the three treatment alternatives for replacing congenitally missing lateral incisors.

  13. Contribution of mesenchymal proliferation in tooth root morphogenesis.

    Science.gov (United States)

    Sohn, W-J; Choi, M-A; Yamamoto, H; Lee, S; Lee, Y; Jung, J-K; Jin, M-U; An, C-H; Jung, H-S; Suh, J-Y; Shin, H-I; Kim, J-Y

    2014-01-01

    In mouse tooth development, the roots of the first lower molar develop after crown formation to form 2 cylindrical roots by post-natal day 5. This study compared the morphogenesis and cellular events of the mesial-root-forming (MRF) and bifurcation-forming (BF) regions, located in the mesial and center of the first lower molar, to better define the developmental mechanisms involved in multi-rooted tooth formation. We found that the mesenchyme in the MRF showed relatively higher proliferation than the bifurcation region. This suggested that spatially regulated mesenchymal proliferation is required for creating cylindrical root structure. The mechanism may involve the mesenchyme forming a physical barrier to epithelial invagination of Hertwig's epithelial root sheath. To test these ideas, we cultured roots in the presence of pharmacological inhibitors of microtubule and actin polymerization, nocodazole and cytochalasin-D. Cytochalasin D also inhibits proliferation in epithelium and mesenchyme. Both drugs resulted in altered morphological changes in the tooth root structures. In particular, the nocodazole- and cytochalasin-D-treated specimens showed a loss of root diameter and formation of a single-root, respectively. Immunolocalization and three-dimensional reconstruction results confirmed these mesenchymal cellular events, with higher proliferation in MRF in multi-rooted tooth formation.

  14. Radicular cyst of primary tooth associated with maxillary sinus

    National Research Council Canada - National Science Library

    Bahadure, Rakesh N; Khubchandani, Monika; Thosar, Nilima R; Singh, Rajeev Kumar

    2013-01-01

    .... It is inflammatory in nature and found mostly in relation to a non-vital tooth. It usually presents at a later stage in life because the formation of the cyst is the last step in the progression of inflammatory events after a periapical infection...

  15. [Application of micro-power system in the surgery of tooth extraction].

    Science.gov (United States)

    Kaijin, Hu; Yongfeng, Li

    2015-02-01

    Tooth extraction is a common operation in oral surgery. Traditional-extraction instruments, such as bone chisel, elevator, and bone hammer, lead to not only severe trauma but also unnecessary complications, and patients easily become nervous and apprehensive if tooth extraction is performed using these violent instruments. In recent years, with the develop- ment of minimally invasive concept and technology, various micro-power instruments have been used for tooth extraction. This innovative technology can reduce the iatrogenic trauma and complications of tooth extraction. Additionally, this technology can greatly decrease the patient's physical and mental pressure. The new equipment compensates for the deficiency of traditional tooth extraction equipment and facilitates the gradual replacement of the latter. Diverse micro-power systems have distinct strengths and weaknesses, so some auxiliary instruments are still needed during tooth extraction. This paper focuses on the various micro-power systems for tooth extraction and tries to compare the advantages and disadvantages of these systems. Selection and usage of auxiliary equipment are also introduced. Thus, this paper provides reference for the proper application of the micro-power systems in tooth extraction.

  16. Treatment of a horizontal root-fractured tooth with decoronation procedure: case report

    Directory of Open Access Journals (Sweden)

    Selen Esin Yoldaş

    2016-05-01

    Full Text Available INTRODUCTION: Early loss of permanent anterior teeth due to trauma can cause esthetic and functional problems for young patients. In such cases, replacement of the missing tooth with traditional approaches is possible; however such approaches will reduce the chance of the patient to receive an esthetic and consistent treatment in the future. CASE REPORT: A 12-year-old male patient referred to our clinic with a history of trauma. Complicated crown fracture in tooth no.11 and horizontal root fracture in tooth no. 21 was detected. Following root canal treatment, tooth no. 11 was restored with a fiber post and a strip crown. To avoid alveolar bone loss due to early tooth extraction, decoronation procedure, an alternative approach, was applied to tooth no. 21. This procedure consisted of leaving the root fragment inside the alveolar socket following the removal of the crown. For the rehabilitation of the missing crown, a partial removable prosthesis was implemented. The patient was recalled in 6., 12. and 18. months. Within the follow-up period, no reduction in the alveolar bone level was seen. No sign of infection was evident. The remaining root fragment kept on resorbing. Tooth no. 11 remained symptom-free as well. The patient is still being followed. CONCLUSION: Decoronation is essentially a treatment choice for preventing alveolar bone loss in ankylosed teeth considered for extraction. In this case report, decoronation was shown to be a suitable alternative also for a fractured, non-ankylosed tooth.

  17. Biomaterial Selection for Tooth Regeneration

    OpenAIRE

    2011-01-01

    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or s...

  18. [A tooth or an implant--literature based decision making].

    Science.gov (United States)

    Bar On, H; Sharon, E; Lipovezky-Adler, M; Haramaty, O; Smidt, A

    2014-07-01

    The common use of dental implants in the daily practice led to a profound change in the available treatment strategies. The option of replacing a diagnosed doubtful tooth with an implant has become widely accepted and often used. The prognosis systems in use today are based on the three major disciplines: endodontics, periodontics and prosthodontics. Combining these three may impair and bias the decision making process and increase the tendency to base it on subjective clinical experience and personal preference. Reading and reviewing the relevant literature gives no clear tool for use. Root canal treatment is considered a highly predictable treatment procedure and a treated tooth is affected mainly by the quality and type of the fabricated restoration and the risk of caries. Periodontal treatment followed by a suitable maintenance regimen will likely allow long term tooth survival. When comparing the success rates of natural teeth rehabilitation versus implant supported restorations, it appears that with implants an additional treatment is demanded along the years. This coincides with the fact that to date there is no consensus regarding the extent of perimplantitis and perimucositis that is to be expected around a restored implant. In addition, a peri implant tissue problem or a failure of a dental implant may prove to be more challenging than a failure of a tooth. It is important to remember that a dental implant is made to substitute a missing tooth and it is a treatment modality with known and clear indications for rehabilitation of an edentulous space. The aim of this paper is to review and discuss the various aspects of whether to maintain a compromised or a doubtful tooth or to prefer a treatment modality using dental implants. In conclusion it is advised here, to incorporate the discussed issues in the decision making process towards the most suitable treatment plan.

  19. Melatonin Effects on Hard Tissues: Bone and Tooth

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2013-05-01

    Full Text Available Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

  20. Formats

    Directory of Open Access Journals (Sweden)

    Gehmann, Ulrich

    2012-03-01

    Full Text Available In the following, a new conceptual framework for investigating nowadays’ “technical” phenomena shall be introduced, that of formats. The thesis is that processes of formatting account for our recent conditions of life, and will do so in the very next future. It are processes whose foundations have been laid in modernity and which will further unfold for the time being. These processes are embedded in the format of the value chain, a circumstance making them resilient to change. In addition, they are resilient in themselves since forming interconnected systems of reciprocal causal circuits.Which leads to an overall situation that our entire “Lebenswelt” became formatted to an extent we don’t fully realize, even influencing our very percep-tion of it.

  1. Analysis of split tooth as an unstudied reason for tooth extraction

    OpenAIRE

    Osaghae, Ifueko Patience; Azodo, Clement Chinedu

    2014-01-01

    Background Split tooth is an unstudied reason for tooth extraction. The purpose of this study was to determine and analyze split tooth as a reason for extraction in a dental clinic in Benin City. Methods The prospective study was carried out on 669 patients having tooth extraction between May, 2005 and December, 2012. Over the period of the study, diagnosis and tooth extraction were done by three dentists of more five years practice experience. The indications for tooth extraction were noted ...

  2. Hedgehog signaling is required at multiple stages of zebrafish tooth development

    Directory of Open Access Journals (Sweden)

    Stock David W

    2010-11-01

    Full Text Available Abstract Background The accessibility of the developing zebrafish pharyngeal dentition makes it an advantageous system in which to study many aspects of tooth development from early initiation to late morphogenesis. In mammals, hedgehog signaling is known to be essential for multiple stages of odontogenesis; however, potential roles for the pathway during initiation of tooth development or in later morphogenesis are incompletely understood. Results We have identified mRNA expression of the hedgehog ligands shha and the receptors ptc1 and ptc2 during zebrafish pharyngeal tooth development. We looked for, but did not detect, tooth germ expression of the other known zebrafish hedgehog ligands shhb, dhh, ihha, or ihhb, suggesting that as in mammals, only Shh participates in zebrafish tooth development. Supporting this idea, we found that morphological and gene expression evidence of tooth initiation is eliminated in shha mutant embryos, and that morpholino antisense oligonucleotide knockdown of shha, but not shhb, function prevents mature tooth formation. Hedgehog pathway inhibition with the antagonist compound cyclopamine affected tooth formation at each stage in which we applied it: arresting development at early stages and disrupting mature tooth morphology when applied later. These results suggest that hedgehog signaling is required continuously during odontogenesis. In contrast, over-expression of shha had no effect on the developing dentition, possibly because shha is normally extensively expressed in the zebrafish pharyngeal region. Conclusion We have identified previously unknown requirements for hedgehog signaling for early tooth initiation and later morphogenesis. The similarity of our results with data from mouse and other vertebrates suggests that despite gene duplication and changes in the location of where teeth form, the roles of hedgehog signaling in tooth development have been largely conserved during evolution.

  3. Hedgehog signaling is required at multiple stages of zebrafish tooth development.

    Science.gov (United States)

    Jackman, William R; Yoo, James J; Stock, David W

    2010-11-30

    The accessibility of the developing zebrafish pharyngeal dentition makes it an advantageous system in which to study many aspects of tooth development from early initiation to late morphogenesis. In mammals, hedgehog signaling is known to be essential for multiple stages of odontogenesis; however, potential roles for the pathway during initiation of tooth development or in later morphogenesis are incompletely understood. We have identified mRNA expression of the hedgehog ligands shha and the receptors ptc1 and ptc2 during zebrafish pharyngeal tooth development. We looked for, but did not detect, tooth germ expression of the other known zebrafish hedgehog ligands shhb, dhh, ihha, or ihhb, suggesting that as in mammals, only Shh participates in zebrafish tooth development. Supporting this idea, we found that morphological and gene expression evidence of tooth initiation is eliminated in shha mutant embryos, and that morpholino antisense oligonucleotide knockdown of shha, but not shhb, function prevents mature tooth formation. Hedgehog pathway inhibition with the antagonist compound cyclopamine affected tooth formation at each stage in which we applied it: arresting development at early stages and disrupting mature tooth morphology when applied later. These results suggest that hedgehog signaling is required continuously during odontogenesis. In contrast, over-expression of shha had no effect on the developing dentition, possibly because shha is normally extensively expressed in the zebrafish pharyngeal region. We have identified previously unknown requirements for hedgehog signaling for early tooth initiation and later morphogenesis. The similarity of our results with data from mouse and other vertebrates suggests that despite gene duplication and changes in the location of where teeth form, the roles of hedgehog signaling in tooth development have been largely conserved during evolution.

  4. Hedgehog signaling is required at multiple stages of zebrafish tooth development

    Science.gov (United States)

    2010-01-01

    Background The accessibility of the developing zebrafish pharyngeal dentition makes it an advantageous system in which to study many aspects of tooth development from early initiation to late morphogenesis. In mammals, hedgehog signaling is known to be essential for multiple stages of odontogenesis; however, potential roles for the pathway during initiation of tooth development or in later morphogenesis are incompletely understood. Results We have identified mRNA expression of the hedgehog ligands shha and the receptors ptc1 and ptc2 during zebrafish pharyngeal tooth development. We looked for, but did not detect, tooth germ expression of the other known zebrafish hedgehog ligands shhb, dhh, ihha, or ihhb, suggesting that as in mammals, only Shh participates in zebrafish tooth development. Supporting this idea, we found that morphological and gene expression evidence of tooth initiation is eliminated in shha mutant embryos, and that morpholino antisense oligonucleotide knockdown of shha, but not shhb, function prevents mature tooth formation. Hedgehog pathway inhibition with the antagonist compound cyclopamine affected tooth formation at each stage in which we applied it: arresting development at early stages and disrupting mature tooth morphology when applied later. These results suggest that hedgehog signaling is required continuously during odontogenesis. In contrast, over-expression of shha had no effect on the developing dentition, possibly because shha is normally extensively expressed in the zebrafish pharyngeal region. Conclusion We have identified previously unknown requirements for hedgehog signaling for early tooth initiation and later morphogenesis. The similarity of our results with data from mouse and other vertebrates suggests that despite gene duplication and changes in the location of where teeth form, the roles of hedgehog signaling in tooth development have been largely conserved during evolution. PMID:21118524

  5. Three-dimensional analysis of mandibular growth and tooth eruption

    DEFF Research Database (Denmark)

    Krarup, S.; Darvann, Tron Andre; Larsen, Per

    2005-01-01

    , relocated laterally during growth. Furthermore, the position of tooth buds remained relatively stable inside the jaw until root formation started. Eruption paths of canines and premolars were vertical, whereas molars erupted in a lingual direction. The 3D method would seem to offer new insight into jaw......Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth...... and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Bjork in 1969 from two to three dimensions. As longitudinal CT data from normal children are not available (for ethical reasons), CT data from children...

  6. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans

    Science.gov (United States)

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (~2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.

  7. Role of Homeobox Genes in Tooth Morphogenesis: A Review

    Science.gov (United States)

    Suryadeva, Sreevalli

    2015-01-01

    In oral cavity, disturbances due to genetic alterations may range from lack of tooth development to morphological defects. Due to technical advances in genetic engineering and molecular biology, valuable information regarding dentofacial growth could be studied in detailed manner. This helped us to explain the aetiology and pathogenesis of many dentofacial disorders. The success in treatment lies first in determining the aetiology of tooth anomalies and finally differentiating the effect of genes and environment on the orofacial diseases of that particular individual. Several genes belonging to class II homeobox families are expressed during odontogenesis however homeobox genes are not directly imvolved in tooth formation as they are not directly expressed in the first branchial arch derivatives. PMID:25859538

  8. Tooth wear patterns in the deciduous dentition.

    Science.gov (United States)

    Warren, John J; Yonezu, Takuro; Bishara, Samir E

    2002-12-01

    Tooth wear is common in the deciduous dentition. A recent study suggests that tooth wear in the deciduous dentition is related to subsequent tooth wear in adults, so that early identification of factors related to tooth wear could be of long-term benefit. The purposes of this study were to describe patterns of tooth wear in the deciduous dentition and to relate tooth wear to occlusal characteristics and longitudinal dietary patterns. Data were collected as part of a longitudinal study of a cohort of children recruited at birth from Iowa hospitals. Stone casts were obtained in the deciduous dentition stage, and 355 children, 4 to 5 years old, met the selection criteria. Tooth wear was categorized for each tooth as none, mild, moderate, or severe, and related to occlusal characteristics and longitudinal data on fruit juice and soft drink consumption. All children exhibited some tooth wear on at least 1 tooth, and nearly 16% of them had at least 1 tooth with severe wear. Tooth wear was generally more severe in the maxillary arch and the anterior teeth. Severe tooth wear on the molars was significantly related to posterior crossbites, but severe tooth wear on the incisors was related to Class III canine relationships. There were no statistically significant relationships between tooth wear and soft drink or fruit juice consumption. Based on our results, we concluded that mild tooth wear is universal in the deciduous dentition, but only a few occlusal factors are related to severe tooth wear. Tooth wear was not related to any dietary patterns we investigated.

  9. Fibroblast growth factor signaling in mammalian tooth development.

    Science.gov (United States)

    Li, Chun-Ying; Prochazka, Jan; Goodwin, Alice F; Klein, Ophir D

    2014-01-01

    In this review, we discuss the central role of fibroblast growth factor (FGF) signaling in mammalian tooth development. The FGF family consists of 22 members, most of which bind to four different receptor tyrosine kinases, which in turn signal through a cascade of intracellular proteins. This signaling regulates a number of cellular processes, including proliferation, differentiation, cell adhesion and cell mobility. FGF signaling first becomes important in the presumptive dental epithelium at the initiation stage of tooth development, and subsequently, it controls the invagination of the dental epithelium into the underlying mesenchyme. Later, FGFs are critical in tooth shape formation and differentiation of ameloblasts and odontoblasts, as well as in the development and homeostasis of the stem cell niche that fuels the continuously growing mouse incisor. In addition, FGF signaling is critical in human teeth, as mutations in genes encoding FGF ligands or receptors result in several congenital syndromes characterized by alterations in tooth number, morphology or enamel structure. The parallel roles of FGF signaling in mouse and human tooth development demonstrate the conserved importance of FGF signaling in mammalian odontogenesis.

  10. Regeneration of tooth-like hydroxyapatite depended on amelogenin functional section monolayer: a new approach for tooth repair.

    Science.gov (United States)

    Tian, Kun; Peng, Min; Ren, Xiaohua; Liao, Chuhang; Fei, Wei

    2012-08-01

    Tooth defect due to caries, trauma, or acid corrosion are common in mankind. Ceramics, metal and resin were used to repaired tooth defect in the past hundred years, but they cannot instead enamel and dentin in depth in clinic usage for the difference in structure and element. So the formation of organized nanocrystals that resemble enamel is crucial for successful enamel remineralization. Now synthesizing a mimicking structure of human enamel using acellular methods has attracted much interest from research groups who have tried using recombinant enamel making proteins like amelogenin, surfactants, to mimic the biomineralization process to restore the enamel layer. Since amelogenin can be used in the assembly of functional nanostructures, we hypothesis that rationally designed β-sheet-forming peptides that spontaneously form three-dimensional fibrillar scaffolds in response to specific environmental triggers may potentially be used in inducing tooth-like hydroxyapatite crystal ex vivo which important to treatment/prevention of dental caries, via bioactive surface groups.

  11. Primary culprit for tooth loss!!

    Directory of Open Access Journals (Sweden)

    Sailavanya Nuvvula

    2016-01-01

    Full Text Available Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A questionnaire containing 10 items was distributed to the dental practitioners, which included age, gender, no of teeth indicated for extraction, the reason for extraction, and the periodontal parameters that are involved with the extracted tooth and were requested to complete the form on every extraction they were to undertake. the study form was collected at the end of the study period and data was subjected to statistical analysis. Results: A total of 502 patients were enrolled during the study period, and a total of 1055 teeth were extracted for several reasons. we found that 51.14%extractions are due to dental caries in case of 20-30years age groups, which is more when compared to tooth loss due to periodontal diseases in this age group. whereas in case of >40years of age group periodontal diseases account for 54.11%, and dental caries accounts for only 29.11%. Showing more teeth were lost due to periodontal disease. Conclusion: therefore we concluded that, caries is the dominant reason for extraction in patients with 20–30 years of age while periodontal disease accounts for the majority of tooth extraction in patients older than 40 years.

  12. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014...

  13. Development of the vestigial tooth primordia as part of mouse odontogenesis.

    Science.gov (United States)

    Peterková, R; Peterka, M; Viriot, L; Lesot, H

    2002-01-01

    The mouse functional dentition comprises one incisor separated from three molars by a toothless diastema in each dental quadrant. Between the incisor and molars, the embryonic tooth pattern also includes vestigial dental primordia, which undergo regression involving apoptosis in their epithelium. Apoptosis appears to play an important role in achieving the specific tooth pattern in the mouse. We documented similarities in the folding mechanism allowing the formation of the dental lamina in mice as well as in reptiles. While further budding on this dental lamina gives rise to many individual simple tooth primordia in crocodiles and lizards, budding morphogenesis of several simple tooth primordia appears to be integrated in the mouse, giving rise to enamel organs of a complex nature. The differentiation of a mammalian tooth germ during both ontogeny and phylogeny might thus include the concrescence (connation) of more primordia, putatively corresponding to simple teeth in mammalian ancestors.

  14. A SINGLE VISIT IMMEDIATE TEMPORIZATION WITH NATURAL TOOTH PONTIC FOR PERIODONTALLY INVOLVED ANTERIOR TEETH : ANESTHETIC AND INNOVATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Nilofer Sultan Sheikh, Neelima S. Rajhans, Preeti Mundhe, Gabriela Jude Fernandez, Nilkanth Mhaske, Nikesh Moolya, Sudeep HM

    2015-01-01

    Full Text Available Aim and Objectives: Sudden loss of anterior tooth is a dreadful situation. It can be as a result of trauma, endodontic failure or periodontal disease which is a true aesthetic emergency for a patient. Along with the patient, the dentist also emphasizes on saving an anterior tooth for the primary reason of aesthetics. If the tooth crown is intact, is not grossly decayed, broken down or discoloured, it can be used as a natural tooth pontic in designing an interim prosthesis. Case: A chair side technique for replacing the missing tooth using the patient’s own natural tooth as a pontic in the three dimensional original position using a fibre reinforced composite resin splint thus restoring the aesthetics and relieving the apprehension of the patient, as described in this case report. Conclusion: The concept of Natural tooth pontic placement is a simple, economical, minimal intervention, viable and an easy to handle treatment option and promises an excellent transient aesthetic solution for a lost tooth as well as require minimal or no tooth preparation, thus is a reversible technique and avoids the laboratory cost.

  15. Orthodontic Tooth Movement: A Historic Prospective.

    Science.gov (United States)

    Will, Leslie A

    2016-01-01

    The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement. In this theory, fluid from the vasculature, lymphatic system and intercellular spaces responds to the forces of tooth movement, damping the force and limiting movement. Bien and Baumrind expanded on this theory with their own studies in the 1960s. It is clear that both the pressure-tension and fluid flow concepts have merit, but considerable work needs to be done to ascertain the details so that tooth movement can be managed and controlled.

  16. Current knowledge of tooth development: patterning and mineralization of the murine dentition.

    Science.gov (United States)

    Catón, Javier; Tucker, Abigail S

    2009-04-01

    The integument forms a number of different types of mineralized element, including dermal denticles, scutes, ganoid scales, elasmoid scales, fin rays and osteoderms found in certain fish, reptiles, amphibians and xenarthran mammals. To this list can be added teeth, which are far more widely represented and studied than any of the other mineralized elements mentioned above, and as such can be thought of as a model mineralized system. In recent years the focus for studies on tooth development has been the mouse, with a wealth of genetic information accrued and the availability of cutting edge techniques. It is the mouse dentition that this review will concentrate on. The development of the tooth will be followed, looking at what controls the shape of the tooth and how signals from the mesenchyme and epithelium interact to lead to formation of a molar or incisor. The number of teeth generated will then be investigated, looking at how tooth germ number can be reduced or increased by apoptosis, fusion of tooth germs, creation of new tooth germs, and the generation of additional teeth from existing tooth germs. The development of mineralized tissue will then be detailed, looking at how the asymmetrical deposition of enamel is controlled in the mouse incisor. The continued importance of epithelial-mesenchymal interactions at these later stages of tooth development will also be discussed. Tooth anomalies and human disorders have been well covered by recent reviews, therefore in this paper we wish to present a classical review of current knowledge of tooth development, fitting together data from a large number of recent research papers to draw general conclusions about tooth development.

  17. Tooth Retained Implant: No More an Oxymoron

    OpenAIRE

    Divya Bhat

    2011-01-01

    Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1) Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2) Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth be...

  18. MICROWAVE PROPAGATION IN TOOTH AND DENTAL DEFECT

    Directory of Open Access Journals (Sweden)

    Maria Papezova

    2016-09-01

    Full Text Available INTRODUCTION:The most common method of conventional dental diagnosisinvolves X-rays, such as Radio Tomography (RT or Computer Tomography (CT. Such methods are used for diagnosing pores in dental material that can lead to premature failure of dental material. Diagnosis by X-ray provides an objective analysis. However, repeated radiation from X-rays can cause biological damage to human tissues. From this point of view, there is a significant need to progress to quantitative non-invasive and non-destructive testing (NDT methods to measure dental material and improve treatment options. This article focuses on applying microwave technology to characterize teeth and teeth replacements. Knowledge of microwave propagation in biomaterial with no defects, using a defined microwave frequency range, and subsequently comparing the result with defective material could provide a means of dental diagnosis without the risk of radiation for the patient, i.e. without X-ray. OBJECTIVES: The primary objective of this study was to examine microwave technology in the field of dental medical diagnosis as a new NDT method. METHODS: The basic concept of applying microwave technology to characterize teeth in dental diagnosis was examined using a basic algorithm designed in the MATLAB programming language. Tests used dielectric properties of tooth and tooth decay and propagated electromagnetic (EM waves to show different characteristics of chosen materials.RESULTS: The analyses of frequency dependent reflection and transmission coefficients of the chosen material, specificallyteeth, atfrequency range 0 GHz to 30 GHz, computed differences between healthy and defective dental material.CONCLUSION: Thus, this could be used in providing a dental diagnosis without exposing patients to radiation, i.e. without X-ray. The next stage will involve creating a complete model of a jaw with teeth, and designing a sensor for crack detection for comparisons using this basic algorithm.

  19. Multiphoton microscopy imaging of developing tooth germs

    Directory of Open Access Journals (Sweden)

    Pei-Yu Pan

    2014-01-01

    Conclusion: In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.

  20. 21 CFR 872.3920 - Porcelain tooth.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  1. [Tooth regeneration--dream to reality].

    Science.gov (United States)

    Wang, Song-Ling; Wang, Xue-Jiu

    2008-04-01

    Tooth or dentition missing compromises human health physically and psychiatrically. Although several prosthesis methods are used to restore tooth loss, these restorations are still non-biological methods. It is a dream for human being to regenerate a real tooth for hundreds years. There are two ways to regenerate the tooth. One is application of conventional tissue engineering techniques including seed cells and scaffold. The other is regeneration tooth using dental epithelium and dental mesenchymal cells based on the knowledge of tooth initiation and development. Marked progress has been achieved in these two ways, while there is still a long way to go. Recently a new concept has been proposed for regeneration of a biological tooth root based on tooth-related stem cells and tissue engineering technique. A biological tooth root has been regenerated in swine. It may be a valuable method for restoration of tooth loss before successful whole tooth regeneration. A latest research showed that a subpopulation in bone marrow cells can give rise to ameloblast-like cells when mixed with embryonic epithelium and reassociation with integrated mesenchyme, which may provide a new seed cell source for tooth regeneration.

  2. Hippo pathway/Yap regulates primary enamel knot and dental cusp patterning in tooth morphogenesis.

    Science.gov (United States)

    Kwon, Hyuk-Jae Edward; Li, Liwen; Jung, Han-Sung

    2015-11-01

    The shape of an individual tooth crown is primarily determined by the number and arrangement of its cusps, i.e., cusp patterning. Enamel knots that appear in the enamel organ during tooth morphogenesis have been suggested to play important roles in cusp patterning. Animal model studies have shown that the Hippo pathway effector Yap has a critical function in tooth morphogenesis. However, the role of the Hippo pathway/Yap in cusp patterning has not been well documented and its specific roles in tooth morphogenesis remain unclear. Here, we provide evidence that Yap is a key mediator in tooth cusp patterning. We demonstrate a correlation between Yap localization and cell proliferation in developing tooth germs. We also show that, between the cap stage and bell stage, Yap is crucial for the suppression of the primary enamel knot and for the patterning of secondary enamel knots, which are the future cusp regions. When Yap expression is stage-specifically knocked down during the cap stage, the activity of the primary enamel knot persists into the bell-stage tooth germ, leading to ectopic cusp formation. Our data reveal the importance of the Hippo pathway/Yap in enamel knots and in the proper patterning of tooth cusps.

  3. Mechanism of human tooth eruption

    DEFF Research Database (Denmark)

    Kjær, Inger

    2014-01-01

    discussed in the introduction. Human studies, mainly clinical and radiological, have focused on normal eruption and gender differences. Why a tooth begins eruption and what enables it to move eruptively and later to end these eruptive movements is not known. Pathological eruption courses contribute...

  4. Three dimensional mathematical model of tooth for finite element analysis

    Directory of Open Access Journals (Sweden)

    Puškar Tatjana

    2010-01-01

    Full Text Available Introduction. The mathematical model of the abutment tooth is the starting point of the finite element analysis of stress and deformation of dental structures. The simplest and easiest way is to form a model according to the literature data of dimensions and morphological characteristics of teeth. Our method is based on forming 3D models using standard geometrical forms (objects in programmes for solid modeling. Objective. Forming the mathematical model of abutment of the second upper premolar for finite element analysis of stress and deformation of dental structures. Methods. The abutment tooth has a form of a complex geometric object. It is suitable for modeling in programs for solid modeling SolidWorks. After analyzing the literature data about the morphological characteristics of teeth, we started the modeling dividing the tooth (complex geometric body into simple geometric bodies (cylinder, cone, pyramid,.... Connecting simple geometric bodies together or substricting bodies from the basic body, we formed complex geometric body, tooth. The model is then transferred into Abaqus, a computational programme for finite element analysis. Transferring the data was done by standard file format for transferring 3D models ACIS SAT. Results. Using the programme for solid modeling SolidWorks, we developed three models of abutment of the second maxillary premolar: the model of the intact abutment, the model of the endodontically treated tooth with two remaining cavity walls and the model of the endodontically treated tooth with two remaining walls and inserted post. Conclusion Mathematical models of the abutment made according to the literature data are very similar with the real abutment and the simplifications are minimal. These models enable calculations of stress and deformation of the dental structures. The finite element analysis provides useful information in understanding biomechanical problems and gives guidance for clinical research.

  5. [Three dimensional mathematical model of tooth for finite element analysis].

    Science.gov (United States)

    Puskar, Tatjana; Vasiljević, Darko; Marković, Dubravka; Jevremović, Danimir; Pantelić, Dejan; Savić-Sević, Svetlana; Murić, Branka

    2010-01-01

    The mathematical model of the abutment tooth is the starting point of the finite element analysis of stress and deformation of dental structures. The simplest and easiest way is to form a model according to the literature data of dimensions and morphological characteristics of teeth. Our method is based on forming 3D models using standard geometrical forms (objects) in programmes for solid modeling. Forming the mathematical model of abutment of the second upper premolar for finite element analysis of stress and deformation of dental structures. The abutment tooth has a form of a complex geometric object. It is suitable for modeling in programs for solid modeling SolidWorks. After analysing the literature data about the morphological characteristics of teeth, we started the modeling dividing the tooth (complex geometric body) into simple geometric bodies (cylinder, cone, pyramid,...). Connecting simple geometric bodies together or substricting bodies from the basic body, we formed complex geometric body, tooth. The model is then transferred into Abaqus, a computational programme for finite element analysis. Transferring the data was done by standard file format for transferring 3D models ACIS SAT. Using the programme for solid modeling SolidWorks, we developed three models of abutment of the second maxillary premolar: the model of the intact abutment, the model of the endodontically treated tooth with two remaining cavity walls and the model of the endodontically treated tooth with two remaining walls and inserted post. Mathematical models of the abutment made according to the literature data are very similar with the real abutment and the simplifications are minimal. These models enable calculations of stress and deformation of the dental structures. The finite element analysis provides useful information in understanding biomechanical problems and gives guidance for clinical research.

  6. Erosive Potential of Cola and Orange Fruit Juice on Tooth Colored ...

    African Journals Online (AJOL)

    is defined as an irreversible loss of dental hard tissue by a chemical process ... replacement of lost tooth structure is usually desired to restore esthetics and .... Specimens were finished and polished with Sof‑Lex disks. (3M, St. Paul, MN, USA) ...

  7. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare.

    Science.gov (United States)

    Grier-Lowe, Candace K; Anthony, James

    2015-08-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  8. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare

    OpenAIRE

    2015-01-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  9. Intra-epithelial requirement of canonical Wnt signaling for tooth morphogenesis.

    Science.gov (United States)

    Zhu, XiaoJing; Zhao, Pan; Liu, YuDong; Zhang, XiaoYun; Fu, Jiang; Ivy Yu, H-M; Qiu, Mengsheng; Chen, YiPing; Hsu, Wei; Zhang, Zunyi

    2013-04-26

    Multiple Wnt ligands are expressed in the developing tooth and play important and redundant functions during odontogenesis. However, the source of Wnt ligands and their targeting cells and action mechanism in tooth organogenesis remain largely elusive. Here we show that epithelial inactivation of Gpr177, the mouse Wntless (Wls) whose product regulates Wnt sorting and secretion, leads to arrest of tooth development at the early cap stage and abrogates tooth-forming capability of the dental epithelium. Gpr177 in the epithelium is necessary for the activation of canonical Wnt signaling in the dental epithelium and formation of a functional enamel knot. Epithelial deletion of Gpr177 results in defective gene expression and cellular behavior in the dental epithelium but does not alter odontogenic program in the mesenchyme. Furthermore, deletion of Axin2, a negative intracellular regulator of canonical Wnt signaling, rescues the tooth defects in mice carrying Gpr177 mutation in the dental epithelium. Together with the fact that active Wnt canonical signaling is present predominantly in the dental epithelium during tooth development, our results demonstrate that Gpr177-mediated Wnt ligands in the dental epithelium act primarily in an intra-epithelial context to regulate enamel knot formation and subsequent tooth development.

  10. COMPUTED TOMOGRAPHY OF TOOTH RESORPTION IN CATS.

    Science.gov (United States)

    Lang, Linda G; Wilkinson, Thomas E; White, Tammy L; Farnsworth, Raelynn K; Potter, Kathleen A

    2016-09-01

    Tooth resorption is the most common dental disease in cats and can be a source of oral pain. The current clinical gold standard for diagnosis includes a combination of oral exam and dental radiography, however early lesions are not always detected. Computed tomography (CT) of the skull, including the dental arches, is a commonly performed diagnostic procedure, however the appearance of tooth resorption on CT and the diagnostic ability of CT to detect tooth resorption have not been evaluated. The purpose of this prospective, descriptive, diagnostic accuracy study was to characterize the CT appearance of tooth resorption in a sample of affected cats and to evaluate the sensitivity and specificity of CT for tooth resorption compared to the clinical gold standard of oral exam and intraoral dental radiography. Twenty-eight cat cadaver specimens were recruited for inclusion. Each specimen was evaluated using oral exam, intraoral dental radiography, and computed tomography (four different slice thicknesses). Each tooth was evaluated for the presence or absence of tooth resorption. Teeth with lesions and a subset of normal teeth were evaluated with histopathology. On CT, tooth resorption appeared as irregularly marginated hypoattenuating defects in the mineral attenuating tooth components, most commonly involving the root or cementoenamel junction. Sensitivity for CT detection of tooth resorption was fair to poor (42.2-57.7%) and specificity was good to excellent (92.8-96.3%). Findings from this study indicated that CT has high specificity but low sensitivity for detection of tooth resorption in cats.

  11. Fluoridation and tooth wear in Irish adults.

    LENUS (Irish Health Repository)

    Burke, F M

    2010-10-01

    The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

  12. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    HR/SOC

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), in order to fill in a 'fiche individuelle' form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format. The French card in their possession. An A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done...

  13. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division; Cards.Service@cern.ch

    2001-01-01

    The French Ministry of Foreign Affairs is currently replacing all diplomatic cards, special cards and employment permits («attestations de fonctions») held by members of the personnel and their families. These cards are replaced by secure, computerized equivalents. The old cards may no longer be used after 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015) between 8h30 and 12h30, in order to fill in a «fiche individuelle» form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, the French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested...

  14. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel are asked to go to the cards office (33/1-015), taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, The French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested to take these items to the c...

  15. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. A 'personnel office' stamped photocopy of the old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), between 8:30 and 12:30, in order to fill a 'fiche individuelle' form (in black ink only), which has to be personally signed by themselves and another separately signed by members of their family, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format (signed on the back) The French card in their possession an A4 photocopy of the same Fre...

  16. Maturogenesis by revascularization in an infected immature permanent tooth.

    Science.gov (United States)

    Amit, Vanka; Jain, Ankur; Nayak, Ullal Anand; Bhat, Manohar

    2014-01-01

    Root canal treatment in teeth with incomplete root formation is a challenge. A case of maturogenesis in an immature infected tooth along with probable factors needed for success is discussed. Although clinical and radiographic evidence points to healing and root development, the long-term prognosis and the behavior of tissue occupying the canal space needs further investigation before the procedure can be adopted into routine clinical practice.

  17. Maturogenesis by revascularization in an infected immature permanent tooth

    Directory of Open Access Journals (Sweden)

    Vanka Amit

    2014-01-01

    Full Text Available Root canal treatment in teeth with incomplete root formation is a challenge. A case of maturogenesis in an immature infected tooth along with probable factors needed for success is discussed. Although clinical and radiographic evidence points to healing and root development, the long-term prognosis and the behavior of tissue occupying the canal space needs further investigation before the procedure can be adopted into routine clinical practice.

  18. [Changes in the microvascular pattern of the periodontal ligament in an experimental tooth extrusion].

    Science.gov (United States)

    Kobayashi, K

    1989-08-01

    Forty eight adult cats were employed to investigate the serial changes of vascular patterns of the periodontal ligament on tooth extrusion. The right upper canines have been successively extruded (initial load 40 gr) with a open coil spring. The experimental periods were set on 1, 2, 3, 4 and 6 weeks respectively. On each experimental period, the microvascular casts of the periodontal ligament and alveolar bone around the experimental tooth were prepared for the scanning electron microscopy, utilizing the acrylic plastic injection method (Taniguchi and Ohta, et al. 1952 and 1955). And the serial sections of the surrounding tissues of the experimental tooth were made. In order to elucidate the mode of the tooth movement, the load of applied force and the distance of extrusion were measured. Results obtained were as follows: 1. The experimental tooth was extruded rapidly during first two weeks. The speed reduced gradually afterwards. 2. The new vascularization was seen around the apex first, then widely spread in the periodontal ligament. And the remarkable trabecula-shaped bone formation were observed around the venous networks of the root apex after two week period. 3. The tissue reactions after the tooth extrusion delayed in comparison with the movement of the tooth. 4. Although the tissue reactions of the root apex of the extruded tooth were originally similar to the one in the transverse tooth movement, slight differences were found in timing of the tissue change and shape of the capillary network. The findings of the tissue change showed that the light force was indicated in extrusion of the tooth. And the range of action of the force applied should be limited in orthodontic clinic.

  19. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    Directory of Open Access Journals (Sweden)

    Toru Nikaido

    2012-10-01

    Full Text Available It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to tooth. Recently, thin-film coating dental materials based on all-in-one adhesive technology were introduced for resin coating of indirect restorations. The thin coating materials are applied in a single clinical step and create a barrier-like film layer on the prepared dentin. The thin coatings play an important role in protecting the dentin from physical, chemical, and biological irritation. In addition, these thin-film coating materials reportedly prevent marginal leakage beneath inlays or crown restorations. In light of the many benefits provided by such a protective layer, these all-in-one adhesive materials may therefore also have the potential to cover exposed root dentin surfaces and prevent caries formation. In this paper, recent progress of the dental coating materials and their clinical applications are reviewed.

  20. Malformations of the tooth root in humans

    Directory of Open Access Journals (Sweden)

    Hans Ulrich eLuder

    2015-10-01

    Full Text Available The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on

  1. Cutting blade dentitions in squaliform sharks form by modification of inherited alternate tooth ordering patterns

    Science.gov (United States)

    Underwood, Charlie; Johanson, Zerina; Smith, Moya Meredith

    2016-11-01

    The squaliform sharks represent one of the most speciose shark clades. Many adult squaliforms have blade-like teeth, either on both jaws or restricted to the lower jaw, forming a continuous, serrated blade along the jaw margin. These teeth are replaced as a single unit and successor teeth lack the alternate arrangement present in other elasmobranchs. Micro-CT scans of embryos of squaliforms and a related outgroup (Pristiophoridae) revealed that the squaliform dentition pattern represents a highly modified version of tooth replacement seen in other clades. Teeth of Squalus embryos are arranged in an alternate pattern, with successive tooth rows containing additional teeth added proximally. Asynchronous timing of tooth production along the jaw and tooth loss prior to birth cause teeth to align in oblique sets containing teeth from subsequent rows; these become parallel to the jaw margin during ontogeny, so that adult Squalus has functional tooth rows comprising obliquely stacked teeth of consecutive developmental rows. In more strongly heterodont squaliforms, initial embryonic lower teeth develop into the oblique functional sets seen in adult Squalus, with no requirement to form, and subsequently lose, teeth arranged in an initial alternate pattern.

  2. Replacement of tyrosine residues by phenylalanine in cytochrome P450cam alters the formation of Cpd II-like species in reactions with artificial oxidants.

    Science.gov (United States)

    Spolitak, Tatyana; Dawson, John H; Ballou, David P

    2008-05-01

    Our previous rapid-scanning stopped-flow studies of the reaction of substrate-free cytochrome P450cam with peracids [Spolitak et al. (2005) J Biol Chem 280:20300-20309; (2006) J Inorg Biochem 100:2034-2044] spectrally characterized compound I [ferryl iron plus a porphyrin pi-cation radical (Fe(IV) = O/Por(+))], as well as Cpd ES (Fe(IV) = O/Tyr.). In the present studies, we report how the substitutions in Y75F, Y96F, and Y96F/Y75F P450cam variants permit the formation of a species we attribute to Cpd II (Fe(IV) = O) in reactions with peracids and cumene hydroperoxide. These variants produce changes in hydrogen bonding patterns and increased hydrophobicity that affect the ratio of heterolytic to homolytic pathways in reactions with cumene hydroperoxide, resulting in a shift of this ratio from 84/16 for WT to 72/28 for the Y96F/Y75F double mutant. Various ways of generating the Cpd II-like species were explored, and it was possible, especially with the more hydrophobic variants, to generate large fractions of the P450cam variants as Cpd II. The Cpd II-like species is ineffective at hydroxylating camphor, but can be readily reduced by ascorbate (as well as other peroxidase substrates) to ferric P450cam, which could then bind camphor to form the high-spin heme. The difference in the spectral properties of Cpd ES and Cpd II was rationalized as possibly being due to different states of protonation.

  3. Formation of metal complex ions from amino acid in the presence of Li+, Na+ and K+ by electrospray ionization: metal replacement of hydrogen in the ligands.

    Science.gov (United States)

    Jang, Soonmin; Song, Min Ju; Kim, Hyunsik; Choi, Sung-Seen

    2011-05-01

    Alkali metal cations easily form complexes with proteins in biological systems; understanding amino acid clusters with these cations can provide useful insight into their behaviors at the molecular level including diagnosis and therapy of related diseases. For the purpose of characterization of basic interaction between amino acids and alkali metal, each of the 20 naturally occurring amino acids were ionized in the presence of lithium, sodium and potassium cations by electrospray ionization, and the resulting product ions were analyzed. We focus our attention on the gas phase alkali metal ion-proton exchanged complexes in current study, specifically complexes with serine, threonine, asparagine and glutamine, which share characteristic pattern unlike other amino acids. All amino acids generated [M + H](+) and [M + Na](+) ions, where M stands for the neutral amino acid. Serine, threonine, asparagine and glutamine generated cluster ions of [nM - nH + (n + 1)Na](+) and [nM - (n - 1)H + (n - 1)Na + K](+) , where n = 1-7. While the (M - H + Li) and (M - H + K) species were not observed, the neutral (M - H + Na) species formed by proton-sodium cation exchange had a highly stable cyclic structure with ketone and amine ligand sites, suggesting that (M - H + Na) serves as a building block in cluster ion formation. Cluster ion intensity distributions of [nM - nH + (n + 1)Na](+) and [nM - (n - 1)H + (n - 1)Na + K](+) showed a magic number at n = 3 and 4, respectively. Extensive B3LYP-DFT quantum mechanical calculations were carried out to elucidate the geometry and energy of the cluster ions, and they provided a reasonable explanation for the stability and structure of the cluster ions. Copyright © 2011 John Wiley & Sons, Ltd.

  4. Tooth sensitivity: mechanisms and management.

    Science.gov (United States)

    Markowitz, K

    1993-08-01

    Tooth sensitivity is a common complaint encountered in clinical practice. Exposed superficial dentin is free of nerve endings, yet sensitive. Experimental evidence indicates that stimuli, such as probing the dentin surface and air blasts, induce fluid movements in the dentinal tubules and these fluid movements, in turn, activate the intradental nerves. The condition of the dentin surface is critically important in allowing this process. In addition, the internal environment of the pulp may influence nerve excitability. Therapies for tooth sensitivity include both agents that obstruct the dentinal tubules and agents that can decrease the excitability of the intradental nerves. The exact treatment used depends on the etiology of the individual's problem and the extent of dentinal tissue damage.

  5. Towards tooth friendly soft drinks.

    Science.gov (United States)

    Kolahi, Jafar; Fazilati, Mohamad; Kadivar, Mahdi

    2009-10-01

    Most soft drinks contain high concentration of simple carbohydrates and have a pH of 3 or even lower. Therefore, they are harmful for tooth structure. A tooth friendly soft drink (T.F.S.D) should have the following characteristics and elements; fluoride (approximately 1 ppm), casein phosphopeptide-amorphous calcium phosphate (2%), xylitol (4-6g/serving), tea polyphenols (2-4 mg/ml), cranberry extract (250 mg/ml of the flavonoids quercetin and myricetin), sugar free, pH close to 5.5 and super oxygenation (240,000 ppm) vs. carbonation. T.F.S.D can be packaged in a container which gaseous oxygen is dissolved in a liquid in the form of bubbles. However, looking at opportunities for so-called sophisticated soft drinks, T.F.S.D will be an example for a functional and health oriented soft drink.

  6. Supernumerary Jawbone Tooth: Clinical Case

    OpenAIRE

    Rivas Gutiérrez, Jesús; Carlos Sánchez, María Dolores

    2016-01-01

    Introduction: supernumerary teeth are dental development anomalies, alsoknown as hyperdontia or extra teeth. Their prevalence ranges between 0.3% and 3.8%.Their morphology may be normal or dismorphic and are associated to the etiology ofocclusal alterations. It is important to make an early diagnostic through a radiographicalstudy. Case presentation:this article presents a clinical case of a supernumerary tooth thatcaused rotation and crowding of the anterior bottom teeth, which was addressed...

  7. Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Reilly, Mary M

    2011-03-01

    Charcot-Marie-Tooth (CMT) disease is the commonest inherited neuromuscular disorder affecting at least 1 in 2,500. Over the last two decades, there have been rapid advances in understanding the molecular basis for many forms of CMT with more than 30 causative genes now described. This has made obtaining an accurate genetic diagnosis possible but at times challenging for clinicians. This review aims to provide a simple, pragmatic approach to diagnosing CMT from a clinician\\'s perspective.

  8. Optical spectroscopy and tooth decay

    Science.gov (United States)

    Misra, P.; De, T.; Singh, R.

    2005-11-01

    Optical spectroscopy in the ultraviolet, visible and mid-infrared spectral regions has been used to discriminate between healthy and diseased teeth of patients in the age range 15-75 years. Spectral scans of absorbance versus wavenumber and fluorescence intensity versus wavelength have been recorded and investigated for caries and periodontal disease. Such optical diagnostics can prove very useful in the early detection and treatment of tooth decay.

  9. Characterization of glycosaminoglycans during tooth development and mineralization in the axolotl, Ambystoma mexicanum.

    Science.gov (United States)

    Wistuba, J; Völker, W; Ehmcke, J; Clemen, G

    2003-10-01

    Glycosaminoglycans (GAGs) involved in the formation of the teeth of Ambystoma mexicanum were located and characterized with the cuprolinic blue (CB) staining method and transmission electron microscopy (TEM). Glycosaminoglycan-cuprolinic blue precipitates (GAGCB) were found in different compartments of the mineralizing tissue. Various populations of elongated GAGCB could be discriminated both according to their size and their preferential distribution in the extracellular matrix (ECM). GAGCB populations that differ in their composition could be attributed not only to the compartments of the ECM but also to different zones and to different tooth types (early-larval and transformed). Larger precipitates were only observed within the dentine matrix of the shaft of the early-larval tooth. The composition of the populations differed significantly between the regions of the transformed tooth: pedicel, shaft and dividing zone. In later stages of tooth formation, small-sized GAGCBs were seen as intracellular deposits in the ameloblasts. It is concluded that the composition of GAGCB populations seems to play a role in the mineralization processes during tooth development in A. mexicanum and influence qualitative characteristics of the mineral in different tooth types and zones, and it is suggested that GAGs might be resorbed by the enamel epithelium during the late phase of enamel formation.

  10. Endodontic treatment and esthetic management of a primary double tooth with direct composite using silicone buildup guide.

    Science.gov (United States)

    Kulkarni, Vinaya Kumar; Ragavendra, T Raju; Deshmukh, Jeevanand; Vanka, Amit; Duddu, Mahesh Kumar; Patil, Anand Kumar G

    2012-04-01

    Gemination and fusion are morphological dental anomalies, characterized by the formation of a clinically wide tooth. Gemination occurs when one tooth bud tries to divide, while fusion occurs if two buds unite. The terms double teeth, double formation, conjoined teeth, geminifusion, vicinifusion and dental twinning are often used to describe fusion and gemination. Double teeth are associated with clinical problems such as poor esthetics, spacing problems and caries susceptibility. Management of such cases requires a comprehensive knowledge of the clinical entity as well as the problems associated with it. This report presents a case of primary double tooth in a 6-year-old boy involving maxillary left central incisor. The anomalous tooth was carious and pulpally involved. This was treated conservatively by endodontic treatment and esthetic rehabilitation was done with direct composite restoration using a silicone buildup guide. The treated tooth was followed up until exfoliation.

  11. Endodontic treatment and esthetic management of a primary double tooth with direct composite using silicone buildup guide

    Directory of Open Access Journals (Sweden)

    Vinaya Kumar Kulkarni

    2012-01-01

    Full Text Available Gemination and fusion are morphological dental anomalies, characterized by the formation of a clinically wide tooth. Gemination occurs when one tooth bud tries to divide, while fusion occurs if two buds unite. The terms double teeth, double formation, conjoined teeth, geminifusion, vicinifusion and dental twinning are often used to describe fusion and gemination. Double teeth are associated with clinical problems such as poor esthetics, spacing problems and caries susceptibility. Management of such cases requires a comprehensive knowledge of the clinical entity as well as the problems associated with it. This report presents a case of primary double tooth in a 6-year-old boy involving maxillary left central incisor. The anomalous tooth was carious and pulpally involved. This was treated conservatively by endodontic treatment and esthetic rehabilitation was done with direct composite restoration using a silicone buildup guide. The treated tooth was followed up until exfoliation.

  12. Epithelial histogenesis during tooth development.

    Science.gov (United States)

    Lesot, H; Brook, A H

    2009-12-01

    This paper reviews the current understanding of the progressive changes mediating dental epithelial histogenesis as a basis for future collaborative studies. Tooth development involves morphogenesis, epithelial histogenesis and cell differentiation. The consecutive morphological stages of lamina, bud, cap and bell are also characterized by changes in epithelial histogenesis. Differential cell proliferation rates, apoptosis, and alterations in adhesion and shape lead to the positioning of groups of cells with different functions. During tooth histo-morphogenesis changes occur in basement membrane composition, expression of signalling molecules and the localization of cell surface components. Cell positional identity may be related to cell history. Another important parameter is cell plasticity. Independently of signalling molecules, which play a major role in inducing or modulating specific steps, cell-cell and cell-matrix interactions regulate the plasticity/rigidity of particular domains of the enamel organ. This involves specifying in space the differential growth and influences the progressive tooth morphogenesis by shaping the epithelial-mesenchymal junction. Deposition of a mineralized matrix determines the final shape of the crown. All data reviewed in this paper were investigated in the mouse.

  13. Tooth brushing for oral prophylaxis

    Directory of Open Access Journals (Sweden)

    Haruaki Hayasaki, DDS, PhD

    2014-08-01

    Full Text Available Control of plaque and debris is essential for the prevention of inflammatory periodontal diseases and dental caries, because plaque is the primary etiological factor in the introduction and development of both of these infection-oriented diseases. Plaque removal with a toothbrush is the most frequently used method of oral hygiene. Powered toothbrushes were developed beginning in the 1960s and are now widely used in developed countries. The bristles of a toothbrush should be able to reach and clean efficiently most areas of the mouth, and recently the design of both manual and powered toothbrushes has focused on the ability to reach and clean interproximal tooth surfaces. An individual's tooth brushing behavior, including force, duration, motivation and motion, are also critical to tooth brushing efficacy. Dental floss and the type of toothpaste play additional important roles as auxiliary tools for oral prophylaxis. Dental professionals should help their care-receivers’ meet the requirements of oral hygiene to maintain their QOL. This article reviews these topics.

  14. The effect of fluoride on enamel and dentin formation in the uremic rat incisor

    NARCIS (Netherlands)

    Lyaruu, D.M.; Bronckers, A.L.J.J.; Santos, F.; Mathias, R.; Denbesten, P.K.

    2008-01-01

    Renal impairment in children is associated with tooth defects that include enamel pitting and hypoplasia. However, the specific effects of uremia on tooth formation are not known. In this study, we used rat mandibular incisors, which continuously erupt and contain all stages of tooth formation, to

  15. The effect of fluoride on enamel and dentin formation in the uremic rat incisor

    NARCIS (Netherlands)

    Lyaruu, Donacian; Bronckers, Antonius; Santos, Fernando; Mathias, Robert; Besten, Pamela Den

    2008-01-01

    Renal impairment in children is associated with tooth defects that include enamel pitting and hypoplasia. However, the specific effects of uremia on tooth formation are not known. In this study, we used rat mandibular incisors, which continuously erupt and contain all stages of tooth formation,

  16. The effect of fluoride on enamel and dentin formation in the uremic rat incisor

    NARCIS (Netherlands)

    Lyaruu, Donacian; Bronckers, Antonius; Santos, Fernando; Mathias, Robert; Besten, Pamela Den

    2008-01-01

    Renal impairment in children is associated with tooth defects that include enamel pitting and hypoplasia. However, the specific effects of uremia on tooth formation are not known. In this study, we used rat mandibular incisors, which continuously erupt and contain all stages of tooth formation, to c

  17. Performance of collagen sponge as a 3-D scaffold for tooth-tissue engineering.

    Science.gov (United States)

    Sumita, Yoshinori; Honda, Masaki J; Ohara, Takayuki; Tsuchiya, Shuhei; Sagara, Hiroshi; Kagami, Hideaki; Ueda, Minoru

    2006-06-01

    Tooth structure can be regenerated by seeding dissociated tooth cells onto polyglycolic acid fiber mesh, although the success rate of tooth production is low. The present study was designed to compare the performance of collagen sponge with polyglycolic acid fiber mesh as a 3-D scaffold for tooth-tissue engineering. Porcine third molar teeth at the early stage of crown formation were enzymatically dissociated into single cells, and the heterogeneous cells were seeded onto collagen sponge or the polyglycolic acid fiber mesh scaffolds. Scaffolds were then cultured to evaluate cell adhesion and ALP activity in vitro. An in vivo analysis was performed by implanting the constructs into the omentum of immunocompromised rats and evaluating tooth production up to 25 weeks. After 24h, there were a significantly higher number of cells attached to the collagen sponge scaffold than the polyglycolic acid fiber mesh scaffold. Similarly, the ALP activity was significantly higher for the collagen sponge scaffold was than the polyglycolic acid fiber mesh scaffold after 7 days of culture. The area of calcified tissue formed in the collagen sponge scaffold was also larger than in the polyglycolic acid fiber mesh scaffold. The results from in vivo experiments show conclusively that a collagen sponge scaffold allows tooth production with a higher degree of success than polyglycolic acid fiber mesh. Taken together, the results from this study show that collagen sponge scaffold is superior to the polyglycolic acid fiber mesh scaffold for tooth-tissue engineering.

  18. Shoulder Joint Replacement

    Science.gov (United States)

    ... Shoulder Replacement Options Shoulder replacement surgery is highly technical. It should be performed by a surgical team ... area and will meet a doctor from the anesthesia department. You, your anesthesiologist, and your surgeon will ...

  19. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  20. Tooth erosion caused by chewing aspirin.

    Science.gov (United States)

    Grace, Edward G; Sarlani, Eleni; Kaplan, Sarit

    2004-07-01

    Although the effects of aspirin on the oral mucosa are well-documented, there is little documentation of the effects of aspirin-chewing on the enamel and dentin. The authors present two cases of patients with damage to their tooth enamel and dentin. Both patients had similiar symptoms, but had not been told that chewing aspirin could harm tooth structure. The authors identify clinical signs and symptoms and discuss ways to prevent erosion. The common factor in these cases is that aspirin was the only possible cause of the tooth erosion. Dentists should be aware of the effects of aspirin-chewing on tooth structure and advise their patients accordingly.

  1. Cracked tooth syndrome: Overview of literature

    OpenAIRE

    Hasan, Shamimul; Singh, Kuldeep; Salati, Naseer

    2015-01-01

    Pain is defined as an “unpleasant sensory and emotional feeling which is associated with actual or potential injury of tissue or expressed in terms of such injury.” Tooth pain usually refers to pain around the teeth or jaws mainly as a result of a dental condition. Mostly, toothaches are caused by a carious cavity, a broken tooth, an exposed tooth root or gum disease. The toothache may sometimes be the result of radiating pain from structures in the vicinity of tooth and jaws (cardiac pain, e...

  2. Hard tissue regeneration capacity of apical pulp derived cells (APDCs) from human tooth with immature apex.

    Science.gov (United States)

    Abe, Shigehiro; Yamaguchi, Satoshi; Watanabe, Akihiko; Hamada, Keiichi; Amagasa, Teruo

    2008-06-20

    Recent studies indicate that dental pulp is a new source of adult stem cells. The human tooth with an immature apex is a developing organ, and the apical pulp of this tooth may contain a variety of progenitor/stem cells, which participate in root formation. We investigated the hard tissue regeneration potential of apical pulp derived cells (APDCs) from human tooth with an immature apex. APDCs cultured with a mineralization-promoting medium showed alkaline phosphatase activity in porous hydroxyapatite (HA) scaffolds. The composites of APDCs and HA were implanted subcutaneously in immunocompromised rats and harvested at 12 weeks after implantation. In histological analysis, the APDCs/HA composites exhibited bone- and dentine-like mineralized tissues in the pore areas of HA. This study suggests that the human tooth with an immature apex is an effective source of cells for hard tissue regeneration.

  3. Proteoglycans and orthodontic tooth movement.

    Science.gov (United States)

    Waddington, R J; Embery, G

    2001-12-01

    Proteoglycans represent an important and diverse family of extracellular matrix components within the connective tissues of the periodontium. This review focuses on the function and metabolism of the various proteoglycans in periodontal tissues, such as alveolar bone and periodontal ligament, and considers their potential fate in response to an orthodontic force. Such considerations provide an important background in evaluating the potential for proteoglycan metabolites, alongside other connective tissue metabolites, as biomarkers for assessing the deep-seated metabolic changes and as a diagnostic tool in monitoring orthodontic tooth movement.

  4. Esthesioneuroblastoma presenting as tooth pain

    Directory of Open Access Journals (Sweden)

    Parvathi Devi

    2014-01-01

    Full Text Available Esthesioneuroblastoma, also called olfactory neuroblastoma, is a rare malignant tumor originating in the olfactory epithelium in the upper nasal cavity with intracranial extension and may also be associated with secondary sinus diseases. Esthesioneuroblastoma has been observed to cause death by distant metastasis or by invasion through the cribriform plate and secondary meningitis. It usually produces nasal obstruction, epistaxis and less commonly anosmia, headache and pain. We report a case of esthesioneuroblastoma in a 50-year-old female who reported with tooth pain as a presenting symptom.

  5. Esthesioneuroblastoma presenting as tooth pain.

    Science.gov (United States)

    Devi, Parvathi; Bhavle, Radhika; Aggarwal, Avanti; Walia, Cherry

    2014-09-01

    Esthesioneuroblastoma, also called olfactory neuroblastoma, is a rare malignant tumor originating in the olfactory epithelium in the upper nasal cavity with intracranial extension and may also be associated with secondary sinus diseases. Esthesioneuroblastoma has been observed to cause death by distant metastasis or by invasion through the cribriform plate and secondary meningitis. It usually produces nasal obstruction, epistaxis and less commonly anosmia, headache and pain. We report a case of esthesioneuroblastoma in a 50-year-old female who reported with tooth pain as a presenting symptom.

  6. Cell fate determination during tooth development and regeneration.

    Science.gov (United States)

    Mitsiadis, Thimios A; Graf, Daniel

    2009-09-01

    Teeth arise from sequential and reciprocal interactions between the oral epithelium and the underlying cranial neural crest-derived mesenchyme. Their formation involves a precisely orchestrated series of molecular and morphogenetic events, and gives us the opportunity to discover and understand the nature of the signals that direct cell fates and patterning. For that reason, it is important to elucidate how signaling factors work together in a defined number of cells to generate the diverse and precise patterned structures of the mature functional teeth. Over the last decade, substantial research efforts have been directed toward elucidating the molecular mechanisms that control cell fate decisions during tooth development. These efforts have contributed toward the increased knowledge on dental stem cells, and observation of the molecular similarities that exist between tooth development and regeneration.

  7. Towards unraveling the human tooth transcriptome: the dentome.

    Directory of Open Access Journals (Sweden)

    Shijia Hu

    Full Text Available The goal of the study was to characterize the transcriptome profiles of human ameloblasts and odontoblasts, evaluate molecular pathways and advance our knowledge of the human "dentome". Laser capture microdissection was used to isolate odontoblasts and ameloblasts from human tooth buds (15-20week gestational age from 4 fetuses. RNA was examined using Agilent 41k whole genome arrays at 2 different stages of enamel formation, presecretory and secretory. Probe detection was considered against the array negative control to control for background noise. Differential expression was examined using Significance Analysis of Microarrays (SAM 4.0 between different cell types and developmental stages with a false discovery rate of 20%. Pathway analysis was conducted using Ingenuity Pathway Analysis software. We found that during primary tooth formation, odontoblasts expressed 14,802 genes, presecretory ameloblasts 15,179 genes and secretory ameloblasts 14,526 genes. Genes known to be active during tooth development for each cell type (eg COL1A1, AMELX were shown to be expressed by our approach. Exploring further into the list of differentially expressed genes between the motile odontoblasts and non-motile presecretory ameloblasts we found several genes of interest that could be involved in cell movement (FN1, LUM, ASTN1. Furthermore, our analysis indicated that the Phospholipase C and ERK5 pathways, that are important for cell movement, were activated in the motile odontoblasts. In addition our pathway analysis identified WNT3A and TGFB1 as important upstream contributors. Recent studies implicate these genes in the development of Schimke immuno-osseous dysplasia. The utility of laser capture microdissection can be a valuable tool in the examination of specific tissues or cell populations present in human tooth buds. Advancing our knowledge of the human dentome and related molecular pathways provides new insights into the complex mechanisms regulating

  8. Towards Unraveling the Human Tooth Transcriptome: The Dentome

    Science.gov (United States)

    2015-01-01

    The goal of the study was to characterize the transcriptome profiles of human ameloblasts and odontoblasts, evaluate molecular pathways and advance our knowledge of the human “dentome”. Laser capture microdissection was used to isolate odontoblasts and ameloblasts from human tooth buds (15-20week gestational age) from 4 fetuses. RNA was examined using Agilent 41k whole genome arrays at 2 different stages of enamel formation, presecretory and secretory. Probe detection was considered against the array negative control to control for background noise. Differential expression was examined using Significance Analysis of Microarrays (SAM) 4.0 between different cell types and developmental stages with a false discovery rate of 20%. Pathway analysis was conducted using Ingenuity Pathway Analysis software. We found that during primary tooth formation, odontoblasts expressed 14,802 genes, presecretory ameloblasts 15,179 genes and secretory ameloblasts 14,526 genes. Genes known to be active during tooth development for each cell type (eg COL1A1, AMELX) were shown to be expressed by our approach. Exploring further into the list of differentially expressed genes between the motile odontoblasts and non-motile presecretory ameloblasts we found several genes of interest that could be involved in cell movement (FN1, LUM, ASTN1). Furthermore, our analysis indicated that the Phospholipase C and ERK5 pathways, that are important for cell movement, were activated in the motile odontoblasts. In addition our pathway analysis identified WNT3A and TGFB1 as important upstream contributors. Recent studies implicate these genes in the development of Schimke immuno-osseous dysplasia. The utility of laser capture microdissection can be a valuable tool in the examination of specific tissues or cell populations present in human tooth buds. Advancing our knowledge of the human dentome and related molecular pathways provides new insights into the complex mechanisms regulating odontogenesis and

  9. Stem cell sources for tooth regeneration: current status and future prospects

    Directory of Open Access Journals (Sweden)

    Keishi eOtsu

    2014-02-01

    Full Text Available Stem cells are capable of renewing themselves through cell division and have the remarkable ability to differentiate into many different types of cells. They therefore have the potential to become a central tool in regenerative medicine. During the last decade, advances in tissue engineering and stem cell-based tooth regeneration have provided realistic and attractive means of replacing lost or damaged teeth. Investigation of embryonic and adult (tissue stem cells as potential cell sources for tooth regeneration has led to many promising results. However, technical and ethical issues have hindered the availability of these cells for clinical application. The recent discovery of induced pluripotent stem (iPS cells has provided the possibility to revolutionize the field of regenerative medicine (dentistry by offering the option of autologous transplantation. In this article, we review the current progress in the field of stem cell-based tooth regeneration and discuss the possibility of using iPS cells for this purpose.

  10. Future dentistry: cell therapy meets tooth and periodontal repair and regeneration.

    Science.gov (United States)

    Catón, Javier; Bostanci, Nagihan; Remboutsika, Eumorphia; De Bari, Cosimo; Mitsiadis, Thimios A

    2011-05-01

    Cell-based tissue repair of the tooth and - tooth-supporting - periodontal ligament (PDL) is a new attractive approach that complements traditional restorative or surgical techniques for replacement of injured or pathologically damaged tissues. In such therapeutic approaches, stem cells and/or progenitor cells are manipulated in vitro and administered to patients as living and dynamic biological agents. In this review, we discuss the clonogenic potential of human dental and periodontal tissues such as the dental pulp and the PDL and their potential for tooth and periodontal repair and/or regeneration. We propose novel therapeutic approaches using stem cells or progenitor cells, which are targeted to regenerate the lost dental or periodontal tissue.

  11. Stem cell sources for tooth regeneration: current status and future prospects.

    Science.gov (United States)

    Otsu, Keishi; Kumakami-Sakano, Mika; Fujiwara, Naoki; Kikuchi, Kazuko; Keller, Laetitia; Lesot, Hervé; Harada, Hidemitsu

    2014-01-01

    Stem cells are capable of renewing themselves through cell division and have the remarkable ability to differentiate into many different types of cells. They therefore have the potential to become a central tool in regenerative medicine. During the last decade, advances in tissue engineering and stem cell-based tooth regeneration have provided realistic and attractive means of replacing lost or damaged teeth. Investigation of embryonic and adult (tissue) stem cells as potential cell sources for tooth regeneration has led to many promising results. However, technical and ethical issues have hindered the availability of these cells for clinical application. The recent discovery of induced pluripotent stem (iPS) cells has provided the possibility to revolutionize the field of regenerative medicine (dentistry) by offering the option of autologous transplantation. In this article, we review the current progress in the field of stem cell-based tooth regeneration and discuss the possibility of using iPS cells for this purpose.

  12. Post-Odontoma autotransplantation of an impacted tooth: A case report.

    Science.gov (United States)

    Robindro Singh, Waikhom; Aheibam, Kirankumar; Nameirakpam, Anthopia

    2015-01-01

    After years of relegation by dental implants, autotransplantation has recently become more popular because of a better understanding of its science. The prognosis of autotransplantation primarily depends upon the presence of an intact alveolar bone at the transplant site and the regeneration of a functional periodontal ligament of the transplant. Replacement of an unsalvaged or a missing tooth by a natural tooth with normal periodontium within a short duration of treatment is the ultimate challenge of autotransplantation. Meanwhile, Platelet Rich Fibrin (PRF) is popular as a biomaterial which helps in the regeneration of bone and periodontal tissues. To improve the prognosis, and also shorten the treatment time in a rare case of autotransplantation of an impacted tooth in a post-odontoma site, we did a two-stage surgical procedure aided by synthetic bone granules (Biograft) and PRF. The clinical and radiological findings at 6 months follow-up showed good result and promise.

  13. Pediatric tooth extractions under sedoanalgesia

    Science.gov (United States)

    Arpaci, Ayse Hande; Isik, Berrin

    2016-01-01

    Objective: The present study aims to evaluate intravenous ketamine and inhalation sedation in children, their unwanted side-effects and surgeon satisfaction. Methods: In this study, data of 922 children aged between 1-18 who underwent tooth extraction under sedoanalgesia in our department between September 2015-January 2016 were gathered and anesthesia approaches, unwanted side effects and surgical satisfaction was investigated. Postoperative recovery emergence agitation or delirium was evaluated with Watcha Behavior Scale (WBS). Results: Patients were grouped and compared according to acceptance of intravenous line placement (Group-1) or not (Group- 2). Group 1 received intravenous ketamine anesthesia (n=822), Group 2 received inhalation anesthesia with sevoflurane (n=100). Number of patients, age, weight and gender was significantly different in two groups. When side effects were investigated nausea was observed in 30 patients (3.6%), skin rashes were observed in 26 patients (3.2%) in Group-1 while skin rashes were observed in one patient (1%) in Group 2. 95% of surgeons reported intravenous anesthesia, 18% of surgeons reported inhalation anesthesia to be the anesthesia of choice. Emergence of postoperative recovery agitation (WBS≥3) was observed more frequent in Group 2 (p<0.05) than Group 1. Conclusion: Ketamine, which has analgesic, hypnotic and amnestic effects and which does not alter pharyngeal and laryngeal reflexes thus minimizes aspiration possibility, is a safe and effective anesthetic agent for tooth extractions of the pediatric population under sedoanalgesia. PMID:27882039

  14. Replacement of hopeless retained primary teeth by immediate dental implants: a case report.

    Science.gov (United States)

    de Oliveira, Rafael R; Macedo, Guilherme O; Muglia, Valdir A; Souza, Sérgio L S; Novaes, Arthur B; Taba, Mário

    2009-01-01

    Hopeless retained primary teeth without permanent successors represent a restorative challenge for clinicians, along with esthetic and functional problems for patients. While various treatment approaches for congenitally missing teeth have been proposed, the replacement of a missing tooth with a dental implant offers specific advantages, such as preservation of the alveolar crest and elimination of the need to restore the adjacent teeth, over other options for tooth replacement. The aim of this article was to illustrate the surgical and prosthetic treatment with implants of a patient with primary teeth without permanent successors.

  15. Addressing Tooth Decay in Head Start Children

    Science.gov (United States)

    Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

    2012-01-01

    Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

  16. Side effects of external tooth bleaching

    DEFF Research Database (Denmark)

    Bruzell, E.M.; Pallesen, Ulla; Thoresen, N.R.

    2013-01-01

    General practices and university clinics during the years 2007‑2009 in Scandinavia. Subjects Patients with tooth bleaching as part of the treatment plan. Results The prevalence of experienced tooth sensitivity at first follow-up was independent of bleaching procedure (at-home = 50.3% [n = 143]; in...

  17. Addressing Tooth Decay in Head Start Children

    Science.gov (United States)

    Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

    2012-01-01

    Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

  18. Tooth Enamel, the Result of the Relationship between Matrix Proteins and Hydroxyapatite Crystals

    Directory of Open Access Journals (Sweden)

    Carmen Mihaela MIHU

    2008-12-01

    Full Text Available Enamel, a structure of epithelial origin, represents a protective tooth cover. The cells responsible for the formation of enamel, ameloblasts, are lost at the time of tooth eruption, so that enamel becomes an acellular structure that can no longer regenerate. In order to compensate for this particular phenomenon, enamel has acquired a complex structural organization and a high mineralization degree, in its mature state. This reflects the particular life cycle of ameloblasts and the unique physico-chemical characteristics of matrix proteins, which regulate the formation of the extremely long crystals of enamel. These characteristics differentiate enamel from all the other tissues of the organism.

  19. Biologically Based Restorative Management of Tooth Wear

    Directory of Open Access Journals (Sweden)

    Martin G. D. Kelleher

    2012-01-01

    Full Text Available The prevalence and severity of tooth wear is increasing in industrialised nations. Yet, there is no high-level evidence to support or refute any therapeutic intervention. In the absence of such evidence, many currently prevailing management strategies for tooth wear may be failing in their duty of care to first and foremost improve the oral health of patients with this disease. This paper promotes biologically sound approaches to the management of tooth wear on the basis of current best evidence of the aetiology and clinical features of this disease. The relative risks and benefits of the varying approaches to managing tooth wear are discussed with reference to long-term follow-up studies. Using reference to ethical standards such as “The Daughter Test”, this paper presents case reports of patients with moderate-to-severe levels of tooth wear managed in line with these biologically sound principles.

  20. Primary cilia regulate Shh activity in the control of molar tooth number.

    Science.gov (United States)

    Ohazama, Atsushi; Haycraft, Courtney J; Seppala, Maisa; Blackburn, James; Ghafoor, Sarah; Cobourne, Martyn; Martinelli, David C; Fan, Chen-Ming; Peterkova, Renata; Lesot, Herve; Yoder, Bradley K; Sharpe, Paul T

    2009-03-01

    Primary cilia mediate Hh signalling and mutations in their protein components affect Hh activity. We show that in mice mutant for a cilia intraflagellar transport (IFT) protein, IFT88/polaris, Shh activity is increased in the toothless diastema mesenchyme of the embryonic jaw primordia. This results in the formation of ectopic teeth in the diastema, mesial to the first molars. This phenotype is specific to loss of polaris activity in the mesenchyme since loss of Polaris in the epithelium has no detrimental affect on tooth development. To further confirm that upregulation of Shh activity is responsible for the ectopic tooth formation, we analysed mice mutant for Gas1, a Shh protein antagonist in diastema mesenchyme. Gas1 mutants also had ectopic diastema teeth and accompanying increased Shh activity. In this context, therefore, primary cilia exert a specific negative regulatory effect on Shh activity that functions to repress tooth formation and thus determine tooth number. Strikingly, the ectopic teeth adopt a size and shape characteristic of premolars, a tooth type that was lost in mice around 50-100 million years ago.

  1. A Case of Simultaneous Ectopic Tooth Extraction and Removal of Migrated Dental Implant from Maxillary Sinus.

    Science.gov (United States)

    Furuya, Yoshitaka; Norizuki, Yoshie; Yajima, Yasutomo

    2015-01-01

    When a dental implant migrates to the maxillary sinus it should be extracted immediately as it may cause sinusitis or further migrate to one of the other paranasal sinuses. Although usually detected due to symptoms such as nasal obstruction, nasal discharge, and nasal bleeding, an ectopic tooth in the maxillary sinus can sometimes be revealed incidentally on radiographic examination. Here, we report a case of simultaneous extraction of a dental implant that had migrated to the maxillary sinus and removal of an ectopic tooth that had arisen in the same location. The patient was a 73-year-old man who had received the implant to replace the first left maxillary molar at a local dental office. The implant had subsequently migrated to the left maxillary sinus and the patient was referred to us for its removal. On locating the implant on a CT scan at our hospital, an ectopic tooth was also observed at the base of the maxillary sinus. With patient consent, the decision was made to remove the ectopic tooth and extract the implant simultaneously. Excision of the lateral wall of the maxillary sinus allowed easy extraction of the implant. The ectopic tooth was removed by slightly expanding a fenestration in the sinus wall. Ectopic teeth in the maxillary sinus are sometimes put on follow-up if asymptomatic. Removal should be considered, however, if there is a risk of it becoming infected due to implantation-induced inflammation.

  2. Human Umbilical Cord Mesenchymal Stem Cells: A New Therapeutic Option for Tooth Regeneration.

    Science.gov (United States)

    Chen, Yuanwei; Yu, Yongchun; Chen, Lin; Ye, Lanfeng; Cui, Junhui; Sun, Quan; Li, Kaide; Li, Zhiyong; Liu, Lei

    2015-01-01

    Tooth regeneration is considered to be an optimistic approach to replace current treatments for tooth loss. It is important to determine the most suitable seed cells for tooth regeneration. Recently, human umbilical cord mesenchymal stem cells (hUCMSCs) have been regarded as a promising candidate for tissue regeneration. However, it has not been reported whether hUCMSCs can be employed in tooth regeneration. Here, we report that hUCMSCs can be induced into odontoblast-like cells in vitro and in vivo. Induced hUCMSCs expressed dentin-related proteins including dentin sialoprotein (DSP) and dentin matrix protein-1 (DMP-1), and their gene expression levels were similar to those in native pulp tissue cells. Moreover, DSP- and DMP-1-positive calcifications were observed after implantation of hUCMSCs in vivo. These findings reveal that hUCMSCs have an odontogenic differentiation potency to differentiate to odontoblast-like cells with characteristic deposition of dentin-like matrix in vivo. This study clearly demonstrates hUCMSCs as an alternative therapeutic cell source for tooth regeneration.

  3. Effects of carbonated soft drink consumption on orthodontic tooth movements in rats.

    Directory of Open Access Journals (Sweden)

    Hossein Agha Aghili

    2014-04-01

    Full Text Available The aim of this animal study was to evaluate the possible effects of Carbonated Soft Drink consumption on the rate of orthodontic tooth movement in rats.Thirty-six adult male Sprague-Dawley rats were randomly divided into two experimental groups and one control group. In the experimental groups (A&B, the water in the dietary regimen was replaced with soft drinks (Fanta® in group A and Cola® in group B two weeks before placement of orthodontic appliances. Then 5-mm nickel-titanium closed-coil springs were placed between the maxillary right first molars and first incisors under general anesthesia. This regimen continued for two weeks more and animals drank soft drink ad libitum. At the end of the experimental period, the rats were sacrificed, and interproximal tooth movements were measured.The mean amounts of tooth movement were 0.19mm in group A, 0.22mm in group B and 0.37mm in group C. Statistical analysis with analysis of variance (ANOVA test showed significant differences between all groups. The least movement occurred in group A that had received Fanta® drink.CSDs consumption decreases the rate of orthodontic tooth movement. The role of soft drinks in decreasing tooth movement might be related to its effects on bone metabolism.

  4. Aeronautical Information System Replacement -

    Data.gov (United States)

    Department of Transportation — Aeronautical Information System Replacement is a web-enabled, automation means for the collection and distribution of Service B messages, weather information, flight...

  5. Morphological study of tooth development in podoplanin-deficient mice

    Science.gov (United States)

    Takara, Kenyo; Maruo, Naoki; Oka, Kyoko; Kaji, Chiaki; Hatakeyama, Yuji; Sawa, Naruhiko; Kato, Yukinari; Yamashita, Junro; Kojima, Hiroshi; Sawa, Yoshihiko

    2017-01-01

    Podoplanin is a mucin-type highly O-glycosylated glycoprotein identified in several somatyic cells: podocytes, alveolar epithelial cells, lymphatic endothelial cells, lymph node stromal fibroblastic reticular cells, osteocytes, odontoblasts, mesothelial cells, glia cells, and others. It has been reported that podoplanin-RhoA interaction induces cytoskeleton relaxation and cell process stretching in fibroblastic cells and osteocytes, and that podoplanin plays a critical role in type I alveolar cell differentiation. It appears that podoplanin plays a number of different roles in contributing to cell functioning and growth by signaling. However, little is known about the functions of podoplanin in the somatic cells of the adult organism because an absence of podoplanin is lethal at birth by the respiratory failure. In this report, we investigated the tooth germ development in podoplanin-knockout mice, and the dentin formation in podoplanin-conditional knockout mice having neural crest-derived cells with deficiency in podoplanin by the Wnt1 promoter and enhancer-driven Cre recombinase: Wnt1-Cre;PdpnΔ/Δmice. In the Wnt1-Cre;PdpnΔ/Δmice, the tooth and alveolar bone showed no morphological abnormalities and grow normally, indicating that podoplanin is not critical in the development of the tooth and bone. PMID:28222099

  6. Decoronation of an ankylosed tooth for preservation of alveolar bone prior to implant placement.

    Science.gov (United States)

    Filippi, A; Pohl, Y; von Arx, T

    2001-04-01

    A 12-year-old patient sustained avulsions of both permanent maxillary central incisors. Subsequently, both teeth developed replacement resorption. The left incisor was extracted alio loco. The right incisor was treated by decoronation (removal of crown and pulp, but preservation of the root substance). Comparison of both sites demonstrated complete preservation of the height and width of the alveolar bone at the decoronation site, whereas the tooth extraction site showed considerable bone loss. In addition, some vertical bone apposition was found on top of the decoronated root. Decoronation is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It must be considered as a treatment option for teeth affected by replacement resorption if tooth transplantation is not feasible.

  7. Tooth-bone morphogenesis during postnatal stages of mouse first molar development.

    Science.gov (United States)

    Lungová, Vlasta; Radlanski, Ralf J; Tucker, Abigail S; Renz, Herbert; Míšek, Ivan; Matalová, Eva

    2011-06-01

    The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue. The M1 completed crown formation between postnatal (P) days 0-2, and the development of the tooth root was initiated at P4. From P2 until P12, cell proliferation in the dental epithelium reduced and shifted downward to the apical region of the forming root. In contrast, proliferation was maintained or increased in the mesenchymal cells of the dental follicle. At later stages, before tooth eruption (P20), cell proliferation suddenly ceased. This withdrawal from the cell cycle correlated with tooth mineralization and mesenchymal differentiation. Apoptosis was observed during all stages of M1 postnatal morphogenesis, playing a role in the removal of cells such as osteoblasts in the mandibular region and working together with osteoclasts to remodel the bone around the developing tooth. At more advanced developmental stages, apoptotic cells and bodies accumulated in the cell layers above the tooth cusps, in the path of eruption. Three-dimensional reconstruction of the developing postnatal tooth and bone indicates that the alveolar crypts form by resorption underneath the primordia, whereas the ridges form by active bone growth between the teeth and roots to form a functional complex. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

  8. Tooth-bone morphogenesis during postnatal stages of mouse first molar development

    Science.gov (United States)

    Lungová, Vlasta; Radlanski, Ralf J; Tucker, Abigail S; Renz, Herbert; Míšek, Ivan; Matalová, Eva

    2011-01-01

    The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue. The M1 completed crown formation between postnatal (P) days 0–2, and the development of the tooth root was initiated at P4. From P2 until P12, cell proliferation in the dental epithelium reduced and shifted downward to the apical region of the forming root. In contrast, proliferation was maintained or increased in the mesenchymal cells of the dental follicle. At later stages, before tooth eruption (P20), cell proliferation suddenly ceased. This withdrawal from the cell cycle correlated with tooth mineralization and mesenchymal differentiation. Apoptosis was observed during all stages of M1 postnatal morphogenesis, playing a role in the removal of cells such as osteoblasts in the mandibular region and working together with osteoclasts to remodel the bone around the developing tooth. At more advanced developmental stages, apoptotic cells and bodies accumulated in the cell layers above the tooth cusps, in the path of eruption. Three-dimensional reconstruction of the developing postnatal tooth and bone indicates that the alveolar crypts form by resorption underneath the primordia, whereas the ridges form by active bone growth between the teeth and roots to form a functional complex. PMID:21418206

  9. Tooth Retained Implant: No More an Oxymoron

    Directory of Open Access Journals (Sweden)

    Divya Bhat

    2011-03-01

    Full Text Available Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1 Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2 Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dam-pen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration.Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

  10. Spectroscopic investigations of carious tooth decay.

    Science.gov (United States)

    Thareja, R K; Sharma, A K; Shukla, Shobha

    2008-11-01

    We report on the elemental composition of healthy and infected part of human tooth using laser induced breakdown spectroscopy (LIBS). We have used prominent constituent transitions in laser-excited tooth to diagnose the state of the tooth. A nanosecond laser pulse (355nm, 5ns) was used as an ablating pulse and the sodium (3s2S-3p2P) at 588.99 and (3s2S-3p2P) at 589.99nm, strontium (5s21S-1s5P) at 460.55nm, and calcium (3d3D-4f 3F0) at 452.55nm transitions for spectroscopic analysis. The spectroscopic observations in conjunction with discriminate analysis showed that calcium attached to the hydroxyapatite structure of the tooth was affected severely at the infected part of the tooth. The position-time plots generated from two-dimensional (2D) images conclusively showed a decrease in calcium concentration in the infected region of the irradiated tooth. Using the technique, we could distinguish between the healthy and carious parts of the tooth with significant accuracy.

  11. Transplantation of premolars as an approach for replacing avulsed teeth

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Schwartz, Ole; Kofoed, Thomas

    2009-01-01

    . Secondly the tooth precipitates growth of the alveolar procces and allows treatment to be performed at an early age (10-12 years) where the trauma incidence is at its maximum. Finally transplanted teeth can be moved orthodontically. These characteristics make implant solutions appealing in a number...... of situations. The procedure consist in selecting a premolar in a optimal root development stage which is approximately three fourths root formation where optimal pulp and periodontal ligament healing can be achieved in more than 90 percent of the cases. The tooth is later after slight crown remodeling restored...

  12. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  13. TOOTH CONTACT ANALYSIS OF CONICAL INVOLUTE GEARS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mathematical model of conical involute gears is developed based on the theory of gearing and the generating mechanism. Tooth contact analysis (TCA) is performed to examine the meshing and bearing contact of the conical involute gear pairs with intersected and crossed axes. In addition, the principal directions and curvatures of the gear surfaces are investigated and the contact ellipses of the mating tooth surfaces are also studied. Finally, the numerical illustrative examples are provided to demonstrate the computational results, test gears are made for tooth-bearing tests, and the conclusion is verified that the theory has the applicability.

  14. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review.

    Science.gov (United States)

    Park, Yun-Jong; Cha, Seunghee; Park, Young-Seok

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry have aimed at tooth structure regeneration; however, the application in other than tooth structures has been attempted extensively. The availability from discarded or removed teeth can be an innate benefit as a source of autologous cells. Their origin from the neural crest results in exploitation of neurological and numerous other applications. This review briefly highlights current and future perspectives of the regenerative applications of tooth derived stem cells in areas beyond tooth regeneration.

  15. Tooth resorption in cats: contribution of vitamin D and inflammation

    NARCIS (Netherlands)

    Vrieling, H.E.

    2010-01-01

    Tooth resorption in cats Tooth resorption affecting several teeth is a painful disease with a prevalence of up to 75% in household cats and is often accompanied by periodontitis. Tooth resorption is caused by an increased number and activity of tooth-resorbing odontoclasts, cells that share function

  16. Essential roles of G9a in cell proliferation and differentiation during tooth development.

    Science.gov (United States)

    Kamiunten, Taichi; Ideno, Hisashi; Shimada, Akemi; Arai, Yoshinori; Terashima, Tatsuo; Tomooka, Yasuhiro; Nakamura, Yoshiki; Nakashima, Kazuhisa; Kimura, Hiroshi; Shinkai, Yoichi; Tachibana, Makoto; Nifuji, Akira

    2017-08-15

    Teeth develop through interactions between epithelial and mesenchymal tissues mediated by a signaling network comprised of growth factors and transcription factors. However, little is known about how epigenetic modifiers affect signaling pathways and thereby regulate tooth formation. We previously reported that the histone 3 lysine 9 (H3K9) methyltransferase (MTase) G9a is specifically enriched in the tooth mesenchyme during mouse development. In this study, we investigated the functions of G9a in tooth development using G9a conditional knockout (KO) mice. We used Sox9-Cre mice to delete G9a in the tooth mesenchyme because Sox9 is highly expressed in the mesenchyme derived from the cranial neural crest. Immunohistochemical analyses revealed that G9a expression was significantly decreased in the mesenchyme of Sox9-Cre;G9afl/fl (G9a cKO) mice compared with that in Sox9-Cre;G9a fl/+(control) mice. Protein levels of the G9a substrate H3K9me2 were also decreased in the tooth mesenchyme. G9a cKO mice showed smaller tooth germ after embryonic day (E) 16.5 and E17.5, but not at E15.5. The developing cusp tips, which were visible in control mice, were absent in G9a cKO mice at E17.5. At 3 weeks after birth, small first molars with smaller cusps and unseparated roots were formed. Organ culture of tooth germs derived from E15.5 cKO mouse embryos showed impaired tooth development, suggesting that tooth development per se is affected independently of skull development. BrdU labeling experiments revealed that the proliferation rates were decreased in the mesenchyme in G9a cKO mice at E17.5. In addition, the proliferation rates in the tooth inner enamel epithelium were also decreased. In situ hybridization revealed altered localization of genes associated with tooth development. In cKO mice, intensively localized expression of mRNAs encoding bone morphogenic protein (Bmp2 and Bmp4) was observed in the tooth mesenchyme at E17.5, similar to the expression patterns observed in

  17. Radiology of total hip replacement

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, H.J.; Lovelock, J.E.; McCollister Evarts, C.; Geyer, D.

    1984-06-01

    The radiology of total hip replacement (THR) and its complications is reviewed in conjunction with a long-term follow-up study on 402 patients with 501 prostheses. The indications, contraindications, biomechanics, and operative management of these patients is discussed. Clinical complications such as deep vein thrombosis, pulmonary embolism, and hemorrhage are mentioned. Postoperative infections including granulomatous pseudotumors, dislocations and fractures, true loosening of the prosthesis, and heterotopic bone formation (HBF) are discussed and illustrated. The importance of differentiating the lucent line from true loosening is stressed. Mechanical and other clinical complications which are largely ignored by radiologists are also discussed. The uses of arthrography and bone scanning are included.

  18. Impacted supernumerary tooth in coronoid process: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Se; Lee, Je Ho; Park, Hyok; Jung, Ho Gul; Kim, Kee Deog [Yonsei University College of Dentistry, Seoul (Korea, Republic of)

    2010-06-15

    Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

  19. Critical appraisal. In-office tooth whitening: pulpal effects and tooth sensitivity issues.

    Science.gov (United States)

    Kwon, So Ran; Swift, Edward J

    2014-01-01

    In-office bleaching is an effective method for whitening teeth.Tooth sensitivity associated with in-office whitening is reversible and may range from mild to considerable. The incidence and severity of tooth sensitivity can be reduced by pretreatment with a desensitizer such as potassium nitrate. Histologic studies and clinical studies on long-term pulpal effects are lacking to definitively support the safety of in-office tooth whitening. Future studies on the etiology of tooth sensitivity related to whitening might greatly improve the means of preventing and managing this side effect.

  20. The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias.

    Science.gov (United States)

    French, G C A; Stürup, M; Rizzuto, S; van Wyk, J H; Edwards, D; Dolan, R W; Wintner, S P; Towner, A V; Hughes, W O H

    2017-10-01

    Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems. © 2017 The Fisheries Society of the British Isles.

  1. Materials science: Lessons from tooth enamel

    Science.gov (United States)

    Espinosa, Horacio D.; Soler-Crespo, Rafael

    2017-03-01

    A remarkable composite material has been made that mimics the structure of tooth enamel. This achievement opens up the exploration of new composite materials and of computational methods that reliably predict their properties. See Letter p.95

  2. Genetics And Tooth Anomalies - An Update

    Directory of Open Access Journals (Sweden)

    Aswathy Brahmanandan

    2013-01-01

    Full Text Available Tooth development like the development of all epithelial appendages is regulated by inductive tissue interactions between epithelium and mesenchyme. Numerous genes interact, either act in conjunction or antagonize each other in odontogenesis. A number of different mesenchymal molecules and their receptors act as mediators in epithelial mesenchymal interactions. Several genes linked with early tooth positioning and developments belong to signaling pathways and have morphogenesis regulatory functions in morphogenesis of other organs. Their mutations often show pleiotropic effects beyond dental morphogenesis. In contrast, certain genes involved in enamel and dentin structures are highly specific for tooth. Mutations in these genes have been identified as causes of Amelogenesis Imperfecta (AI, Dentinogenesis Imperfecta (DI, Dentin Dysplasia (DD and anomalies in tooth number. This article focuses on genetic basis of inherited non-syndromic teeth disorders.

  3. Charcot-Marie-Tooth and Related Diseases

    Science.gov (United States)

    ... of France, and Howard Henry Tooth of the United Kingdom. Although most people have never heard of CMT, ... CMT provided by patients and families. (See http://neurology.med. wayne.edu/neurogenetics/na_database. php.) MDA ...

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Dentist Your Family's Oral Health About the AGD Dental care and oral health information you need from ... Child First See a Dentist? The History of Dental Advances Check Menstrual Calendar for Tooth Extraction Temporomandibular ...

  5. [Biological basis of orthodontic tooth movement].

    Science.gov (United States)

    Maltha, J C; van Leeuwen, E J

    2000-04-01

    The effect of orthodontic therapy is dependent of the biological possibilities and limitations of the dento-alveolar complex. Biomechanical effects determine the first phase of tooth movement. In the second phase hyalinisation occurs in almost all cases. Elimination of the hyalinised tissue is associated with undermining bone resorption. Next, 'real' tooth movement starts. At the pressure side the normal structure of the periodontal ligament is destroyed and so is the tooth attachment. At the tension side deposition of trabecular bone is found and the tooth attachment remains. The regulation of these processes is still not completely understood, but cytokines and growth factors play an important role. The biological system does not react according to a simple dose-response relation and large individual differences in susceptibility of the system exist.

  6. Determination of tooth clearances at trochoidal pump

    OpenAIRE

    Ivanović, Lozica T.; Erić, Milan D.; Stojanović, Blaža Ž.; id_orcid 0000-0003-4790-2856; Ilić, Andreja B.

    2011-01-01

    The paper describes the development of a mathematical model of trochoidal gearing with clearances. Gearing of a trochoidal pump's gear set with an outer gear having one gear tooth more than an inner gear is analyzed. The inner gear tooth profile is described by peritrochoidal equidistance and the outer gear profile by a circular arc. Upon the basic principles of ideal profile generation, a mathematical model of gearing with clearances is developed. Using an analytical model, the calculation o...

  7. Computer simulation of gear tooth manufacturing processes

    Science.gov (United States)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  8. Tooth enamel and enameloid in actinopterygian fish

    Institute of Scientific and Technical Information of China (English)

    I.SASAGAWA; M.ISHIYAMA; H.YOKOSUKA; M.MIKAMI; T.UCHIDA

    2009-01-01

    The morphological features of tooth enamel and enameloid in actinopterygian fish are reviewed to provide basic data concerning the biomineralization of teeth in lower vertebrates. Enameloid, which covers the tooth surface, is a unique well-mineralized tissue and usually has the same functions as mammalian tooth enamel. However, the development of enameloi is different from that of the enamel produced by dental epithelial cells. Enameloid is made by a combination of odontoblasts and dental epithelial cells. An organic matrix that contains collagen is provided by odontoblasts, and then dental epithelial cells dissolve the degenerate matrix and suooly inorganic ions during advanced crystal growth in enameloid. It is likely that enameloid is a good model for studying the growth of well-mineralized hard tissues in vertebrates. Some actinopterygian fish possess a collar enamel layer that is situated at the surface of the tooth shaft, indicating that the origin of tooth enamel is found in fish. Collar enamel is thought to be a precursor of mammalian enamel, although it is thin and not well mineralized in comparison with enameloid. In Lepisosteus and Polypterus, both of which are living actinopterygians,both enameloid and enamel are found in the same tooth. Therefore, they ace suitable materials for examining the developmental processes of enameloid and enamel and the relationship among them.

  9. Cracked tooth syndrome: Overview of literature.

    Science.gov (United States)

    Hasan, Shamimul; Singh, Kuldeep; Salati, Naseer

    2015-01-01

    Pain is defined as an "unpleasant sensory and emotional feeling which is associated with actual or potential injury of tissue or expressed in terms of such injury." Tooth pain usually refers to pain around the teeth or jaws mainly as a result of a dental condition. Mostly, toothaches are caused by a carious cavity, a broken tooth, an exposed tooth root or gum disease. The toothache may sometimes be the result of radiating pain from structures in the vicinity of tooth and jaws (cardiac pain, ear, nose, throat pain, and sinusitis). Therefore, evaluation by both dentists and physicians are sometimes necessary to diagnose medical illnesses causing "toothache." Cracked tooth syndrome is a major diagnostic challenge in clinical practice. Accurate diagnosis and appropriate treatment are complicated due to lack of awareness of this condition and its bizarre clinical features. Early diagnosis has been linked with successful restorative management and good prognosis. This article provides a detailed literature on the causes, classification, signs and symptoms, diagnosis, and treatment planning of cracked tooth syndrome.

  10. Frictional Effects on Gear Tooth Contact Analysis

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2013-01-01

    Full Text Available The present paper concentrates on the investigations regarding the situations of frictional shear stress of gear teeth and the relevant frictional effects on bending stresses and transmission error in gear meshing. Sliding friction is one of the major reasons causing gear failure and vibration; the adequate consideration of frictional effects is essential for understanding gear contact behavior accurately. An analysis of tooth frictional effect on gear performance in spur gear is presented using finite element method. Nonlinear finite element model for gear tooth contact with rolling/sliding is then developed. The contact zones for multiple tooth pairs are identified and the associated integration situation is derived. The illustrated bending stress and transmission error results with static and dynamic boundary conditions indicate the significant effects due to the sliding friction between the surfaces of contacted gear teeth, and the friction effect can not be ignored. To understand the particular static and dynamic frictional effects on gear tooth contact analysis, some significant phenomena of gained results will also be discussed. The potentially significant contribution of tooth frictional shear stress is presented, particularly in the case of gear tooth contact analysis with both static and dynamic boundary conditions.

  11. Design of face-hobbed spiral bevel gears with reduced maximum tooth contact pressure and transmission errors

    Institute of Scientific and Technical Information of China (English)

    Vilmos Simon

    2013-01-01

    The aim of this study is to define optimal tooth modifications,introduced by appropriately chosen head-cutter geometry and machine tool setting,to simultaneously minimize tooth contact pressure and angular displacement error of the driven gear (transmission error) of face-hobbed spiral bevel gears.As a result of these modifications,the gear pair becomes mismatched,and a point contact replaces the theoretical line contact.In the applied loaded tooth contact analysis it is assumed that the point contact under load is spreading over a surface along the whole or part of the “potential” contact line.A computer program was developed to implement the formulation provided above.By using this program the influence of tooth modifications introduced by the variation in machine tool settings and in head cutter data on load and pressure distributions,transmission errors,and fillet stresses is investigated and discussed.The correlation between the ease-off obtained by pinion tooth modifications and the corresponding tooth contact pressure distribution is investigated and the obtained results are presented.

  12. Hormone Replacement Therapy

    Science.gov (United States)

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  13. Knee joint replacement

    Science.gov (United States)

    ... of your kneecap. Your kneecap is called the patella. The replacement part is usually made from a ... long. Then your surgeon will: Move your kneecap (patella) out of the way, then cut the ends ...

  14. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the ... to slide 4 out of 4 Overview The knee is a complex joint. It contains the distal ...

  15. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    Purpose – It is argued in this article that too little is known about product platforms and how to deal with them from a manager's point of view. Specifically, little information exists regarding when old established platforms are replaced by new generations in R&D and production environments...... originality and value is achieved by focusing on product platform replacements believed to represent a growing management challenge....

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

    Directory of Open Access Journals (Sweden)

    Rokhsareh Sadeghi

    2016-01-01

    Conclusion: Based on the findings of this study, both materials have positive effect on 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.

  17. The grinding tip of the sea urchin tooth exhibits exquisite control over calcite crystal orientation and Mg distribution.

    Science.gov (United States)

    Ma, Yurong; Aichmayer, Barbara; Paris, Oskar; Fratzl, Peter; Meibom, Anders; Metzler, Rebecca A; Politi, Yael; Addadi, Lia; Gilbert, P U P A; Weiner, Steve

    2009-04-14

    The sea urchin tooth is a remarkable grinding tool. Even though the tooth is composed almost entirely of calcite, it is used to grind holes into a rocky substrate itself often composed of calcite. Here, we use 3 complementary high-resolution tools to probe aspects of the structure of the grinding tip: X-ray photoelectron emission spectromicroscopy (X-PEEM), X-ray microdiffraction, and NanoSIMS. We confirm that the needles and plates are aligned and show here that even the high Mg polycrystalline matrix constituents are aligned with the other 2 structural elements when imaged at 20-nm resolution. Furthermore, we show that the entire tooth is composed of 2 cooriented polycrystalline blocks that differ in their orientations by only a few degrees. A unique feature of the grinding tip is that the structural elements from each coaligned block interdigitate. This interdigitation may influence the fracture process by creating a corrugated grinding surface. We also show that the overall Mg content of the tooth structural elements increases toward the grinding tip. This probably contributes to the increasing hardness of the tooth from the periphery to the tip. Clearly the formation of the tooth, and the tooth tip in particular, is amazingly well controlled. The improved understanding of these structural features could lead to the design of better mechanical grinding and cutting tools.

  18. Expression of dynamin II in odontoblast during mouse tooth development.

    Science.gov (United States)

    Oh, Jong-Hwa; Choi, Baik-Dong; Park, Jin-Ju; Jeong, Soon-Jeong; Kim, Jin-Soo; Kim, Jae-Duk; Lim, Do-Seon; Kim, Byung-Hoon; Cho, Yong-Ick; Jeong, Moon-Jin

    2011-08-01

    Odontoblasts secrete a collagen-based matrix and release numerous membrane-bound matrix vesicles, which are involved in dentin formation during tooth development. Dynamin II is a GTPase protein that contributes a variety of vesicular budding events, such as endocytotic membrane fission, caveolae internalization and protein trafficking in the Golgi apparatus. However, the expression and function of dynamin II in odontoblasts has not been reported. Therefore, this study examined the expression and possible role of dynamin II in odontoblasts during tooth development and mineralization. The levels of mRNA and protein expression in MDPC23 cells were significantly high at the early stages of differentiation and then decreased gradually thereafter. Immunohistochemistry showed that dynamin II was not expressed near the region of the odontoblasts at embryonic day 17 (E17) and E21. However, dynamin II was expressed strongly in the odontoblast layer at postnatal day 1 (PN1) and decreased gradually at PN3 and PN5. In addition, at PN15 in the functional stage, the dynamin II protein was also expressed in the odontoblast process as well as adjacent to the nuclear region. In conclusion, dynamin II may be involved in the transport of vesicles containing collageneous and non-collageneous proteins for dentin formation in odontoblast, suggesting that it is a good nanomolecule as a candidate to regulate the secretion of collagen on the bone and other nano material.

  19. Cellular and molecular mechanisms of tooth root development.

    Science.gov (United States)

    Li, Jingyuan; Parada, Carolina; Chai, Yang

    2017-02-01

    The tooth root is an integral, functionally important part of our dentition. The formation of a functional root depends on epithelial-mesenchymal interactions and integration of the root with the jaw bone, blood supply and nerve innervations. The root development process therefore offers an attractive model for investigating organogenesis. Understanding how roots develop and how they can be bioengineered is also of great interest in the field of regenerative medicine. Here, we discuss recent advances in understanding the cellular and molecular mechanisms underlying tooth root formation. We review the function of cellular structure and components such as Hertwig's epithelial root sheath, cranial neural crest cells and stem cells residing in developing and adult teeth. We also highlight how complex signaling networks together with multiple transcription factors mediate tissue-tissue interactions that guide root development. Finally, we discuss the possible role of stem cells in establishing the crown-to-root transition, and provide an overview of root malformations and diseases in humans. © 2017. Published by The Company of Biologists Ltd.

  20. CHARCOT-MARIE-TOOTH DISEASE

    Directory of Open Access Journals (Sweden)

    Lea Leonardis

    2003-09-01

    Full Text Available Background. Charcot-Marie-Tooth (CMT disease is a common inherited disorder of the peripheral nervous system. In our paper, different types of CMT are described with their typical clinical pictures, electrophysiological signs and molecular genetic studies. CMT is classified as demyelinative and axonal type and distal motor neuronopathy.Conclusions. CMT can be of autosomal dominant, recessive and X-linked inheritance. The most frequent form of CMT is the result of the dominantly inherited duplication of chromosome 17p11.2 and is marked as CMT1A. The same group involves also rare patients with point mutation in the peripheral myelin protein-22 gene. CMT1B is associated with point mutations in protein zero gene. CMT1C is linked to chromosome 16p13.1–12.3. Patients with point mutations in early growth response 2 gene (EGR2 are included in group CMT1D. The disease can be also inhereted X-linked (CMTX with the mutations in connexin-32 gene. In autosomal recessive inherited demyelinating polyneuropathies (CMT4, mutations are found in the myotubularin-related protein-2 (CMT4B, N-myc downstream-regulated gene 1 (CMT4D, EGR2 (CMT4E, and in the periaksin (CMT4F genes. In axonal inherited neuropathy, mutations are found in KIF1beta (CMT2A and in light neurofilament (CMT2E genes, other forms map to different chromosomal loci (CMT2B, CMT2D, CMT2F. Some suggestions for the diagnostic procedures of patients with CMT are given.

  1. Tooth by tooth survival analysis of dental health in girls with epilepsy.

    Science.gov (United States)

    Rajavaara, P; Vainionpää, L; Rättyä, J; Knip, M; Pakarinen, A; Isojärvi, J; Larmas, M

    2003-06-01

    The aim of this study was to analyse, tooth by tooth, the timing of caries attacks leading to dental restoration in girls with epilepsy. The series comprised 60 girls with epilepsy, 8-18 years old, treated in the Departments of Paediatrics or Neurology of the Oulu University Hospital. A group of healthy age matched girls served as control. A tooth by tooth survival analysis of the time between tooth eruption and caries attacks to a stage leading to the restorations of the permanent teeth was conducted retrospectively using data from the dental health records with annual examinations. The rate of dental restorations placed due to caries was constantly higher in the girls with epilepsy than in their controls. The difference was significant between the first molars (p=epilepsy, the antiepileptic medication in particular, might increase the risk of caries.

  2. Tooth regeneration from newly established cell lines from a molar tooth germ epithelium.

    Science.gov (United States)

    Komine, Akihiko; Suenaga, Momoko; Nakao, Kazuhisa; Tsuji, Takashi; Tomooka, Yasuhiro

    2007-04-13

    In order to investigate tooth development, several cell lines of the dental epithelium and ectomesenchyme have been established. However, no attempt has been reported to regenerate teeth with cell lines. Here, we have established several clonal cell lines of the dental epithelium from a p53-deficient fetal mouse. They expressed specific markers of the dental epithelium such as ameloblastin and amelogenin. A new method has been developed to bioengineer tooth germs with dental epithelial and mesenchymal cells. Reconstructed tooth germs with cell lines and fetal mesenchymal cells were implanted under kidney capsule. The germs regenerated teeth with well-calcified structures as seen in natural tooth. Germs without the cell lines developed bone. This is the first success to regenerate teeth with dental epithelial cell lines. They are useful models in vitro for investigation of mechanisms in morphogenesis and of cell lineage in differentiation, and for clinical application for tooth regeneration.

  3. Tooth tissue engineering: tooth decellularization for natural scaffold

    Science.gov (United States)

    de Sousa Iwamoto, Luciana Aparecida; Duailibi, Monica Talarico; Iwamoto, Gerson Yoshinobu; Juliano, Yara; Duailibi, Michel Silvio; Ossamu Tanaka, Francisco André; Duailibi, Silvio Eduardo

    2016-01-01

    Aim: Tissue engineering is a multidisciplinary science that aims to produce replacement organs and biological substitutes. One of the techniques involves decellularizing a biological organ without altering its structure. One challenge is how to demonstrate which method would be better for this process. Methodology: Fifty premolar teeth were divided into five groups: G1 (control): solution of 10% formaldehyde; G2: phosphate buffer saline (PBS), 28 g of tetrasodium ethylenediaminetetraacetic (EDTA), sodium hypochlorite 2.5% (SH); G3: PBS, EDTA and 40v hydrogen peroxide (HP); G4: PBS, EDTA, SH, enzymatic detergent (ED); and G5: PBS, EDTA, HP, ED. Each group was analyzed by scanning electron microscopy (SEM), x-ray, measured weights and color and received statistical analysis. Conclusion: This study demonstrated that G5 was the most appropriate method to obtain a natural scaffold. PMID:28031968

  4. Wnt5a regulates growth, patterning, and odontoblast differentiation of developing mouse tooth

    Science.gov (United States)

    Lin, Minkui; Li, Lu; Liu, Chao; Liu, Hongbing; He, Fenglei; Yan, Fuhua; Zhang, Yanding; Chen, YiPing

    2011-01-01

    Wnt/β-catenin signaling is essential for tooth development beyond the bud stage, but little is known about the role of non-canonical Wnt signaling in odontogenesis. Here we compared the expression of Wnt5a, a representative of noncanonical Wnts, with that of Ror2, the Wnt5a receptor for non-canonical signaling, in the developing tooth, and analyzed tooth phenotype in Wnt5a mutants. Wnt5a deficient mice exhibit retarded tooth development beginning from E16.5, leading to the formation of smaller and abnormally patterned teeth with a delayed odontoblast differentiation at birth. These defects are associated with upregulated Axin2 and Shh expression in the dental epithelium and reduced levels of cell proliferation in the dental epithelium and mesenchyme. Retarded tooth development and defective odontoblast differentiation were also observed in Ror2 mutant mice. Our results suggest that Wnt5a regulates growth, patterning, and odontoblast differentiation during odontogenesis, at least partially by modulating Wnt/β-catenin canonical signaling. PMID:21246660

  5. Fate of developing tooth buds located in relation to mandibular fractures in three infancy cases.

    Science.gov (United States)

    Yamamoto, Kazuhiko; Matsusue, Yumiko; Murakami, Kazuhiro; Horita, Satoshi; Matsubara, Yuri; Kuraki, Miho; Kurihara, Miyako; Imai, Yuichiro; Sugiura, Tsutomu; Kirita, Tadaaki

    2010-08-01

    The fate of developing tooth buds located in relation to mandibular fractures was investigated in three infancy cases. Three infants, 2 girls and a boy, aged from 1 year and 5-months old to 2 years and 6-months old, were treated for dislocated mandibular fracture in the symphyseal region by manual reduction and fixation with a thermoforming splint and circumferential wiring under general anesthesia. Fracture healing was uneventful in all cases. A few years later, no obvious deformity of the jaw or malocclusion was observed; however, malformation of the crown was found in one of the permanent teeth on the fracture line in the first case. In the second case, no abnormality was observed in one of the permanent teeth on the fracture line, but the effect on the other tooth could not be evaluated due to abnormality of the tooth probably not related to the injury. In the third case, root formation was arrested in one of the permanent teeth on the fracture line and the tooth was lost early after eruption. The development of tooth buds on the fracture line is not predictable and therefore, should be monitored by regular follow up.

  6. Temporospatial tissue interactions regulating the regeneration of the enamel knot in the developing mouse tooth.

    Science.gov (United States)

    Cho, Sung-Won; Kim, Jae-Young; Cai, Jinglei; Lee, Jong-Min; Kim, Eun-Jung; Lee, Hyun-A; Yamamoto, Hitoshi; Jung, Han-Sung

    2007-02-01

    The enamel knot (EK), which is a transient signaling center in the tooth germ, regulates both the differential growth of the dental epithelium and the tooth shape. In this study, the regeneration of the EK was evaluated. The EK regions were removed from the E14 and E16 dental epithelia, and the remaining epithelia were recombined with their original dental mesenchymes. All these tooth germs could develop into calcified teeth after being transplanted into the kidney capsule for 3 weeks. One primary EK was regenerated earlier, and two or three secondary EKs were regenerated later in culture. When simply recombined without removing the EK, the tooth germ, which had four secondary EKs and four cuspal areas of the dental papilla, generated one primary EK first and subsequent secondary EKs. These results indicate that the patterning of the EK in all tooth germs always starts from a primary EK independent of the direct epithelial or mesenchymal control. This suggests that neither the dental epithelium nor the dental mesenchyme can dictate the pattern or number of the EK formation, but the interaction between the dental epithelium and the dental mesenchyme is essential for the regeneration and patterning of the EKs.

  7. The tooth, the whole tooth: an unusual fight bite with an unnoticed embedded tooth in the hand.

    Science.gov (United States)

    Vijayan, Roshan; Awad, Guirgis

    2015-05-02

    A 19-year-old man presented to the plastic surgeons with a wound between his fourth and fifth metacarpophalangeal joints, with associated hand swelling and pain. He admitted to accidentally striking his brother in the mouth the previous evening. His brother reportedly made a hasty exit, and the patient dismissed the wound to his hand until waking up the next morning with swelling, pain and ascending lymphangitis. Radiographs revealed the unusual extent of his 'fight bite' injury with an entire human tooth embedded in his hand. Removal of the tooth and aggressive debridement was performed in theatre. Establishing an accurate account of events in these injuries can be difficult, with the orientation of the tooth in the soft tissues being more consistent with an uppercut than the reported jab. The patient made a good recovery following elevation, intravenous antibiotics, rigorous surgical debridement and postoperative hand therapy. 2015 BMJ Publishing Group Ltd.

  8. Tooth morphogenesis and ameloblast differentiation are regulated by micro-RNAs.

    Science.gov (United States)

    Michon, Frederic; Tummers, Mark; Kyyrönen, Marika; Frilander, Mikko J; Thesleff, Irma

    2010-04-15

    Teeth form as appendages of the ectoderm and their morphogenesis is regulated by tissue interactions mediated by networks of conserved signal pathways. Micro-RNA (miRNA) pathway has emerged as important regulator of various aspects of embryonic development, but its function in odontogenesis has not been elucidated. We show that the expression of RNAi pathway effectors is dynamic during tooth morphogenesis and differentiation of dental cells. Based on microarray profiling we selected 8 miRNAs expressed during morphogenesis and 7 miRNAs in the incisor cervical loop containing the stem cell niche. These miRNAs were mainly expressed in the dental epithelium. Conditional deletion of Dicer-1 in the epithelium (Dcr(K14)(-)(/)(-)) resulted in rather mild but significant aberrations in tooth shape and enamel formation. The cusp patterns of the Dcr(K14)(-)(/)(-) molar crowns resembled the patterns of both ancestral muroid rodents and mouse mutants with modulated signal pathways. In the Dcr(K14)(-)(/)(-) incisors, longitudinal grooves formed on the labial surface and these were shown to result from ectopic budding of the progenitor epithelium in the cervical loop. In addition, ameloblast differentiation was impaired and resulted in deficient enamel formation in molars and incisors. To help the identification of candidate target genes of the selected tooth enriched miRNAs, we constructed a new ectodermal organ oriented database, miRTooth. The predicted targets of the selected miRNAs included several components of the main morphogenetic signal pathways regulating tooth development. Based on our findings we suggest that miRNAs modulate tooth morphogenesis largely by fine tuning conserved signaling networks and that miRNAs may have played important roles during tooth evolution.

  9. Tooth loss and alveolar remodeling in Sinosaurus triassicus (Dinosauria: Theropoda) from the Lower Jurassic strata of the Lufeng Basin, China

    Institute of Scientific and Technical Information of China (English)

    XING LiDa; BELL Phil R; ROTHSCHILD Bruce M; RAN Hao; ZHANG JianPing; DONG ZhiMing; ZHANG Wei

    2013-01-01

    Pathological or traumatic loss of teeth often results in the resorption and remodeling of the affected alveoli in mammals.However,instances of alveolar remodeling in reptiles are rare.A remodeled alveolus in the maxilla of the Chinese theropod Sinosaurus (Lower Jurassic Lower Lufeng Formation) is the first confirmed example of such dental pathology in a dinosaur.Given the known relationship between feeding behavior and tooth damage in theropods (teeth with spalled enamel,tooth crowns embedded in bone) and the absence of dentary,maxillary,and premaxillary osteomyelitis,traumatic loss of a tooth is most likely the cause of alveolar remodeling.Based on the extent of remodeling,the injury and subsequent tooth loss were non-fatal in this individual.

  10. Pain experience after simple tooth extraction.

    Science.gov (United States)

    Al-Khateeb, Taiseer Hussain; Alnahar, Amir

    2008-05-01

    To assess pain experience after simple uncomplicated tooth extraction and to see if there is a need to prescribe analgesic drugs after such a procedure. A random sample of patients presenting for tooth extraction at the Maxillofacial Unit, Jordan University of Science and Technology was included. A baseline assessment of previously experienced general and dental pains using numeric scales was done. Subsequently, tooth extractions were done and telephone interviews were made during evenings for a week. Pain intensity was assessed on a numeric scale, and use of analgesic drugs and pain quality were recorded. At the evening of extraction 81.8% of patients had pain. Female gender predominance in pain reporting was statistically significant on postextraction days 3 and 5. Chronically inflamed teeth caused the highest mean pain intensity scores and nonsmokers showed significantly higher mean pain intensity scores compared with smokers. Mild pain was experienced by most patients (38.6%) on the evening of extraction. It was found that 55.3% of participants (largely females) used analgesic drugs on the evening of extraction, and 6.8% of participants still used analgesic drugs on day 7 postextraction. There was a significant correlation between mean pain intensity score and previous dental injection pain. Patients, notably females, experienced pain of varying intensity after simple uncomplicated tooth extraction maximally at the evening of extraction; and greater than 50% of the patients used analgesic drugs. We recommend offering regular analgesic drugs during the first week after tooth extraction.

  11. Detecting Tooth Damage in Geared Drive Trains

    Science.gov (United States)

    Nachtsheim, Philip R.

    1997-01-01

    This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

  12. Controlled Deposition of HAp Mimicking Tooth Enamel

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chemical compositions and microsturcture of mature human tooth enamel were investigated by XRD , FTIR and SEM to further understand the characteristics of tooth enamel. In order to obtain apatite crystals chemically and structurally similar to those in tooth enamel, biomimetic way was employed. Selfassembled monolyers terminated with-SO3 H groups were used as deposition substrates and 1.5 SBF ( the concentrations of Ca2+ and PO43- ions 1.5 times than those in simulated body fluid ) with and without 5 ppm F- were used as soaking medium. The XRD and FTIR results showed that both the deposited fluoride-substituted hydroxyapatite( F-HAp ) crystals in 1.5 SBF with F- and hydroxyapatite ( HAp ) crystals in 1.5 SBF were carbonate-containing, mimicking human tooth enamel in chemical compositions. The SEM photos showed that needle-like F-HAp crystals bad large aspect ratios and grew in bundles, which were similar to the crystals in human tooth enamel.The results provide available information on dental restoration.

  13. The evolution of dinosaur tooth enamel microstructure.

    Science.gov (United States)

    Hwang, Sunny H

    2011-02-01

    The evolution of tooth enamel microstructure in both extinct and extant mammalian groups has been extensively documented, but is poorly known in reptiles, including dinosaurs. Previous intensive sampling of dinosaur tooth enamel microstructure revealed that: (1) the three-dimensional arrangement of enamel types and features within a tooth-the schmelzmuster-is most useful in diagnosing dinosaur clades at or around the family level; (2) enamel microstructure complexity is correlated with tooth morphology complexity and not necessarily with phylogenetic position; and (3) there is a large amount of homoplasy within Theropoda but much less within Ornithischia. In this study, the examination of the enamel microstructure of 28 additional dinosaur taxa fills in taxonomic gaps of previous studies and reinforces the aforementioned conclusions. Additionally, these new specimens reveal that within clades such as Sauropodomorpha, Neotheropoda, and Euornithopoda, the more basal taxa have simpler enamel that is a precursor to the more complex enamel of more derived taxa and that schmelzmusters evolve in a stepwise fashion. In the particularly well-sampled clade of Euornithopoda, correlations between the evolution of dental and enamel characters could be drawn. The ancestral schmelzmuster for Genasauria remains ambiguous due to the dearth of basal ornithischian teeth available for study. These new specimens provide new insights into the evolution of tooth enamel microstructure in dinosaurs, emphasizing the importance of thorough sampling within broadly inclusive clades, especially among their more basal members.

  14. Glucose uptake mediated by glucose transporter 1 is essential for early tooth morphogenesis and size determination of murine molars.

    Science.gov (United States)

    Ida-Yonemochi, Hiroko; Nakatomi, Mitsushiro; Harada, Hidemitsu; Takata, Hiroki; Baba, Otto; Ohshima, Hayato

    2012-03-01

    Glucose is an essential source of energy for body metabolism and is transported into cells by glucose transporters (GLUTs). Well-characterized class I GLUT is subdivided into GLUTs1-4, which are selectively expressed depending on tissue glucose requirements. However, there is no available data on the role of GLUTs during tooth development. This study aims to clarify the functional significance of class I GLUT during murine tooth development using immunohistochemistry and an in vitro organ culture experiment with an inhibitor of GLUTs1/2, phloretin, and Glut1 and Glut2 short interfering RNA (siRNA). An intense GLUT1-immunoreaction was localized in the enamel organ of bud-stage molar tooth germs, where the active cell proliferation occurred. By the bell stage, the expression of GLUT1 in the dental epithelium was dramatically decreased in intensity, and subsequently began to appear in the stratum intermedium at the late bell stage. On the other hand, GLUT2-immunoreactivity was weakly observed in the whole tooth germs throughout all stages. The inhibition of GLUTs1/2 by phloretin in the bud-stage tooth germs induced the disturbance of primary enamel knot formation, resulting in the developmental arrest of the explants and the squamous metaplasia of dental epithelial cells. Furthermore, the inhibition of GLUTs1/2 in cap-to-bell-stage tooth germs reduced tooth size in a dose dependent manner. These findings suggest that the expression of GLUT1 and GLUT2 in the dental epithelial and mesenchymal cells seems to be precisely and spatiotemporally controlled, and the glucose uptake mediated by GLUT1 plays a crucial role in the early tooth morphogenesis and tooth size determination. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Transient thermal and stress analysis of maxillary second premolar tooth using an exact three-dimensional model

    Directory of Open Access Journals (Sweden)

    Hashemipour Maryam

    2010-01-01

    Full Text Available Aim : In this paper, the temperature and stress distributions in an exact 3D-model of a restored maxillary second premolar tooth are obtained with finite element approach. Objective : The carious teeth need to restore with appropriate restorative materials. There are too many restorative materials which can be used instead of tooth structures; since tooth structures are being replaced, the restorative materials should be similar to original structure as could as possible . Materials and Methods : In the present study, a Mesial Occlusal Distal (MOD type of restoration is chosen and applied to a sound tooth model. Four cases of restoration are investigated: two cases in which base are used under restorative materials and two cases in which base is deleted. The restorative materials are amalgam and composite and glass-inomer is used as a base material. Modeling is done in the solid works ambient by means of an exact measuring of a typical human tooth dimensions. Tooth behavior under thermal load due to consuming hot liquids is analyzed by means of a three dimensional finite element method using ANSYS software. The highest values of tensile and compressive stresses are compared with tensile and compressive strength of the tooth and restorative materials and the value of shear stress on the tooth and restoration junctions is compared with the bond strength. Also, sound tooth under the same thermal load is analyzed and the results are compared with those obtained for restored models. Results : Temperature and stress distributions in the tooth are calculated for each case, with a special consideration in the vicinity of pulp and restoration region. Numerical results show that in two cases with amalgam, using the base material (Glass-ionomer under the restorative material causes to decrease the maximum temperature in the restorative teeth . In the stress analysis, it is seen that the principal stress has its maximum values in composite restorations

  16. Discrimination of tooth layers and dental restorative materials using cutting sounds.

    Science.gov (United States)

    Zakeri, Vahid; Arzanpour, Siamak; Chehroudi, Babak

    2015-03-01

    Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

  17. PKA regulatory subunit expression in tooth development.

    Science.gov (United States)

    de Sousa, Sílvia Ferreira; Kawasaki, Katsushige; Kawasaki, Maiko; Volponi, Ana Angelova; Gomez, Ricardo Santiago; Gomes, Carolina Cavaliéri; Sharpe, Paul T; Ohazama, Atsushi

    2014-05-01

    Protein kinase A (PKA) plays critical roles in many biological processes including cell proliferation, cell differentiation, cellular metabolism and gene regulation. Mutation in PKA regulatory subunit, PRKAR1A has previously been identified in odontogenic myxomas, but it is unclear whether PKA is involved in tooth development. The aim of the present study was to assess the expression of alpha isoforms of PKA regulatory subunit (Prkar1a and Prkar2a) in mouse and human odontogenesis by in situ hybridization. PRKAR1A and PRKAR2A mRNA transcription was further confirmed in a human deciduous germ by qRT-PCR. Mouse Prkar1a and human PRKAR2A exhibited a dynamic spatio-temporal expression in tooth development, whereas neither human PRKAR1A nor mouse Prkar2a showed their expression in odontogenesis. These isoforms thus showed different expression pattern between human and mouse tooth germs. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Effect of drugs on orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Siti Sarah Aulia Amrullah

    2016-06-01

    Full Text Available Orthodontic tooth movement is basically a biological response to mechanical forces given to the teeth in orthodontic treatment, which involving the periodontal tissue and alveolar bone, resulting in the release of numerous substances from the dental tissues and surrounding structure. Remodeling changes in periodontal tissues are considered to be essential in effecting orthodontic tooth movement which is the base of orthodontic correction. Molecules produced in various diseased tissues or drugs and nutrients consumed regularly by patients, can influence mechanically stressed periodontal tissue through the circulation and interact with target cell combination of which may be inhibitory, additive or synergize. Medications might have an important influence on the rate of tooth movement, and information on their consumption is essential to adequately discuss treatment planning with patients. Therefore it is imperative to the practitioners being in medical profession, must pay close attention to the drug consumption history of every patient before and during the course of treatment.

  19. Signaling networks regulating tooth organogenesis and regeneration, and the specification of dental mesenchymal and epithelial cell lineages.

    Science.gov (United States)

    Jussila, Maria; Thesleff, Irma

    2012-04-01

    Teeth develop as ectodermal appendages from epithelial and mesenchymal tissues. Tooth organogenesis is regulated by an intricate network of cell-cell signaling during all steps of development. The dental hard tissues, dentin, enamel, and cementum, are formed by unique cell types whose differentiation is intimately linked with morphogenesis. During evolution the capacity for tooth replacement has been reduced in mammals, whereas teeth have acquired more complex shapes. Mammalian teeth contain stem cells but they may not provide a source for bioengineering of human teeth. Therefore it is likely that nondental cells will have to be reprogrammed for the purpose of clinical tooth regeneration. Obviously this will require understanding of the mechanisms of normal development. The signaling networks mediating the epithelial-mesenchymal interactions during morphogenesis are well characterized but the molecular signatures of the odontogenic tissues remain to be uncovered.

  20. Moessbauer Studies of Stannous Fluoride Reactivity with Synthetic Tooth Enamel - A Model for the Tooth Cavity Protection Actions of Novel Dentifrices

    Energy Technology Data Exchange (ETDEWEB)

    Denes, Georges, E-mail: gdenes@vax2.concordia.ca; Muntasar, Abdualhafeed [Concordia University, Laboratory of Moessbauer Spectroscopy and Solid State Chemistry, Laboratories for Inorganic Materials, Department of Chemistry and Biochemistry (Canada); Kozak, Kathy M.; Baig, Arif A.; White, Donald J. [Procter and Gamble Company (United States)

    2002-06-15

    SnF{sub 2} is an important toothpaste ingredient, added for the provision of clinical efficacy for hard and soft tissue diseases and in breath protection. Synthetic calcium hydroxyapatite powders were exposed to liquid supernates (25 w/w% toothpaste water slurries, centrifuged) of Crest Gum Care (registered) (SnF{sub 2}) dentifrice. One-minute treatments were followed by 3x water washing, centrifugation and lyophilization. Post treatment, powders were analyzed by Moessbauer spectroscopy with 0.5-1 gram of treated apatite powder. Results show that tooth mineral stannous fluoride interactions include: (1) formation of surface reaction products with both Sn(II) and Sn(IV) oxidation states; (2) Sn-F binding on mineral surfaces with no evidence of SnO. The surface binding is, however, not pure Sn-F but contains contributions of other ligands, probably oxygens from surface phosphates or hydroxyl groups. Results also suggest that surface reacted stannous tin is oxidized with time, even when bound as a layer on the tooth surface. This study demonstrates for the first time the presence of Sn-F on tooth enamel post treatment and the contribution of passivation to long term stannous chemistry on tooth surfaces. The study also illustrates the practical applications of the Moessbauer technique.

  1. Robotic mitral valve replacement.

    Science.gov (United States)

    Senay, Sahin; Gullu, Ahmet Umit; Kocyigit, Muharrem; Degirmencioglu, Aleks; Karabulut, Hasan; Alhan, Cem

    2014-01-01

    Robotic surgical techniques allow surgeons to perform mitral valve surgery. This procedure has gained acceptance, particularly for mitral valve repair in degenerative mitral disease. However, mitral repair may not always be possible, especially in severely calcified mitral valve of rheumatic origin. This study demonstrates the basic concepts and technique of robotic mitral valve replacement for valve pathologies that are not suitable for repair.

  2. Replacing America's Job Bank

    Science.gov (United States)

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  3. Replacing America's Job Bank

    Science.gov (United States)

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  4. Maxillary tooth displacement in the infratemporal fossa.

    Science.gov (United States)

    Roshanghias, Korosh; Peisker, Andre; Zieron, Jörg Olaf

    2016-01-01

    Wisdom tooth operations are sometimes accompanied by complications. This case report shows complications during upper jaw third molar removal. Expectable problems during oral surgery should be planned to be solved in advance. Displacement of the third molar during oral surgeries as a considerable complication is rarely discussed scientifically. A good design of flap, adequate power for extraction, and clear view on the surgical field are crucial. Three-dimensional radiographic diagnostics in terms of cone beam computed tomography is helpful after tooth displacement into the infratemporal fossa.

  5. Maxillary tooth displacement in the infratemporal fossa

    Directory of Open Access Journals (Sweden)

    Korosh Roshanghias

    2016-01-01

    Full Text Available Wisdom tooth operations are sometimes accompanied by complications. This case report shows complications during upper jaw third molar removal. Expectable problems during oral surgery should be planned to be solved in advance. Displacement of the third molar during oral surgeries as a considerable complication is rarely discussed scientifically. A good design of flap, adequate power for extraction, and clear view on the surgical field are crucial. Three-dimensional radiographic diagnostics in terms of cone beam computed tomography is helpful after tooth displacement into the infratemporal fossa.

  6. Ectopic tooth in maxillary sinus: Case series.

    Science.gov (United States)

    Ramanojam, Shandilya; Halli, Rajshekhar; Hebbale, Manjula; Bhardwaj, Smita

    2013-01-01

    Ectopic eruption of a tooth within the dentate region of the jaws is often noticed in clinical practice and is well documented in the literature. But the ectopic eruption into the non dentate region is rare and scantly documented. The maxillary sinus is one such a non dentate region, apart from nasal septum, mandibular condyle, coronoid process and the palate, to accommodate such ectopic eruptions of teeth. Due to its rarity and lack of consensus over its management, the incidence deserves to be added to the literature and discussed. Early surgical intervention for removal of ectopic tooth along with enucleation of the associated cyst, if any, is the treatment of choice.

  7. [Ectopic molar tooth in the maxillary sinus].

    Science.gov (United States)

    Altun, Hüseyin; Teker, Ayşenur Meriç; Ceran, Murat; Gedikli, Orhan

    2007-01-01

    The development of intranasal ectopic teeth is rare. Although they are more commonly seen in the palate and maxillary sinus, they can also be found in the mandibular condyle, coronoid process, and nasal cavity. A 30-year-old male patient presented with a complaint of headache. Computed tomography of the paranasal sinuses showed a bony mass in the right maxillary sinus wall, 1 cm in size. He did not have any history of maxillofacial trauma or operation. The mass was removed via a Caldwell-Luc procedure. It looked like a tooth. Histopathologic diagnosis was made as ectopic molar tooth. The patient was asymptomatic two weeks after the operation.

  8. Nasomaxillary hypoplasia with a congenitally missing tooth treated with LeFort II osteotomy, autotransplantation, and nickel-titanium alloy wire.

    Science.gov (United States)

    Ishida, Takayoshi; Ikemoto, Shigehiro; Ono, Takashi

    2015-09-01

    In some skeletal Class III adult patients with nasomaxillary hypoplasia, the LeFort I osteotomy provides insufficient correction. This case report describes a 20-year-old woman with a combination of nasomaxillary hypoplasia and a protrusive mandible with a congenitally missing mandibular second premolar. We performed a LeFort II osteotomy for maxillary advancement. Autotransplantation of a tooth was also performed; the donor tooth was used to replace the missing permanent tooth. To increase the chance of success, we applied light continuous force with an improved superelastic nickel-titanium alloy wire technique before extraction and after transplantation. The patient's profile and malocclusion were corrected, and the autotransplanted tooth functioned well. The postero-occlusal relationships were improved, and ideal overbite and overjet relationships were achieved. The methods used in this case represent a remarkable treatment. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  9. REMINDER REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division; Cards.Service@cern.ch

    2001-01-01

    The French Ministry of Foreign Affairs is currently replacing all diplomatic cards, special cards and employment permits («attestations de fonctions») held by members of the personnel and their families. These cards are replaced by secure, computerized equivalents. The old cards may no longer be used after 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015) between 8h30 and 12h30, in order to fill in a «fiche individuelle» form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, the French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested...

  10. 3D analysis of craniofacial growth and tooth eruption

    DEFF Research Database (Denmark)

    Kreiborg, Sven

    The 9th International Congress on Cleft Palate and Related Craniofacial Anomalies, 3D analysis, craniofacial growth, tooth eruption......The 9th International Congress on Cleft Palate and Related Craniofacial Anomalies, 3D analysis, craniofacial growth, tooth eruption...

  11. Seal Out Tooth Decay: A Fact Sheet for Parents

    Science.gov (United States)

    ... Institute of Dental and Craniofacial Research Seal Out Tooth Decay A Fact Sheet for Parents What are dental ... important reason for getting sealants is to avoid tooth decay. • Fluoride in toothpaste and in drinking water protects ...

  12. 21 CFR 872.3200 - Resin tooth bonding agent.

    Science.gov (United States)

    2010-04-01

    .... A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be painted on the interior of a prepared cavity of a tooth to improve retention of a restoration, such as...

  13. The management of dental fracture on tooth 61 in a child with attention deficit hyperactivity disorders

    Directory of Open Access Journals (Sweden)

    Veranica Veranica

    2010-12-01

    Full Text Available Background: Attention deficit hyperactivity disorder (ADHD is often characterized as a neurobehavioral developmental disorder, impaired concentration, impaired motor skills, impulsivity, and hyperactivity, and also diagnosed as psychiatric disorders. Children with ADHD would have a tendency of the traumatized anterior teeth because of their hyperactive behavior. Dental trauma is actually one of factors causing the damages of the deciduous teeth and the permanent teeth. Dental and mouth care for children with special needs, such as children with ADHD, requires special treatment. Purpose: This study is aimed to report the case management of the dental fracture of the tooth 61 in a child with ADHD. Case: A four-year old girl suffered from both ADHD and dental fracture involving the dentin of the tooth 61. Case management: The examination of the patient with dental fracture consists of emergency examination and further investigation. The emergency examination covers general condition and clinical situation. Based on the dental radiographic assessment, it is known that the dental fracture of the tooth 61 had involved the dentine, the resorption had reached 1/3 of the apical teeth and the permanent teeth had been formed. The application of calcium hydroxide on the opened dentin is aimed to improve the formation of the secondary dentin served as pulp protector. Next, the restoration of the traumatized teeth used compomer since it does not only meet all the aesthetic requirements, but it also releases fluoride. Management of the patient’s behavior with ADHD was conducted by non-pharmacological method; tell show do (TSD method combined with restrain method. Conclusion: It can be concluded that the application of calcium hydroxide and the restoration of the teeth with compomer could provide maximum results through the combination of TSD and restrain methods that can effectively increase the positive value to replace the negative behaviors that have been

  14. Cellular and Molecular Changes in Orthodontic Tooth Movement

    Directory of Open Access Journals (Sweden)

    Shahrul Hisham Zainal Ariffin

    2011-01-01

    Full Text Available Tooth movement induced by orthodontic treatment can cause sequential reactions involving the periodontal tissue and alveolar bone, resulting in the release of numerous substances from the dental tissues and surrounding structures. To better understand the biological processes involved in orthodontic treatment, improve treatment, and reduce adverse side effects, several of these substances have been proposed as biomarkers. Potential biological markers can be collected from different tissue samples, and suitable sampling is important to accurately reflect biological processes. This paper covers the tissue changes that are involved during orthodontic tooth movement such as at compression region (involving osteoblasts, tension region (involving osteoclasts, dental root, and pulp tissues. Besides, the involvement of stem cells and their development towards osteoblasts and osteoclasts during orthodontic treatment have also been explained. Several possible biomarkers representing these biological changes during specific phenomenon, that is, bone remodelling (formation and resorption, inflammation, and root resorption have also been proposed. The knowledge of these biomarkers could be used in accelerating orthodontic treatment.

  15. Hyaluronan in human deciduous tooth germs in the bell stage. Histochemistry and immunohistochemistry

    DEFF Research Database (Denmark)

    Matthiessen, Martin Ebbe; Garbarsch, Charly; Olsen, Birgitte Engelbrecht

    1997-01-01

    Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry......Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry...

  16. Functional Properties of Tooth Pulp Neurons Responding to Thermal Stimulation

    OpenAIRE

    Ahn, D.K.; Doutova, E.A.; McNaughton, K.; Light, A.R.; Närhi, M.; Maixner, W.

    2012-01-01

    The response properties of tooth pulp neurons that respond to noxious thermal stimulation of the dental pulp have been not well-studied. The present study was designed to characterize the response properties of tooth pulp neurons to noxious thermal stimulation of the dental pulp. Experiments were conducted on 25 male ferrets, and heat stimulation was applied by a computer-controlled thermode. Only 15% of tooth pulp neurons (n = 39) responded to noxious thermal stimulation of the teeth. Tooth ...

  17. A panorama of tooth wear during the medieval period.

    Science.gov (United States)

    Esclassan, Rémi; Hadjouis, Djillali; Donat, Richard; Passarrius, Olivier; Maret, Delphine; Vaysse, Frédéric; Crubézy, Eric

    2015-01-01

    Tooth wear is a natural phenomenon and a universal occurrence that has existed from the origin of humankind and depends on the way of life, especially diet. Tooth wear was very serious in ancient populations up to the medieval period. The aim of this paper is to present a global view of tooth wear in medieval times in Europe through different parameters: scoring systems, quantity and direction of wear, gender, differences between maxilla and mandible, relations with diet, caries, tooth malpositions and age.

  18. The regulation of tooth morphogenesis is associated with epithelial cell proliferation and the expression of Sonic hedgehog through epithelial-mesenchymal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Kentaro; Murofushi, Mayumi [Faculty of Industrial Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Nakao, Kazuhisa; Morita, Ritsuko [Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Ogawa, Miho [Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Organ Technologies Inc., Tokyo 101-0048 (Japan); Tsuji, Takashi, E-mail: t-tsuji@rs.noda.tus.ac.jp [Faculty of Industrial Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Organ Technologies Inc., Tokyo 101-0048 (Japan)

    2011-02-18

    Research highlights: {yields} Bioengineered teeth regulated the contact area of epithelium and mesenchyme. {yields} The crown width is regulated by the contact area of the epithelium and mesenchyme. {yields} This regulation is associated with cell proliferation and Sonic hedgehog expression. {yields} The cusp number is correlated with the crown width of the bioengineered tooth. {yields} Cell proliferation and Shh expression areas regulate the tooth morphogenesis. -- Abstract: Ectodermal organs, such as the tooth, salivary gland, hair, and mammary gland, develop through reciprocal epithelial-mesenchymal interactions. Tooth morphologies are defined by the crown width and tooth length (macro-morphologies), and by the number and locations of the cusp and roots (micro-morphologies). In our current study, we report that the crown width of a bioengineered molar tooth, which was reconstructed using dissociated epithelial and mesenchymal cells via an organ germ method, can be regulated by the contact area between epithelial and mesenchymal cell layers. We further show that this is associated with cell proliferation and Sonic hedgehog (Shh) expression in the inner enamel epithelium after the germ stage has formed a secondary enamel knot. We also demonstrate that the cusp number is significantly correlated with the crown width of the bioengineered tooth. These findings suggest that the tooth micro-morphology, i.e. the cusp formation, is regulated after the tooth width, or macro-morphology, is determined. These findings also suggest that the spatiotemporal patterning of cell proliferation and the Shh expression areas in the epithelium regulate the crown width and cusp formation of the developing tooth.

  19. A prospective study of Astra single tooth implants.

    Science.gov (United States)

    Palmer, R M; Smith, B J; Palmer, P J; Floyd, P D

    1997-06-01

    A new design of single tooth implant (AstraTech, Molndal Sweden) featuring a microthreaded conical neck and TiO blast surface was evaluated clinically and radiographically after 2 years in function. Fifteen patients (age range 16 to 48) with missing maxillary anterior teeth (6 central incisors, 8 laterals, 1 bicuspid) had 4, 13 mm and 11, 15 mm implants placed under local anaesthesia and left for a period of 6 months before exposure and abutment connection/crown fabrication. All patients were seen at 4 to 6 monthly intervals for hygienist maintenance. Radiographs using Rinn holders and a long cone technique were taken at the crown insertion and after 1 year (14 subjects) and 2 years (12 subjects). All implants were successfully integrated at stage 2, and no implants have been lost. The internal conical seal design of the abutment/implant interface facilitated connection and there were no cases of abutment screw loosening. No soft tissue problems were observed, and the gingival morphology/health was well maintained. One crown was recemented after 18 months in function, and 1 crown was replaced because of a fracture to the porcelain incisal edge. At crown insertion, the mean bone level was 0.46 to 0.48 mm apical to the top of the implant and there were no statistically significant changes in the bone level over the 2 years of the study. In conclusion, the single tooth Astra implants were highly successful and bone changes within the first 2 years of function were comparable with other systems reporting high long-term success rates.

  20. Implant-supported single-tooth restorations. A 12-year prospective study.

    Science.gov (United States)

    Donati, Mauro; Ekestubbe, Annika; Lindhe, Jan; Wennström, Jan L

    2016-10-01

    The aim of this study was to evaluate prospectively the 12-year outcome of implant-supported single-tooth restorations. Originally 45 self-tapping Astra Tech TiOblast(®) ST-implants were installed by a two-stage protocol in 40 subjects requiring single-tooth prosthetic replacement for a missing tooth. Clinical and radiologic examinations were performed at completion of the prosthetic treatment 4-7 months after implant installation surgery and after 5 and 12 years in function. At 12 years 31 patients and 35 implants were available for evaluation. The overall failure rate after 12 years was 10.3% on the subject level and 9.1% on the implant level. The mean bone loss amounted to 0.67 mm (SD 2.20) on a subject level and 0.47 mm (1.72) on an implant level. Three subjects (10%) and three implants (8.6%) were diagnosed with peri-implantitis. Five subjects had experienced technical complications; three incidences of loosening of the abutment retention screw during the first 5 years and two minor porcelain fracture of the crown (two patients) between 5- and 12-years of follow-up. The findings reported in this 12-year prospective case series suggest that the use of the Astra Tech dental implants may be a valid treatment alternative for single-tooth replacement prostheses. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Dental histology of Coelophysis bauri and the evolution of tooth attachment tissues in early dinosaurs.

    Science.gov (United States)

    Fong, Raymond K M; LeBlanc, Aaron R H; Berman, David S; Reisz, Robert R

    2016-07-01

    Studies of dinosaur teeth have focused primarily on external crown morphology and thus, use shed or in situ tooth crowns, and are limited to the enamel and dentine dental tissues. As a result, the full suites of periodontal tissues that attach teeth to the jaws remain poorly documented, particularly in early dinosaurs. These tissues are an integral part of the tooth and thus essential to a more complete understanding of dental anatomy, development, and evolution in dinosaurs. To identify the tooth attachment tissues in early dinosaurs, histological thin sections were prepared from the maxilla and dentary of a partial skull of the early theropod Coelophysis bauri from the Upper Triassic (Rhaetian- 209-201 Ma) Whitaker Quarry, New Mexico, USA. As one of the phylogenetically and geologically oldest dinosaurs, it is an ideal candidate for examining dental tissues near the base of the dinosaurian clade. The teeth of C. bauri exhibited a fibrous tooth attachment in which the teeth possessed five tissues: enamel, dentine, cementum, periodontal ligament (PDL), and alveolar bone. Our findings, coupled with those of more recent studies of ornithischian teeth, indicate that a tripartite periodontium, similar to that of crocodilians and mammals, is the plesiomorphic condition for dinosaurs. The occurrence of a tripartite periodontium in dinosaurs adds to the growing consensus that the presence of these tissues is the plesiomorphic condition for the major amniote clades. Furthermore, this study establishes the relative timing of tissue development and growth directions of periodontal tissues and provides the first comparative framework for future studies of dinosaur periodontal development, tooth replacement, and histology. J. Morphol. 277:916-924, 2016. © 2016 Wiley Periodicals, Inc.

  2. The Importance of Tooth Decay Prevention in Children under Three

    Science.gov (United States)

    Milgrom, Peter; Huebner, Colleen; Chi, Donald

    2010-01-01

    Tooth decay and tooth loss was once the norm but public health interventions have led to major improvements for most people. Nevertheless, not all children have benefited. Dental disease in young children is unacceptably high. Tooth decay is preventable. Early childhood educators are often the first to notice the problem. Professional…

  3. The Importance of Tooth Decay Prevention in Children under Three

    Science.gov (United States)

    Milgrom, Peter; Huebner, Colleen; Chi, Donald

    2010-01-01

    Tooth decay and tooth loss was once the norm but public health interventions have led to major improvements for most people. Nevertheless, not all children have benefited. Dental disease in young children is unacceptably high. Tooth decay is preventable. Early childhood educators are often the first to notice the problem. Professional…

  4. Tooth-marked small theropod bone: an extremely rare trace

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland

    2001-01-01

    Tooth-marked dinosaur bones provide insight into feeding behaviours and biting strategies of theropod dinosaurs. The majority of theropod tooth marks reported to date have been found on herbivorous dinosaur bones, although some tyrannosaurid bones with tooth marks have also been reported. In 1988...

  5. 21 CFR 872.3690 - Tooth shade resin material.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section...

  6. Formation of charge separated state P+OA- and triplet state 3P at low temperature in Rhodobacter sphaeroides (R-26) reaction centers in which bacteriopheophytin a is replaced by plant pheophytin a.

    Science.gov (United States)

    Shkuropatov Aya; Proskuryakov, I I; Shkuropatova, V A; Zvereva, M G; Shuvalov, V A

    1994-09-05

    Low temperature optical and photochemical properties of Rhodobacter sphaeroides (R-26) reaction centers, in which bacteriopheophytin a has been replaced by plant pheophytin a, are reported. Modified reaction centers preserve the ability for photoinduced electron transfer from the primary electron donor P to the primary quinone acceptor QA at 80K. The triplet state ESR signal of modified reaction centers with prereduced QA at 10K shows an electron spin polarization pattern and ZFS parameters analogous to those for the triplet state 3P in non-treated reaction centers. It was found that at low temperature both P+QA- and 3P states are formed via a precursor radical pair P+I- in which I is the introduced plant pheophytin molecule. This shows that acceptor systems of bacterial and plant (photosystem II) reaction centers are mutually replacable in structural and functional aspects.

  7. Storing tooth segments for optimal esthetics

    NARCIS (Netherlands)

    Tuzuner, T.; Turgut, S.; Özen, B.; Kılınç, H.; Bagis, B.

    2016-01-01

    Objective: A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Study design: Sixty c

  8. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Bomberman atari oyunlarý bakugan oyunlarý geta poker friv Home InfoBites Find an AGD Dentist Your Family's Oral ... words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | ...

  9. Age effect on orthodontic tooth movement

    NARCIS (Netherlands)

    Ren, Yijin

    2003-01-01

    This study was performed to investigate the effect of age on the efficiency of orthodontic tooth movement based on critical literature reviews, studies on a standardized orthodontic animal model and a non-invasive clinical investigation. A systematic review was performed on the optimum force for ort

  10. Bleaching of the discolored traumatized tooth

    DEFF Research Database (Denmark)

    Dahl, Jon E.; Kopperud, Siemen E.; Pallesen, Ulla

    2017-01-01

    This chapter focuses on the treatment of discolored traumatized teeth, most of them being non-vital and subsequently, endodontically treated. Tooth bleaching based upon hydrogen peroxide as the active agent, applied directly or produced in a chemical reaction from sodium perborate or carbamide...

  11. Early Onset Charcot-Marie-Tooth Disease

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-06-01

    Full Text Available The clinical signs and genetic analysis of early-onset Charcot-Marie-Tooth disease (CMT in a 2-year-old boy and members of his family are reported from the Academic Medical Center, Amsterdam, and Sophia Children’s Hospital, Rotterdam, the Netherlands.

  12. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Jaw Pain? Check Your Posture! Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ... | Terms and Conditions © 1996-2017 Academy of General Dentistry. All Rights Reserved.

  13. Restoration of the endodontically treated posterior tooth

    Directory of Open Access Journals (Sweden)

    Andrea Polesel

    2014-06-01

    Results and conclusions: Direct adhesive restorations, indirect bonded restorations and traditional full crown are three therapeutic options for the single posterior endodontically treated teeth. The amount of remaining sound tooth structure is the most significant factor influencing the therapeutic approach. The clinician's operative skill is a determining aspect for long-term success of adhesive inlays.

  14. psychosocial aspect of anterior tooth discoloration among ...

    African Journals Online (AJOL)

    tooth colour7 and 28% of adults in the UK were dissatisfied with the ... often results in loss of self-esteem and damage to physical and ... childhood and adolescence can have a significant effect on psychosocial ... the school authorities. Written ...

  15. Tooth loss: Are the patients prepared?

    African Journals Online (AJOL)

    this has on their lives. ... (12.9%) cases, depression in 11 (6.4%), feeling of losing body part in 24 (14%), feeling of aging in 4 (2.3%), .... and the quality of life of the individuals following tooth ... However, in the elderly, periodontal diseases are.

  16. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... friv Home InfoBites Find an AGD Dentist Your Family's Oral Health About the AGD Dental care and ... Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | ...

  17. Computed tomography to quantify tooth abrasion

    Science.gov (United States)

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  18. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... friv Home InfoBites Find an AGD Dentist Your Family's Oral Health About the AGD Dental care and ... Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | ...

  19. Antagonistic Functions of USAG-1 and RUNX2 during Tooth Development

    Science.gov (United States)

    Togo, Yumiko; Takahashi, Katsu; Saito, Kazuyuki; Kiso, Honoka; Tsukamoto, Hiroko; Huang, Boyen; Yanagita, Motoko; Sugai, Manabu; Harada, Hidemitsu; Komori, Toshihisa; Shimizu, Akira; MacDougall, Mary; Bessho, Kazuhisa

    2016-01-01

    Supernumerary teeth and tooth agenesis are common morphological anomalies in humans. We previously obtained evidence that supernumerary maxillary incisors form as a result of the successive development of the rudimentary maxillary incisor tooth germ in Usag-1 null mice. The development of tooth germs is arrested in Runx2 null mice, and such mice also exhibit lingual epithelial buds associated with the upper molars and incisors. The aim of this study is to investigate the potential crosstalk between Usag-1 and Runx2 during tooth development. In the present study, three interesting phenomena were observed in double null Usag-1-/-/Runx2-/- mice: the prevalence of supernumerary teeth was lower than in Usag-1 null mice; tooth development progressed further compared than in Runx2 null mice; and the frequency of molar lingual buds was lower than in Runx2 null mice. Therefore, we suggest that RUNX2 and USAG-1 act in an antagonistic manner. The lingual bud was completely filled with odontogenic epithelial Sox2-positive cells in the Usag-1+/+/Runx2-/- mice, whereas almost no odontogenic epithelial Sox2-positive cells contributed to supernumerary tooth formation in the rudimentary maxillary incisors of the Usag-1-/-/Runx2+/+ mice. Our findings suggest that RUNX2 directly or indirectly prevents the differentiation and/or proliferation of odontogenic epithelial Sox2-positive cells. We hypothesize that RUNX2 inhibits the bone morphogenetic protein (BMP) and/or Wnt signaling pathways regulated by USAG-1, whereas RUNX2 expression is induced by BMP signaling independently of USAG-1. PMID:27518316

  20. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review

    OpenAIRE

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry ha...

  1. Ulnar head replacement.

    Science.gov (United States)

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  2. Effect of curd suppression in a milk replacer on physiological ...

    African Journals Online (AJOL)

    ... to determine the effect of abomasal curd suppression on selected blood profiles. ... Fasting (0 h) plasma free essential amino acid (EAA) concentration tended to be ... Keywords: Blood profiles, calves, casein curd formation, milk replacers, ...

  3. Implant-supported single-tooth restorations: a 5-year prospective study.

    Science.gov (United States)

    Wennström, Jan L; Ekestubbe, Annika; Gröndahl, Kerstin; Karlsson, Stig; Lindhe, Jan

    2005-06-01

    Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements. To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations. Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech ST-implants)--40 in the maxilla and five in the mandible--were installed in a two-stage procedure. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression. Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to -0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was -0.14 mm (1.04) on subject level and -0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of > or =1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss. The present clinical trial on single-tooth replacements with the Astra Tech implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was

  4. Chondrichthyans from the Pennsylvanian (Desmoinesian) Naco Formation of central Arizona

    Science.gov (United States)

    Elliott, D.K.; Irmis, R.B.; Hansen, M.C.; Olson, T.J.

    2004-01-01

    Teeth, spines, and dermal denticles of chondrichthyans are reported from the Middle Pennsylvanian (Desmoinesian) Naco Formation of central Arizona. The most common elements are crushing teeth of the cochliodont Deltodus angularis, less common are teeth of D. sublaevis, Venustodus leidyi, Lagarodus angustus, "Cladodus" occidentalis, Petalodus ohioensis, Orodus sp., and Hybodontoidea. Fin spines of Acondylacanthus sp., Amelacanthus sp., and Physonemus sp., and the dermal denticle Petrodus patelliformis are also present. The material of Venustodus leidyi shows for the first time that this animal was heterodont, having arched anterior teeth with a v-shaped profile grading posteriorly into lower crescentic, and finally flattened teeth. Lagarodus angustus is shown to have at least three tooth morphotypes, and a new tooth arrangement is proposed in which small anterior teeth are replaced posteriorly by large crushing teeth arranged in whorls. This fauna is similar to others in New Mexico, Colorado, and Ohio and constitutes a western extension of such faunas in North America. In addition, the presence of Deltodus sublaevis and Lagarodus angustus documents a range extension from a known European distribution, reinforcing the cosmopolitan nature of chondrichthyan faunas at this time. ?? 2004 by the Society of Vertebrate Paleontology.

  5. Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

    LENUS (Irish Health Repository)

    Harding, M A

    2010-03-01

    To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.

  6. Stages and transitions in the development of tooth brushing skills in children of Mexican immigrant families: a qualitative study.

    Science.gov (United States)

    Benadof, Dafna; Polk, Deborah; Documet, Patricia

    2015-01-01

    Compared with white children, the oral health of Latino children in the United States is much worse. One factor contributing to oral health is tooth brushing. Few studies have addressed the formation of the tooth brushing habit in children, and only one of them studied a Latino population. The purpose of this study is to explore the development of the tooth brushing habit in children of Mexican immigrant families and develop hypothesis based on its results. This is an exploratory qualitative study, with a case study design based on 20 in-depth interviews. Participants were Mexican immigrant mothers living in Pittsburgh and Philadelphia, PA. Participants had at least one child six-years-old or younger. Interviews were recorded, transcribed verbatim, and analyzed using qualitative analysis procedures. Four stages were identified in the tooth brushing learning process: initiation and entirely dependent tooth brushing, assisted tooth brushing, road to tooth brushing independence, and independent tooth brushing. Two factors influenced parents' teaching approaches: parents' perceptions of their child's achievement of physical, cognitive, and motor developmental milestones and parents' knowledge about oral hygiene. We identified four distinct stages and found evidence to hypothesize that transitions from one stage to the next are triggered not by the age of the child but by parents' knowledge about oral hygiene and their perceptions of their child's achievement of physical, cognitive, and motor developmental milestones. Future quantitative research studies should be conducted to test this hypothesis in larger groups of Latinos as well as other ethnic groups. © 2015 American Association of Public Health Dentistry.

  7. Replacement of Missing Anterior Teeth in a Patient with Chronic Mouth Breathing and Tongue Thrusting

    Directory of Open Access Journals (Sweden)

    Satheesh B. Haralur

    2013-01-01

    Full Text Available The loss of anterior teeth has serious functional, esthetic disabilities, in addition to compromising the patients' quality of life. Various etiologies can be attributed to the anterior tooth loss, including trauma, caries, and periodontal diseases. The chronic mouth breathing due to nasal adenoids is known to enhance the gingival and periodontal diseases. The dental literature proves the association of nasal breathing, tongue thrusting, and anterior open bite. Arch shape and tooth position are primarily determined by the equilibrium of the forces from tongue and perioral musculature. Increased force from tongue musculature in the tongue thrusting patient leads to flaring of anterior teeth, making them susceptible for periodontal and traumatic tooth loss. Replacement of the anterior teeth in this patient will also help in restoration of anterior guidance, which is critical for the health of temporomandibular joint, posterior teeth, and musculature.

  8. Replacement of missing anterior teeth in a patient with chronic mouth breathing and tongue thrusting.

    Science.gov (United States)

    Haralur, Satheesh B; Al-Qahtani, Ali Saad

    2013-01-01

    The loss of anterior teeth has serious functional, esthetic disabilities, in addition to compromising the patients' quality of life. Various etiologies can be attributed to the anterior tooth loss, including trauma, caries, and periodontal diseases. The chronic mouth breathing due to nasal adenoids is known to enhance the gingival and periodontal diseases. The dental literature proves the association of nasal breathing, tongue thrusting, and anterior open bite. Arch shape and tooth position are primarily determined by the equilibrium of the forces from tongue and perioral musculature. Increased force from tongue musculature in the tongue thrusting patient leads to flaring of anterior teeth, making them susceptible for periodontal and traumatic tooth loss. Replacement of the anterior teeth in this patient will also help in restoration of anterior guidance, which is critical for the health of temporomandibular joint, posterior teeth, and musculature.

  9. [A new method for combined auto-alloplastic tooth reimplantation with a parallel A1203-ceramic root].

    Science.gov (United States)

    Kirschner, H; Bolz, U; Enomoto, S; Hüttemann, R W; Meinel, W; Sturm, J

    1978-09-01

    The operative procedure for partially replacing the root with A12O3 ceramic represents a good possibility for preserving teeth in which the pulpa is devitalized. The method used in connection with the well known autoplastic reimplantation not only presents an alternative to the traditional apicoectomy but also provides additional stabilization of the tooth by lengthing the root with cocotostabile and biocompatible A1203 ceramic. The method was tested in humans and monkeys. Argumentation was based on histological examination via light microscopy.

  10. Prevention of dental anomalies in children by prosthetics defects hard tooth tissues and dentitions: the need to possibilities

    OpenAIRE

    Suetenkov D.Ye.; Pudovkina Е.А.; Venatovskaya N.V.; Proshin A.G.

    2011-01-01

    This article presents the possibility of restore the function and anatomy of the tooth and replacement of defects of dentition by prosthesis in children under the removable bite as a method of prevention of dentoalveolar anomalies. Identified the need for prosthetic treatment of children and the willingness of dentists as primary health care professional to address the problems identified. A clinical analysis of complex treatment of defects in the teeth with fixed restorations

  11. Prevention of dental anomalies in children by prosthetics defects hard tooth tissues and dentitions: the need to possibilities

    Directory of Open Access Journals (Sweden)

    Suetenkov D.Ye.

    2011-03-01

    Full Text Available This article presents the possibility of restore the function and anatomy of the tooth and replacement of defects of dentition by prosthesis in children under the removable bite as a method of prevention of dentoalveolar anomalies. Identified the need for prosthetic treatment of children and the willingness of dentists as primary health care professional to address the problems identified. A clinical analysis of complex treatment of defects in the teeth with fixed restorations

  12. A TOOTH TATTOO WITH A PURPOSE: AN INNOVATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Neetu

    2014-01-01

    Full Text Available Skin is not the only place that can be decorated with a tattoo. You can decorate your tooth with amazing tattoos. Tooth tattoos and tooth jewels have become one of the hottest fashion trends , and a very popular arrival in cosmetic dentistry. But won’t it be a boon if it had some preventive or medicinal v alue. Yes tooth tattoos can act as indicators of once illness. These tiny electronic sensors can diagnose illnesses by 'tasting' your breath. This paper is an insight into how a tooth tattoos can pick up early warning signs of sickness or infection by bact eria in people's breath.

  13. Tooth regeneration: challenges and opportunities for biomedical material research.

    Science.gov (United States)

    Du, Chang; Moradian-Oldak, Janet

    2006-03-01

    Tooth regeneration presents many challenges to researchers in the fields of biology, medicine and material science. This review considers the opportunities for biomedical material research to contribute to this multidisciplinary endeavor. We present short summaries and an overview on the collective knowledge of tooth developmental biology, advances in stem-cell research, and progress in the understanding of the tooth biomineralization principles as they provide the foundation for developing strategies for reparative and regenerative medicine. We emphasize that various biomaterials developed via biomimetic strategies have great potential for tooth tissue engineering and regeneration applications. The current practices in tooth tissue engineering approaches and applications of biomimetic carriers or scaffolds are also discussed.

  14. 华南地区栖霞组菊花状天青石的交代 及其地质意义%Replacement of Chrysanthemum_Shaped Celestite in the Chihsia Formation of South China and Its Geological Implications

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    本文在收集大量菊花石标本的基础上,通过岩石薄片镜下鉴定及X射线衍射分析,识别了华南地区栖霞组菊花石假象内矿物的成因类型,建立了矿物交代序列,并通过对菊花石假象内各种矿物成分的电子探针分析和对交代方解石、脉方解石及其围岩的氧、碳同位素分析,探讨了菊花石交代过程中的成岩环境变化,合理地解释了菊花石内正延性玉髓和栖霞组内海泡石的成因。%Chrysanthemum_shaped celestite is a diagenetic nodule widelydistributed in the Permian Chihsia Formation of South China. As precipitated in the very early diagenesis and replaced by subsequent diagenesis, most of the celestite nodules are pseudomorphs dominantly composed of calcite, chalcedony and minor dolomite. This paper deals with the establishment of a replacement succession in the pseudomorph and the evolution of related diagenetic environments. The replacement initiated in very early diagenesis by fine cloudy calcite, followed by length_slow chalcedony and fine granular calcite. The last two components originated respectively from an episode of chalcedony veining and a calcite veining. Celestite was also noted replaced directly by chalcedony. These replacements took place in fluids rich in silica and Mg2+, revealed by microprobe analyses on the replacement calcite and the occurrence of length_slow chalcedony. Chert nodules and sepiolite in the host rock were contemporary. Late replacements include euhedral calcite crystals in the chalcedony and coarse granular calcite that stemmed from an episode of calcite veining, resulting from diagenetic fluids with relative low Mg2+/Ca2+ ratio.

  15. 'Split posterior tooth': conservative clinical re-attachment.

    Science.gov (United States)

    Abraham, Sathish; Chacko, Lisa Neelathil

    2014-07-30

    Trauma is the prime causative factor for fracture of teeth/dentition. Many procedural management options are followed successfully in relation to the anterior teeth. However, most posterior cases where the tooth is fractured have only limited options to pursue to save the tooth. Fractured teeth, whether they are vital/non-vital, are predominantly managed with surgical options. This paper discusses a conservative approach to reattaching a split posterior tooth. A split tooth situation is mostly an absolute indication for extraction, but the clinician may go in for extensive surgical procedures if he/she wishes to save it. The reattachment of the tooth can be successfully done and it can be put to function. This paper discusses how a split posterior tooth can be treated successfully, although depending on multiple factors. A full crown cemented after successful reattachment and root canal therapy would provide sufficient support in order for the tooth to heal.

  16. Multilobed mesiodens: a supernumerary tooth with unusual morphology.

    Science.gov (United States)

    Dave, Bhavna; Patel, Jalark; Swadas, Milan; Mallikarjuna, Rachappa

    2013-02-06

    An 8-year-old boy came with a chief complaint of an abnormally shaped tooth situated in upper front teeth region. On examination a supernumerary tooth with multiple lobes was present palatally to the maxillary right permanent central incisor. The morphology of the tooth crown was found to be unusual due to the presence of five lobes in the crown portion. Because of the supernumerary tooth, the permanent right central incisor was displaced labially. Radiographic examination showed a completely formed supernumerary tooth with dilacerated root. On the basis of clinical and radiographic examination, the supernumerary tooth was diagnosed as multilobed mesiodens. Since patient expressed dissatisfaction with the presence of supernumerary tooth, it was decided to extract this mesiodens followed by orthodontic treatment for alignment of labially placed maxillary right permanent central incisor.

  17. 基于替换有格式文本空间特征信息的隐藏策略%Replaced with Formatted Text Based on Spatial Characteristics of Information Hiding Strategy

    Institute of Scientific and Technical Information of China (English)

    张鑫

    2011-01-01

    In this paper, a small change in the text line spacing and word spacing, spatial characteristics, we propose a use of space characteristics of the replacement text and extract hidden information embedded in the strategy.%利用少量转变文本的行间距与字间距等空间特征,提出了一种利用替换文本空间特征进行隐藏信息嵌入和提取的策略.

  18. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European...... countries. METHODS: A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early...

  19. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  20. Orthodontic retraction of autotransplanted premolar to replace ankylosed maxillary incisor with replacement resorption.

    Science.gov (United States)

    Choi, Yoon Jeong; Shin, Sujung; Kim, Kyung-Ho; Chung, Chooryung J

    2014-04-01

    This case report describes the successful treatment of an adult with lip protrusion and a previously traumatized maxillary central incisor that had experienced replacement root resorption. An extracted premolar was transplanted into the incisor space and retracted orthodontically. Autotransplantation was successful with complete root formation and, combined with orthodontic treatment, provided a satisfying esthetic outcome.

  1. The pure relationship and below replacement fertility

    Directory of Open Access Journals (Sweden)

    David R. Hall

    2003-12-01

    interest from demographers. Despite the fact that researchers have extensively modeled recent demographic changes such as skyrocketing divorce rates, rising common-law union formation, delayed childbearing, and the decline to belowreplacement fertility levels, our understanding of the causes of these trends, and the possible connections between them remains theoretically fragmented and incomplete. The goal of this paper is to advance our understanding in this area by exploring the insights on modern family formation of prominent sociologist Anthony Giddens. Specifically, this study examines whether Giddens’ “pure relationship” concept can shed light on the trend toward very low fertility. The results of this inquiry suggest that couples in both marriages and common-law unions who conform to key aspects of Giddens pure relationship are more likely to have uncertain or below-replacement fertility intentions, and less likely to embrace above-replacement fertility goals.

  2. The Optimum Replacement of Weapon

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao; ZHANG Jin-chun

    2002-01-01

    The theory of LCC (Life Cycle Cost) is applied in this paper. The relation between the economic life of weapon and the optimum replacement is analyzed. The method to define the optimum replacement time of weapon is discussed.

  3. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self‐funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty‐three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  4. Total disc replacement.

    Science.gov (United States)

    Vital, J-M; Boissière, L

    2014-02-01

    Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University's aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  6. Faster Replacement Paths

    CERN Document Server

    Williams, Virginia Vassilevska

    2010-01-01

    The replacement paths problem for directed graphs is to find for given nodes s and t and every edge e on the shortest path between them, the shortest path between s and t which avoids e. For unweighted directed graphs on n vertices, the best known algorithm runtime was \\tilde{O}(n^{2.5}) by Roditty and Zwick. For graphs with integer weights in {-M,...,M}, Weimann and Yuster recently showed that one can use fast matrix multiplication and solve the problem in O(Mn^{2.584}) time, a runtime which would be O(Mn^{2.33}) if the exponent \\omega of matrix multiplication is 2. We improve both of these algorithms. Our new algorithm also relies on fast matrix multiplication and runs in O(M n^{\\omega} polylog(n)) time if \\omega>2 and O(n^{2+\\eps}) for any \\eps>0 if \\omega=2. Our result shows that, at least for small integer weights, the replacement paths problem in directed graphs may be easier than the related all pairs shortest paths problem in directed graphs, as the current best runtime for the latter is \\Omega(n^{2.5...

  7. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  8. Seasonal variation in kangaroo tooth enamel oxygen and carbon isotopes in southern Australia

    Science.gov (United States)

    Brookman, Tom H.; Ambrose, Stanley H.

    2012-09-01

    Serial sampling of tooth enamel growth increments for carbon and oxygen isotopic analyses of Macropus (kangaroo) teeth was performed to assess the potential for reconstructing paleoseasonality. The carbon isotope composition of tooth enamel apatite carbonate reflects the proportional intake of C3 and C4 vegetation. The oxygen isotopic composition of enamel reflects that of ingested and metabolic water. Tooth enamel forms sequentially from the tip of the crown to the base, so dietary and environmental changes during the tooth's formation can be detected. δ13C and δ18O values were determined for a series of enamel samples drilled from the 3rd and 4th molars of kangaroos that were collected along a 900 km north-south transect in southern Australia. The serial sampling method did not yield pronounced seasonal isotopic variation patterns in Macropus enamel. The full extent of dietary isotopic variation may be obscured by attenuation of the isotopic signal during enamel mineralisation. Brachydont (low-crowned) Macropus teeth may be less sensitive to seasonal variation in isotopic composition due to time-averaging during mineralisation. However, geographic variations observed suggest that there may be potential for tracking latitudinal shifts in vegetation zones and seasonal environmental patterns in response to climate change.

  9. Mineralogical correlation between primary and replacement dolomites

    Institute of Scientific and Technical Information of China (English)

    黄志诚; 杨守业; 陈智娜

    1997-01-01

    Primary dolostones occur in the Upper Sinian Dengying Formation. Based on mineralogieal study the indicators for correlation between the primary dolomites which are not influenced by the diagenesis and the replacement dolomites of different periods have been obtained. It is shown that the primary dolomites are characterized by crystal forms precipitated and deposited directly from sea water, stable and homogeneous distribution of Mg and Ca, ideal chemical composition, regular modulated microstructures, low positive δ13C and low negative δ18O.

  10. New method of control of tooth whitening

    Science.gov (United States)

    Angelov, I.; Mantareva, V.; Gisbrecht, A.; Valkanov, S.; Uzunov, Tz.

    2010-10-01

    New methods of control of tooth bleaching stages through simultaneous measurements of a reflected light and a fluorescence signal are proposed. It is shown that the bleaching process leads to significant changes in the intensity of a scattered signal and also in the shape and intensity of the fluorescence spectra. Experimental data illustrate that the bleaching process causes essential changes in the teeth discoloration in short time as 8-10 min from the beginning of the application procedure. The continuation of the treatment is not necessary moreover the probability of the enamel destroy increases considerably. The proposed optical back control of tooth surface is a base for development of a practical set up to control the duration of the bleaching procedure.

  11. Distribution of amelotin in mouse tooth development.

    Science.gov (United States)

    Gao, Yuguang; Wang, Wanchun; Sun, Yan; Zhang, Juanjuan; Li, Dongliang; Wei, Yahong; Han, Tingting

    2010-01-01

    Amelotin is expressed and secreted by ameloblasts in tooth development, but amelotin distribution during enamel development is not clear. In this report, we first investigated amelotin expression in developing teeth by immunohistochemistry. Amelotin was detected in the enamel matrix at the secretion and maturation stages of enamel development. Amelotin was also observed at Tomes' processes on the apical ends of secretory ameloblasts. We then compared amelotin gene expression with those of amelogenin, enamelin, and ameloblastin in the mandibles of postnatal mice by RT-PCR. The expression of amelotin was detected as early as in postnatal day 0 mandibles and amelotin was coexpressed with amelogenin, ameloblastin, and enamelin during tooth development. These data strongly suggest that amelotin is an enamel matrix protein expressed at the secretion and maturation stages of enamel development. (c) 2009 Wiley-Liss, Inc.

  12. Two stage gear tooth dynamics program

    Science.gov (United States)

    Boyd, Linda S.

    1989-01-01

    The epicyclic gear dynamics program was expanded to add the option of evaluating the tooth pair dynamics for two epicyclic gear stages with peripheral components. This was a practical extension to the program as multiple gear stages are often used for speed reduction, space, weight, and/or auxiliary units. The option was developed for either stage to be a basic planetary, star, single external-external mesh, or single external-internal mesh. The two stage system allows for modeling of the peripherals with an input mass and shaft, an output mass and shaft, and a connecting shaft. Execution of the initial test case indicated an instability in the solution with the tooth paid loads growing to excessive magnitudes. A procedure to trace the instability is recommended as well as a method of reducing the program's computation time by reducing the number of boundary condition iterations.

  13. Tooth in Ethmoid Sinus: A Case Report

    Directory of Open Access Journals (Sweden)

    Tayebe Kazemei

    2009-09-01

    Full Text Available Ectopic eruption of teeth occurs in a variety of locations.Commonly seen in palate and maxillary sinus, they have alsobeen reported in nasal cavity, orbit, mandibular condyle,coronoid process, and facial skin.Here, we report a rare case of recurrent sinusitis caused byectopic tooth in right ethmoid sinus and successful endoscopicremoval of it. The symptoms of the patient disappeared aftersurgery. Such case has not been yet reported in the Englishliterature.Ectopic tooth is an uncommon cause of sinusitis. It shouldbe considered in patients presenting with recurrent sinusitis unresponsiveto medical treatment. Computed tomography of thesinuses is the modality of choice for diagnosis. Endoscopic sinussurgery is the best method for management of such cases.

  14. Expression of Sox genes in tooth development.

    Science.gov (United States)

    Kawasaki, Katsushige; Kawasaki, Maiko; Watanabe, Momoko; Idrus, Erik; Nagai, Takahiro; Oommen, Shelly; Maeda, Takeyasu; Hagiwara, Nobuko; Que, Jianwen; Sharpe, Paul T; Ohazama, Atsushi

    2015-01-01

    Members of the Sox gene family play roles in many biological processes including organogenesis. We carried out comparative in situ hybridization analysis of seventeen sox genes (Sox1-14, 17, 18, 21) during murine odontogenesis from the epithelial thickening to the cytodifferentiation stages. Localized expression of five Sox genes (Sox6, 9, 13, 14 and 21) was observed in tooth bud epithelium. Sox13 showed restricted expression in the primary enamel knots. At the early bell stage, three Sox genes (Sox8, 11, 17 and 21) were expressed in pre-ameloblasts, whereas two others (Sox5 and 18) showed expression in odontoblasts. Sox genes thus showed a dynamic spatio-temporal expression during tooth development.

  15. Interdisciplinary management of single-tooth implants.

    Science.gov (United States)

    Spear, F M; Mathews, D M; Kokich, V G

    1997-03-01

    Orthodontists treat many patients who are missing maxillary lateral incisors and/or mandibular second premolars. In the past, if the canines could not be substituted for lateral incisors, conventional full-coverage bridges were the common restoration. Recently, resin-bonded Maryland bridges became a popular substitute for conventional bridges to avoid crowns on the nonrestored abutments. However, resin-bonded bridges have a poor long-term prognosis for retention, lasting on average about 10 years. Since implants were introduced into dentistry by Swedish researchers in the mid-1980s, they have become a promising substitute for conventional or resin-bonded bridges. However, to successfully place and restore single-tooth implants in young orthodontic patients several questions must be answered. This article will discuss the many interdisciplinary issues that are involved in placing and restoring single-tooth implants in orthodontic patients.

  16. Esthetics and vertical tooth position: orthodontic possibilities.

    Science.gov (United States)

    Kokich, V G

    1997-12-01

    Throughout the 1990s, esthetic dentistry has become a prominent part of the treatment protocol of most dentists. Patients have become more conscious of the benefits of a beautiful smile and are willing to invest time and money to improve the appearance of their teeth. Many of these patients can be treated with routine restorative procedures (crowns, composites, laminates) to achieve the desired results. However, some patients have problems with tooth position that create significant discrepancies in gingival levels which can compromise the esthetic result of restorative dentistry. Prerestorative orthodontic therapy can often resolve these tooth position problems and enhance the esthetic restoration. This article describes the indication, methods, and results achieved when orthodontics preceded restorative dentistry in the treatment of various esthetic challenges.

  17. Non-surgical management of tooth hypersensitivity.

    Science.gov (United States)

    Clark, Danielle; Levin, Liran

    2016-10-01

    Tooth sensitivity is a common complaint of patients in dental practices. Studies have demonstrated dentinal hypersensitivity to affect 10-30% of the population. There are various potential causes of tooth sensitivity and a variety of available treatment options. This narrative review will discuss the possible aetiology of this condition, as well as the treatment modalities available. A tailor-made treatment plan that starts with the most non-invasive treatment options and escalates only when those options have proven insufficient in alleviating symptoms should be provided for each patient. Only after all non- and less-invasive methods have failed to reduce the symptoms should more invasive treatment options, such as root-coverage, be considered.

  18. Expression of Sox genes in tooth development

    Science.gov (United States)

    KAWASAKI, KATSUSHIGE; KAWASAKI, MAIKO; WATANABE, MOMOKO; IDRUS, ERIK; NAGAI, TAKAHIRO; OOMMEN, SHELLY; MAEDA, TAKEYASU; HAGIWARA, NOBUKO; QUE, JIANWEN; SHARPE, PAUL T.; OHAZAMA, ATSUSHI

    2017-01-01

    Members of the Sox gene family play roles in many biological processes including organogenesis. We carried out comparative in situ hybridization analysis of seventeen sox genes (Sox1-14, 17, 18, 21) during murine odontogenesis from the epithelial thickening to the cytodifferentiation stages. Localized expression of five Sox genes (Sox6, 9, 13, 14 and 21) was observed in tooth bud epithelium. Sox13 showed restricted expression in the primary enamel knots. At the early bell stage, three Sox genes (Sox8, 11, 17 and 21) were expressed in pre-ameloblasts, whereas two others (Sox5 and 18) showed expression in odontoblasts. Sox genes thus showed a dynamic spatio-temporal expression during tooth development. PMID:26864488

  19. The pure relationship and below replacement fertility

    Directory of Open Access Journals (Sweden)

    Hall, David R.

    2003-01-01

    Full Text Available Of the many changes which have characterized the second demographic transition, shifts in fertility and union formation have attracted a great deal of interest from demographers. Despite the fact that researchers have extensively modeled recent demographic changes such as skyrocketing divorce rates, rising common-law union formation, delayed childbearing, and the decline to below-replacement fertility levels, our understanding of the causes of these trends, and the possible connections between them remains theoretically fragmented and incomplete. The goal of this paper is to advance our understanding in this area by exploring the insights on modern family formation of prominent sociologist Anthony Giddens. Specifically, this study examines whether Giddens' "pure relationship" concept can shed light on the trend toward very low fertility. The results of this inquiry suggest that couples in both marriages and common-law unions who conform to key aspects of Giddens pure relationship are morel likely to have uncertain or below-replacement fertility intentions, and less likely to embrace above-replacement fertility goals.

  20. Frictional Effects on Gear Tooth Contact Analysis

    OpenAIRE

    Zheng Li; Ken Mao

    2013-01-01

    The present paper concentrates on the investigations regarding the situations of frictional shear stress of gear teeth and the relevant frictional effects on bending stresses and transmission error in gear meshing. Sliding friction is one of the major reasons causing gear failure and vibration; the adequate consideration of frictional effects is essential for understanding gear contact behavior accurately. An analysis of tooth frictional effect on gear performance in spur gear is presented us...

  1. Bivalent histone modifications during tooth development

    Institute of Scientific and Technical Information of China (English)

    Li-Wei Zheng; Bin-Peng Zhang; Ruo-Shi Xu; Xin Xu; Ling Ye; Xue-Dong Zhou

    2014-01-01

    Histone methylation is one of the most widely studied post-transcriptional modifications. It is thought to be an important epigenetic event that is closely associated with cell fate determination and differentiation. To explore the spatiotemporal expression of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) epigenetic marks and methylation or demethylation transferases in tooth organ development, we measured the expression of SET7, EZH2, KDM5B and JMJD3 via immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis in the first molar of BALB/c mice embryos at E13.5, E15.5, E17.5, P0 and P3, respectively. We also measured the expression of H3K4me3 and H3K27me3 with immunofluorescence staining. During murine tooth germ development, methylation or demethylation transferases were expressed in a spatial–temporal manner. The bivalent modification characterized by H3K4me3 and H3K27me3 can be found during the tooth germ development, as shown by immunofluorescence. The expression of SET7, EZH2 as methylation transferases and KDM5B and JMJD3 as demethylation transferases indicated accordingly with the expression of H3K4me3 and H3K27me3 respectively to some extent. The bivalent histone may play a critical role in tooth organ development via the regulation of cell differentiation.

  2. Expression of HMGB1 during tooth development.

    Science.gov (United States)

    Sugars, R; Karlström, E; Christersson, C; Olsson, M-L; Wendel, M; Fried, K

    2007-03-01

    High mobility group box 1 (HMGB1) is a nuclear and cytosolic protein that can act as a transcription factor, a growth factor, or a cytokine. To elucidate a possible role for HMGB1 in tooth development, we have studied the expression of HMGB1 and its receptor RAGE (receptor for advanced glycation end-products) during the late fetal and early postnatal period of rat by using light- and electron-microscopic immunohistochemistry. Low HMGB1 protein expression was observed during fetal and newborn stages of tooth development. However, from postnatal day 5 (P5) onward, a marked increase occurred in the levels of the protein in most dental cell types. Expression was particularly high in ameloblasts and odontoblasts at regions of ongoing mineralization. Although most HMGB1 immunoreactivity was confined to cell nuclei, it was also present in odontoblast cytoplasm. At P5, ameloblasts and odontoblasts also showed RAGE immunoreactivity, and reverse transcription-polymerase chain reaction demonstrated both HMGB1 and RAGE mRNA in human dental pulp cells in vitro. Immunoblots performed on extracts from bovine dentin demonstrated a principal band at approximately 27 kDa, indicating that HMGB1 participates in tooth mineralization. The expression of both ligand and receptor suggests an autocrine/paracrine HMGB1 signalling axis in odontoblasts.

  3. Iatrogenic traumatic brain injury during tooth extraction.

    Science.gov (United States)

    Troxel, Mark

    2015-01-01

    An 8 yr old spayed female Yorkshire terrier was referred for evaluation of progressive neurological signs after a routine dental prophylaxis with tooth extractions. The patient was circling to the left and blind in the right eye with right hemiparesis. Neurolocalization was to the left forebrain. MRI revealed a linear tract extending from the caudal oropharynx, through the left retrobulbar space and frontal lobe, into the left parietal lobe. A small skull fracture was identified in the frontal bone through which the linear tract passed. Those findings were consistent with iatrogenic trauma from slippage of a dental elevator during extraction of tooth 210. The dog was treated empirically with clindamycin. The patient regained most of its normal neurological function within the first 4 mo after the initial injury. Although still not normal, the dog has a good quality of life. Traumatic brain injury is a rarely reported complication of extraction. Care must be taken while performing dental cleaning and tooth extraction, especially of the maxillary premolar and molar teeth to avoid iatrogenic damage to surrounding structures.

  4. Influence of musical instruments on tooth positions.

    Science.gov (United States)

    Herman, E

    1981-08-01

    A 2-year longitudinal investigation was conducted at five New York City junior high schools on 11- to 13-year-old children starting instrumental music education to determine what tooth movement, if any, resulted from the playing of certain musical instruments. Questionnaires, interviews, oral examinations, and dental casts were used at the start of instrumental study, after one year, and then after a second year. Statistically significant anterior tooth movements occurred in an overwhelming majority of the instrumentalists, while negligible movements were recorded for the controls over this period. As a result of this study, certain recommendations can be made by dentists when they are asked to suggest instruments which are dentally suited for children. In most cases they can suggest more than one instrument which would be of benefit dentally to the individual child, especially in the increase or reduction of overjet and overbite. The playing of the correct musical instrument can serve as an adjunct to the dentist or orthodontist in trying to accomplish certain tooth movements.

  5. Tooth reattachment: An immediate esthetic restorative procedure for crown root fracture

    Directory of Open Access Journals (Sweden)

    Meenu G Singla

    2012-01-01

    Full Text Available Crown root fractures in the maxillary anterior region represent an intriguing challenge for clinicians. An interdisciplinary approach based on exposing fractured margins and the definitive prosthetic rehabilitation represent the standard modality of treatment for these conditions to restore the appropriate biologic dimension and esthetics. However, if the margins of the fragment and the tooth show perfect juxtaposition with no interfragmentary space and immediate esthetic replacement is needed, reattachment of the fractured segment using adhesives may be indicated. The aim of this case report is to describe the treatment of a crown root fracture at CEJ of an endodontically treated tooth having porcelain fused to metal crown by means of metal post placement and reattactment of the fragment using Glass ionomer cement with follow up of one year. Conclusion: Reattachment of a tooth fragment is a viable technique that restores function and aesthetics with a very conservative approach in a single visit and can be considered when treating patients with crown/root fractures of the anterior teeth.

  6. Octacalcium phosphate (OCP) collagen composites enhance bone healing in a dog tooth extraction socket model.

    Science.gov (United States)

    Iibuchi, S; Matsui, K; Kawai, T; Sasaki, K; Suzuki, O; Kamakura, S; Echigo, S

    2010-02-01

    The authors have reported that a scaffold constructed of synthetic octacalcium phosphate (OCP) and porcine atelocollagen sponge (OCP/Col) enhanced bone regeneration more than sintered beta-tricalcium phosphate collagen composite or sintered hydroxyapatite collagen composite with a rat calvarial defect model. To aim for clinical application, the present study investigated whether OCP/Col would enhance bone healing in a dog tooth extraction socket model. Six adult, male, beagle dogs were used. The tooth extraction socket model was made by extracting bilateral third maxillary incisors and the subsequent removal of buccal bone. Disks of OCP/Col were implanted into one side of the model and the other side was untreated. The specimens were fixed 1 or 3 months after implantation. In radiographic analysis, the OCP/Col-treated group showed a wider range of radiopacity than the untreated control. Histologically, the OCP/Col-treated group showed more abundant newly formed bone than untreated control, and the implanted OCP was gradually resorbed. In morphometrical analysis, enlargement of the buccal alveolus in the OCP/Col group was significantly greater than in the untreated control. This study showed that implanted OCP/Col would be replaced by newly formed bone and OCP/Col implantation would enhance bone healing in a tooth socket model.

  7. ESR dosimetry using eggshells and tooth enamel for accidental dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Toshihide; Yamanaka, Chihiro; Ikeya, Motoji [Department of Earth and Space Science, Faculty of Science, Osaka Univ., Toyonaka, Osaka (Japan)

    1997-07-01

    The CO{sub 2}{sup -} signal of eggshells showed a good dose linearity and was appropriate in the wide dose range from 1 to 10 kGy, while ESR signal of CO{sub 2}{sup -} in sea and fresh water shells were saturated at a dose od below 10 kGy. The minimum detectable dose and G-value of CO{sub 2}{sup -} in eggshells were estimated 0.3 Gy and 0.28, respectively. The lifetime of CO{sub 2}{sup -} in eggshells could not be determined exactly because of overlapping organic signals, however it is still sufficiently long for practical use as ESR dosimeter materials. Various bird`s or reptile`s eggshells would be available as natural retrospective ESR dosimeter materials after nuclear accidents. Eggshells will be useful for the food irradiation dosimetry in the dose range of about a few kGy. Tooth enamel is one of the most useful dosimeter materials in public at a accident because of its high sensitivity. ESR dosimetry will replace TLD in near future if the cost of an ESR reader is further reduced . (author)

  8. Toleration, Synthesis or Replacement?

    DEFF Research Database (Denmark)

    Holtermann, Jakob v. H.; Madsen, Mikael Rask

    2016-01-01

    to have considerable problems keeping a clear focus on the key question: What are the implications of this empirical turn in terms of philosophy of legal science, of the social understanding of IL, and, not least, of the place of doctrinal scholarship after the alleged Wende? What is needed, we argue......, in order to answer is not yet another partisan suggestion, but rather an attempt at making intelligible both the oppositions and the possibilities of synthesis between normative and empirical approaches to law. Based on our assessment and rational reconstruction of current arguments and positions, we...... therefore outline a taxonomy consisting of the following three basic, ideal-types in terms of the epistemological understanding of the interface of law and empirical studies: toleration, synthesis and replacement. This tripartite model proves useful with a view to teasing out and better articulating...

  9. 2H Stable Isotope Analysis of Tooth Enamel: A Pilot Study

    Science.gov (United States)

    Holobinko, Anastasia; Kemp, Helen; Meier-Augenstein, Wolfram; Prowse, Tracy; Ford, Susan

    2010-05-01

    Stable isotope analysis of biogenic tissues such as tooth enamel and bone mineral has become a well recognized and increasingly important method for determining provenance of human remains, and has been used successfully in bioarchaeological studies as well as forensic investigations (Lee-Thorp, 2008; Meier-Augenstein and Fraser, 2008). Particularly, 18O and 2H stable isotopes are well established proxies as environmental indicators of climate (temperature) and source water and are therefore considered as indicators of geographic life trajectories of animals and humans (Hobson et al., 2004; Schwarcz and Walker, 2006). While methodology for 2H analysis of human hair, fingernails, and bone collagen is currently used to determine geographic origin and identify possible migration patterns, studies involving the analysis of 2H in tooth enamel appear to be nonexistent in the scientific literature. The apparent lack of research in this area is believed to have two main reasons. (1) Compared to the mineral calcium hydroxylapatite Ca10(PO4)6(OH)2, in tooth enamel forming bio-apatite carbonate ions replace some of the hydroxyl ions at a rate of one CO32 replacing two OH, yet published figures for the degree of substitution vary (Wopenka and Pasteris, 2005). (2) Most probably due to the aforementioned no published protocols exist for sample preparation and analytical method to obtain δ2H-values from the hydroxyl fraction of tooth enamel. This dilemma has been addressed through a pilot study to establish feasibility of 2H stable isotope analysis of ground tooth enamel by continuous-flow isotope ratio mass spectrometry (IRMS) coupled on-line to a high-temperature conversion elemental analyzer (TC/EA). An array of archaeological and modern teeth has been analyzed under different experimental conditions, and results from this pilot study are being presented. References: Lee-Thorp, J.A. (2008) Archaeometry, 50, 925-950 Meier-Augenstein, W. and Fraser, I. (2008) Science & Justice

  10. [Study on the appropriate parameters of automatic full crown tooth preparation for dental tooth preparation robot].

    Science.gov (United States)

    Yuan, F S; Wang, Y; Zhang, Y P; Sun, Y C; Wang, D X; Lyu, P J

    2017-05-09

    Objective: To further study the most suitable parameters for automatic full crown preparation using oral clinical micro robot. Its purpose is to improve the quality of automated tooth preparing for the system and to lay the foundation for clinical application. Methods: Twenty selected artificial resin teeth were used as sample teeth. The micro robot automatic tooth preparation system was used in dental clinic to control the picosecond laser beam to complete two dimensional cutting on the resin tooth sample according to the motion planning path. Using the laser scanning measuring microscope, each layer of cutting depth values was obtained and the average value was calculated. The monolayer cutting depth was determined. The three-dimensional (3D) data of the target resin teeth was obtained using internal scanner, and the CAD data of full-crown tooth preparation was designed by CAD self-develged software. According to the depth of the single layer, 11 complete resin teeth in phantom head were automatically prepared by the robot controlling the laser focused spot in accordance with the layer-cutting way. And the accuracy of resin tooth preparation was evaluated with the software. Using the same method, monolayer cutting depth parameter for cutting dental hard tissue was obtained. Then 15 extracted mandibular and maxillary first molars went through automatic full crown tooth preparation. And the 3D data of tooth preparations were obtained with intra oral scanner. The software was used to evaluate the accuracy of tooth preparation. Results: The results indicated that the single cutting depth of cutting resin teeth and in vitro teeth by picosecond laser were (60.0±2.6) and (45.0±3.6) μm, respectively. Using the tooth preparation robot, 11 artificial resin teeth and 15 complete natural teeth were automatically prepared, and the average time were (13.0±0.7), (17.0±1.8) min respectively. Through software evaluation, the average preparation depth of the occlusal surface

  11. Influence of tooth profile modification on spur gear dynamic tooth strain

    Science.gov (United States)

    Oswald, Fred B.; Townsend, Dennis P.

    1995-06-01

    This paper presents results of dynamic strain gage measurements performed on the NASA gear-noise rig. The experiments were part of a joint research program between NASA and the U.S. Army Research Laboratory to advance the technology of rotorcraft transmissions. Tests were performed on six sets of low contact ratio spur gears with different tooth profile modifications. Results presented include static and dynamic measurements of gear tooth strain taken over a matrix of operating conditions. The results demonstrate that a well-designed tooth profile modification can significantly reduce dynamic loads in spur gears, especially for gears which operate at high speed and under high torque. The two parabolic modifications tested were not as effective as linear modifications, possibly because the modification zone was too long.

  12. Requirement of Smad4-mediated signaling in odontoblast differentiation and dentin matrix formation

    Science.gov (United States)

    Yun, Chi-Young; Choi, Hwajung; You, Young-Jae; Yang, Jin-Young

    2016-01-01

    Dentin is the major part of tooth and formed by odontoblasts. Under the influence of the inner enamel epithelium, odontoblasts differentiate from ectomesenchymal cells of the dental papilla and secrete pre-dentin which then undergo mineralization into dentin. Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP) signaling is essential for dentinogenesis; however, the precise molecular mechanisms remain unclear. To understand the role of TGF-β/BMP signaling in odontoblast differentiation and dentin formation, we generated mice with conditional ablation of Smad4, a key intracellular mediator of TGF-β/BMP signaling, using Osr2 or OC-Cre mice. Here we found the molars of Osr2CreSmad4 mutant mice exhibited impaired odontoblast differentiation, and normal dentin was replaced by ectopic bone-like structure. In Osr2CreSmad4 mutant mice, cell polarity of odontoblast was lost, and the thickness of crown dentin was decreased in later stage compared to wild type. Moreover, the root dentin was also impaired and showed ectopic bone-like structure similar to Osr2CreSmad4 mutant mice. Taken together, our results suggest that Smad4-dependent TGF-β/BMP signaling plays a critical role in odontoblast differentiation and dentin formation during tooth development. PMID:27722013

  13. Role of stretch therapy in comprehensive physical habilitation of patients with Charcot–Marie–Tooth hereditary neuropathy

    Directory of Open Access Journals (Sweden)

    N. A. Shnayder

    2015-01-01

    Full Text Available Charcot–Marie–Tooth hereditary neuropathy (Charcot–Marie–Tooth disease, CMT is the most common form of hereditary neuropathies, accompanied by sensory disorders, progressive muscle weakness with the formation of disabling contractures of the limbs. Currently, the main treatment program is effective CMT habilitation, which can prevent the development of limb deformities and thereby improve the life quality of the patient. Stretch therapy is one of the most effective methods of prevention and treatment of contractures in patients with CMT. This article provides a brief review of the literature regarding the use of stretching as physical therapy program of CMT habilitation.

  14. Maturogenesis of an Early Erupted Immature Permanent Tooth: A Case Report With 7-Year Follow-Up.

    Science.gov (United States)

    Atabek, D; Sillelioğlu, H; Çinar, Ç; Ölmez, A

    2015-01-01

    The main objective of treatment of an undeveloped tooth (immature) is to provide vital pulp therapy to allow continued development of root dentin. A case report is presented that demonstrates the use of calcium hydroxide (CaOH₂) as an indirect pulp-copping material for the purpose of continued maturogenesis of an early-erupted permanent tooth with severe mobility and almost-begun root formation. Seven-year radiographic and clinical follow-up demonstrated a vital pulp and physiologic root development without any endodontic failure clinically or radiographicaly.

  15. Correlation of natural tooth colour with aging in the Spanish population.

    Science.gov (United States)

    Gómez Polo, Cristina; Gómez Polo, Miguel; Montero, Javier; Martínez Vazquez De Parga, Juan Antonio; Celemin Viñuela, Alicia

    2015-10-01

    To analyse natural tooth colour in the Spanish population according to the colour coordinates lightness (L*), chroma (C*), hue (h*), red-green axis (a*) and yellow-blue axis (b*) in order to quantify the correlation and changes of tooth colour with age and sex. Natural tooth colour was measured in a sample of 1,361 Spanish participants of both sexes distributed within an age range of 16 to 89 years. The Easyshade Compact spectrophotometer was used and the CIELAB and CIELCh systems were followed. Pearson's bivariate correlations between age and colour coordinates were highly significant for L* (r=-0.674, P≤0.001), h* (r=-0.468, P≤0.001) and C* (r=0.417, P≤0.001). The correlation between age and colour coordinates was stronger for men than for women, for all colour coordinates. The results showed that C*, b* and a* increased by 0.60, 0.56 and 0.26 units/year on average, respectively, whereas L* and h* decreased progressively with age (by 0.60 units/year, on average), and colour differences increased in a systematic way as the gap between the ages being compared grew wider. The strongest correlation was found between age and L*, then between age and h* (both inverse relationships) and then between age and a*, C* and b* (direct relationships). In addition, a similar degree of change in the colour coordinates L*, C* and h* (of 0.60 units/year on average) was observed for natural tooth colour. Knowledge of the chromatic range of natural teeth may help to choose colour for the replacement of missing elements. © 2015 FDI World Dental Federation.

  16. Rapid tooth movement through distraction osteogenesis of the periodontal ligament in dogs

    Institute of Scientific and Technical Information of China (English)

    AI Hong; XU Qing-feng; LU Hong-fei; MAI Zhi-hui; AN Ai-qun; LIU Guo-ping

    2008-01-01

    Background Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament.Methods Modified distraction devices were placed on eight dogs between the first and third mandibular premolars on the left sides;similar placement of traditional straight wise appliances on the right sides served as the control.The experimental distractors were activated(0.25 mm/d)twice a day and the control devices were activated(100 g)for two weeks with consolidation periods at weeks two,three,six,and ten.Two dogs were sacrificed at each consolidation time point;rates and patterns of tooth movement,loss of anchorage,and periapical films were evaluated,and the aftected premolars and surrounding periodontal tissues were decalcified and examined histologically.General observations,X-ray periapical filming and histology examination were performed.Results Distal movement((3.66±0.1 4)mm)measured two weeks after modified distraction exceeded that achieved using the traditional device((1.15±0.21)mm;P<0.05).Loss of anchorage was minimally averaged(0.34±0.06)mm and (0.32±0.07)mm in the experimental and control sides,respectively.By radiography,apical and lateral surface root resorptions on both sides were minimal.Alveolar bone Iesions were never evident.Fibroblasts were endched in periodontal ligaments and bone spicules formed actively along directions of distraction.Conclusions The canine model is suitable for the study of rapid tooth movement through distraction osteogenesis of the periodontal ligament.The technique accelerates tooth movement,periodontal remodeling,alveolar bone absorption,and may induce fibroblast formation,as compared to the traditional orthodontic method,without adversely affecting root absorption,bone loss,tooth mobility and anchorage loss.

  17. Sequence analysis of candidate genes in two Roma families with severe tooth agenesis

    Directory of Open Access Journals (Sweden)

    Gabriková Dana

    2016-01-01

    Full Text Available Selective tooth agenesis is the most common congenital disorder affecting the formation of dentition in humans. Both its forms (hypodontia and more severe oligodontia can be found either in isolated form and they can be associated with systemic condition (syndromic tooth agenesis. In addition to previously known genes (PAX9, MSX1 and AXIN2 mutations in EDA, EDARADD and WNT10 gene were recently found to be involved in isolated forms of tooth agenesis. The objective of this study was to characterize the phenotype of affected members in two large families of Roma origin segregating severe isolated tooth agenesis with very variable phenotype and to perform mutation analysis of seven genes with aim to find causal mutation. 26 family members were clinically examined and coding regions of seven genes (MSX1, PAX9, AXIN2, EDA, EDAR, EDARADD and WNT10A were sequenced. With exclusion of third molars, average number of missing teeth was 8.2 ± 4.9 in family 1 and 7.1 ± 2.3 in family 2. The most frequently missing teeth were maxillary lateral incisors and first premolars and mandibular central incisors. Sequencing revealed four potentially damaging variants (g.Ala40Gly in MSX1, g.Ala240Pro in PAX9, g.Pro50Ser in AXIN2 and g.Met9Ile in EDARADD; however, none of them was present in all affected family members. Variable phenotype in both families examined in this study is in favour of heterogeneous genetic cause of tooth agenesis in these families: possible interaction of several defected genes, sequence variants in regulatory regions and additional environmental factors is assumed.

  18. Endogenous and Exogenous Substances Influencing the Orthodontic Tooth Movement

    Directory of Open Access Journals (Sweden)

    Mine Geçgelen Cesur

    2016-08-01

    Full Text Available Orthodontic tooth movement occurs as a result of prolonged application of controlled mechanical forces. Recent studies have focused on the effects of systemic or local applications of medications and the intake of dietary supplements as well as the mechanical forces. Factors affecting the orthodontic tooth movement are parathyroid hormone, thyroid hormones, estrogen, vitamin D3, eicosanoids, nonsteroidal anti-inflammatory drugs (NSAIDs, paracetamol, corticosteroids, bisphosphonates, cholesterol drugs, anticonvulsants, oral contraceptives, alcohol and nicotine use, nitric oxide, and fluoride. These medications have an important effect on the rate of tooth movement and treatment time. NSAIDs decrease tooth movement, but paracetamol has no effect. Parathyroid and thyroxin hormones increase tooth movement. Bisphosphonates have a strong inhibitory effect. Vitamin D3 stimulates tooth movement and dietary calcium seems to reduce it. It is important to discuss with patients about the consumption of these substances during orthodontic treatment.

  19. IBA analysis of a possible therapeutic ancient tooth inlay

    Science.gov (United States)

    Andrade, E.; Pineda, J. C.; Zavala, E. P.; Murillo, G.; Chavez, R.; Lazcurain, R.; Espinosa, Ma. L.; Villanueva, O.

    1998-03-01

    Five pre-Columbian human teeth from the same skeleton found during excavation in an ancient ceremonial center in Mexico, have been analyzed by two conventional Ion Beam Analysis (IBA) techniques: PIXE and 4He RBS. The anthropologists have estimated that the skeleton is about 2000 years old. X-ray radiography studies of one of these teeth have revealed that they contain an inlay in the tooth crown. The IBA methods have been used to study the inlay materials and also the tooth enamel. The IBA studies show that the tooth inlay materials have almost the same atomic composition as the tooth enamel. These results suggest that the tooth inlay were made for therapeutic purposes, using healthy tooth grains as inlay materials which were glued into the prepared teeth to fill it up.

  20. Sonosurgery for atraumatic tooth extraction: a clinical report.

    Science.gov (United States)

    Papadimitriou, Dimitrios E V; Geminiani, Alessandro; Zahavi, Thomas; Ercoli, Carlo

    2012-12-01

    The preservation of an intact labial plate during tooth extraction is a critical determinant of whether an immediate implant can be placed and is also an important predictor of the esthetic result. The purpose of this clinical report was to present a method for atraumatic tooth extraction by using an air-driven sonic instrument with specially designed inserts. This surgical technique provides the clinician with an efficient method for atraumatic tooth extraction and preservation of an intact labial plate.

  1. Modular Permanent Magnet Machines with Alternate Teeth Having Tooth Tips

    OpenAIRE

    Li, G. J.; Zhu, Z.Q.; Foster, M. P.; Stone, D. A.; Zhan, H.L.

    2015-01-01

    This paper presents single layer modular permanent magnet machines with either wound or unwound teeth with tooth tips. The structures with wound teeth having tooth tips are suitable for modular machines with slot number higher than pole number to compensate for the drop in winding factor due to the flux gaps in alternate stator teeth, accordingly to maintain or even to increase their average torques. However, the structures with unwound teeth having tooth tips are suitable for modular machine...

  2. Esthetic Reconstruction of Diastema with Adhesive Tooth-Colored Restorations and Hyaluronic Acid Fillers

    Directory of Open Access Journals (Sweden)

    Supawadee Naorungroj

    2017-01-01

    Full Text Available Objective. This report presents a comprehensive esthetic treatment with adhesive tooth-colored restorations in a combination with hyaluronic acid (HA fillers of diastema in an orthodontic patient with relapse. Case Report. A 36-year-old female patient consulted about 1.5–2 mm midline diastema after an orthodontic relapse of replacing missing central incisors with lateral incisors and dark-colored gingival tissue as a result of a metal post and core with porcelain fused to a metal (PFM crown at the left lateral incisor. Restorative treatments included replacing the PFM with all-ceramic material and placing a ceramic veneer on the right lateral incisor. To close the space, crown forms of both lateral incisors were altered. A direct resin composite was then used to reform right and left canines to a more ideal lateral incisor shape. An HA fillers injection was used to fill the remaining open gingival embrasure. Eighteen months after treatment, the interdental papilla remained stable and the patient was satisfied with the result. Conclusion. Esthetic reconstruction of diastema and open gingival embrasure in this case can be accomplished without orthodontic retreatment. Tooth-colored restorations and HA filler injection appear as a promising modality to address this patient’s esthetic concern.

  3. [Preserving the natural tooth versus extraction and implant placement: making a rational clinical decision].

    Science.gov (United States)

    Tsesis, I; Nemkowsky, C E; Tamse, E; Rosen, E

    2010-01-01

    Modern dental practice offers a wide variety of treatment alternatives and modalities. With the wider scale of treatment options, new dilemmas emerged. A common dilemma is the decision whether to preserve the natural tooth by endodontic treatment, or to extract the tooth and replace it with a single dental implant. The clinician needs to remember that the basic goal of dental implants is to replace missing teeth, and not present teeth. Prosthodontic, periodontal, and esthetic considerations should be integrated in the treatment planning process. Long-term prognosis, the capabilities offered by the modern endodontic treatment, the alternatives in case of treatment failure, post treatment quality of life and patient's preferences should all be recognized and incorporated in the dentist decision making. An important factor is the communication between the prosthodontist and the endodontist before and during the treatment in order to avoid possible risks or treatment failure. The integration of these factors would assist the clinician to achieve a rational treatment plan for the benefit of the patient.

  4. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

    Directory of Open Access Journals (Sweden)

    Sam Vandenplas

    Full Text Available The Atlantic salmon (Salmo salar and African bichir (Polypterus senegalus are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1 determine the localization and extent of proliferating cells in the dental epithelial layers, (2 describe cell dynamics and (3 investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks and P. senegalus (eight weeks and twelve weeks, we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement.

  5. Predatory behaviour of carnivorous dinosaurs: Ecological interpretations based on tooth marked dinosaur bones and wear patterns of theropod teeth

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland

    Predation marks on bones are a source on information on the feeding behaviour of the carnivores involved. Although predator damaged bone is common in the fossil record, published reports of such marks on dinosaur bones are rare. Patterns of bone modification by mammalian carnivores overlap patterns...... left by theropod dinosaurs.Differences in tooth morphology can also be correlated with characteristics of the marks left by the teeth. In a study of tooth marks on dinosaur bones from the Dinosaur Park Formation of Alberta, Canada, it was possible to identify the feeding theropods to family, generic...... different taxa and different skeletal elements produced some interesting results. The frequency of tooth marked dinosaur bones is higher than expected. Up to 14 % of the observed hadrosaur bones were predator damaged. The lower incidence of damage in ceratopsian bones can be explained by the fact...

  6. Repair or replacement of amalgam restorations: decisions at a USA and a UK dental school.

    Science.gov (United States)

    Setcos, James C; Khosravi, Reza; Wilson, Nairn H F; Shen, Chiayi; Yang, Mark; Mjör, Ivar A

    2004-01-01

    Whereas replacement of failed restorations is the major treatment for adults in dental practice, repair is an important alternative with the potential to save tooth structure and increase the longevity of restorations at a lower cost. This in vitro study recorded the choices of treatment for the same set of teeth with defective Class II amalgam restorations by students and faculty at two dental schools (University of Manchester, UK and University of Florida, USA). Treatment options (monitor, refurbish, repair and replace) and reason(s) for the choice of treatment for 24 marked amalgam restorations were selected. Overall, participants more frequently chose replacement of restorations; whereas, repair was the least favored option. The reasons cited the most to replace restorations were secondary caries including unsightly appearance, partially lost restoration and tooth fracture; for repair, the major reasons included loss of part of the restoration and marginal ditching; and for refurbishment, the major reasons included poor anatomic form and marginal ditching. There was a significant difference between the students and faculties at the two sites in their choice of treatment (p<0.0001; Chi-square test). The treatment decision to "monitor" the restorations was more frequent for the Manchester site than the Florida site. Conversely, the combined treatment decisions to "refurbish, repair and replace" were more frequently chosen in Florida than in Manchester.

  7. Comparison between normal and special chain-drive toothing

    Energy Technology Data Exchange (ETDEWEB)

    Dolipski, M.

    1985-12-01

    A comparison of these two types of tooth arrangements on chain drives with round-link chains comes out clearly in favour of the special toothing. The article describes the advantages of this type of toothing. A proposal is made to use the special tooth arrangement in the construction of drive pocket wheels. Such a move would prevent the disastrous effects of links becoming jammed in the pockets during running-in and would consequently improve the service life of both chain and drive sprocket.

  8. Patient Discomfort Following Single-Tooth Implant Placement

    DEFF Research Database (Denmark)

    Spin-Neto, Rubens; Pontes, Ana Emília Farias; Wenzel, Ann

    2014-01-01

    Aims: Evaluate postoperative discomfort (pain, bleeding and swelling) in single-tooth implant patients submitted to immediate or conventional tooth restoration together with assessment of treatment time. Methods: Twenty-four patients who received single-tooth maxillary dental implants were randomly...... assigned to an IR (Immediate Restoration) or CR (Conventional Restoration) group. In IR, an implant was inserted and a provisional tooth crown was delivered within the same session, while in CR it was delivered three months after implantation. Pain (first three days), bleeding (first day) and swelling...

  9. Iron replacement therapy

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Coskun, Mehmet; Weiss, Günter

    2016-01-01

    PURPOSE OF REVIEW: Approximately, one-third of the world's population suffers from anemia, and at least half of these cases are because of iron deficiency. With the introduction of new intravenous iron preparations over the last decade, uncertainty has arisen when these compounds should be admini...... treatment, when to follow-up for relapse, which dosage and type of therapy should be recommended or not recommended, and if some patients should not be treated....... be administered and under which circumstances oral therapy is still an appropriate and effective treatment. RECENT FINDINGS: Numerous guidelines are available, but none go into detail about therapeutic start and end points or how iron-deficiency anemia should be best treated depending on the underlying cause...... of iron deficiency or in regard to concomitant underlying or additional diseases. SUMMARY: The study points to major issues to be considered in revisions of future guidelines for the true optimal iron replacement therapy, including how to assess the need for treatment, when to start and when to stop...

  10. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    Directory of Open Access Journals (Sweden)

    Saroea Geoffrey

    2008-08-01

    Full Text Available Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C and human saliva (D. Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances using the L*a*b scale: lightness (L*, red-green (a and yellow-blue (b. Results Medicated chewing gums (A and B removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

  11. FHL2 mediates tooth development and human dental pulp cell differentiation into odontoblasts, partially by interacting with Runx2.

    Science.gov (United States)

    Du, Jianxin; Wang, Qiang; Yang, Pishan; Wang, Xiaoying

    2016-04-01

    The differentiation of mesenchymal cells in tooth germ and dental pulp cells into odontoblasts is crucial for dentin formation, and the transcription factor runt-related transcription factor (Runx2) is necessary for odontoblast differentiation. Our previous study demonstrated that four and a half LIM domains 2 (FHL2) may play an important role in tooth development and human dental pulp cell differentiation. This study aimed to determine whether FHL2 mediated the mesenchymal cells in tooth development and human dental pulp cell differentiation into odontoblasts by interacting with Runx2. The expression patterns of FHL2 and Runx2 were examined at the early stages of mouse molar development using double immunofluorescence staining. Western blot analysis and co-immunoprecipitation (Co-IP) were conducted for the preliminary study of the relationship between FHL2 and Runx2 in human dental pulp cell differentiation into odontoblasts. Results of double immunofluorescence staining showed that FHL2 and Runx2 exhibited similar expression patterns at the early stages of tooth development. Western blot analysis indicated that the expression patterns of FHL2 and Runx2 were synchronized on day 7 of induction, whereas those on day 14 differed. Co-IP analysis revealed positive bands of protein complexes, revealing the interaction of FHL2 and Runx2 on days 0, 7 and 14 of induction. Our data suggested that FHL2 might interact with Runx2 to mediate mesenchymal cell differentiation at the early stages of tooth development and human dental pulp cell differentiation.

  12. RNA-Sequencing Analyses Demonstrate the Involvement of Canonical Transient Receptor Potential Channels in Rat Tooth Germ Development

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2017-06-01

    Full Text Available Tooth development depends on multiple molecular interactions between the dental epithelium and mesenchyme, which are derived from ectodermal and ectomesenchymal cells, respectively. We report on a systematic RNA sequencing analysis of transcriptional expression levels from the bud to hard tissue formation stages of rat tooth germ development. We found that GNAO1, ENO1, EFNB1, CALM1, SIAH2, ATP6V0A1, KDELR2, GTPBP1, POLR2C, SORT1, and members of the canonical transient receptor potential (TRPC channel family are involved in tooth germ development. Furthermore, Cell Counting Kit 8 (CCK8 and Transwell migration assays were performed to explore the effects of these differentially expressed genes (DEGs on the proliferation and migration of dental pulp stem cells. Immunostaining revealed that TRPC channels are expressed at varying levels during odontogenesis. The identified genes represent novel candidates that are likely to be vital for rat tooth germ development. Together, the results provide a valuable resource to elucidate the gene regulatory mechanisms underlying mammalian tooth germ development.

  13. Shark tooth morphogenesis. An SEM and EDX analysis of enameloid and dentin development in various shark species.

    Science.gov (United States)

    Risnes, S

    1990-09-01

    The study provides a survey of shark tooth morphogenesis based on SEM and EDX analyses of whole tooth families in six shark species. The teeth, demonstrating different stages of development, were acid-etched and coated with palladium. Calcium content was determined semi-quantitatively by using the palladium coating as an internal standard. Due to the rapid development of the enameloid, all major events took place in the two or three youngest teeth of a tooth family. Enameloid appeared to develop as a transformation of the peripheral part of the dental papilla. Mineralization started immediately. Based on morphological criteria the middle zone of the enameloid was established at an early stage, excluding the possibility of an unambiguous centrifugal or centripetal direction of growth. Substantial mineral increase first occurred in the middle zone, spreading from the tooth tip toward the base. Dentin formed after the enameloid was completely established. Dentin formation started basally as a direct prolongation of the enameloid cap, then spreading toward the tooth tip, first along the edges. It is concluded that shark enameloid has a mesenchymal background, but a role played by the inner dental epithelium can not be excluded.

  14. Prevalence of tooth agenesis and peg-shaped maxillary lateral incisor associated with palatally displaced canine (PDC) anomaly.

    Science.gov (United States)

    Peck, S; Peck, L; Kataja, M

    1996-10-01

    Fifty-eight nonsyndromic North American white orthodontic patients with palatal displacement of one or both maxillary canine teeth were studied for associated tooth agenesis and peg-shaped maxillary lateral incisors. Agenesis of permanent teeth was identified by x-ray film analysis. Conical crown-size reduction (peg-shape anomaly) of the maxillary lateral incisor (l2) was determined by direct observation. Increases in absence of third molars and second premolars associated with the palatally displaced canine (PDC) anomaly were statistically very highly significant compared with normative data for tooth-agenesis prevalence. In contrast, the prevalence of l2 agenesis in the PDC sample showed no difference statistically compared with reference values. Reasons for this posterior site-specific suppression of tooth formation are not clear. The l2 peg-shape anomaly exceeded a 10-fold elevation in expression in the PDC sample, a very highly significant increase from normal prevalence. The findings are consistent with a hypothesis that the anomalies of tooth agenesis, tooth-size reduction, and PDC are biologic covariables in a complex of genetically related dental disturbances.

  15. 重组人BMP-2修饰的β磷酸三钙/胶原材料制备及其诱导成牙性能的初步研究%PREPARATION OF RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN 2 DECORATED β TRICALCIUM PHOSPHATE/COLLAGEN AND PRELIMINARY STUDIES ON ITS PROPERTIES OF INDUCING TOOTH FORMATION

    Institute of Scientific and Technical Information of China (English)

    张文涛; 刘建华; 王慧明; 李志勇

    2011-01-01

    性良好,可作为牙组织工程支架材料的良好选择.%Objective To explore a novel nanometer biomaterial which could induce the regeneration of tooth tissues intelligently, and to evaluate the feasibility of using this kind of biomaterial as the scaffold for tooth tissue engineering by investigating the role it plays in tooth tissue engineering.Methods The scaffold for tooth tissue engineering containing recombinant human bone morphogenetic protein 2 (rhBMP-2) was prepared by mixing nanoscale β tricalcium phosphate (β-TCP)/collagen particles.Forty-six 8-10 weeks old specific pathogen free Sprague Dawley (SD) rats, including 34 females and 12 males, weighing 250-300 g, were involved in this study.Tooth germs were removed under a stereomicroscope from the mandible of newborn SD rat, then digested and suspended.Scanning electronic microscope (SEM), adhesion rate of cells, and MTT assay were used to evaluate the effects of the scaffold on the tooth germ cells cultured in vitro.The tissue engineered tooth germ which was constructed by tooth germ cells and scaffold was transplanted under SD rat's kidney capsule as the experimental group (n=12); the tooth germ cells (cell-control group, n=12) or scaffold without cells (material-control group, n=4) were transplanted separately as control groups.Specimens were harvested to perform general and histological observations at 4 and 8 weeks after transplantation.Results β-TCP/collagen showed a loose and porous appearance with soft texture and excellent hydrophilicity.Tooth germ cells grew well and could attach to the scaffold tightly 3 days after coculture.The adhesion rates of tooth germ cells were 27.20% ± 2.37%,44.52% ± 1.87%, and 73.81% ± 4.15% when cocultured with scaffold for 4, 8, and 12 hours, respectively.MTT assay showed that the cell proliferation status of experimental group was similar to that of the control group, showing no significant difference (P >0.05).Some white calcified specimens

  16. Gene expression profiling during murine tooth development

    Directory of Open Access Journals (Sweden)

    Maria A dos Santos silva Landin

    2012-07-01

    Full Text Available The aim of this study was to describe the expression of genes, including ameloblastin (Ambn, amelogenin X chromosome (Amelx and enamelin (Enam during early (pre-secretory tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24h intervals, starting at the eleventh embryonic day (E11.5 and up to the seventh day after birth (P7. The profile search function of Spotfire software was used to select genes with similar expression profile as the enamel genes (Ambn, Amelx and Enam. Microarray results where validated using real-time Reverse Transcription-Polymerase Chain Reaction (real-time RT-PCR, and translated proteins identified by Western blotting. In situ localisation of the Ambn, Amelx and Enam mRNAs were monitored from E12.5 to E17.5 using deoxyoligonucleotide probes. Bioinformatics analysis was used to associate biological functions with differentially (p ≤0.05 expressed (DE genes.Microarray results showed a total of 4362 genes including Ambn, Amelx and Enam to be significant differentially expressed throughout the time-course. The expression of the three enamel genes was low at pre-natal stages (E11.5-P0 increasing after birth (P1-P7. Profile search lead to isolation of 87 genes with significantly similar expression to the three enamel proteins. The mRNAs expressed in dental epithelium and epithelium derived cells. Although expression of Ambn, Amelx and Enam were lower during early tooth development compared to secretory stages enamel proteins were detectable by Western blotting. Bioinformatic analysis associated the 87 genes with multiple biological functions. Around thirty-five genes were associated with fifteen transcription factors.

  17. Restoration of the Severely Decayed Tooth Using Crown Lengthening with Simultaneous Tooth-Preparation

    OpenAIRE

    2010-01-01

    This clinical case describes a treatment approach that combines, in a single appointment, a crown lengthening procedure and the final crown preparation for the restoration of a severely decayed tooth. This approach allows for a more accurate placement of the crown margin in relation to the bone crest while reducing treatment time.

  18. Restoration of the severely decayed tooth using crown lengthening with simultaneous tooth-preparation.

    Science.gov (United States)

    Park, Jun-Beom

    2010-04-01

    This clinical case describes a treatment approach that combines, in a single appointment, a crown lengthening procedure and the final crown preparation for the restoration of a severely decayed tooth. This approach allows for a more accurate placement of the crown margin in relation to the bone crest while reducing treatment time.

  19. Pediatric Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Jani-Acsadi, Agnes; Ounpuu, Sylvia; Pierz, Kristan; Acsadi, Gyula

    2015-06-01

    Heritable diseases of the peripheral nerves (Charcot-Marie-Tooth disease [CMT]) affect the motor units and sensory nerves, and they are among the most prevalent genetic conditions in the pediatric patient population. The typical clinical presentation includes distal muscle weakness and atrophy, but the severity and progression are largely variable. Improvements in supportive treatment have led to better preservation of patients' motor functions. More than 80 genes have been associated with CMT. These genetic discoveries, along with the developments of cellular and transgenic disease models, have allowed clinicians to better understand the disease mechanisms, which should lead to more specific treatments. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Combined periodontic-orthodontic-endodontic interdisciplinary approach in the treatment of periodontally compromised tooth

    Directory of Open Access Journals (Sweden)

    Deepa D

    2010-01-01

    Full Text Available Orthodontic treatment in adult patients is one of the most frequently encountered components involving multidisciplinary approaches. In the present report, a 28-year-old male patient was treated for localized chronic periodontitis with pocket formation, mobility, pathologic migration and malalignment of maxillary left lateral incisor tooth #22. The periodontal therapy included motivation, education and oral-hygiene instructions (O.H.I., scaling and root planing and periodontal flap surgery. Subsequently on resolution of periodontal inflammation, orthodontic therapy was carried out using the orthodontic aligner for a period of 6 months. Post-treatment (3 years results showed complete resolution of infrabony pocket with significant bone fill, reduced tooth mobility and complete alignment of the affected maxillary left lateral incisor, thus restoring the esthetics and function.

  1. Histochemical demonstration of activity of acid phosphatase and beta-glucuronidase in bovine incisor tooth germs

    DEFF Research Database (Denmark)

    Kirkeby, S; Salling, E; Moe, D

    1983-01-01

    Activity of acid phosphatase and beta-glucuronidase was shown in bovine preodontoblasts and preameloblasts prior to the onset of secretion. In the preameloblasts the rather weak reaction consisted of small discrete granules dispersed in the cytoplasm apical, lateral, and proximal to the nucleus....... After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells...... are located to the Golgi complex. The differences in activity of acid hydrolases between bone and tooth forming cells are expounded....

  2. Tooth Germ-Like Construct Transplantation for Whole-Tooth Regeneration: An In Vivo Study in the Miniature Pig.

    Science.gov (United States)

    Yang, Kai-Chiang; Kitamura, Yutaka; Wu, Chang-Chin; Chang, Hao-Hueng; Ling, Thai-Yen; Kuo, Tzong-Fu

    2016-04-01

    The purpose of this study was to demonstrate the feasibility of whole-tooth regeneration using a tooth germ-like construct. Dental pulp from upper incisors, canines, premolars, and molars were extracted from sexually mature miniature pigs. Pulp tissues were cultured and expanded in vitro to obtain dental pulp stem cells (DPSCs), and cells were differentiated into odontoblasts and osteoblasts. Epithelial cells were isolated from gingival epithelium. The epithelial cells, odontoblasts, and osteoblasts were seeded onto the surface, upper, and lower layers, respectively, of a bioactive scaffold. The lower first and second molar tooth germs were removed bilaterally and the layered cell/scaffold constructs were transplanted to the mandibular alveolar socket of a pig. At 13.5 months postimplantation, seven of eight pigs developed two teeth with crown, root, and pulp structures. Enamel-like tissues, dentin, cementum, odontoblasts, and periodontal tissues were found upon histological inspection. The regenerated tooth expressed dentin matrix protein-1 and osteopontin. All pigs had regenerated molar teeth regardless of the original tooth used to procure the DPSCs. Pigs that had tooth germs removed or who received empty scaffolds did not develop teeth. Although periodontal ligaments were generated, ankylosis was found in some animals. This study revealed that implantation of a tooth germ-like structure generated a complete tooth with a high success rate. The implant location may influence the morphology of the regenerated tooth.

  3. Influence of composite insertion technique on gap formation

    Directory of Open Access Journals (Sweden)

    Neha Kapoor

    2016-01-01

    Full Text Available Aim: To compare newer bulk-fill composites with an incrementally filled composite for adaptability and subsequent gap formation at the pulpal floor. Materials and Methods: Class I cavities were prepared in 60 intact molars, with a shallow depression in the center of the pulpal floor. The samples were divided into four groups (n = 15, according to the material used; smart dentine replacement (SDR, SonicFill, Ever X Flow and Z350 XT, restored to a depth of 4 mm. Following thermocycling, samples were sectioned buccolingually and examined under a stereomicroscope. Seven samples from each group were coated with nail varnish except for approximately 1 mm around the tooth restoration junction. These samples were examined under stereomicroscope after staining with 2% buffered methylene blue dye. The remaining samples were examined under a scanning electron microscope for gap formation. The data were statistically analyzed using one-way ANOVA and post-hoc Bonferroni test. Results: SDR showed the significantly best adaptability as compared to both SonicFill and Ever X Flow (comparable. However, significantly least adaptive capacity was seen in the incrementally filled group (Z350 XT. Conclusion: Bulk-fill composites performed better than incremental composites, demonstrating better adaptability and less gap formation at the pulpal floor.

  4. Using your shoulder after replacement surgery

    Science.gov (United States)

    Joint replacement surgery - using your shoulder; Shoulder replacement surgery - after ... You have had shoulder replacement surgery to replace the bones of your shoulder joint with artificial parts. The parts include a stem made of metal and a ...

  5. Tooth enamel maturation reequilibrates oxygen isotope compositions and supports simple sampling methods

    Science.gov (United States)

    Trayler, Robin B.; Kohn, Matthew J.

    2017-02-01

    Oxygen isotope and major element zoning patterns of several disparate ungulate teeth were collected to evaluate the timing and geometry of enamel formation, records of isotope zoning, and tooth enamel sampling strategies. Isotopic zoning in mammalian tooth enamel encodes a sub-annual time series of isotopic variation of an animal's body water composition, with a damping factor that depends on the specifics of how enamel mineralizes. Enamel formation comprises two stages: precipitation of appositional enamel with a high CO3:PO4 ratio, followed by precipitation of maturational enamel with a lower CO3:PO4. If appositional and maturational enamel both contribute to isotope compositions (but with different CO3:PO4), and if isotope compositions vary seasonally, paired δ18O values from CO3 and PO4 profiles should show a spatial separation. CO3 isotope patterns should be shifted earlier seasonally than PO4 isotope patterns. Such paired profiles for new and published data show no resolvable shifts, i.e. CO3 and PO4 δ18O profiles show coincident maxima and minima. This coincidence suggests that enamel maturation reequilibrates appositional isotope compositions. If enamel maturation establishes enamel isotope compositions, the geometry of maturation, not apposition, should be considered when devising sampling protocols. X-ray maps of Ca zoning show that the majority of enamel (inner and middle layers) mineralizes heavily at a high angle to the external tooth surface and the enamel-dentine junction over length scales of 2-4 mm, while the outer enamel surface mineralizes more slowly. These data suggest that isotopic sampling strategies should parallel maturational geometry and focus on interior enamel to improve data fidelity. The magnitude of isotopic damping is also smaller than implied in previous studies, so tooth enamel zoning more closely reflects original body water isotopic variations than previously assumed.

  6. REPLACEMENT CONTROL OF INNOVATION MANAGERS: ORGANIZATIONAL AND ECONOMIC ASPECTS

    Directory of Open Access Journals (Sweden)

    E. V. Gurina

    2011-01-01

    Full Text Available The paper substantiates phases of specialists’ replacement ensuring innovation development of the national economy in Belarus, i.e. managers of innovation activity. Realization of replacement phases is presented within the system consisting of four blocks – objective, managing, controllable and providing. Analysis results of the current state of the innovation activity managers replacement system reveal main problems in interaction of its basic agents. The paper considers solution of specified problems in the context of formation of organizational and economic approaches to managing the innovation activity managers replacement system which presupposes modernization of organizational interrelations between state- run public authorities in the managing block and micro-incentive structures in the controllable block as well as the usage of the process approach in every phase of the replacement process. 

  7. Hierarchical structure and biomineralization in cricket tooth

    CERN Document Server

    Xing, Xueqing; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhongjun; Wu, Zhonghua

    2012-01-01

    Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a d...

  8. Inadvertent tooth movement with fixed lingual retainers.

    Science.gov (United States)

    Shaughnessy, Timothy G; Proffit, William R; Samara, Said A

    2016-02-01

    Fixed retainers are effective in maintaining the alignment of the anterior teeth more than 90% of the time, but they can produce inadvertent tooth movement that in the most severe instances requires orthodontic retreatment managed with a periodontist. This is different from relapse into crowding when a fixed retainer is lost. These problems arise when the retainer breaks but remains bonded to some or all teeth, or when an intact retainer is distorted by function or was not passive when bonded. In both instances, torque of the affected teeth is the predominant outcome. A fixed retainer made with dead soft wire is the least likely to create torque problems but is the most likely to break. Highly flexible twist wires bonded to all the teeth appear to be the most likely to produce inadvertent tooth movement, but this also can occur with stiffer wires bonded only to the canines. Orthodontists, general dentists, and patients should be aware of possible problems with fixed retainers, especially those with all teeth bonded, because the patient might not notice partial debonding. Regular observations of patients wearing fixed retainers by orthodontists in the short term and family dentists in the long term are needed.

  9. Educating My Replacement

    Science.gov (United States)

    Tarter, Jill

    , in partnership with the dedicated teachers out there, I think I can help promote the critical thinking skills and scientific literacy of the next generation of voters. Hopefully, I can also help train my replacement to be a better scientist, capable of seizing all the opportunities generated by advances in technology and our improved understanding of the universe to craft search strategies with greater probability of success than those I have initiated.

  10. [Ascending aorta replacement late after aortic valve replacement].

    Science.gov (United States)

    Hayashi, Yasunari; Ito, Toshiaki; Maekawa, Atsuo; Sawaki, Sadanari; Fujii, Genyo; Hoshino, Satoshi; Tokoro, Masayoshi; Yanagisawa, Junji

    2013-07-01

    Replacement of the asceding aorta is indicated in patients undergoing aortic valve replacement( AVR), if the diameter of the ascending aorta is greater than 5.0 cm. If the diameter of the asceding aorta is from 4.0 to 5.0 cm, it was arguable whether replacement of the ascending aorta should be performed. Nine patients who underwent reoperative ascending aorta replacement after AVR were reviewed retrospectively. Reoperation on the asending aorta replacement was performed 11.8±7.2 years (range 1y5m~23y3m) after AVR. Mean patient age was 69.9±6.3 (range 60~81). In 2 cases, reoperations were performed early year after AVR. Although ascending aorta was dilated at the 1st operation, replacement wasn't performed for the age and minimally invasive cardiac surgery (MICS). In 3 cases, reoperations were performed more than 10 years later. On these cases, ascending aorta aneurysm and dissection occurred with no pain and were pointed out by computed tomography(CT) or ultrasonic cardiogram(UCG). We think that patients with dilatation of the ascending aorta should undergo AVR and aorta replacement at the 1st operation regardness of age. It is important that patients who underwent AVR should undergo a regular checkup on the ascending aorta.

  11. Patterns of tooth agenesis in patients with orofacial clefts

    NARCIS (Netherlands)

    Hermus, Ruurd R.; van Wijk, Arjen J.; Tan, Stephan P. K.; Kramer, Gem J. C.; Ongkosuwito, Edwin M.

    2013-01-01

    Orofacial clefts are a common oral disorder associated with tooth agenesis. As information on the simultaneous absence of teeth can be an aid in treatment planning, a large sample of orofacial cleft patients was examined. The sample consisted of 910 patients with cleft lip and palate. Tooth agenesis

  12. Severe tooth wear: European consensus statement on management guidelines

    DEFF Research Database (Denmark)

    Loomans, Bas AC; Opdam, Niek JM; Attin, Thomas

    2017-01-01

    This paper reports a European expert consensus statement on guidelines for the management of severe tooth wear. It focuses on the definition of physiological versus pathological tooth wear and recommends diagnosis, monitoring and counseling to define the activity of the wear. Restorative...

  13. [Tooth regeneration in the guinea pig (Cavia porcellus)].

    Science.gov (United States)

    Stephan, F; Artis, J P; Lanot, R

    1977-01-01

    The first inferior molar has been extracted, a part of its being reimplanted or not. A new molar of normal form regenerated, apparently from the apex of the tooth germ, in all cases in which the alveolus was left free or implanted with a tooth freagment deprived of pulpa.

  14. Two-Dimensional Identification of Fetal Tooth Germs.

    Science.gov (United States)

    Seabra, Mariana; Vaz, Paula; Valente, Francisco; Braga, Ana; Felino, António

    2017-03-01

      To demonstrate the efficiency and applicability of two-dimensional ultrasonography in the identification of tooth germs and in the assessment of potential pathology.   Observational, descriptive, cross-sectional study.   Prenatal Diagnosis Unit of Centro Hospitalar de Vila Nova de Gaia / Espinho-Empresa Pública in Portugal.   A total of 157 white pregnant women (median age, 32 years; range, 14 to 47 years) undergoing routine ultrasound exams.   Description of the fetal tooth germs, as visualized by two-dimensional ultrasonography, including results from prior fetal biometry and detailed screening for malformations.   In the first trimester group, ultrasonography identified 10 tooth germs in the maxilla and 10 tooth germs in the mandible in all fetuses except for one who presented eight maxillary tooth germs. This case was associated with a chromosomal abnormality (trisomy 13) with a bilateral cleft palate. In the second and third trimesters group, ultrasonography identified a larger range of tooth germs: 81.2% of fetuses showed 10 tooth germs in the maxilla and 85.0% of fetuses had 10 tooth germs in the mandible. Hypodontia was more prevalent in the maxilla than in the mandible, which led us to use qualitative two-dimensional ultrasonography to analyze the possible association between hypodontia and other variables such as fetal pathology, markers, head, nuchal, face, and spine.   We recommend using this method as the first exam to evaluate fetal morphology and also to help establish accurate diagnosis of abnormalities in pregnancy.

  15. [Tooth decay and its complication prognosis in smokers].

    Science.gov (United States)

    Orekhova, L Iu; Osipova, M V

    2014-01-01

    The study focuses on complicated and non-complicated tooth decay course and prognosis in smokers. Oral status, prevention and treatment effectiveness was assessed in 330 non-smokers and 345 smoking patients. The results allowed concluding with guidelines for tooth decay prevention and treatment in smokers.

  16. The Prevalence of Tooth Wear in the Dutch Adult Population

    NARCIS (Netherlands)

    Wetselaar, Peter; Vermaire, Jan H; Visscher, Corine M; Lobbezoo, Frank; Schuller, Annemarie A

    2016-01-01

    This study aimed to assess the prevalence of tooth wear in different age groups of the Dutch adult population and to determine this tooth wear distribution by gender, socioeconomic class, and type of teeth. Results were compared with the outcomes of a previous study in a comparable population. As pa

  17. Association between Severity of Tooth Wear and Dentinal Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Ashok Ayer

    2016-11-01

    Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

  18. Peroxide dental bleaching via laser microchannels and tooth color measurements

    Science.gov (United States)

    Altshuler, Gregory; Belikov, Andrey; Skrypnik, Alexei; Feldchtein, Felix; Pushkareva, Alexandra; Shatilova, Ksenia; Cernavin, Igor; Tuchin, Valery

    2016-12-01

    The aim of this study was to use microchannels drilled by an Er:YAG laser into a human tooth through the enamel into the dentin for direct injection of hydrogen peroxide (HP) to produce a minimally invasive, rapid, tooth bleaching effect. The experiments were conducted in vitro. Five microchannels with a diameter of ˜200 μm and a depth of ˜2 mm were drilled through the palatal side of a human tooth crown using the microbeam of an Er:YAG-laser with a wavelength of 2.94 μm. After injection of an aqueous solution of 31%-HP through the microchannels, the tooth color was evaluated using a VITA shade guide and International Commission on Illumination L*ab color parameters. A tooth model used for the evaluation of the distribution of HP concentration was created and the amount of HP which can be injected into tooth dentin to bleach it safely was estimated. Injection of 1.5±0.1 mm3 of 31%-HP into the tooth led to noticeable bleaching within 3 h and significant improvement of tooth color within 24 h.

  19. 3D Simulation Modeling of the Tooth Wear Process.

    Science.gov (United States)

    Dai, Ning; Hu, Jian; Liu, Hao

    2015-01-01

    Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

  20. 3D Simulation Modeling of the Tooth Wear Process.

    Directory of Open Access Journals (Sweden)

    Ning Dai

    Full Text Available Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.