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Sample records for dental arch width

  1. Comparative study of dental arch width in plaster models, photocopies and digitized images

    Directory of Open Access Journals (Sweden)

    Maria Cristina Rosseto

    2009-06-01

    Full Text Available The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65, both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (α = 0.05. Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width; 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width; 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width. There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

  2. Dental arch width, overbite, and overjet in a Finnish population with normal occlusion between the ages of 7 and 32 years.

    Science.gov (United States)

    Heikinheimo, Kaisa; Nyström, Marjatta; Heikinheimo, Tuomas; Pirttiniemi, Pertti; Pirinen, Sinikka

    2012-08-01

    The aims of the present study were to provide data on growth changes in the dental arches from age 7 to 32 in Finns with untreated normal Angle Class I occlusions. The material consisted of 33 series of dental casts of 18 women and 15 men. The subjects had been examined and study models taken at the ages of 7, 10, 12, 15, and 32. Dental arch width, overbite, and overjet were measured. Our longitudinal findings show that both the dental arches of young adults are slightly narrowed from adolescence to 32 years of age. All increases in width dimensions took place before 15 years of age. The means of the changes were mostly small, in the order of 0.5 to a few millimetres. Variability in age changes was considerable. In both genders, each variable increased in some subjects and decreased in others during every age interval. Differences between growth changes in the mesial, distal, and gingival intermolar widths indicate that both the maxillary and the mandibular first molars rotate mesiolingually and that the maxillary first molars also become more upright during late occlusal development. We expect the present findings of the changes occurring in the arch dimensions of subjects with untreated normal occlusions to help clinicians in following up occlusal development, choosing an optimal treatment time, and making orthodontic treatment and retention plans. However, because of the wide variability, accurate prediction of future development cannot be made on the individual level.

  3. Relationship among Lower Arch Length, Arch Width and Arch Perimeter in Crowding and Non-Crowding Groups

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    Selmani Mimoza

    2015-03-01

    Full Text Available Crowding is one of the causes of class I malocclusion. The purpose of the present study was to examine the relationship between arch length, arch width and arch perimeter in crowded and non-crowded arches, as well as to made comparison of the right and left sides between them and to find out the contributing factor in lower arch crowding. The study groups consisted of 60 subjects aged 16 to 21 years. First group consisted of 30 pairs of dental study models with class I normal occlusion. The second group consisted of 30 pairs of study models with class I crowding. Measurements of arch length and width were made as defined by Lavelle and Foster, using Korkhaus callipers. Arch perimeter was measured by Lundstrom method’s using manual calliper with sharp points. Differences between these measurements were made by Mann-Whitney U test (Z/U.

  4. Space maintainer effects on intercanine arch width and length.

    Science.gov (United States)

    Dincer, M; Haydar, S; Unsal, B; Turk, T

    1996-01-01

    In order to investigate the effects of space maintainers in intercanine arch width and length, twenty cases, characterized with the early loss of mandibular primary molars were selected and divided into two groups. The treatment group used removable space maintainers, while the other ten cases served as the control group. The first dental casts of the treatment and control groups were obtained when the primary canines were in the mouth. After the eruption of permanent canines second dental casts were obtained in both groups. Six measurements were made on the dental casts of each patient. No parameter was found to be statistically significant in the treatment group. In the control group the increase in intercanine arch width and perimeter were found to be statistically significant. Also the increase at the buccal and lingual bone measurements were found to be statistically significant. These results showed that space maintainers might cease the increase in intercanine arch width and length during the transition period between the primary and permanent canines.

  5. Relationship between Dental Arch Dimensions and Vertical Facial Morphology in Class I Subjects

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    Amit Kumar Khera

    2012-01-01

    Results: The results showed that, for both males and females, there was a trend that as vertical facial height increased, arch width, arch perimeter and overbite decreased but palatal height and curve of Spee increased and males have significantly larger arch dimensions than those of females. Conclusion: It was concluded that dental arch dimensions were associated with facial vertical morphology and gender. Thus, using individualized archwires according to each patient′s pretreatment arch form and width is suggested during orthodontic treatment.

  6. Model analysis of changes in dental arch width before and after orthodontic treatment with MBT appliance%MBT矫治前后牙弓宽度变化的模型分析研究

    Institute of Scientific and Technical Information of China (English)

    张良

    2012-01-01

    目的 分析牙列拥挤患者不拔牙与拔牙的MBT矫治对牙弓宽度变化的影响.方法 选择我院正畸科2008-2011年MBT矫治器治疗的牙列拥挤患者40例.其中轻中度牙列拥挤患者20例,使用MBT矫治器进行不拔牙正畸;中重度牙列拥挤患者20例,使用MBT矫治器进行拔除4颗第一前磨牙的拔牙正畸.测量术前术后石膏模型的牙弓宽度,对矫治前后不拔牙组和拔牙组的测量数据分别进行组内、组间统计学分析.结果 矫治前后不拔牙组:上颌尖牙间宽度增大,上下颌第一前磨牙、第一磨牙间宽度增大,有统计学意义;拔牙组:上颌尖牙间宽度增大,上下颌第二前磨牙、第一磨牙间宽度变小,有统计学意义.矫治前2组上下颌尖牙、第一磨牙间牙弓宽度相近,无统计学差异;矫治后不拔牙组上下颌第一磨牙间牙弓宽度大于拔牙组,有统计学意义,2组上下颌尖牙间牙弓宽度相近,差异无统计学意义.结论 不拔牙矫治牙弓宽度变化与拥挤部位、拥挤程度有关,拔牙矫治牙弓宽度变化主要与牙齿移动方向有关.拔牙矫治后尖牙间宽度不会减小.%Objective To investigate the changes of dental arch width after extraction and nonextraction treatment with MBT appliance. Methods 40 patients with crowded denture who received treatment with MBT appliance from 2008 to 2011 in our hospital were randomly selected. 20 patients with mild dental crowding who received nonextraction treatment were in the nonextraction group, while 20 patients with severe dental crowding whose 4 first premolars were extracted in the treatment with MBT appliance were in the extraction group. SPSS 11.0 software package was used for paired-samples t Test and independent-samples t Test. Results The upper inter-canine widths, the upper and lower inter-first bicuspid widths, the upper and lower inter-first molar widths of nonextraction cases increased significantly after the treatment. The

  7. Occlusal stability in shortened dental arches.

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    Witter, D J; Creugers, N H; Kreulen, C M; de Haan, A F

    2001-02-01

    Shortened dental arches consisting of anterior and premolar teeth have been shown to meet oral functional demands. However, the occlusal stability may be at risk as a result of tooth migration. The aim of this nine-year study was to investigate occlusal stability in shortened dental arches as a function over time. Occlusal stability indicators were: 'interdental spacing', 'occlusal contacts of anterior teeth in Intercuspal Position', 'overbite', 'occlusal tooth wear', and 'alveolar bone support'. Subjects with shortened dental arches (n = 74) were compared with subjects with complete dental arches (controls, n = 72). Repeated-measurement regression analyses were applied to assess age-dependent variables in the controls and to relate the occlusal changes to the period of time since the treatment that led to the shortened dental arches. Compared with complete dental arches, shortened dental arches had similar overbite and occlusal tooth wear. They showed more interdental spacing in the premolar regions, more anterior teeth in occlusal contact, and lower alveolar bone scores. Since the differences remained constant over time, we conclude that shortened dental arches can provide long-term occlusal stability. Occlusal changes were self-limiting, indicating a new occlusal equilibrium.

  8. CORRELATION BETWEEN DURATION OF BOTTLE-FEEDING AND DENTAL ARCH MEASUREMENT IN DECIDUOUS DENTITION

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    Meldo Mahniza

    2015-06-01

    Full Text Available The purpose of this study was to observe the correlation between duration of bottle feeding and dental arch measurement in deciduous dentition. Duration of bottle feeding was divided into 4 groups: ≤ 24 months, 25 – 36 months, 37 – 48 months, and > 48 months. The subjects were 120 kindergarten pupils, aged 3 – 5 years old. Measurements was done on the models of maxilla and mandible with digital caliper for the width and length of dental arch and using flexible curve for dental arch circumference. Pearson correlation showed a weak association for anterior arch width (r=0.206, posterior arch width (r=0.195, and anterior circumference (r=0.206 of maxilla and posterior arch width (r=0.279, anterior circumference (r=0.226 of mandible. One-way Anova was performed to analyze the differences of dental arch measurements among duration of bottle-feeding groups. The results showed that there were significant differences of dental arch measurements for anterior arch width of maxilla, posterior arch width of mandible, and anterior circumference of mandible (p<0,05.

  9. Measurement of width on labial keratinized gingiva of anterior dental arch of 120 Chinese Han-nationality youth%120名汉族青年前段牙弓唇侧角化龈宽度的测量

    Institute of Scientific and Technical Information of China (English)

    张艳玲; 张豪; 胡文杰; 孟焕新

    2010-01-01

    Objective To measure the width of keratinized gingiva and attached gingiva of anterior dental arch in order to establish reference guidance for periodontal surgery. Methods A total of 120 healthy Chinese Hart-nationality volunteers aged 20-30 years with healthy gingival tissue were recruited. The width of anterior labial dental arch, keratinized gingiva of gingival zenith, depth of gingival sulcus, and the width of coronal-apical keratinized gingiva of interdental papilla were measured respectively and the data were statistically analyzed. Results The width of keratinized gingiva and attached gingiva at gingival zenith varied for each individual and tooth location, ranging up to (5.6 ± 1.3) mm in the anterior maxillary region and (4. 5 ± 1.1 ) mm in the anterior submandibular region. The width decreased over the canine and first premolar and increased slightly over the second premolar. The width of keratinized gingiva at interdental papilla ranged from ( 6. 2 ± 1.3 ) mm to ( 8. 9 ± 1.4) mm in the maxilla and from ( 5. 8 ± 1.0 ) mm to (7.6 ±0. 9) mm in the mandible. The narrowest width of keratinized gingiva at interdental papilla was located over central incisors. Conclusions There is a variation of width on labial keratinized gingiva of anterior dental arch of Han nationality youth among different individuals and tooth locations.%目的 通过测量获取前段牙弓唇侧角化龈和附着龈宽度的相关数据,以期为牙周解剖和牙周手术提供参考.方法 选择20~30岁牙龈健康的汉族青年120人,分别测量前段牙弓唇侧龈缘高点处角化龈宽度及龈沟深度、邻间牙龈乳头尖端处冠根向角化龈宽度,并对数据进行统计学分析.结果 龈缘高点相应处角化龈宽度在上颌前段牙弓最宽可达(5.6±1.3)mm,在下颌前段牙弓最宽可达(4.5±1.1)mm,且以切牙区最宽,尖牙、第一前磨牙其宽度逐渐变窄,第二前磨牙开始增宽;上、下颌前段牙弓邻间牙龈乳头尖端相

  10. Dental Arch Dimension of Malay Ethnic Group

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    H. A. Mohammad

    2011-01-01

    Full Text Available Problem statement: Many previous studies tried to define and put specific measurements for dental arches dimension in different ethnics groups. However, these studies may be specific to an ethnic group and cannot always be applied to other ethnic types. The aim of this study: is to obtain specific dental arch dimensions for Malaysian Malay ethnic groups and compare between both genders. Approach: Involved clinical examination, collection and analysis of 60 dental cast of Malaysian Malay subjects from pure ethnic group (30 males and 30 females, 20-24 years old. All dental landmarks were located and determined and subsequently measurements had been done according to specific points have been selected. Statistical analysis were done using t-test. Results: Dental arch dimension were established in normal occlusion for Malaysian Malay ethnic group in this study. No significant difference was observed in arch dimensions between male and female of Malaysian Malay. Conclusion: These measurement should be considered during treatment, especially in prosthodontics and orthodontics where arch dimension can be modified appreciably.

  11. Effect of serial extraction alone on crowding: relationships between tooth width, arch length, and crowding.

    Science.gov (United States)

    Yoshihara, T; Matsumoto, Y; Suzuki, J; Sato, N; Oguchi, H

    1999-12-01

    In this study, we examined the effect of serial extraction alone on crowding. We also investigated the relationships between tooth width, arch length, and irregularity index. Maxillary dental casts from 32 subjects who had undergone only serial extraction were analyzed at 3 stages: before deciduous canines extraction, after first premolars extraction, and at the end of the observation period. The mean of the irregularity index decreased significantly as serial extraction proceeded and further decreased during the observation period. In cases where the width of the incisor was more than 2 standard deviations above the means for the control subjects, there was a significant correlation between tooth width of the lateral incisors and irregularity index before extraction as well as a significant correlation between the summation of tooth widths of the central and lateral incisors and irregularity index at that time. There was a significant negative correlation between arch length discrepancy and irregularity index before extraction and also a significant correlation between arch length discrepancy and correction of the irregularity index from before deciduous canines extraction to after first premolars extraction. These results suggest that tooth width and arch length discrepancy might preferentially affect the degree of anterior crowding in cases of severe crowding. There was no aggravation of the average crowding level during the observation period in the present study. The present study quantitatively suggested that serial extraction was useful for the purpose of correcting crowding in most cases.

  12. Differences between dentitions with palatally and labially located maxillary canines observed in incisor width, dental morphology and space conditions

    DEFF Research Database (Denmark)

    Artmann, L; Larsen, H J; Sørensen, H B;

    2010-01-01

    To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases.......To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases....

  13. Dental arch diameters and relationships to oral habits.

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    Aznar, T; Galán, A F; Marín, I; Domínguez, A

    2006-05-01

    The objective was to analyze variations in dental arch width in relation to oral habits. Maxillary and mandibular intercanine and intermolar distance were determined in relation to certain oral habits in 1297 children (ages 3 to 6 years). After an oral examination, the parents of each child completed a questionnaire about oral habits, including the use of a dummy or a bottle (or both), finger sucking, mouth breathing, breast- or bottle-feeding, and duration of these habits. Data were subjected to statistical analysis by the chi-square test for qualitative variables and analysis of variance for quantitative variables with homogeneous variances. Statistical significance was P habits, the maxillary intercanine distance was less in children who used a dummy, especially one of a round design (P = .003). The maxillary intercanine distance was also less in children who breathed through their mouth (P = .002). In most cases, dummy use and mouth breathing were associated with a reduction in the intercanine distance in the maxillary arch. A dummy habit leads to a reduction in maxillary arch width, and mouth breathing causes a reduction in the size of both arches.

  14. The association between dental arch dimensions and occurrence of Finnish dental consonant misarticulations in cleft lip/palate children.

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    Laitinen, J; Ranta, R; Pulkkinen, J; Haapanen, M L

    1998-10-01

    The aim of this study was to examine whether maxillary and mandibular dental arch width, length, and palatal height dimensions are associated with the occurrence of misarticulations (phonetic or phonologic errors) in the dental consonants /r/, /s/, and /1/ in different cleft types and sexes. The subjects were 263 (109 girls, 154 boys) 6-year-old Finnish-speaking non-syndromic children with isolated cleft palate (CP, n=79), deft lip/alveolus (CL(A), n=77), unilateral (UCLP, n=80), and bilateral (BCLP, n=27) cleft lip and palate. Dental plaster casts were measured by two authors using the technique of Moorrees, and auditive speech was analyzed with high reliability by two speech pathologists. The results showed that the occurrence of misarticulations increased and dental arch dimensions decreased with the severity of the cleft. Narrower and shorter maxillary arches as well as shallower palates were related to problems with the studied dental consonants. Mandibular arch dimensions were not related to the misarticulations. However, statistical analysis did not reveal significant differences in dental arch dimensions between subjects with and without misarticulations when they were compared separately for different cleft types. The etiology of clefting per se--isolated deft palate versus cleft lip with or without deft palate--did not seem to explain the associations between dental arch dimensions and the studied misarticulations.

  15. Description of dental arch form using the Fourier series.

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    Valenzuela, A Patricia; Pardo, Marco A; Yezioro, Salomon

    2002-01-01

    The aim of this study was to describe the form of the human superior dental arch using Fourier transformations. Forty models made in dental stone from impressions of the maxillary dental arch were used to obtain the reference data, which were expressed in Cartesian coordinates, from the mesovestibular cuspid vertices of molar teeth, vestibular cuspid of premolars, and incisal edge. Fourth-grade equations and Fourier series were calculated from these data. The results indicate that Fourier series more precisely express the form and size of different dental arches, with mixed or permanent dentition, than fourth-grade equations. Details of the mathematical procedure and the precision obtained were provided.

  16. Knowledge and attitudes of dentists toward shortened dental arch ...

    African Journals Online (AJOL)

    2015-08-03

    Aug 3, 2015 ... Key words: Attitude, dentist, knowledge, shortened dental arch. Date of Acceptance: ... practice of SDA therapy among dentists in Saudi Arabia, no studies are available in ..... partial denture was similar. Therefore, the attitude ...

  17. Effects of Asthma and Inhalation corticosteroids on the dental arch morphology in children

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    S S Kumar

    2012-01-01

    Full Text Available Background: Hereditary, environmental and developmental factors play an important role in dentofacial development, as well as the initiation of malocclusion disorder. Allergic phenomenon such as asthma that induces an alternative mode of breathing in patients is a contributing factor in development of the dental arch. Aim: Our aim in this study was to evaluate the dentoalveolar morphology in asthmatic children and to analyze the effects of asthmatic medications on the dental arch. Setting and Design : This study is centered on 44 asthmatic children aged between 6-12 years from J.S.S Hospital, Mysore. Selected variables from model analysis of the casts of the asthmatic group were subjected to comparison with those of the non-asthmatic group, which comprised of 44 non-asthmatic children. Selected parameters were arch width, arch length and palatal depth. Materials and Methods : Impressions of upper and lower arches were made with rubber based impression material. A sliding digital caliper was used to measure the casts for arch width and arch length. A palatal depth gauge was used to measure the palatal depth. Statistical Analysis : Differences in arch widths, arch lengths and palatal depths between asthmatics and non-asthmatics groups were evaluated by independent sample t-tests. Chi-square test was applied to assess the frequency of occurrence of malocclusion in the asthmatic children. Result: The results obtained revealed that the arch length and palatal depth of asthmatic group had higher values compared to that of non-asthmatic groups for both age groups (6 to 8-year-old males and females, 10 to 12-year-old males and females. Inter molar width showed a significant lower value in asthmatics in the maxillary arches of 10 to 12-year-old females. Fifty percent of the asthmatic children aged 10 to 12-years had open-bite. Children under regular medication showed significant deviation in the dentoalveolar morphology as compared to those under

  18. Arch width changes in patients with Class II division 1 malocclusion treated with maxillary first premolar extraction and non-extraction method.

    Science.gov (United States)

    Shirazi, Sajjad; Kachoei, Mojgan; Shahvaghar-Asl, Naiemeh; Shirazi, Samaneh; Sharghi, Reza

    2016-10-01

    The aim of this study was to determine arch width changes during maxillary first premolars extraction and non-extraction treatment in patients with Class II division 1 malocclusion. Dental casts of 91 Class II division 1 patients (36 males and 55 females) were evaluated. The minimum age of the subjects at the beginning of treatment was above 16 years. 48 patients were treated with extraction of the maxillary first premolars and 43 patients were treated without extraction. Pre- and post-treatment maxillary and mandibular inter-canine and inter-molar arch widths were measured. At the end of treatment, maxillary and mandibular inter-canine widths of both groups increased significantly. The maxillary inter-molar width decreased in the extraction group and increased in the non-extraction group. The mandibular inter-molar width increased significantly in both groups. No significant differences were observed between males and females. The results of this study indicated that there was a tendency for an increase in arch width during both the extraction and non-extraction treatment except maxillary inter-molar width in the extraction cases. Key words:Dental arch, malocclusion, angle Class II, tooth movement, extraction.

  19. Arch width changes in patients with Class II division 1 malocclusion treated with maxillary first premolar extraction and non-extraction method

    Science.gov (United States)

    Shirazi, Sajjad; Kachoei, Mojgan; Shahvaghar-Asl, Naiemeh; Shirazi, Samaneh

    2016-01-01

    Background The aim of this study was to determine arch width changes during maxillary first premolars extraction and non-extraction treatment in patients with Class II division 1 malocclusion. Material and Methods Dental casts of 91 Class II division 1 patients (36 males and 55 females) were evaluated. The minimum age of the subjects at the beginning of treatment was above 16 years. 48 patients were treated with extraction of the maxillary first premolars and 43 patients were treated without extraction. Pre- and post-treatment maxillary and mandibular inter-canine and inter-molar arch widths were measured. Results At the end of treatment, maxillary and mandibular inter-canine widths of both groups increased significantly. The maxillary inter-molar width decreased in the extraction group and increased in the non-extraction group. The mandibular inter-molar width increased significantly in both groups. No significant differences were observed between males and females. Conclusions The results of this study indicated that there was a tendency for an increase in arch width during both the extraction and non-extraction treatment except maxillary inter-molar width in the extraction cases. Key words:Dental arch, malocclusion, angle Class II, tooth movement, extraction. PMID:27703608

  20. Comparison of maxillary and mandibular dental arch forms by studying Fourier series developed from mathematically estimated dentitions.

    Science.gov (United States)

    Mikami, Hiroko; Nakatsuka, Michiko; Iwai, Yasutomo

    2010-11-01

    We conducted a Fourier analysis on data obtained using correlation and principal component analyses of parallel-standardized dental study models; both maxillary and mandibular dental arches were predominantly round square in shape. The present study compared and determined the contribution ratio and reproducible coefficients of amplitudes (factors affecting dental arch forms), and demonstrated that the 1st to 4th and the 1st to 6th Fourier harmonics reproduced maxillary and mandibular dental arch forms, respectively. The correlation analyses of the constant term and amplitudes demonstrated that significant differences in the 2nd harmonic amplitude was strongly correlated with the curvature of anterior teeth and the length-to-width ratio in maxillary dentitions. By comparison of the constant term and amplitudes between different arch types, we did not observe significant differences in the constant term and the 1st amplitude of maxillary dentitions and in constant term and all amplitudes of mandibular dentitions. Nevertheless, the study revealed high contribution ratios of the 1st (in mandibular dentitions) and the 2nd (in maxillary dentitions) amplitudes essentially affecting the reproducibility of arch forms. The 1st amplitudes demonstrated a bow-like arrangement of all arch types, while the 2nd amplitudes adjusted the anterior-teeth curvature and in particular demonstrated the length-to-width ratio of maxillary dentitions. The 3rd and the 4th amplitudes were also determinants of the anterior-teeth curvature of maxillary dentitions. The 6th amplitude was necessary for reproduction, but showed no difference between varying mandibular dental arch types. Collectively, we conclude that the establishment of a Fourier series significantly reproduced maxillary but not mandibular dental arch forms.

  1. Dental crowding in primary dentition and its relationship to arch and crown dimensions among preschool children of Davangere.

    Science.gov (United States)

    Prabhakar, A R; Ravi, G R; Kurthukoti, Ameet J; Shubha, A B

    2008-01-01

    The purpose of the present study was to evaluate dental crowding in the deciduous dentition and its relationship to the crown and the arch dimensions among preschool children of Davangere. Stratified randomized selection of one hundred, 3-4 year old healthy children with all primary teeth erupted was done and divided into two groups. One group had children with anterior crowding in both the arches while the other had spacing. Alginate impressions of the upper and lower arches were made and the study casts were obtained. The tooth and arch dimensions were determined. Mesiodistal dimensions of all the teeth were significantly larger in the crowded arch group. However, the buccolingual dimensions of the maxillary right central incisor, mandibular lateral incisors and the maxillary molars and the crown shape ratio of maxillary lateral incisors, mandibular canines and mandibular right second molar was statistically different. No significant correlation was found between the arch width and the presence of crowding of deciduous dentition. The arch depth of the spaced dentition was greater when compared to the crowded ones. The arch perimeter of the crowded arches was significantly less than the spaced arches.

  2. Arch width changes in patients with Class II division 1 malocclusion treated with maxillary first premolar extraction and non-extraction method

    OpenAIRE

    Shirazi, Sajjad; Kachoei, Mojgan; Shahvaghar-Asl, Naiemeh; Shirazi, Samaneh; Sharghi, Reza

    2016-01-01

    Background The aim of this study was to determine arch width changes during maxillary first premolars extraction and non-extraction treatment in patients with Class II division 1 malocclusion. Material and Methods Dental casts of 91 Class II division 1 patients (36 males and 55 females) were evaluated. The minimum age of the subjects at the beginning of treatment was above 16 years. 48 patients were treated with extraction of the maxillary first premolars and 43 patients were treated without ...

  3. THE ETIOLOGICAL FACTORS INVOLVED IN DENTAL ARCH PERIMETER SHORTENING

    Directory of Open Access Journals (Sweden)

    Liliana Ioana Vâţă

    2012-12-01

    Full Text Available The main purpose of the study was to highlight the causes that may lead to reduction of arches: early loss of deciduous teeth, with consecutive dental drifting on the arch, followed by narrowing of the space necessary for the eruption of successional teeth, caries of the deciduous teeth or ectopic eruption of the first permanent molars. The mesial position of M1 had a frequency of 19.31% of the total number of analysed cases; maximum frequencies have been registered for the localization on the lower arch; M1 ectopia has rarely occurred on the studied batch; the frequency of lateral group mesial position was of 10.34% on the studied batch, registering maximum values for the localisation on the upper arch. The early loss of deciduous teeth was identified in almost 30% of the analysed cases, while the reduction of the space necessary for the eruption of successional teeth was registered in almost 39% of cases, space narrowing resulting both from the caries of deciduous teeth and from their early loss.

  4. Automatic dental arch detection and panoramic image synthesis from CT images.

    Science.gov (United States)

    Sa-Ing, Vera; Wangkaoom, Kongyot; Thongvigitmanee, Saowapak S

    2013-01-01

    Due to accurate 3D information, computed tomography (CT), especially cone-beam CT or dental CT, has been widely used for diagnosis and treatment planning in dentistry. Axial images acquired from both medical and dental CT scanners can generate synthetic panoramic images similar to typical 2D panoramic radiographs. However, the conventional way to reconstruct the simulated panoramic images is to manually draw the dental arch on axial images. In this paper, we propose a new fast algorithm for automatic detection of the dental arch. Once the dental arch is computed, a series of synthetic panoramic images as well as a ray-sum panoramic image can be automatically generated. We have tested the proposed algorithm on 120 CT axial images and all of them can provide the decent estimate of the dental arch. The results show that our proposed algorithm can mostly detect the correct dental arch.

  5. Effects of removable dental prostheses on masticatory performance of subjects with shortened dental arches: A systematic review

    NARCIS (Netherlands)

    Liang, S.; Zhang, Q.; Witter, D.J.; Wang, Y.; Creugers, N.H.J.

    2015-01-01

    OBJECTIVE: To synthesise data on the effects of distal-extension removable dental prostheses (RDPs) on masticatory performance of subjects with (extreme) shortened dental arches ((E)SDAs). DATA: Search terms were: 'masticatory' respectively 'chewing' combined with 'performance', 'efficiency', or

  6. Three-dimensional digital evaluation of dental arches in infants with cleft lip and/or palate.

    Science.gov (United States)

    Fernandes, Viviane Mendes; Jorge, Paula Karine; Carrara, Cleide Felício Carvalho; Gomide, Márcia Ribeiro; Machado, Maria Aparecida Andrade Moreira; Oliveira, Thais Marchini

    2015-01-01

    The aim of this study was to measure and compare the dimensions of the dental arches on three-dimensional digital study models in children with and without cleft lip and palate before the primary surgery. The sample consisted of 223 digital models of children aged 3-9 months, divided into 5 groups: without craniofacial deformities, unilateral and bilateral incomplete cleft lip and alveolus, unilateral and bilateral complete cleft lip and alveolus, unilateral cleft lip and palate, and bilateral cleft lip and palate. Dental casts of the maxillary dental arches of the children were used. The dental casts underwent a process of scanning through 3D scanner and the measurements used for the correlation among groups were made on the scanned images. Statistical analysis was performed by t test and ANOVA followed by Tukey test. The results showed that the intercanine distance and anterior cleft width was wider in children with unilateral cleft lip and palate. The intertuberosity distances and posterior cleft width was wider in children with bilateral cleft lip and palate among the groups. Children with cleft lip and palate before the primary surgery had wider maxillary arch dimensions than the children without cleft lip and palate.

  7. Effects of tongue volume reduction on craniofacial growth: A longitudinal study on orofacial skeletons and dental arches.

    Science.gov (United States)

    Liu, Zi-Jun; Shcherbatyy, Volodymyr; Gu, Gaoman; Perkins, Jonathan A

    2008-10-01

    The interaction between tongue size/volume and craniofacial skeletal growth is essential for understanding the mechanism of specific types of malocclusion and objectively measuring outcomes of various surgical and/or orthodontic treatments. Currently available information on this interaction is limited. This study was designed to examine how tongue body volume reduction affects craniofacial skeleton and dental arch formation during the rapid growth period in five 12-week-old Yucatan minipig sibling pairs. One of each pair received a standardized reduction glossectomy to reduce tongue volume by 15-17% (reduction group), and the other had the reduction glossectomy incisions without tissue removal (sham group). Before surgery, five stainless steel screws were implanted into standardized craniofacial skeletal locations. A series of cephalograms, lateral and axial, were obtained longitudinally at 1 week preoperative, and 2 and 4 weeks postoperative. These images were traced using superimposition, and linear and angular variables were measured digitally. Upon euthanasia, direct osteometric measurements were obtained from harvested skulls. Five en-bloc bone pieces were further cut for bone mineral examination by dual photon/energy X-ray absorptiometry (DEXA). The results indicate that: (1) while daily food consumption and weekly body weight were not significantly affected, tongue volume reduction showed an overall negative effect on the linear expansion of craniofacial skeletons; (2) premaxilla and mandibular symphysis lengths, and anterior dental arch width were significantly less in reduction than sham animals at 2 and/or 4 weeks after the surgery; (3) both premaxilla/maxilla and mandible bone mineral density and content were lower in reduction than sham animals, significantly lower in anterior mandible; (4) craniofacial skeletal and dental arch size were significantly smaller in reduction than sham animals, being most significant in the mandibular anterior length and

  8. Comparison of dental arch dimensions in models of preschool children with cleft lip/palate repaired by means of surgery alone versus controls.

    Science.gov (United States)

    Burhan, Ahmad S; Nawaya, Fehmieh R

    2016-09-01

    Cleft lip and palate (CLP) anomaly is one of the most prevalent congenital defects causing disturbances of dental arch dimensions. This study aimed at investigating differences in these dimensions between preschool children with cleft lip/palate and a matched control group representing healthy individuals with normal occlusion (NO). The sample of this cross-sectional analytical study consisted of 108 plaster models of children aged from 4 to 5.5 years. They were divided into five groups: the cleft lip group, the cleft palate (CP) group, the unilateral cleft lip and palate group, the bilateral cleft lip and palate group, and the NO group. The NO group was used as a control group. All cleft-affected children were treated only with surgery. Dental arch length and widths were measured. The dental arch dimensions of the cleft lip group were nearly similar to those in the controls. Moreover, the mandibular transverse widths of the CP group were close to those in the controls. However, the mandibular arch length and all maxillary dimensions of the CP group were smaller than those in the controls. In the unilateral cleft lip and palate group, the arch lengths in both jaws and the maxillary transverse widths were smaller than those in the controls, whereas the mandibular transverse widths were similar to those in the controls. In the bilateral cleft lip and palate group, the arch lengths in both jaws were close to those in the controls, but both arches were narrower than those in the controls. The various types of CLP were found to be associated with differences in most maxillary and some mandibular arch dimensions. These data can be used for cleft patient counseling and treatment planning.

  9. [Effect of dental arch length decrease during orthodontic treatment in the upper airway development. A review].

    Science.gov (United States)

    Haddad, Stéphanie; Kerbrat, Jean-Baptiste; Schouman, Thomas; Goudot, Patrick

    2017-03-01

    A possible relation between an upper airway space decrease and the development of obstructive sleep apnea syndrom explains the importance to know the effect of the modification of dental arch length on the upper airway during orthodontic treatment. The aim of this article is to expose recent knowledge about upper airway development and dental arch length decrease factors, to determine the influence of this decrease on upper airway development. A review was done to determine the upper airway normal development, to define dental arch to specify if an ideal position of dental arch on apical base exists. All of the length dental arch decrease factors during orthodontic treatment (dental extraction, dental agenesis and dental malpositions) and their upper airway resounding were searched. Some authors found a diminution of upper airway space after premolars extractions while others didn't found this diminution after extractions premolars when incisor retraction is finished. A decrease of transversal maxillary diameter and nasal cavity may be due to absence of permanent teeth. The effect of dental arch length decrease during orthodontic treatment in the upper airway development was not scientifically proved. However we had to be vigilant and adapt our orthodontic treatment case by case to avoid an upper airway modification. © EDP Sciences, SFODF, 2017.

  10. A 40 years follow-up of dental arch dimensions and incisor irregularity in adults.

    Science.gov (United States)

    Tsiopas, Nikolaos; Nilner, Maria; Bondemark, Lars; Bjerklin, Krister

    2013-04-01

    Dentoalveolar changes in adulthood have not been extensively documented. Such changes may have important implications for the long-term stability of orthodontic treatment. To analyse occlusal and dentoalveolar changes in adults from the age of 20 years to the age of 60 years. The material comprised 18 Swedish dentists, 16 men and 2 women, with no missing teeth and no prosthodontic or orthodontic treatment. Measurements were recorded on study casts made between 1949 and 1989 at the Department of Stomatognathic Physiology at the Faculty of Odontology in Malmö, thus documenting changes over an average period of 38.4 years. Malocclusion traits, overbite, overjet, dental arch length and width, and Little's irregularity index were registered. There was a significant increase in Little's irregularity index in the mandible (1.0 mm, P overjet remained unchanged during the observation period. The results confirm that dentoalveolar changes occur as a continuous process throughout adult life. The findings of potential clinical importance are decreases in arch length and depth, resulting in a decrease in intercanine width and an increase in anterior crowding. In clinical orthodontic practice, these findings have important implications for treatment planning and long-term stability after orthodontic treatment.

  11. Correlation Between Maxillary Central Incisor Crown Morphology And Mandibular Dental Arch Form In Normal Occlusion Subjects

    OpenAIRE

    Paranhos, Luiz Renato; Lima,Carolina Souto; Silva,Ricardo Henrique Alves da; Daruge Júnior,Eduardo; Torres,Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were ob...

  12. MATHEMATICAL ANALYSIS OF DENTAL ARCH OF CHILDREN IN NORMAL OCCLUSION: A LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    M. Abu-Hussein DDS, MScD, MSc, DPD

    2012-03-01

    Full Text Available AIM. This paper is an attempt to compare and analyze the various mathematical models for defining the dental arch curvature of children in normal occlusion based upon a review of available literature. Background. While various studies have touched upon ways to cure or prevent dental diseases and upon surgical ways for teeth reconstitution to correct teeth anomalies during childhood, a substantial literature also exists, attempting to mathematically define the dental arch of children in normal occlusion. This paper reviews these dental studies and compares them analytically. Method. The paper compares the different mathematical approaches, highlights the basic assumptions behind each model, underscores the relevancy and applicability of the same, and also lists applicable mathematical formulae. Results. Each model has been found applicable to specific research conditions, as a universal mathematical model for describing the human dental arch still eludes satisfactory definition. The models necessarily need to include the features of the dental arch, such as shape, spacing between teeth and symmetry or asymmetry, but they also need substantial improvement. Conclusions. While the paper shows that the existing models are inadequate in properly defining the human dental arch, it also acknowledges that future research based on modern imaging techniques and computeraided simulation could well succeed in deriving an allinclusive definition for the human dental curve till now eluding the experts.

  13. Correlation between maxillary central incisor crown morphology and mandibular dental arch form in normal occlusion subjects.

    Science.gov (United States)

    Paranhos, Luiz Renato; Lima, Carolina Souto; da Silva, Ricardo Henrique Alves; Daruge Júnior, Eduardo; Torres, Fernando Cesar

    2012-01-01

    The aim of this study was to evaluate the correlation between the morphology of the mandibular dental arch and the maxillary central incisor crown. Cast models from 51 Caucasian individuals, older than 15 years, with optimal occlusion, no previous orthodontic treatment, featuring 4 of the 6 keys to normal occlusion by Andrews (the first being mandatory) were observed. The models were digitalized using a 3D scanner, and images of the maxillary central incisor and mandibular dental arch were obtained. These were printed and placed in an album below pre-set models of arches and dental crowns, and distributed to 12 dental surgeons, who were asked to choose which shape was most in accordance with the models and crown presented. The Kappa test was performed to evaluate the concordance among evaluators while the chi-square test was used to verify the association between the dental arch and central incisor morphology, at a 5% significance level. The Kappa test showed moderate agreement among evaluators for both variables of this study, and the chi-square test showed no significant association between tooth shape and mandibular dental arch morphology. It may be concluded that the use of arch morphology as a diagnostic method to determine the shape of the maxillary central incisor is not appropriate. Further research is necessary to assess tooth shape using a stricter scientific basis.

  14. Edentulism and shortened dental arch in Brazilian elderly from the National Survey of Oral Health 2003

    Directory of Open Access Journals (Sweden)

    Marco Túlio Freitas Ribeiro

    2011-10-01

    Full Text Available OBJECTIVE: To describe the distribution of edentulism and estimate the prevalence of functional dentition and shortened dental arch among elderly population. METHODS: A population-based epidemiological study was carried out with a sample of 5,349 respondents aged 65 to 74 years obtained from the 2002 and 2003 Brazilian Ministry of Health/Division of Oral Health survey database. The following variables were studied: gender; macroregion of residence; missing teeth; percentage that met the World Health Organization goal for oral health in the age group 65 to 74 years (50% having at least 20 natural teeth; presence of shortened dental arch; number of posterior occluding pairs of teeth. The Chi-square test assessed the association between categorical variables. The Kruskal-Wallis and Mann-Whitney tests were used to assess differences of mean between number of posterior occluding pairs teeth, macro-region and gender. RESULTS: The elderly population had an average of 5.49 teeth (SD: 7.93 with a median of 0. The proportion of completely edentulous respondents was 54.7%. Complete edentulism was 18.2% in the upper arch and 1.9% in the lower arch. The World Health Organization goal was achieved in 10% of all respondents studied. However, only 2.7% had acceptable masticatory function and aesthetics (having at least shortened dental arch and a mean number of posterior occluding pairs of 6.94 (SD=2.97. There were significant differences of the percentage of respondents that met the World Health Organization goal and presence of shortened dental arch between men and women. There were differences in shortened dental arch between macroregions. CONCLUSIONS: The Brazilian epidemiological oral health survey showed high rate of edentulism and low rate of shortened dental arch in the elderly population studied, thus suggesting significant functional and aesthetic impairment in all Brazilian macroregions especially among women.

  15. Decayed/missing/filled teeth and shortened dental arches in Tanzanian adults.

    NARCIS (Netherlands)

    Sarita, P.T.N.; Witter, D.J.; Kreulen, C.M.; Matee, M.I.N.; Hof, M.A. van 't; Creugers, N.H.J.

    2004-01-01

    PURPOSE: This study assessed decayed/missing/filled teeth (DMFT), presence of occlusal units, and prevalence of shortened dental arches in a Tanzanian adult population. MATERIALS AND METHODS: The dental state of samples of the Tanzanian population was studied. Oral examinations were conducted on

  16. Decayed/missing/filled teeth and shortened dental arches in Tanzanian adults.

    NARCIS (Netherlands)

    Sarita, P.T.N.; Witter, D.J.; Kreulen, C.M.; Matee, M.I.N.; Hof, M.A. van 't; Creugers, N.H.J.

    2004-01-01

    PURPOSE: This study assessed decayed/missing/filled teeth (DMFT), presence of occlusal units, and prevalence of shortened dental arches in a Tanzanian adult population. MATERIALS AND METHODS: The dental state of samples of the Tanzanian population was studied. Oral examinations were conducted on 5,5

  17. Predictors of poor dental arch relationship in young children with unilateral cleft lip and palate.

    Science.gov (United States)

    Hsieh, Yuh-Jia; Liao, Yu-Fang; Shetty, Akshai

    2012-08-01

    The aim of this cross-sectional outcome study using retrospective data capture of treatment histories was to examine the characteristics of young children with unilateral cleft lip and palate who had poor dental arch relationship (i.e., Goslon 5). The study sample comprised 120 children born with nonsyndromic complete unilateral cleft lip and palate between 1995 and 2003, and were aged between 5.0 and 7.0 years (mean age, 5.1 years) at the time of data collection. The dental arch relationship was assessed using the Goslon yardstick from intraoral dental photographs. An independent investigator recorded treatment histories from the clinical notes. The inter- and intraexaminer agreements evaluated by weighted kappa statistics were high. There was no association between dental arch relationship and the type of presurgical orthopedics or pharyngeal flap. Dental arch relationship was associated with the initial cleft size (odds ratio, OR = 1.3; 95% confidence interval, CI = 1.1-1.5, p palate repair (OR = 5.0, 95% CI = 1.2-19.9, p cleft, high-volume surgeon, and primary gingivoperiosteoplasty are predictors of poor dental arch relationship outcome in young children with unilateral cleft lip and palate. These findings may improve treatment outcome by modifying the treatment protocol for patients with unilateral cleft lip and palate.

  18. Effects of unilateral premolar extraction treatment on the dental arch forms of Class II subdivision malocclusions.

    Science.gov (United States)

    Dahiya, Ginu; Masoud, Ahmed I; Viana, Grace; Obrez, Ales; Kusnoto, Budi; Evans, Carla A

    2017-08-01

    A retrospective study evaluating posttreatment symmetry in dental arch form and midlines was carried out in Class II subdivision patients treated with unilateral and bilateral maxillary premolar extractions. Using Geomagic (version 14; Geomagic, Research Triangle Park, NC) and MATLAB (version 8.4; MathWorks, Natick, Mass) software, best-fit curves expressed as quartic polynomials were generated for 13 Class II subdivisions treated with unilateral extractions and 20 treated with bilateral maxillary premolar extractions. Transverse and sagittal measurements were recorded to assess symmetry. Dental models were superimposed on constructed reference planes to generate average posttreatment arches. Statistical comparisons were performed with the significance level set at P ≤0.05. The unilateral extraction group showed significant differences in transverse arch forms between the right and left sides in the anterior, anterior-middle, and middle segments of the arch, and all regions other than the posterior segment in the sagittal dimension. Significant differences were found between groups in the anterior and anterior-middle segments of the arch transversely, the middle and middle-posterior segments sagittally, and the midline deviation relative to the midsagittal plane. Superimposed average arches showed similar results. Unilateral maxillary extraction treatment generally results in a narrower and more posteriorly displaced arch form on the extraction side, with a deviated maxillary midline toward the extraction side of the arch. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  19. Transversal changes in dental arches from non-extraction treatment with self ligating brackets

    OpenAIRE

    Liliana Avila Maltagliati; Yasushi Inoue Myiahira; Liana Fattori; Leopoldino Capelozza Filho; Mauricio Cardoso

    2013-01-01

    OBJECTIVE: The present study aimed at analyzing, with the use of dental casts, the transverse changes of the upper and lower dental arches, after non-extraction orthodontic treatment, with self-ligating brackets. METHODS: The sample comprised 29 patients, all presenting Class I malocclusion with upper and lower crowding of at least 4 mm and treated only with a fixed appliance, without stripping, extraction or distalization. The dental casts were obtained before and after leveling with 0.019 x...

  20. An observational cohort study on shortened dental arches--clinical course during a period of 27-35 years

    NARCIS (Netherlands)

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

    2013-01-01

    OBJECTIVES: The objective of this study was to investigate the clinical course of shortened dental arches ('SDA group') compared to SDAs plus removable denture prosthesis ('SDA plus RDP group') and complete dental arches ('CDA group', controls). MATERIALS AND METHODS: Data (numbers of direct and

  1. The effect of sucking habits, cohort, sex, intercanine arch widths, and breast or bottle feeding on posterior crossbite in Norwegian and Swedish 3-year-old children.

    Science.gov (United States)

    Ogaard, B; Larsson, E; Lindsten, R

    1994-08-01

    The upper and lower intercanine arch widths and the prevalence of posterior crossbite were registered for 445 3-year-old children with and without a continuing or previous dummy-sucking or finger-sucking habit in different areas in Sweden and Norway. Sami children from northern Norway also took part in the study, as well as 15 medieval skulls with intact deciduous dentitions. Compared with the nonsuckers, an increased prevalence of posterior crossbite was observed for the finger suckers, especially the Swedish girls. Stepwise logistic regression showed that posterior crossbite could be predicted with upper intercanine arch width alone. The finger sucking variable would not improve prediction; neither did other entities such as cohort (residential area), sex, lower intercanine arch width, nor the difference between upper and lower intercanine arch width. High prevalences of posterior crossbite were registered for dummy suckers (pacifiers) especially the Swedish girls (26%). Stepwise logistic regression showed that posterior crossbite in dummy suckers could be predicted with upper and lower intercanine arch width. Stepwise linear regression showed that both arches tended to be narrower in Swedes and girls, and that dummy sucking decreased the upper and increased the lower intercanine arch width. Analyses of covariance revealed that at least 2 years of dummy sucking is necessary to produce a significant effect in the upper jaw and 3 years in the lower jaw.

  2. Transversal changes in dental arches from non-extraction treatment with self ligating brackets

    Directory of Open Access Journals (Sweden)

    Liliana Avila Maltagliati

    2013-06-01

    Full Text Available OBJECTIVE: The present study aimed at analyzing, with the use of dental casts, the transverse changes of the upper and lower dental arches, after non-extraction orthodontic treatment, with self-ligating brackets. METHODS: The sample comprised 29 patients, all presenting Class I malocclusion with upper and lower crowding of at least 4 mm and treated only with a fixed appliance, without stripping, extraction or distalization. The dental casts were obtained before and after leveling with 0.019 x 0.025-in stainless steel archwires. CONCLUSION: The results indicated that the majority of transverse changes occurred at the premolar areas, both the first and the second, as well as on the upper and lower dental arches. The intercanine distance increased 0.75 mm, on average, in the upper arch and 1.96 mm in the lower arch. The molars also demonstrated a tendency towards an increase in their transverse dimension, however, at a lower intensity comparing to premolars. All measurements presented statistically significant differences with the exception of the maxillary second molars.

  3. Effect of dental arch convexity and type of archwire on frictional forces

    NARCIS (Netherlands)

    Fourie, Zacharias; Ozcan, Mutlu; Sandham, John

    2009-01-01

    Introduction: Friction measurements in orthodontics are often derived from models by using brackets placed on flat models with various straight wires. Dental arches are convex in some areas. The objectives of this study were to compare the frictional forces generated in conventional flat and convex

  4. Effect of dental arch convexity and type of archwire on frictional forces

    NARCIS (Netherlands)

    Fourie, Zacharias; Ozcan, Mutlu; Sandham, John

    Introduction: Friction measurements in orthodontics are often derived from models by using brackets placed on flat models with various straight wires. Dental arches are convex in some areas. The objectives of this study were to compare the frictional forces generated in conventional flat and convex

  5. Effects of different types of palatal lateral excisions on growth and development of maxilla and dental arch

    Institute of Scientific and Technical Information of China (English)

    Jun WU; Qian ZHENG; Bing SHI; Tian MENG; Yan WANG; Sheng LI; Lishu LIAO

    2008-01-01

    Obiective:This study aimed to explore the effects of different types of palatal lateral excisions on the growth and deveiopment of the maxilla and dental arch.and to investigate the underlying mechanisms.Methods:A total of 1123-week-old Sprague-Dawley(SD)male rats were randomly divided into a control and 3 experimental groups:the mucoperiosteal denudation group,the mucosal flap excision group,and the periosteum excision group.In the experimental groups,bilateral mucoperiosteal,mucosal flap and periosteum were excised respectively in the lateral one half of the palate.Four rats in each group were randomly chosen for sacrifice every two weeks.The maxilla was dissected following the excision.The widths of the maxilla and dental arch were measured and the histological phenomena were investigated at different phases.At the same time.12 animals in each group were sequentially injected with calcein every two weeks.Three animals in each group,whose fluorescent labeling was used,were sacrificed for investigating bone formation at Week 8 following injection.Results:(1)Each experimental group presented the constriction of the maxilla and dental arch.The upper first molars in the experimental groups inclined medially.The mucoperiosteal denudation group showed the largest degree of effect followed by the periosteum excision group.The indices of the mucosal flap excision group,which retained the structures of the periosteum layer,had the most approximate values to the control group;(2)Different histological changes among the experimental groups were detected.The fibers penetrated into the palatal bone asSharpey's fibers in the mucoperiosteal denudation group.The pattern of bone deposition was the bundle type.Sharpey's fiberswerenotfoundinthemucosaI flapandperiosteum excisiongroups andthedepositions ofpalatalbonewerethelamellartypeasthose in the control group;(3)The rates ofbone deposition in the experimental groups decreased compared with the control group.The rates in different

  6. Secular changes in tooth size and dental arch dimensions in the mixed dentition.

    Science.gov (United States)

    Lindsten, Rune

    2003-01-01

    Secular changes in the mixed dentition were studied. Permanent tooth size and dental arch dimensions were examined in Norwegian children born in the 1960s and 1980s, Swedish children born in the 1960s and 1980s, Norwegian Sami children born in the 1980s, and a sample of Norwegian skulls dating from the 14th to the 19th century. The Norwegian Sami children were nomadic in the summertime. A sample of pigs was studied before and after a maceration process to determine what dimensional changes might occur in such a process. A shrinkage of 0.3%-1.7% was found. This information was used when the skulls were compared with the modern groups. Lateral dental arch lengths were shorter in the children born in the 1960s compared with the children born in the 1980s. This was a result of the higher prevalence of caries in the second deciduous molars in the 1960s groups. Children who had lost a deciduous canine prematurely were found to have smaller dental arch perimeters. When compared with other data, this was blamed on a pre-existing crowding. Permanent tooth size was smaller in the skulls compared with the modern groups. Improved nutrition is considered to be the main reason for the difference. Relative dental arch space differed in the group born in the 1960s from that in the other groups, indicating a greater prevalence of crowding in the former. Relative dental arch space in the skulls and in the group born in the 1980s was similar. A more traditional way of living, as practised by the Sami group in this thesis, was not favorable for relative dental arch space. The transverse intermaxillary relation in boys changed from the 1960s to the 1980s, which indicated that the 1980s group ran a greater risk of developing a posterior cross-bite. Before the same conclusion could be made in the girls, the mesial drift of the first permanent molars had to be corrected for, because of a higher prevalence of caries in the 1960s group. The sex-pooled analysis of the skulls and the

  7. Effect of dental arch convexity and type of archwire on frictional forces.

    Science.gov (United States)

    Fourie, Zacharias; Ozcan, Mutlu; Sandham, Andrew

    2009-07-01

    Friction measurements in orthodontics are often derived from models by using brackets placed on flat models with various straight wires. Dental arches are convex in some areas. The objectives of this study were to compare the frictional forces generated in conventional flat and convex dental arch setups, and to evaluate the effect of different archwires on friction in both dental arch models. Two stainless steel models were designed and manufactured simulating flat and convex maxillary right buccal dental arches. Five stainless steel brackets from the maxillary incisor to the second premolar (slot size, 0.22 in, Victory, 3M Unitek, Monrovia, Calif) and a first molar tube were aligned and clamped on the metal model at equal distances of 6 mm. Four kinds of orthodontic wires were tested: (1) A. J. Wilcock Australian wire (0.016 in, G&H Wire, Hannover, Germany); and (2) 0.016 x 0.022 in, (3) 0.018 x 0.022 in, and (4) 0.019 x 0.025 in (3M Unitek GmbH, Seefeld, Germany). Gray elastomeric modules (Power O 110, Ormco, Glendora, Calif) were used for ligation. Friction tests were performed in the wet state with artificial saliva lubrication and by pulling 5 mm of the whole length of the archwire. Six measurements were made from each bracket-wire combination, and each test was performed with new combinations of materials for both arch setups (n = 48, 6 per group) in a universal testing machine (crosshead speed: 20 mm/min). Significant effects of arch model (P = 0.0000) and wire types (P = 0.0000) were found. The interaction term between the tested factors was not significant (P = 0.1581) (2-way ANOVA and Tukey test). Convex models resulted in significantly higher frictional forces (1015-1653 g) than flat models (680-1270 g) (P model, significantly lower frictional forces were obtained with wire types 1 (679 g) and 3 (1010 g) than with types 2 (1146 g) and 4 (1270 g) (P model, the lowest friction was obtained with wire types 1 (1015 g) and 3 (1142 g) (P >0.05). Type 1 wire

  8. Comparison of two treatment protocols in children with unilateral complete cleft lip and palate: Tridimensional evaluation of the maxillary dental arch.

    Science.gov (United States)

    Jorge, Paula Karine; Gnoinski, Wanda; Vaz Laskos, Karine; Felício Carvalho Carrara, Cleide; Gamba Garib, Daniela; Okada Ozawa, Terumi; Andrade Moreira Machado, Maria Aparecida; Pinelli Valarelli, Fabrício; Oliveira, Thais Marchini

    2016-09-01

    The aim of this study was to evaluate the dimensional alterations of the maxillary dental arches after lip repair in children with unilateral complete cleft lip and palate of two different protocols. The sample was composed of 94 digital models and divided in two groups: Group I - 23 children, (protocol 1) - with presurgical orthopedic intervention: Hotz plate; Group II - 24 children, (protocol 2) - without presurgical orthopedic intervention. The three dimensional images of the maxillary arch were obtained before lip repair (stage 1) and at approximately 1 year of age (stage 2). Interstages changes for each group were evaluated using dependent t test and Wilcoxon test, and in the intergroup were used independent t test, and Mann-Whitney test. The comparison of the dimensional alterations of dental arches between the two protocols exhibited differences: in the stage 1, the intercanine was smaller in Group II; in the stage 2, the anterior cleft width, the intercanine and the anteroposterior cleft were smaller in Group II. The results reported here suggest that the use of infant orthopedic plate as applied in protocol 1 may favor correct arch form establishment in infants with unilateral complete cleft lip and palate. Copyright © 2016. Published by Elsevier Ltd.

  9. Dental arch changes from 22 to 43 years of age: are they different in individuals with high versus low mandibular plane angle?

    Science.gov (United States)

    Bondevik, Olav; Espeland, Lisen; Stenvik, Arild

    2015-08-01

    To investigate whether individuals with high and low mandibular plane angles, respectively, have different patterns of long-term dental arch changes in adulthood. The material comprised 16 low-angle (≤ 24.4 degree) and 10 high-angle individuals (≥38.7 degree). Mean age was 22.7 years when the first recordings were made (T1), and new recordings were made 10 (T2) and 20 (T3) years later. The individuals were orthodontically untreated except for three who had been out of retention for more than 5 years before T1. Lateral cephalograms and study casts were obtained on all three occasions. For the total observation period, the greatest mean changes were observed as a 1mm decrease of lower intercanine width and arch depths in both groups. Intermolar widths increased less than 0.5mm. Upper and lower crowding increased in the range of 0.5-0.7mm in the two groups. Only small changes occurred in overjet and overbite. Differences between groups were not significant except for lower anterior arch depth which decreased more in the low-angle group, and overjet which increased in the high- and decreased in the low-angle group. During both periods the changes were generally in the same direction. Changes in dental arch dimensions from third to fifth decade of life are small and generally similar in individuals with high versus low mandibular plane angles. The changes are for most variables in the same direction in the two periods examined. The only significant differences between the groups are the changes in lower arch depth and overjet. © The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Three-dimensional dental arch curvature in human adolescents and adults.

    Science.gov (United States)

    Ferrario, V F; Sforza, C; Poggio, C E; Serrao, G; Colombo, A

    1999-04-01

    The three-dimensional arrangement of dental cusps and incisal edges in human dentitions has been reported to fit the surface of a sphere (the curve of Monson), with a radius of about 4 inches in adults. The objective of the current study was to compare the three-dimensional curvature of the mandibular dental arch in healthy permanent dentitions of young adults and adolescents. The mandibular casts of 50 adults (aged 19 to 22 years) and 20 adolescents (aged 12 to 14 years) with highly selected sound dentitions that were free from temporomandibular joint problems were obtained. The three coordinates of cusp tips excluding the third molars were digitized with a three-dimensional digitizer, and used to derive a spherical model of the curvature of the occlusal surfaces. From the best interpolating sphere, the radii of the left and right curves of Spee (quasi-sagittal plane) and of molar curve of Wilson (frontal plane) were computed. Mandibular arch size (interdental distances) was also calculated. The occlusal curvature of the mandibular arch was not significantly influenced by sex, although a significant effect of age was found (Student t, P curves of Spee, and curve of Wilson in the molar area were about 101 mm in adults, and about 80 mm in adolescents. Arch size was not influenced by either sex or age. The different curvatures of the occlusal plane in adolescents and adults may be explained by a progressive rotation of the major axis of the teeth moving the occlusal plane toward a more buccal position. These dental movements should be performed in a frontal plane on an anteroposterior axis located next to the dental crown.

  11. Mandibular incisor alignment and dental arch changes 1 year after extraction of deciduous canines.

    Science.gov (United States)

    Sjögren, Anders; Arnrup, Kristina; Lennartsson, Bertil; Huggare, Jan

    2012-10-01

    This study investigated the early effects on mandibular incisor irregularity and rotation together with dental arch dimensions of the extraction of four deciduous canines. Children, during early mixed dentition, were randomized into one extraction (n = 32) and one control (n = 41) group. Dental casts from baseline (T0) and 1 year follow-up (T1) were used to evaluate changes in the irregularity index and in mandibular incisor rotation, dental arch dimensions, overjet, and overbite. Median mandibular incisor irregularity decreased over time, significantly more in the extraction than the control group (1.2 versus 0.7 mm; P extraction group (42 versus 20 per cent; P extraction group versus 34 per cent in the control group (P extraction group (1.3, 1.1 mm and 2.4, 2.0 mm, respectively; P extraction of the deciduous canines, small improvements in mandibular incisor alignment were seen, together with reduced arch dimensions. Little's index underestimated malalignment related to tooth rotation.

  12. A new yardstick for rating dental arch relationship in patients with complete bilateral cleft lip and palate

    NARCIS (Netherlands)

    Ozawa, T.O.; Shaw, W.C.; Katsaros, C.; Kuijpers-Jagtman, A.M.; Hagberg, C.; Ronning, E.; Semb, G.

    2011-01-01

    Objective: To develop yardsticks for assessment of dental arch relationship in young individuals with repaired complete bilateral cleft lip and palate appropriate to different stages of dental development. Participants: Eleven cleft team orthodontists from five countries worked on the projects for 4

  13. A new operative method for obtaining full-arch prostheses for immediate loading dental implants.

    Science.gov (United States)

    de Mello, Guilherme Paulo Scarpel; Mello, Elaine Duarte Artuso de; Corazza, Pedro Henrique

    2017-04-01

    Implant supported full-arch immediate prosthesis (also called the immediate Brånemark protocol) revolutionized dental clinical practice due to the aesthetic/functional benefits it offers to the patient. This work presents a simplified and efficient technique for implant supported full-arch immediate prosthesis fabrication. After diagnosing the necessity of the protocol, the implants were installed with a minimum torque of 35Ncm. For implant impression, the use of previously prepared castable cylinders (dispensing with impression posts), and a U-shaped acrylic (Mello technique) generated a cast without distortion. The Brånemark protocol was fabricated on this cast without the metal test specimen. The simplified technique proposed in this article for Brånemark protocol fabrication seemed to be effective. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  14. Evaluation of sexual dimorphism and the relationship between craniofacial, dental arch and masseter muscle characteristics in mixed dentition

    OpenAIRE

    Marquezin, Maria Carolina Salomé; Andrade, Annicele da Silva; Rossi, Moara de; Gameiro, Gustavo Hauber; Gavião, Maria Beatriz Duarte; Castelo,Paula Midori

    2014-01-01

    Purpose: to evaluate sexual dimorphism and the relationship between craniofacial characteristics, dental arch morphology and masseter muscle thickness in children in the mixed dentition stage. Methods: the study sample comprised 32 children, aged 6-10 years (14♀/18♂) with normal occlusion. Craniofacial characteristics, dental morphology and masseter muscle thickness were evaluated by means of posteroanterior cephalometric radiographs, dental cast evaluation and ultrasound exam, respectively. ...

  15. Is there any association between facial type and mandibular dental arch form in subjects with normal occlusion?

    Directory of Open Access Journals (Sweden)

    Luiz Renato Paranhos

    2014-03-01

    The aim of this study was investigate the association between the mandibular arch morphology and the facial type of Brazilian Caucasians with natural normal occlusion. For this, we used a sample comprised of lateral radiographs and respective dental casts of 51 individuals (21 male and 30 female, presenting at least 4 of the 6 Andrews’ keys to normal occlusion without previous orthodontic treatment. Angle’s first molar relationship was considered indispensable for the sample. The facial type was defined by two cephalometric measurements (SN.SGn and SN.GoGn. After scanning the models (3D and radiographs, the images were evaluated by 12 orthodontists. A modified Kappa test evaluated the agreement between examiners to classify the morphology of the dental arch. The chi-square test was used to verify the association between the facial type (dolichofacial, mesofacial, or brachyfacial and the dental arch morphology (square, oval, or tapered, using significance level of 5%. Casual and systematic errors (p > 0.05 showed no significant results and the Kappa test showed significant agreement among examiners for the dental arch form (0.55 with a p < 0.001, considered as ‘moderate’. The chi-square test indicated no significant association. The null hypothesis was accepted, as the facial type was not associated with dental arch morphology in individuals with normal occlusion.

  16. Measurementand correlation analysis between the mandibular dental and basal arch forms in three skeletalmalocclusions%三类骨性错牙合下颌牙弓和基骨弓的测量及相关性分析

    Institute of Scientific and Technical Information of China (English)

    林思豆; 吴补领; 孙风阳; 田智慧; 钟恩意; 慈博雯; 黄文华

    2016-01-01

    目的:探讨骨性错牙合与个别正常牙合下颌牙弓、基骨弓的形态差异及相关性。方法27例骨性Ⅰ类错牙合、30例骨性Ⅱ类错牙合、20例骨性Ⅲ类错牙合及27例个别正常牙合于正畸治疗前进行锥形束CT扫描,获得下颌虚拟模型,分别测量牙弓、基骨弓的长、宽度,分析指标间的差异及相关性,并拟合牙弓、基骨弓的形态曲线。结果Ⅲ类错牙合的基骨弓长、宽度显著大于其余三组,牙弓宽度显著大于Ⅱ类错牙合,Ⅱ类错牙合的前牙牙弓长度显著大于其余三组。牙弓、基骨弓在尖牙间、磨牙间宽度及全牙段长度的相关系数r分别为0.818、0.836、0.818,前牙长度r为0.395。结论Ⅲ类错牙合基骨发育过度,Ⅱ类错牙合前牙弓最长以弥补其基骨发育不足;牙弓与基骨弓存在相关。%Objective To investigate the differences and correlations between the mandibular dental and basal arch forms in subjects with normal occlusion and those of skeletal malocclusions. Methods Virtual pretreatment mandibular models of patients (27 Class I,30 Class II, 20 Class III and 27 normal occlusion) were selected to measure widths and lengths of dental and basal arch. The differences and correlations between indicators were analyzed, and then fitting curves of dental and basal arch were made. Results The mandibular basal arch widths and lengths were significantly greater in the Class III group compared to other groups, the dental arch widths were significantly greater in the ClassⅢgroup compared to the Class II group, the anterior dental lengths were significantly greater in the Class Ⅱ group compared to other groups. The widths in canine, molar regions and the whole arch lengths of dental and basal arch demonstrated high correlation coefficient (r=0.818, 0.836, 0.818), the anterior arch lengths demonstrated low correlation coefficient(r=0.395). Conclusions The basal arch of Class III group is

  17. Evaluation of dental arch changes in patients following the use of Y shape appliance expansion

    Directory of Open Access Journals (Sweden)

    Ahmad Akhondi MS

    2001-09-01

    Full Text Available The purpose of this study was to evaluate Y shape appliance for expansion on maxillary arch of patients in their mixed dentition age. Eight patients, 6 girls and 2 boys, with maxillary constriction, retrusion of maxillary anteriors, and space deficiency of upper canine were treated by Y-plate expansion. For each patient 8 parameters on upper cast and 7 parameters on lower cast were measured. Statistical analysis was conducted by calculating the mean, standard deviation and p-value, of parameters. Since these parameters change during natural growth, the results were compared to normal growth changes of similar patients group form another study as control. Results showed significant increase in maxillary and mandibular cervical and coronal intercanine and intermolar width (P<0.005. The results also showed significant increase in maxillary arch length and perimeter.

  18. Evaluation of facial morphology and sagittal relationship between dental arches in primary and mixed dentition.

    Science.gov (United States)

    Traldi, Aline; Valdrighi, Heloísa Cristina; de Souza, Luciane Zanin; Vedovello, Silvia Amélia Scudeler

    2015-01-01

    To assess facial morphology (Pattern) and sagittal relationship between dental arches (Class), and establish a potential association between them and the variables sex, age and ethnicity, among schoolchildren aged between 4 and 9 years old (mean age of 6.7 years) in primary and mixed dentitions. The sample comprised 875 children (457 males and 418 females) attending schools in Descalvado, São Paulo, Brazil. An attempt was made with a view to establish a potential association between children's morphological features with sex, age and ethnicity. Descriptive analysis revealed a predominance of facial Pattern I (69.9 %) and Class I (67.4 %). Statistical tests (p Afro-descendant subjects.

  19. Evaluation of facial morphology and sagittal relationship between dental arches in primary and mixed dentition

    Directory of Open Access Journals (Sweden)

    Aline Traldi

    2015-08-01

    Full Text Available OBJECTIVE: To assess facial morphology (Pattern and sagittal relationship between dental arches (Class, and establish a potential association between them and the variables sex, age and ethnicity, among schoolchildren aged between 4 and 9 years old (mean age of 6.7 years in primary and mixed dentitions.METHODS: The sample comprised 875 children (457 males and 418 females attending schools in Descalvado, São Paulo, Brazil. An attempt was made with a view to establish a potential association between children's morphological features with sex, age and ethnicity.RESULTS: Descriptive analysis revealed a predominance of facial Pattern I (69.9 % and Class I (67.4 %. Statistical tests (p < 0.001 showed that Class I was more frequent among Pattern I children, whereas Class II prevailed among Pattern II, and Class III was frequent among Pattern I and III children. Ethnicity was the only variable associated with facial pattern.CONCLUSIONS: Results suggest that facial pattern and sagittal relationship between dental arches tend to be correlated. Ethnicity was associated with facial pattern, with Pattern I being the most recurrent among Caucasians and facial Pattern II being recurrent among Afro-descendant subjects.

  20. The Morphology of the Primary Dental Arch of Chinese Children in Shijiazhuang-City Part-I: Research concerning the size of the primary tooth crown, primary dental arch and the condition of primary occlusion

    OpenAIRE

    岩崎, 浩; 林, 于昉; 宮沢, 裕夫; 宮崎, 顕道; 須澤, 弥生子; 張, 暁燕; 李, 憲起; 徐, 兵; 海, 懐麗; 張, 英懐; 廉, 雲敏; 牛, 夢勇; 王, 躍進; 蘇, 強; 小林, 茂夫

    1994-01-01

    The purpose of this study was to investigate the size of the primary tooth crowns, primary dental arches, standard values and frequency distribution of primary occlusion in Chinese children. With the cooperation of a kindergarten in Shijiazhuang-city, China, the dental plasters from 55 children (36 boys and 19 girls, age range from 3-6 years old) with normal primary occlusion were collected. Because of different growth rates of the children, these children were divided into two groups, one co...

  1. [Cross-sectional study of the evolution of the primary dentition: shape of dental arches, overjet and overbite].

    Science.gov (United States)

    de Castro, Liana Amado; Modesto, Adriana; Vianna, Roberto; Soviero, Vera Lígia Mendes

    2002-01-01

    The aim of this study was to evaluate the characteristics (shape of dental arches, overjet and overbite) of the primary dentition of 6- to 39-month-old children from four nurseries of Rio de Janeiro, Brazil, and to associate them to gender and dentition phase. It was observed that 68.6% of the children presented round upper arch, while 31.4% had triangular upper arch; 92% of the children presented U-shaped lower arch and 8% had square-shaped lower arch. Moderate overjet was observed in 38.3% of the children, and slight overjet, in 30.3%. Severe (26.6%) and negative (25.5%) overbites were the most prevalent modalities of that condition. There was no association between gender and the studied characteristics. There was statistically significant association between the dentition phase and the shape of the arch, overjet and overbite (p < 0.001, chi-square test). It was possible to observe, in the present study, that early signs of malocclusions appeared when first primary molars erupted, as the posterior vertical dimension of occlusion increased. It was, thus, verified that early signs of malocclusions appear as the primary dentition develops. It is very important that the first dental visit occur during the first year of age, since it allows the pediatric dentist to prevent or carry out an early diagnosis of malocclusions in the primary dentition.

  2. Rating dental arch relationships and palatal morphology with the EUROCRAN index on three different formats of dental casts in children with unilateral cleft lip and palate

    NARCIS (Netherlands)

    Sabelis, A.J.; Kuijpers, M.A.; Nada, R.M.; Chiu, Y.T.; Bronkhorst, E.M.; Kuijpers-Jagtman, A.M.; Fudalej, P.S.

    2016-01-01

    BACKGROUND: The EUROCRAN index has been used in inter-center studies to assess dental arch relationship (DAR) and palatal morphology (PM) in children with unilateral cleft lip and palate (UCLP). For this type of inter-center research, a scoring method that could be performed over the internet would

  3. Dental Arch Form Analysis in Gujarati Males and Females having Normal Occlusion

    Directory of Open Access Journals (Sweden)

    Vishnu Jagdishbhai Patel

    2012-01-01

    Results: As moving from anterior to posterior, both the arches diverge proportionally, except in second molar area where slight convergence toward midline was noted. Females had proportionally narrower arch dimensions than those for males. Five arch forms were determined according to relative deviations of various ratio combinations, and all subjects were classified for mandibular arch form by nonhierarchical stepwise method.

  4. 三维数字化牙模的牙弓线探测%Dental Arch Detection of 3D Dental Model

    Institute of Scientific and Technical Information of China (English)

    袁天然; 廖文和; 戴宁; 崔海华; 王长伟; 俞青

    2008-01-01

    提出了一种在三维数字化牙颌模型上直接探测牙弓线的方法.首先,根据给定的顶点法向和咬合面的夹角阈值过滤出初始特征点,并拟和得到初始牙弓线;其次,对初始特征点集进行等分并找出对应的局部最高顶点,对局部最高顶点进行拟和得到最终的牙弓线.通过对多副牙颌模型的实验表明,所提方法稳定、有效.%A robust detection method for dental arch directly applied on 3D dental model was proposed which could be easily acquired through intra or extra oral measurement methods. Firstly, the initial dental arch was obtained through fitting the initial feature points filtered out according to the given threshold of the angle between the normal of the model point and the occlusal plane. Then the set of the initial feature points was divided into subsets using planes perpendicular to the initial dental arch with equal arch length between each two adjacent planes. The local peak point was found out for each subset according to the distance value between the point of the corresponding subset and the occlusal plane, and the curve fitting to the local peak points was also the final dental arch. The method was tested on models with various types of malocclusions and is proved to be robust and accurate.

  5. Clinical evaluation of a collagen matrix to enhance the width of keratinized gingiva around dental implants

    OpenAIRE

    Lee, Kang-Ho; Kim, Byung-Ock; Jang, Hyun-Seon

    2010-01-01

    Purpose The purpose of this study was to evaluate the effect of collagen matrix with apically positioned flap (APF) on the width of keratinized gingiva, comparing to the results of APF only and APF combined with free gingival graft (FGG) at the second implant surgery. Methods Nine patients were selected from those who had received treatments at the Department of Periodontics, Chosun University Dental Hospital, Gwangju, Korea. We performed APF, APF combined with FGG, and APF combined with coll...

  6. The randomized shortened dental arch study (RaSDA: design and protocol

    Directory of Open Access Journals (Sweden)

    Kern Matthias

    2010-02-01

    Full Text Available Abstract Background Various treatment options for the prosthetic treatment of jaws where all molars are lost are under discussion. Besides the placement of implants, two main treatment types can be distinguished: replacement of the missing molars with removable dental prostheses and non-replacement of the molars, i.e. preservation of the shortened dental arch. Evidence is lacking regarding the long-term outcome and the clinical performance of these approaches. High treatment costs and the long time required for the treatment impede respective clinical trials. Methods/design This 14-center randomized controlled investigator-initiated trial is ongoing. Last patient out will be in 2010. Patients over 35 years of age with all molars missing in one jaw and with at least both canines and one premolar left on each side were eligible. One group received a treatment with removable dental prostheses for molar replacement (treatment A. The other group received a treatment limited to the replacement of all missing anterior and premolar teeth using fixed bridges (treatment B. A pilot trial with 32 patients was carried out. Two hundred and fifteen patients were enrolled in the main trial where 109 patients were randomized for treatment A and 106 for treatment B. The primary outcome measure is further tooth loss during the 5-year follow-up. The secondary outcome measures encompassed clinical, technical and subjective variables. The study is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG WA 831/2-1, 2-2, 2-3, 2-4, 2-5. Discussion The particular value of this trial is the adaptation of common design components to the very specific features of complex dental prosthetic treatments. The pilot trial proved to be indispensable because it led to a number of adjustments in the study protocol that considerably improved the practicability. The expected results are of high clinical relevance and will show the efficacy of two common

  7. A Study on the Effect of Exit Widths and Crowd Sizes in the Formation of Arch in Clogged Crowds

    CERN Document Server

    Castro, Francisco Enrique Vicente G

    2015-01-01

    The arching phenomenon is an emergent pattern formed by a $c$-sized crowd of intelligent, goal-oriented, autonomous, heterogeneous individuals moving towards a $w$-wide exit along a long $W$-wide corridor, where $W>w$. We collected empirical data from microsimulations to identify the combination effects of~$c$ and~$w$ to the time~$T$ of the onset of and the size~$S$ of the formation of the arch. The arch takes on the form of the perimeter of a half ellipse halved along the minor axis. We measured the~$S$ with respect to the lengths of the major~$M$ and minor~$m$ axes of the ellipse, respectively. The mathematical description of the formation of this phenomenon will be an important information in the design of walkways to control and easily direct the flow of large crowds, especially during panic egress conditions.

  8. 牙弓曲线发生器的运动规划与仿真%Motion Planning and Simulation of Dental Arch Generator

    Institute of Scientific and Technical Information of China (English)

    姜金刚; 张永德

    2013-01-01

    针对牙弓曲线发生器需要协调控制的特点,对牙弓曲线发生器的运动规划进行了研究.基于牙弓曲线幂函数模型构建了牙弓曲线发生器,并进行了运动分析,基于弧长不变理论进行了牙弓曲线发生器控制点运动计算;提出基于牙弓参数等增量法实现了牙弓曲线发生器的运动规划,仿真结果表明:牙弓参数等增量规划法在牙弓曲线发生器运动过程中von mises应力最小,牙弓曲线发生器运动实际轨迹与仿真、理论轨迹近似吻合,结果证实了采用牙弓参数等增量法实现牙弓曲线发生器运动规划的可行性.%Aiming to the characteristics of coordinated control for dental arch generator, motion planning of dental arch generator is studied. Based on power function model of dental arch, dental arch generator is established. Control point positions of dental arch generator are calculated by the arc length constant theory. Dental arch parameter equal increment method is proposed to realize motion planning of dental arch generator. The results show that the maximum von mises hot spots of method 3 for the dental arch generator is small compared to other methods. The experimental motion trajectory of the dental arch generator is approximately in agreement with the simulation and theoretical motion trajectory. The results prove that it is feasible to realize motion planning of dental arch generator using the dental arch parameter equal increment method.

  9. Dental arch Transversal characteristics in boys and girls with orthognathic bite: head shape and face type dependence

    Directory of Open Access Journals (Sweden)

    Gunas Іgor

    2015-03-01

    Full Text Available In this work, we describe the boundary percentile scope values of transversal characteristics of the dental arch of boys and girls of Podillia, with diagnosed orthognathic bite. The study group consists of individuals with different forms of head and face. Our findings are that, in girls, unlike boys, set differences exist in the transversal dimensions of the upper and lower jaw, both in the distribution of the shape of the head, and the type of face. In boys with different head shape, larger values of transversal size of dental arch are evidenced when contrasted with the corresponding groups of girls, regarding the maxilla in 46.7% of all cases and the mandible in 22.2% of all cases, as well as with different types of faces in 66.7% of cases regarding the maxilla and 55.6% in the mandible.

  10. Masticatory efficiency of shortened dental arch subjects with removable partial denture: A comparative study.

    Science.gov (United States)

    Omo, J O; Sede, M A; Esan, T A

    2017-04-01

    The objective of this study was to compare the masticatory efficiency in subjects with shortened dental arch (SDA) before and after restoration with removable partial denture (RPD). This was a prospective study carried out on 36 consecutive patients. The subjects were asked to chew 5 g of a measured portion of fresh raw carrot for 20 specified numbers of strokes. The raw carrot was recovered into a cup and strained through a standard mesh sieve of 5 mm by 1 mm, it was air dried for 30 min and weighed with FEM digital series weighing scale. The masticatory performance ratio was then determined. The age range of the subjects was 34-64 years with the mean age being 52.2 ± 8.2 years. The difference between the total masticatory performance score at the post- and pre-treatment phases was statistically significant (P = 0.001). The improvement in masticatory performance was marked among the younger age groups (P = 0.001), unilateral free end saddle subjects (P = 0.001), and among the male gender (P < 0.05). Masticatory performance improved with the provision of RPD. However, the improvement was marked among the younger age groups, unilateral free end saddle subjects, and the male gender; thereby supporting the need for RPDs in patients with SDA.

  11. Dental arch relationship in children with complete unilateral cleft lip and palate following one-stage and three-stage surgical protocols

    NARCIS (Netherlands)

    Fudalej, P.S.; Katsaros, C.; Bongaarts, C.; Dudkiewicz, Z.; Kuijpers-Jagtman, A.M.

    2011-01-01

    The objective of this study is to compare dental arch relationship following one-stage and three-stage surgical protocols of unilateral cleft lip and palate. Dental casts of 61 children (mean age, 11.2 years; SD, 1.7), consecutively treated in one center with one-stage closure of the complete cleft

  12. Clinical Evaluation of Different Pre-impression Preparation Procedures of Dental Arch

    Science.gov (United States)

    Arora, Nitin; Arora, Monika; Gupta, Naveen; Agarwal, Manisha; Verma, Rohit; Rathod, Pankaj

    2015-01-01

    Background: Bubbles and voids on the occlusal surface impede the actual intercuspation and pre-impression preparation aims to reduce the incidence of air bubbles and voids as well as influences the quality of occlusal reproduction and actual clinical intercuspation in the articulator. The study was undertaken to determine the influence of different pre-impression preparation procedures of antagonistic dental arch on the quality of the occlusal reproduction of the teeth in irreversible hydrocolloid impressions and to determine most reliable pre-impression preparation method to reduce the incidence of air bubbles. Materials and Methods: A total of 20 subjects were selected having full complement of mandibular teeth from second molar to second molar with well demarcated cusp height. 200 impressions were made with irreversible hydrocolloid material. The impressions were divided into five groups of 40 impressions each and each group had one specific type of pre-impression preparation. All the impressions were poured in die stone. A stereomicroscope with graduated eyepiece was used to count the number of bubbles on the occlusal surface of premolars and molars. The mean and standard deviations were calculated for each group. Mann–Whitney U-test was applied to find the significant difference between different groups. Results: Least bubbles were found in the group in which oral cavity was dried by saliva ejector and fluid hydrocolloid was finger painted onto the occlusal surfaces immediately before the placement of impression tray in the mouth. Conclusion: It was found that finger painting the tooth surfaces with fluid hydrocolloid immediately before the placement of loaded impression tray in the mouth was the most reliable method. The oral cavity can be cleared more easily of excess saliva by vacuum suction rather than by use of an astringent solution. PMID:26229376

  13. Loss of space and dental arch length after the loss of the lower first primary molar: a longitudinal study.

    Science.gov (United States)

    Cuoghi, O A; Bertoz, F A; de Mendonca, M R; Santos, E C

    1998-01-01

    The premature loss of primary teeth may harm the normal occlusal development, although there are debates relating to the necessity of using space maintainer appliances. The aim of the study is to evaluate the changes in the dental arch perimeter and the space reduction after the premature loss of the lower first primary molar in the mixed dentition stage. The sample consists of 4 lower arch plaster models of 31 patients, within the period of pre-extraction, 6, 12 and 18 months after the lower first primary molar extraction. A reduction of space was of noted with the cuspid dislocation and the permanent incisors moving toward the space of the extraction site. It was concluded that the lower first molar primary premature loss, during the mixed dentition, implicates an immediate placement of a space maintainer.

  14. Transverse dental arch relationship at 9 and 12 years in children with unilateral cleft lip and palate treated with infant orthopedics: a randomized clinical trial (DUTCHCLEFT).

    Science.gov (United States)

    Noverraz, R L M; Disse, M A; Ongkosuwito, E M; Kuijpers-Jagtman, A M; Prahl, C

    2015-12-01

    A long-term evaluation to assess the transverse dental arch relationships at 9 and 12 years of age in unilateral cleft lip and palate treated with or without infant orthopedics (IO). The hypothesis is that IO has no effect on the transverse dental arch relationship. A prospective two-arm randomized controlled trial (DUTCHCLEFT) in three academic cleft palate centers (Amsterdam, Nijmegen and Rotterdam, the Netherlands). Fifty-four children with complete unilateral cleft lip and palate and no other malformations were enrolled in this evaluation. One group wore passive maxillary plates (IO+) during the first year of life, and the other group did not (IO-). Until the age of 1.5, all other interventions were the same. Hard palate was closed simultaneously with bone grafting according to protocol of all teams. Orthodontic treatment was performed when indicated. The transverse dental arch relationship was assessed on dental casts using the modified Huddart/Bodenham score to measure the maxillary arch constriction at 9 and 12 years of age. No significant differences were found between the IO+ and IO- groups. Differences between the centers increased from 9 to 12 years of age. Transverse dental arch relationships at 9 and 12 years of age do not differ between children with UCLP treated with or without IO. There is no orthodontic need to perform IO as applied in this study in children with UCLP.

  15. A Comparison of Arch Width with Angle Classification and Wits Appraisal in Class 2 Division 1 and Class 1 Individuals.

    Science.gov (United States)

    1983-05-01

    Statistical analysis of the mandibular plane angle, a cephalometric skeletal measure of vertical relationships, revealed no significant differences among the... cephalometrically . 5) to determine, by correlation, what associations may exist among the sagittal, vertical and width measurements. 6) to determine sex differences...mechanism helped guide the teeth into occlusion. No measurements were made to determine if anteroposterior or vertical dimensions were correlated to

  16. Maxillary Arch Dimension Changes of 3-5 Years Old Filipino Children

    Directory of Open Access Journals (Sweden)

    Abdol Hamid Zafarmand

    2014-11-01

    Full Text Available Background: The purpose of this study was to assess the dental arch dimensions in primary dentition of 3-5 years old Filipino children and determining the existence of sexual dimorphism.Materials and Methods: In this descriptive study, 60 Filipino preschool children aged 3-5 years old were selected from Manila city. Study casts were used for measurements of 3 arch dimensions: bicanine width, bimolar width, and arch length. The analyses were performed to compare values within age-groups and within gender-groups, besides reporting mean and standard deviations. The data were subjected to One-way ANOVA and Student t-test.Results: Significant differences were observed regarding dental arch dimensions among different ages and genders (p<0.05. Comparison between genders showed a statistically significant difference in bicanine width at the age of 4 (p=0.04, in bimolar width at age of 5 (p=0.006, and in arch length at age of 4 (p=0.03 and 5 (p=0.02. Differences within male group for different ages showed only arch length dimension was statistically significant (p=0.021. In females, however the comparison between age-groups also revealed a statistically significant difference in bicanine (p= 0.016 and bimolar widths (p=0.027 dimensions.Conclusion: The present study showed that dental arch dimensions, vary among different ages and genders of children. It also showed that a sexual dimorphism does exist between the gender groups.

  17. Is there any association between facial type and mandibular dental arch form in subjects with normal occlusion?

    OpenAIRE

    Luiz Renato Paranhos; Adilson Luiz Ramos; Eduardo de Novaes Benedicto; Liliana Àvila Maltagliati; Maurício de Almeida Cardoso; Leopoldino Capelozza Filho

    2014-01-01

    http://dx.doi.org/10.4025/actascihealthsci.v36i1.17668 The aim of this study was investigate the association between the mandibular arch morphology and the facial type of Brazilian Caucasians with natural normal occlusion. For this, we used a sample comprised of lateral radiographs and respective dental casts of 51 individuals (21 male and 30 female), presenting at least 4 of the 6 Andrews’ keys to normal occlusion without previous orthodontic treatment. Angle’s first molar relationship wa...

  18. Three-dimensional visualisation and analysis of post-operative changes in the size and shape of the dental arch and palate.

    Science.gov (United States)

    Trefný, P; Tauferová, E; Bálková, S

    2005-01-01

    In craniofacial surgery and orthodontics, three-dimensional computer models of the dental arch and palate have recently entered usage in diagnosis assessment, treatment planning, case presentations and evaluation of treatment progress and outcome. In this contribution, we show how effective visualisation and evaluation of changes in the size and shape of the dental arch and palate in a given patient can be performed using superimposition of two or more 3D computer models that record the condition before and after treatment. We also present a method of three-dimensional measurement of the dental arch and palate suitable for evaluation of treatment results within retrospective and prospective studies in larger samples of subjects.

  19. Differences in functional outcomes for adult patients with prosthodontically-treated and -untreated shortened dental arches: a systematic review.

    Directory of Open Access Journals (Sweden)

    Saadika Khan

    Full Text Available This review examined differences in functional outcomes and patient satisfaction when shortened dental arches are left untreated compared to their restoration to complete arch lengths with different prosthodontic interventions.A protocol was developed according to the criteria for a systematic review. All relevant databases were searched to identify appropriate clinical trials regardless of language or publication status. Predetermined eligibility criteria were applied, trial quality assessed and data extracted for each study. Relevant outcomes assessed were: functioning ability, patient satisfaction and harmful effects on oral structures.Searches yielded 101 articles: 81 from electronic databases and 20 from reference lists of retrieved articles (PEARLing searches. Sixty-nine citations were assessed for eligibility after removing 32 duplicate records. After reading titles and abstracts, a total of 41 records were excluded and the full-texts of the remaining 28 records were read. Only 21 records were included for the SR because 7 records were excluded after reading the full-text reports. These 21 records report the outcomes of four randomized controlled trials (RCTs and one non-randomized clinical trial (CT which were pre-specified and used for this review. No on-going studies were found and no eligible studies were excluded for failure to report the reviewer's pre-specified outcomes. Outcomes were reported in the retrieved 21 articles. A narrative explanation of the pre-specified outcomes is reported for the 3 comparison groups (which were based on the different interventions used for the individual clinical trials. The shortened dental arch as a treatment option is encouraging in terms of functioning, patient satisfaction and cost-effectiveness. By using only high quality studies it was expected that the results would be more reliable when making conclusions and recommendations, but some of the included studies had to be downgraded due to

  20. Influence of scanning and reconstruction parameters on quality of three-dimensional surface models of the dental arches from cone beam computed tomography

    NARCIS (Netherlands)

    Hassan, B.; Souza, P.C.; Jacobs, R.; Berti, S.D.; van der Stelt, P.

    2010-01-01

    The study aim is to investigate the influence of scan field, mouth opening, voxel size, and segmentation threshold selections on the quality of the three-dimensional (3D) surface models of the dental arches from cone beam computed tomography (CBCT). 3D models of 25 patients scanned with one image in

  1. Three-dimensional analysis of dental and dental arch changes in maxillary crowding patients treated with self-ligating brackets%自锁托槽解除上颌牙列拥挤后牙弓与牙齿的三维变化研究

    Institute of Scientific and Technical Information of China (English)

    陈上; 厉松

    2016-01-01

    Objective The purpose of this study was to evaluate the three dimensional changes of dental and dental arch after self-ligating treatment.Methods 16 Angle Class Ⅰ patients with moderate crowding were treated with DamonQ self-ligating brackets.The before and after CBCT records were analyzed by Amira ResolveRT software.Results Basal bone widths,alveolar widths and cusp widths were expanded with greater changes in anterior arch segment.Good correlation was found between the changes of basal bone widths and alveolar widths.The tooth inclinations were observed with various degrees except the first molars.Conclusions The anterior basal bone widths were expanded after self-ligating treatment,while the widths of posterior arch were maintained.The alveolar bone widths expansion builds on basal bone widths change.Self-ligating system could expand the arch widths by compensatory teeth inclination in patients with narrow basal bone arch.%目的 探讨自锁托槽解除牙列拥挤后牙弓与牙齿的三维变化.方法 通过DamonQ自锁托槽系统对16例安氏Ⅰ类中度拥挤患者行不拔牙矫治,在上颌牙列排齐前后分别拍摄CBCT,运用Amira ResolveRT软件进行三维重建并测量牙弓和牙齿的三维变化.结果 运用自锁托槽系统排齐后,上颌的基骨弓宽度、牙槽嵴宽度和牙尖宽度有不同程度的增宽,牙弓前段的增宽量大于牙弓后段;牙槽部的宽度与基骨弓的宽度相关性较高;除第一磨牙外,上颌牙齿均发生不同程度颊倾.结论 在牙弓前段,自锁托槽可能体现出少量基骨弓扩大的效果,越靠近牙弓后段,基骨弓的宽度基本维持;牙槽部宽度的变化以基骨弓的宽度为基础,对于牙槽部较窄的个体,自锁托槽系统可能将通过牙齿的倾斜代偿使牙弓宽度在一定程度上增加.

  2. The size of anterior teeth in patients with gaps in the upper dental arch

    National Research Council Canada - National Science Library

    Sękowska, A; Dunin-Wilczyńska, I; Chałas, R

    2015-01-01

    .... Patients with severe malocclusion, missing teeth and periodontal disease were excluded. Width-to-length (W/L) ratio of the clinical crown of the central, lateral incisors and canines for both sides was measured...

  3. Rapid maxillary expansion treatment could produce long-term dental arch changes

    NARCIS (Netherlands)

    Ren, Yijin

    2005-01-01

    : Data Sources: Medline, Medline In-Process, LILACS (Latin American and Caribbean Health Sciences Literature), PUBMED, Embase, Web of Science and the Cochrane Library were searched. Search terms were rapid palatal expansion or rapid maxillary expansion (RME) and tooth or dental changes. Reference li

  4. 正畸治疗对安氏Ⅲ类错患者牙弓宽度的影响%Effects on Arch Width among Angle Class Ⅲ Malocclusion after Orthodontic Treatment

    Institute of Scientific and Technical Information of China (English)

    林晨

    2012-01-01

      目的研究正畸治疗对安氏Ⅲ类错患者牙弓宽度的影响.方法选择45例安氏Ⅲ类错的患者,其中21例采用拔牙矫治,24例采用不拔牙矫治,测量治疗前后的牙模型,分别记录牙弓前、后段的宽度,比较不同矫治方法对牙弓宽度变化的影响.结果两组治疗后上颌牙弓前段宽度均变大(P 0.05).结论拔牙矫治不会导致牙弓宽度的减小,从而影响美观.%  Objective To study the effects on arch width among Angle class Ⅲ malocclusion after extraction and nonextraction orthodontic treatment. Methods Choose 45 Angle class Ⅲ malocclusion cases (21 cases with extraction of 4 bicuspids and 24 nonextraction cases), the intercanine width and intermolar width between the 2 groups were compared. Results After treatment, the intercanine width on the maxillary of two groups increased significantly (P0.05).Conclusion Extraction treatment does not result in narrower arch widths and unesthetic faces.

  5. Comparison of arch forms between Turkish and North American

    Directory of Open Access Journals (Sweden)

    Ahmet A. Celebi

    2016-04-01

    Full Text Available ABSTRACT Objective: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. Methods: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III and 160 North American (60 Class I, 50 Class II, and 50 Class III subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square in order to have frequency distribution compared between ethnic groups in each Angle classification. Results: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. Conclusions: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients.

  6. Comparison of arch forms between Turkish and North American

    Science.gov (United States)

    Celebi, Ahmet A.; Keklik, Hakan; Tan, Enes; Ucar, Faruk I.

    2016-01-01

    ABSTRACT Objective: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. Methods: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III) and 160 North American (60 Class I, 50 Class II, and 50 Class III) subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square) in order to have frequency distribution compared between ethnic groups in each Angle classification. Results: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D) ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. Conclusions: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients. PMID:27275615

  7. A structural equation model to investigate the impact of missing occlusal units on objective masticatory function in patients with shortened dental arches.

    Science.gov (United States)

    Fueki, K; Yoshida, E; Igarashi, Y

    2011-11-01

    The aim of this study was to investigate the impact of missing occlusal units (MOUs) on objective masticatory function with respect to food comminuting and mixing ability. Sixty partially dentate patients (mean age, 64·1 years) with shortened dental arches participated in the study. Food comminuting ability was assessed using a masticatory performance test with peanuts as a test food. Food mixing ability was assessed using a mixing ability test with a two-coloured wax cube. Maximum bite force (MBF) was measured using a pressure-sensitive film as a mediator for food comminuting and mixing ability. A structural equation model was constructed based on a hypothesis that MOUs would be associated with reduced MBF and impairment of food comminuting and mixing ability. Structural equation modelling analysis found significant direct effects of MOU on median particle size and mixing ability index (MAI) (P dental arches.

  8. Influence of third molar space on angulation and dental arch crowding.

    Science.gov (United States)

    Hasegawa, Yuh; Terada, Kazuto; Kageyama, Ikuo; Tsuchimochi, Takashi; Ishikawa, Fujiro; Nakahara, Sen

    2013-01-01

    The influence of the third molars on mandibular incisor crowding has been extensively studied but remains controversial. The purpose of this study was to ascertain whether, in Mongolian subjects, the lower third molar can affect anterior crowding and/or the inclination of teeth in the lower lateral segments. Panoramic radiographs, 45° oblique cephalograms, and dental casts were taken from Mongolian subjects (age range 18.3-24.1 years, mean 21.0 years) exhibiting impaction of all four third molars and an Angle Class I molar relationship. The Ganss ratio was calculated using panoramic radiographs, whereas the gonial angle and angulation of lower canines, premolars and molars were measured using 45° oblique cephalograms. Little's index of irregularity was calculated using dental casts. Significant relationships between the angulation of the third and second molars and between the first molars and second premolars were found. Conversely, there was no significant correlation between the angulation of third molars, first premolars and canines. The Ganss ratio calculations showed that the lower first and second molars and the second premolars inclined mesially if there was insufficient space for the lower third molars. However, there was no significant correlation between Little's index of irregularity and third molar angulation. Furthermore, although the third molar influences the lateral segments, no obvious relationship between the third molar and anterior crowding was observed. Therefore, the angulation of the third molar appears not to cause anterior crowding.

  9. Measurement and Analysis of Patients with TMD on the Occlusal Contact and Arch Width%TMD患者咬合接触情况与牙弓宽度的测量分析

    Institute of Scientific and Technical Information of China (English)

    曲烁; 战德松

    2012-01-01

    目的:通过测量和比较正常人群与TMD患者在牙尖交错位时的咬合接触情况及牙弓宽度情况,探讨这2个解剖特征与TMD发病的相关性.方法:收集120个临床病例分为2组,A组TMD患者50例,B组正常人群(对照组)70例,通过对2组人群的咬合接触情况、牙弓宽度进行测量分析,探讨这2个解剖特征与TMD发病的相关性.结果:牙尖交错位时,TMD患者的无咬合接触牙齿数高于正常人群;牙弓宽度较正常人群窄(P<0.05).结论:TMD发病与咬合接触少,牙弓宽度窄这2个解剖特征有关.%Objective: To investigate relevance between the two anatomical characteristics and the incidence of patients with TMD by measuring and comparing occlusal contact which is in intercuspal position and arch width be-lwccn the normal population and patients with TMD. Methods: There were 120 clinical cases in this study. They were divided into 2 groups. Group A is 50 patients with TMD, Group B is 70 normal populations as control group. To investigate relevance between the two anatomical characteristics and the incidence of patients with TMD by measuring and comparing occlusal contact and arch width between the normal population and patients with TMD. Results; The number of no occlusal contact teeth which are in intercuspal position is higher than the normal population, and patients with TMD have narrower arch width than the normal population (P < 0. 05). Conclusion: The incidence of TMD contacts with the characteristics of less occlusion and narrower arch width.

  10. High arch

    Science.gov (United States)

    Pes cavus; High foot arch ... High foot arches are much less common than flat feet. They are more likely to be caused ... difficult to fit into shoes. People who have high arches most often need foot support. A high ...

  11. Continuous measurements of mandibular cortical width on dental panoramic radiographs for computer-aided diagnosis of osteoporosis

    Science.gov (United States)

    Kavitha, M. S.; Asano, Akira; Taguchi, Akira

    2011-03-01

    The aim of this study is to develop a computer-aided osteoporosis diagnosis system that automatically determines the inferior cortical width of the mandible continuously on dental panoramic radiographs to realize statistically more robust measurements than the conventional one-point measurements. The cortical width was continuously measured on dental panoramic radiographs by enhancing the original image, determining cortical boundaries, and finally evaluating the distance between boundaries continuously throughout the region of interest. The diagnostic performance using the average width calculated from the continuous measurement was compared with BMD at lumbar spine and femoral neck in 100 postmenopausal women of whom 50 to the development of the tool and 50 to its validation with no history of osteoporosis was evaluated. We experimentally showed the superiority of our method with improved sensitivity and specificity of identifying the development subjects were 90.0% and 75.0% in women with low spinal BMD and 81.8% and 69.2% in those with low femoral BMD, respectively. The corresponding values in the validation subjects were 93.3% and 82.9% at the lumbar spine and 92.3% and 75.7% at the femoral neck, respectively in terms of efficacy for diagnosing osteoporosis. We also assessed the diagnosis and classification of women with osteoporosis using support vector machine employing the average and variance of the continuous measurements gave excellent discrimination ability. It yields sensitivity and specificity of 90.9% and 83.8%, respectively with lumbar spine and 90.0% and 69.1%, respectively with femoral neck BMD. Performance comparison and simplicity of this method indicate that our computeraided system is readily applicable to clinical practice.

  12. Form and size of the dental arches in a school population of Amazonian’s aborigines.

    Directory of Open Access Journals (Sweden)

    Sandra Rivera

    2009-11-01

    Full Text Available Objetivo: El propósito del presente estudio es determinar la forma de los arcos dentales, describir las diferencias en las dimensiones transversales y en profundidad de los arcos durante la dentición mixta, con el fin de conocer su incidencia en la disposición de la armonía oclusal en una población de escolares indígenas de Leticia, Amazonas, Colombia. Materiales y métodos: Se realizó un estudio descriptivo transversal donde se incluyeron 64 escolares, 32 niños y 32 niñas distribuidos en dos grupos: con dentición mixta temprana, 31 escolares y el grupo de dentición mixta tardía con 33 estudiantes entre 6 y 12 años. Las variables estudiadas fueron las medidas de los modelos de estudio. Resultados: El arco superior tuvo forma ovalada en 86% de la población y en 14% la forma fue cuadrada; para el arco inferior las formas fueron 75% ovaladas y 25% cuadradas. Casi todas las medidas transversales presentaron diferencias en ambos grupos, la distancia intercanina inferior se mantuvo constante. Las medidas en profundidad, anchura y longitud evidencian armonía en el desarrollo de los arcos en los niños amazónicos. Discusión: En este grupo étnico predominó el arco de forma ovalada, seguida de la forma cuadrada. Se encontraron diferencias para todas las medidas en profundidad del arco, principalmente en el sector anterior que sería el más susceptible a cambios por factores ambientales durante el período de la dentición mixta de transición. Conclusiones: La armonía oclusal de la población estudiada es el resultado de una forma de arco y cambios transversales y en profundidad fisiológicamente normales.

  13. Study on the changes of dental arches used Nickel titanium flat wire in extraction crowding cases%排牙初期弓丝对牙弓形态和咬合维持作用的对比研究

    Institute of Scientific and Technical Information of China (English)

    杨艳; 陈启锋

    2014-01-01

    Objective Applicating nickel titanium flat and round wire in low fangs extraction crowding cases.Researching the influence of dental arch and the occlusion. Methods 40 cases were divided into flat and round wire groups.they were low fangs crowding cases of class Ⅰ Osseous neutronclusion,extracted four first premolars, treated by nickel titanium flat and round wire and active-wing appliance.low fangs were neaarranged.Study model were analysed before and after treatment. The measurement data had statistical analysis,the effect were observed of dental arch width and length. Results Flat wire group:widths of maxillary canines decreased,The upper second bicuspid increased,The upper molar had no change.The distance maxillary incisor and molar to palatal wrinkle had no change.round wire groups:widths of maxillary canines decreased,the upper second bicuspid and upper molar increased. The distance maxillary incisor to palatal wrinkle increased.the distance molar to palatal wrinkle had no change. Conclusion Nickel titanium flat wire and activewing appliance can treat low fangs extraction crowding cases.That can adjust the morphology of dental arch,preserve the stability of functional occlusal plane,Control the incisor protrusion.reduce the new teratogenesis,decrease the speed of orthodontic treatment,short the period of treatment,Clinical curative effect is good.%目的:应用镍钛圆丝和带状弓丝作用在低位尖牙的拥挤拔牙病例上,研究带状镍钛弓丝对尖牙拥挤病例的牙弓形态和咬合的影响。方法:选择40例骨性Ⅰ类错牙合、上颌尖牙低位拥挤病例。随机分为带状弓丝组和圆丝组,拔除4颗第一前磨牙,应用带状弓丝、圆丝和活动翼矫治技术进行治疗。尖牙排齐后,对治疗前后的记存模型进行分析,观察带状弓丝对牙弓宽度和牙弓长度的影响。结果:带状弓丝组:治疗后上颌尖牙的宽度有所减小,第二前磨牙宽度有所增大,第

  14. Dental arch relationships on three-dimensional digital study models and conventional plaster study models for patients with unilateral cleft lip and palate.

    Science.gov (United States)

    Asquith, J A; McIntyre, G T

    2012-09-01

    To determine if three-dimensional (3D) digital study models could replace plaster study models for the evaluation of dental arch relationships for patients with unilateral cleft lip and palate. Observational study involving plaster study models from a records archive. U.K. National Health Service. Thirty sets of study models of 5-year-old patients with unilateral cleft lip and palate were identified and scanned to produce 3D digital study models by ESM Digital Solutions Ltd. (Swords, Co. Dublin, Ireland) using an R250 Orthodontic Study Model Scanner (3Shape A/S, Copenhagen, Denmark). None. The plaster and 3D digital study models were scored using the 5-year-olds' and modified Huddart Bodenham indices and analyzed using the Friedman test (p plaster and 3D digital models. Intra-observer and interobserver reproducibility were good (0.62 to 0.83 and 0.64 to 0.78, respectively). There were no statistically significant differences between the scores for the 3D digital study models when compared to the plaster study models for either the 5-year-olds' index (p  =  .12) or for the modified Huddart Bodenham index (p  =  .506). Three-dimensional digital models are a valid alternative to traditional plaster study models for the evaluation of dental arch relationships in patients with unilateral cleft lip and palate.

  15. Intra-arch dimensional measurement validity of laser-scanned digital dental models compared with the original plaster models: a systematic review.

    Science.gov (United States)

    De Luca Canto, G; Pachêco-Pereira, C; Lagravere, M O; Flores-Mir, C; Major, P W

    2015-05-01

    A systematic review was undertaken to evaluate the validity of intra-arch dimensional measurements made from laser-scanned digital dental models in comparison with measurements directly obtained from the original plaster casts (gold standard). Finally included articles were only those reporting studies that compared measurements from digital models produced from laser scanning against their plaster models. Measurements from the original plaster models should have been made using a manual or digital caliper (gold standard). Articles that used scans from impressions or digital photographs were discarded. Detailed individual search strategies for Cochrane, EMBASE, MEDLINE, PubMed, and LILACS were developed. The references cited in the selected articles were also checked for any references that could have been missed in the electronic database searches. A partial gray literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item quality assessment tool for diagnostic accuracy studies (QUADAS). Only 16 studies were finally included for the qualitative/quantitative synthesis. The selected studies consistently agree that the validity of measurements obtained after using a laser scanner from plaster models is similar to direct measurements. Any stated differences would be unlikely clinically relevant. There is consistent scientific evidence to support the validity of measurements from digital dental models in comparison with intra-arch dimensional measurements directly obtained from them. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Intraoral gothic arch tracing.

    Science.gov (United States)

    Rubel, Barry; Hill, Edward E

    2011-01-01

    In order to create optimum esthetics, function and phonetics in complete denture fabrication, it is necessary to record accurate maxillo-mandibular determinants of occlusion. This requires clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Any errors made while taking maxillo-mandibular jaw relation records will result in dentures that are uncomfortable and, possibly, unwearable. The application of a tracing mechanism such as the Gothic arch tracer (a central bearing device) is a demonstrable method of determining centric relation. Intraoral Gothic arch tracers provide the advantage of capturing VDO and CR in an easy-to-use technique for practitioners. Intraoral tracing (Gothic arch tracing) is a preferred method of obtaining consistent positions of the mandible in motion (retrusive, protrusive and lateral) at a comfortable VDO.

  17. Systematic review of short- (5-10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants.

    Science.gov (United States)

    Kwon, TaeHyun; Bain, Paul A; Levin, Liran

    2014-10-01

    The aim of this systematic review was to investigate the short-term (5-10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants. Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria. A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3-100%) and supporting implants (87.89-100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias). Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Proportional Smile Design: Using the Recurring Esthetic Dental Proportion to Correlate the Widths and Lengths of the Maxillary Anterior Teeth with the Size of the Face.

    Science.gov (United States)

    Ward, Daniel H

    2015-07-01

    Proportional smile design is a useful tool for evaluating and designing smiles that are in harmony with the face. Although not always observed in nature, the recurring esthetic dental proportion is preferred by dentists surveyed to the width proportions observed in nature with normal-length teeth. The width/length ratio of the central incisor is a key determinant in providing a smile that is pleasing to dentists. Using the desired tooth length while maintaining the preferred 78% width/length ratio of the central incisor in conjunction with the recommended recurring esthetic dental proportion is a good method for designing a smile balanced with the face. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. 虚拟牙齿矫正过程中的牙弓绘制方法研究%Research on the Methods of Drawing Dental Arch during Virtual Orthodontics Treatment Process

    Institute of Scientific and Technical Information of China (English)

    王增波

    2011-01-01

    Several mathematic models of dental arch form were reviewed; the drawing methods of dental arch were introduced and compared. Beta function method that determine the ideal dental arch curve is through five points which are the central incisors cusp lips, the double canine cusp tips and the distobuccal cusp tips of the second molars. This method is better than others in approximation, and provides more ideal criteria for tooth or thodontic treatment. It is developed by calling functions from OpenGL graphic library through VC + + ,and re alizes drawing a dental arch curve.%回顾了主要的牙弓形态数学模型,对各种牙弓绘制方法进行了介绍和比较.其中的β函数法通过中切牙接触点、双侧尖牙牙尖点和双侧第二恒磨牙远中颊尖点五个点来确定理想牙弓弓形曲线,该方法较其它的方法拟合度更加好,为牙齿矫正提供了较理想的判别标准.最后采用Visual C++为编程语言,以OpenGL为图形开发工具,实现了牙弓曲线的绘制.

  20. Effects of early and late cheiloplasty on anterior part of maxillary dental arch development in infants with unilateral complete cleft lip and palate

    Directory of Open Access Journals (Sweden)

    Silvia Valentová-Strenáčiková

    2016-02-01

    Full Text Available Objectives. The objective of this study is to compare the impact of early and late reconstruction of complete unilateral cleft lip and palate on the growth and development of the front of the dentoalveolar arch. Methods. This study was carried out in the years 2012–2015 at the Clinic of Plastic, Reconstructive and Aesthetic Surgery in Banska Bystrica. Infants with unilateral complete cleft lip and palate were divided into 2 groups according to the timing of lip reconstruction. Group A consisted of infants with early lip reconstruction–realised in the first 14 days of life. Group B consisted of infants with later lip reconstruction–realised in the third month of age. Maxillary dental casts were obtained for each child in four periods–in the first 14 days of life, in the third month, in the sixth month and in the age of one year. These were followed by the identification, measurement and evaluation of anthropometric parameters. Results. Significant differences were occurred after the reconstruction of the lips in linear and angle measurements between infants in the A and B groups. Conclusion. The early surgical reconstruction of the lips in the first 14 days of life has a positive effect on the growth and development of the anterior segment of the dentoalveolar arch. Early lip reconstruction forms a continuous pressure on the frontal segment, resulting in the earlier remedy of anatomical properties and creates appropriate conditions for the best development of this area.

  1. Clinical effects of canine movement by segmented dental arches%节段正轴辅弓远移尖牙的疗效观察

    Institute of Scientific and Technical Information of China (English)

    张昀; 李传生

    2011-01-01

    AIM: To observe the clinical effects of canine distal removement by segmented dental arches.METHODS: Twelve cases (24 canines) of severely crowded dentation patients were chosen. After extraction of the first premolars, specially bended segmented dental arches were applied to move the canines distally. Overjet and over-bite, interdigitation for posterial molars as well as canines and anchorage molars moving situations were observed. RESULTS:After 5 months, canines were moved 5. 2mm ( 1. 04mm/per month) distally and 3. 8mm (0. 76mm/per month) occlusally by segmented dental arches. MBT straight wire appliance was used for the later stage treatment. After MBT treatment, normal jet and normal bite were achieved. Canines and first molars reached interdigitation relationship. There was no shift in anchorage molars. CONCLUSION: Early stage usage of special segmented dental arches to move canines distally and later stage usage of MBT straight wire appliance are effective on the orthodontic treatment of severely crowded dentition.%目的:探讨重度拥挤伴尖牙近中唇移过低位病人拔除4个第一前磨牙后,早期用节段正轴辅弓远中、黯向移动尖牙,结合直丝弓矫治器的矫治疗效,为临床应用提供依据.方法:对12例(共24个尖牙)前牙拥挤和伴有尖牙近中唇移过低位的病例,在拔除第一前磨牙1周后应用自行弯制的节段正轴辅弓牵引尖牙远中、向移动,同时观察尖牙、磨牙的移动情况和临床效果.结果:经过早期使用节段正轴辅弓,尖牙5个月平均向远中移动5.2mm(速率1.04mm/月),骀向移动5个月平均3.8mm(速率0.76mm/月).通过后期的MWT.直丝弓矫治器,12例病人覆、覆盖正常,尖牙和第一磨牙达到理想的中性咬合关系,上下颌牙齿尖窝交错,咬合关系良好,尖牙轴倾度正常,支抗磨牙无明显移动.结论:早期应用节段正轴辅弓和后期直丝弓矫治器,进行拥挤伴尖牙近中唇移过低位的拔牙矫治,不

  2. 种植支持全牙弓和分段式修复无牙颌的效果观察%Observation on the Effect of Dental Implant Supported the Whole Dental Arch and Segmented Restoration

    Institute of Scientific and Technical Information of China (English)

    范胤

    2016-01-01

    目的:对比种植支持全牙弓和分段式修复无牙颌的效果。方法以我院2015年4月~2016年5月收治的42例无牙颌患者作为研究对象,采用随机数法将患者分为两组,各21例。观察组用种植支持全牙弓治疗,对照组用分段式修复治疗。结果观察组患者治疗后的美观评价水平、维护方便程度、总体满意度高于对照组,比较差异有统计学意义(P<0.05)。结论采用种植支持全牙弓治疗无牙颌治疗效果好。%Objective To compare the effects of dental implant supported total dental arch and segmental restoration in the restoration of the jaw. Methods From April 2015 to May 2016 in our hospital 42 cases of patients with non dental jaw patients as the research object, using the random number method will be divided into two groups, each of 21 cases. The observation group was treated with dental implants, and the control group was treated with staged repair. Results In the observation group after treatment, the level of aesthetic evaluation, maintenance convenience, overall satisfaction rate was higher than the control group, the difference was significant (P<0.05). Conclusion The clinical application of dental implants in the treatment of the patients with no teeth jaw.

  3. A quadrant tray and bite registration as an alternative to dual-arch impressions for fixed prosthetics: a clinical and dental laboratory technique.

    Science.gov (United States)

    Hammond, Barry D; Myers, Michael L; Haywood, Van B

    2011-01-01

    To perform fixed prosthodontic procedures, dentists take a full-arch or quadrant impression and articulate the casts. The dual-arch impression technique is a popular quadrant technique for crown fabrication. The technique described in this article, which uses a quadrant impression and separate interocclusal record, offers several advantages over the traditional dual-arch method.

  4. 牙弓/牙槽骨弓的塑形矫治——基于牙弓形态发育不良的儿童错(拾)畸形诊断与阻断治疗%Dental alveolar bone and dental arch remodeling in children: orthodontic diagnosis and treatments based on individual child arch development

    Institute of Scientific and Technical Information of China (English)

    李小兵

    2016-01-01

    The etiology of malocclusions basically involves both congenital and environmental factors. Malocclusion is the result of the abnormal development of the orofacial complex (including tooth, dental alveolar bone, upper and lower jaws). Early orthodontic interceptive treatments involve the elimination of all congenital and environmental factors that contribute to the malformation of the orofacial complex, as well as interrupt the deviated development of the orofacial complex and the occlusion. Early orthodontic interceptive treatments mainly aim to use children's growth potential to correct abnormal develop-ments of occlusions and orthodontically treat malocclusions more efficiently. The early orthodontic interceptive treatments include correcting the child's bad oral habits, training the abnormal functioned para-oral muscles, maintaining the normal eruptions of succeeding permanent teeth, applying interceptive treatments to the mal-developed teeth, and employing functional orthopedic treatments for abnormal growths of the upper and lower jaws. In orthodontics, correcting mal-positioned teeth is called orthodontic treatment, while rectifying the abnormal relationships of the upper and lower jaws is called functional orthopedic treatment. However, no clear definition is available as regards to the early orthodontic interceptive treatment of malocclusions caused by the deviated development of the dental alveolar bone. This new theory of "early dental alveolar bone and dental arch remodeling technique" was proposed by Professor Li Xiaobing of the Department of Pediatric Dentistry, Faculty of Pediatric Dentistry and Orthodontics in West China Hospital of Stomatology through his clinical analyses and investigation of his early orthodontic interceptive treatments. He defined the early orthodontic corrections of abnormal growth of dental alveolar bone as "remodel". The "early dental alveolar bone and dental arch remodeling theory and technique" is proved useful in

  5. Comparison of Intercanine and Intermolar Width Between Cleft Lip Palate and Normal Class I Occlusion Group.

    Science.gov (United States)

    Wahaj, Aiyesha; Ahmed, Imtiaz

    2015-11-01

    To determine the mean difference of arch dimensions (both intercanine and intermolar width) between cleft lip palate and normal class I occlusion group. Cross-sectional analytic study. Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, [Dow University of Health Sciences (DUHS)], Karachi, from March 2012 to April 2013. Group 1 consisted of 32 subjects with complete repaired, non-syndromic unilateral and bilateral cleft lip palate. Group 2 consisted of 32 subjects with normal facial morphology and class I occlusion. Exclusion criteria were cleft lip palate subjects with systemic diseases, any arch expansion procedure, incomplete repaired palate, open fistulas, developmental or acquired craniofacial muscular deformities, autoimmune conditions, syndromes, endocrine abnormalities, neurological problems, or previous history of orthodontic treatment and signs and symptoms of temporomandibular disorders, history of trauma, impacted or missing teeth, periodontally involved teeth, subdivision molar classification, skeletal base II and III with molar class I. The transverse width (intercanine and intermolar width) of dental casts was measured with the help of digital caliper. The intercanine width was measured between cusp tips of the canine while the intermolar width distance was measured between mesiobuccal cusp tips of first molars, and buccal grooves of the mandibular first molars in both cleft lip palate and normal class I occlusion group, respectively. There were 64 subjects with mean 14.7 ±6.8 years in the cleft palate and 14.7 ±6.3 years in the normal group. There was statistically significant differences found between intercanine and intermolar width in maxillary arch (p < 0.001). In mandibular arch, only intercanine width has showed significant difference (p < 0.001) between cleft and normal occlusion class I group. Maxillary and mandibular intercanine width was found to be significantly reduced in cleft lip palate group (both unilateral and bilateral) as

  6. Long-term effect of quad helix expansion of dental arch*☆%四圈簧扩大牙弓的长期效果*☆

    Institute of Scientific and Technical Information of China (English)

    王峰; 陆怀秀; 林松杉

    2013-01-01

      背景:快速扩大牙弓是快速扩大颌骨的有效方法,而与快速扩展相比,缓慢扩展稳定性更高,复发更少,但四圈簧扩弓的长期稳定性少见报道。目的:回顾性分析正畸临床中四圈簧扩大牙弓的临床效果。方法:混合牙列期及恒牙列早期牙弓狭窄患者22例使用四圈簧扩大牙弓至少3 mm,在扩大牙弓之前(T1期)、Ⅰ期四圈簧扩弓治疗完成或整个治疗结束(T2期)及治疗完成后2年(T3期)分别制取牙齿石膏研究模型并摄取头颅后前位片,在模型上测量两侧第一恒磨牙之间距离,在后前位片上描点(J 点)测量两侧基骨间距离及磨牙倾斜度,评价牙弓扩大的矫正及矫形效果。结果与结论:与扩弓前相比,四圈簧扩弓治疗后患者第一恒磨牙倾斜度和两侧基骨间距离逐渐减小;而四圈簧扩弓治疗后相比,随访2年时,患者两侧第一恒磨牙间距离、第一恒磨牙倾斜度和两侧基骨间距离的差异无显著性意义(P >0.05),提示四圈簧扩大牙弓的长期效果是稳定的,并有矫形效果。%BACKGROUND: Rapid expansion of the dental arch is an effective way to rapidly expanse the jaw. Compared with rapid expansion, the slow expansion has higher stability and less recurrence, but the reports on the long-term stability of quad helix expansion are rare. OBJECTIVE: To retrospectively analyze the clinical effect of quad helix expansion in orthodontics. METHODS: Twenty-two subjects with dental arch stenosis in mixed dentition and early permanent dentition who experienced an expansion of at least 3 mm with quad helix appliance were selected for this study. Plaster dental casts and posteroanterior radiographs were evaluated at the beginning of the treatment (T1), at the completion of phase I quad helix expansion or ful treatment (T2), and approximately 2 years fol owing the completion of treatment (T3). The distance between two first molars was

  7. Implant-supported prosthesis misalignment related to the dental arch: a 14-year clinical follow-up.

    Science.gov (United States)

    das Neves, Flávio Domingues; Coró, Vitor; da Silva Neto, João Paulo; de Mattias Sartori, Ivete Aparecida; do Prado, Ricardo Alves

    2012-08-01

    The purpose of this study was to warn the dental community about a possible problem in function with partial implant-supported prostheses used for long periods. The misalignment between natural teeth and the implant-supported prosthesis on teeth 11 and 12, observed in a 14-year clinical follow-up, illustrates the fact. The metal-ceramic crowns were placed in 1995 after a rigorous occlusal adjustment. Evaluations were made at 4, 6, 9, and 14 years, when it was noticed that the restorations were positioned palatally and extruded in comparison with the natural teeth. After 9 years, a greater discrepancy was noticed, with anterior occlusion and esthetic changes. The possible causes have been discussed: occlusal problems, parafunctional habits, and natural movement. The first 2 options were discarded after clinical analysis and diagnosis. Therefore, the natural movement probably deriving from an interaction of mechanical and genetic factors might have been the cause. The implants do not have periodontal ligaments but rather ankylosis, so they do not suffer those movements. This case emphasizes the need to inform patients that implants can last more than 10 years in function, but this is not the case with restorations, which lose function and esthetics and must be replaced.

  8. Evaluation of accuracy of complete-arch multiple-unit abutment-level dental implant impressions using different impression and splinting materials.

    Science.gov (United States)

    Buzayan, Muaiyed; Baig, Mirza Rustum; Yunus, Norsiah

    2013-01-01

    This in vitro study evaluated the accuracy of multiple-unit dental implant casts obtained from splinted or nonsplinted direct impression techniques using various splinting materials by comparing the casts to the reference models. The effect of two different impression materials on the accuracy of the implant casts was also evaluated for abutment-level impressions. A reference model with six internal-connection implant replicas placed in the completely edentulous mandibular arch and connected to multi-base abutments was fabricated from heat-curing acrylic resin. Forty impressions of the reference model were made, 20 each with polyether (PE) and polyvinylsiloxane (PVS) impression materials using the open tray technique. The PE and PVS groups were further subdivided into four subgroups of five each on the bases of splinting type: no splinting, bite registration PE, bite registration addition silicone, or autopolymerizing acrylic resin. The positional accuracy of the implant replica heads was measured on the poured casts using a coordinate measuring machine to assess linear differences in interimplant distances in all three axes. The collected data (linear and three-dimensional [3D] displacement values) were compared with the measurements calculated on the reference resin model and analyzed with nonparametric tests (Kruskal-Wallis and Mann-Whitney). No significant differences were found between the various splinting groups for both PE and PVS impression materials in terms of linear and 3D distortions. However, small but significant differences were found between the two impression materials (PVS, 91 μm; PE, 103 μm) in terms of 3D discrepancies, irrespective of the splinting technique employed. Casts obtained from both impression materials exhibited differences from the reference model. The impression material influenced impression inaccuracy more than the splinting material for multiple-unit abutment-level impressions.

  9. A CBCT study on Morphological characteristics of dental arches in subjects with unilateral maxillary canine impaction%利用锥形束CT研究单侧上颌尖牙埋伏阻生患者牙弓形态特点

    Institute of Scientific and Technical Information of China (English)

    韩天媛; 刘志杰; 邵玶

    2016-01-01

    目的 利用锥形束CT(Cone beam computed tomography,CBCT)研究单侧上颌尖牙埋伏阻生患者牙弓形态特点,为研究其病因及预防继发病症提供参考.方法 39名单侧上颌尖牙埋伏阻生患者,其中腭侧埋伏19名,唇侧埋伏20名,另设正常对照20名.三组患者年龄无显著性差异.三组患者拍摄CBCT并对牙弓的影像进行测量,比较三组之间以及阻生侧与非阻生侧的牙弓形态特点.结果 尖牙阻生患者的双侧牙弓比较显示,阻生侧前段及整侧牙弓长度均比非阻生侧小(P<0.001).腭侧组第一磨牙到腭中缝距离(24.06±1.68) mm小于唇侧组(24.86±1.31)mm和对照组(24.88±1.12) mm,腭侧组牙弓周长(72.29±3.50) mm小于唇侧组(75.96±5.26) mm,P<0.05.结论 上颌尖牙埋伏阻生可能与牙弓长度(尤其是前段)较短有关,且腭侧阻生可能还与牙弓宽度较小有关.%Objective To examine the relationship between unilateral maxillary canine impaction and the morphological characteristics of the maxillary dental arches using Cone beam computed tomography(CBCT).Methods 39 patients with unilateral impacted canine were selected,including 19 palatal impaction (UPI) (mean age:16.21 ± 4.14 years) and 20 buccal impaction (UBI).20 normal patients served as control,with matched ages.CBCT images for the three groups were taken and compared for arch characterestics.Results The anterior and whole dental arch lengths of impaction side were smaller than that of normal sides (P<0.001).The first molar to midpalatal suture distances of UPI group were smaller than the other groups and the arch perimeter of it was smaller than UBI group(P<0.05).Conclusions The short arch lengths (especially in anterior part) may have effect on the occurrence of unilateral maxillary canine impaction.UPI may also be related to a smaller arch width.

  10. 应用LOM法制作-下颌骨及牙列的三维实体模型%3D Solid Model of Mandible with Dental Arch via LOM Method

    Institute of Scientific and Technical Information of China (English)

    张睿; 李玲; 于力牛; 白瑞军; 张富强; 王成焘; 徐肖云

    2000-01-01

    Objective Based on 3D reconstruction data from CT scaning, a solid model of mandible with dental arch is ob tained via a rapid prototype machine using LOM method. Method 3D reconstruction data is transferred to STL file using software of Delcam(UK) , which will be fed to Magics RP software for detection and rebuilding. Reproduction of the papery model of mandible with dental arch is then performed with highly geometric sunilarity. Result The RP model of mandible with dental arch is obtained. Conclusion Accuracy of the reproduction model meets the demands of studies in prosthetic dentist, which gives the possibility of computer aided design of prosthetic dentistry based on 3D solid model.%采用基于CT断层影像的下颌骨及牙列三维重建数据,利用快速成型中的分层制造方法复制下颌骨 及牙列。方法利用Delcam公司(UK)软件将下颌骨及牙列三维重建的数据文件转换为STL文件,采用Magics RP 软件读入STL文件并进行检验与修补。制作下颌骨及牙列纸质实物模型,与下颌骨及牙列标本模型的几何相似性 良好。结果得到了下颌骨及下牙列的快速原型模型。结论下颌骨及牙列复制模型精度符合口腔修复中的要 求,可在其计算机三维实体模型基础上进行牙列缺损的计算机辅助修复设计。

  11. A study of dentists' preferred maxillary anterior tooth width proportions: comparing the recurring esthetic dental proportion to other mathematical and naturally occurring proportions.

    Science.gov (United States)

    Ward, Daniel H

    2007-01-01

    Presently, there are no generally accepted standards for designing smiles using tooth proportion relationships. The purpose of this study was to determine whether North American dentists prefer smile designs created using the recurring esthetic dental (RED) proportion, other mathematically defined tooth proportion relationships, or naturally occurring tooth-to-tooth width proportions previously reported to occur in the North American population. Three hundred and one North American dentists were surveyed to determine their preferences of imaged smiles exhibiting different anterior tooth width proportions and the primary proportion influencing their decision. One-sample t-tests were used to compare preferences of constructed smiles. Pearson's Chi-square test was used to assess the independence of the relationship between the subjects' demographic attributes and the factors reported as being instrumental in their decision processes. Fifty-seven percent of dentists surveyed preferred the smiles with the 70% RED proportion over the smiles with the naturally occurring maxillary anterior tooth width proportions in normal-length teeth. Dentists preferred the smiles of the naturally occurring maxillary tooth proportions (70%) and the 70% RED proportion (75%) over the golden proportion. In smiles with tall teeth, the golden proportion was preferred by 58% of the surveyed dentists over the naturally occurring tooth-to-tooth width proportions as previously defined by Preston. Sixty-two percent of dentists cited the overall balance as the primary factor affecting their selection. Twenty-three percent made their selection based on the size of the maxillary central incisors, whereas 15% used other teeth or factors. Smiles created using the principles of the RED proportion were preferred by a majority of dentists surveyed. The majority of dentists reported that overall balance was the primary factor affecting their selection. The RED proportion may be useful in creating smiles

  12. Analysis of the relation between dental arch size and upper airway morphology in patients with obstructive sleep apnea hypoventilation syndrome%阻塞性睡眠呼吸暂停低通气综合征患者的牙弓与上气道形态变化及相关性分析

    Institute of Scientific and Technical Information of China (English)

    徐超; 谢宇平; 秦猛; 何健民; 余奕波; 康宏; 马薇; 惠培林

    2016-01-01

    Objective:To study the anatomical correlation between dental arch and the volume of upper airway in patients with obstruc-tive sleep apnea hypoventilation syndrome(OSAHS). Methods: Dental arch architecture and upper airway volume were measured by cone beam CT(CBCT) in the subjects with OSAHS(n=22) and without OSAHS(n=19). The correlation between dental arch and the supper airway volume in OSAHS patients was analyzed. Results:The length of the upper dental arch and the height of palate in OSAHS patients were larger than those of the controls(All, P<0. 05). Cross-sectional area of nasopharynx and retropalatal and the total volume of upper airway were negatively correlated with the palatal height and upper dental arch length(P<0. 05), while positively correlated with upper dental arch of molar regions(P<0. 05). Conclusion:The abnormal shape of upper dental arch is related to the airway vol-ume of nasopharynx and retropalatal region in patients with OSAHS.%目的::比较阻塞性睡眠呼吸暂停低通气综合征( OSAHS)患者与正常人牙弓及上气道形态差异,揭示OSAHS牙弓形态改变与上气道容积对应变化的关系。方法:利用上气道CBCT扫描及口腔模型测量经PSG诊断为OSAHS的男性患者( n=22)与正常男性对照(n=19)的牙弓形态与上气道容积变化,并行相关性分析。结果:OSAHS组上颌牙弓长度与腭弓高度分别大于对照组(均P<0.05);OSAHS组鼻咽段、腭咽段截面积及上气道总容积与腭弓高度、上颌牙弓长度呈负相关(均P<0.05),与上颌后段牙弓宽度呈正相关关系(P<0.05)。结论:OSAHS患者上颌牙弓形态的异常与鼻咽段和腭咽段容积的变化有关联。

  13. 安氏Ⅱ1类错(牙合)拔牙矫治后牙弓形态的变化%Change of arch form after extraction treatment on patients with Angle Ⅱ1 malocclusion

    Institute of Scientific and Technical Information of China (English)

    壮荣; 刘洋; 周云; 晏燕; 曹军

    2014-01-01

    目的:观察安氏Ⅱ1类错(牙合)患者拔牙矫治后牙弓形态的变化规律,为临床治疗该类畸形提供参考.方法:选择拔除4个第一前磨牙进行正畸治疗的安氏Ⅱ1错(牙合)患者30例,取矫治前后石膏模型,通过三维扫描生成数字化牙颌模型,同时建立计算机牙弓形态定量分析系统,通过定位标志点,在牙弓形态分析平面上获取各个牙位的坐标数据,利用三次方程式拟合牙弓曲线,测量牙弓宽度及长度的变化,量化牙弓形态的变化.结果:安氏Ⅱ1类错(牙合)经过拔牙矫治后,①上颌侧切牙区以及尖牙区牙弓宽度明显增加(P <0.01,P<0.05),下颌侧切牙区和尖牙区牙弓宽度无明显变化;②上、下颌前磨牙区及磨牙区牙弓宽度明显减小(P<0.001);③矫治后上、下颌尖牙区长度明显增加(P<0.05),磨牙区长度明显减小(P<0.001).结论:安氏Ⅱ1类错(牙合)拔牙矫治后,上颌前部牙弓变宽,后部牙弓变窄,下颌前部牙弓形态未见明显缩窄.%Objective:To compare and analyze the changes in the arch form after extraction treatment for patients with Angle Ⅱ 1 malocclusion.Methods:A total of 30 patients with Angle Ⅱ1 malocclusion were selected.Before and after tooth extraction treatment,dental cast were obtained and generated the digital dental model by 3-D scanning.Then we positioned the landmark and fitted curve of dental arch,measured dental arch width and length,analyzed the change of the dental arch form by using the computerized system for the arch form quantitative analysis.Results:After the extraction treatment for patients with Angle Ⅱ 1 malocclusion:Dental arch width of maxillary lateral incisor and canines zone had significantly increased after treatment (P < 0.01,P < 0.05),while mandibular lateral incisor and canines zone had no obvious change ; dental arch width of premolar and molar had significantly decreased both in maxillary and mandible (P <0.001); and dental

  14. 基于CT断层影像的下颌骨及下牙列三维几何学仿真%3D Geometric Simulation of Mandible with Dental Arch from CT Data

    Institute of Scientific and Technical Information of China (English)

    李玲; 张睿; 于力牛; 张富强; 王成焘; 徐肖云

    2000-01-01

    进行基于CT断层影像的下颌骨及下牙列三维几何学仿真。方法结合牙CT技术,采用交互式人 机对话提取CT断层影像二维轮廓数据,应用美国PIC公司微机版Pro/Engineer和英国DELCAM公司POWERSHAPE 等应用软件建立下颌骨及下牙列三维线框模型和实体模型。结果得到了具有真实感的下颌骨及下牙列的三维实 体模型,该模型能够进行三维显示,模型可编辑性强。结论几何学仿真模型为快速原型和下颌骨及下牙列的力学 仿真模型等进一步应用和研究打下了基础。本文采用的几何学仿真方法切实可行,在口腔颌面外科、骨科等领域有 良好的应用前景。%A 3D geometric simulation of mandible with dental arch from CT has been obtained in this study. Meth ods This process uses automatic system assisted with interactive action to get 2D contour data from CT images, then 3D wireframe model and solid model were obtained by using CAD/CAM software Pro-E(USA) and DELC AM(UK).Results 3D solid model of mandible with dental arch were presented which can be fully edited. Conclusions This model can be applied to further educa tional and clinical researches such as RP , biomechanics simulation in prosthetic dentistry. The processes of simulation has wide applications in clinical practice of dentistry and dental education.

  15. Comparison of overjet among 3 arch types in normal occlusion.

    Science.gov (United States)

    Kim, Byung-In; Bayome, Mohamed; Kim, Yoonji; Baek, Seung-Hak; Han, Seong Ho; Kim, Seong-Hun; Kook, Yoon-Ah

    2011-03-01

    The purposes of this study were to examine the amounts of overjet in the anterior and posterior segments of 3 arch forms by using facial axis points on 3-dimensional virtual models and to verify the minimum posterior extension required for classification of the arch form in normal occlusions. Facial axis points were digitized on 97 virtual models with normal occlusion, classified into 20 tapered, 25 ovoid, and 52 square arch forms. Intercanine and intermolar arch widths and depths were measured. The best-fitting curves were created, and overjet was measured at each facial axis point. Two-way analysis of variance (ANOVA) was performed to assess the relationship between arch form and overjet in different areas. The minimum posterior extension to determine arch type was analyzed with the chi-square test. Subjects with a tapered arch form had larger overjet compared with those with ovoid and square forms, except at the central incisor. A significant difference in overjet among different areas was found in subjects with a square arch form (P overjet according to arch types. The extension to the first premolar was sufficient to classify arch form type. It might be beneficial to consider more coordinated preformed superelastic archwires according to variations in overjet of different arch types. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  16. Clinical and radiological 12-year follow-up of full arch maxilla prosthetic restoration supported by dental implants positioned through guide flapless surgery.

    Science.gov (United States)

    Soardi, C M; Bramanti, E; Cicciù, M

    2014-03-01

    The computer-guided flapless surgery for implant placement using stereolithographic templates is going to be considered a daily practice technique. The advantages of this kind of surgery are related with its no flap opening, with the precision of the implant positioning and with the possibility of having a quick rehabilitation and low post-surgical discomfort. The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses. This case presented a 12-year follow-up of a maxillary prosthesis supported by dental implant immediately loading and positioned with the first kind of guided flapless surgery technique. Aim of this paper was to report how the guide surgery implant position technique can be considered a predictable and safe technique giving the surgeon excellent long-term results.

  17. Prediction of width of un-erupted incisors, canines and premolars in a Ugandan population: A cross sectional study

    Directory of Open Access Journals (Sweden)

    Buwembo William

    2012-07-01

    Full Text Available Abstract Background Accurate prediction of the space forms an important part of an orthodontic assessment in the mixed dentition. However the most commonly used methods of space analysis are based on data developed on Caucasian populations. In order to provide more accurate local data we set out to develop a formula for predicting the widths of un-erupted canines and premolars for a Ugandan population and to compare the predicted widths of the teeth from this formula with those obtained from Moyers’ tables, and Tanaka and Johnston’s equations. Methods Dental casts were prepared using mandibular and maxillary arch impressions of 220 children (85 boys/135 girls aged 12–17 years recruited from schools in Kampala, Uganda. The mesio-distal width of the mandibular incisors, mandibular and maxillary canines and premolars were measured with a pair of digital calipers. Based on regression analysis, predictive equations were derived and the findings were compared with those presented in Moyers’ probability tables, and Tanaka and Johnston’s equations. Results There were no statistically significant differences between the tooth widths predicted by our equations and those from Moyers’ probability tables at the 65th and 75th percentile probabilities for the girls and at 75th level in boys in the mandibular arch. While in the maxillary arch no statistically significant differences at the 75th and 95th levels were noted in girls. There were statistically significant differences between predicted tooth sizes using equations from the present study and those predicted from the Tanaka and Johnston regression equations. Conclusions In this Ugandan population, Moyers’ probability tables could be used to predict tooth widths at specific percentile probabilities, but generally, Tanaka and Johnston technique tends to overestimate the tooth widths.

  18. Influence of lip closure on alveolar cleft width in patients with cleft lip and palate

    Directory of Open Access Journals (Sweden)

    Schmelzle Rainer

    2011-01-01

    Full Text Available Abstract Background The influence of surgery on growth and stability after treatment in patients with cleft lip and palate are topics still under discussion. The aim of the present study was to investigate the influence of early lip closure on the width of the alveolar cleft using dental casts. Methods A total of 44 clefts were investigated using plaster casts, 30 unilateral and 7 bilateral clefts. All infants received a passive molding plate a few days after birth. The age at the time of closure of the lip was 2.1 month in average (range 1-6 months. Plaster casts were obtained at the following stages: shortly after birth, prior to lip closure, prior to soft palate closure. We determined the width of the alveolar cleft before lip closure and prior to soft palate closure measuring the alveolar cleft width from the most lateral point of the premaxilla/anterior segment to the most medial point of the smaller segment. Results After lip closure 15 clefts presented with a width of 0 mm, meaning that the mucosa of the segments was almost touching one another. 19 clefts showed a width of up to 2 mm and 10 clefts were still over 2 mm wide. This means a reduction of 0% in 5 clefts, of 1-50% in 6 clefts, of 51-99% in 19 clefts, and of 100% in 14 clefts. Conclusions Early lip closure reduces alveolar cleft width. In most cases our aim of a remaining cleft width of 2 mm or less can be achieved. These are promising conditions for primary alveolar bone grafting to restore the dental bony arch.

  19. Information Width

    CERN Document Server

    Ratsaby, Joel

    2008-01-01

    Kolmogorov argued that the concept of information exists also in problems with no underlying stochastic model (as Shannon's information representation) for instance, the information contained in an algorithm or in the genome. He introduced a combinatorial notion of entropy and information $I(x:\\sy)$ conveyed by a binary string $x$ about the unknown value of a variable $\\sy$. The current paper poses the following questions: what is the relationship between the information conveyed by $x$ about $\\sy$ to the description complexity of $x$ ? is there a notion of cost of information ? are there limits on how efficient $x$ conveys information ? To answer these questions Kolmogorov's definition is extended and a new concept termed {\\em information width} which is similar to $n$-widths in approximation theory is introduced. Information of any input source, e.g., sample-based, general side-information or a hybrid of both can be evaluated by a single common formula. An application to the space of binary functions is con...

  20. WIDTHS AND AVERAGE WIDTHS OF SOBOLEV CLASSES

    Institute of Scientific and Technical Information of China (English)

    刘永平; 许贵桥

    2003-01-01

    This paper concerns the problem of the Kolmogorov n-width, the linear n-width, the Gel'fand n-width and the Bernstein n-width of Sobolev classes of the periodicmultivariate functions in the space Lp(Td) and the average Bernstein σ-width, averageKolmogorov σ-widths, the average linear σ-widths of Sobolev classes of the multivariatequantities.

  1. Full-arch dental implant restorationversussectional repair for dentulous mandible%种植支持全牙弓和分段式修复无牙颌患者的对比

    Institute of Scientific and Technical Information of China (English)

    覃太平

    2015-01-01

    背景:临床对于无牙颌骨患者主要采用种植支持全牙弓和分段式修复,这两种治疗方案各有特点,种植支持全牙弓修复有利于种植体及下颌骨的保护,但对修复体不利;分段式修复对修复体更有利。目的:对比种植支持全牙弓和分段式修复无牙颌患者的临床效果和患者满意度。方法:纳入实施无牙颌种植支持式义齿修复治疗的患者40例,其中28例采用全牙弓式修复,12例采用分段式修复,两组全部采用百康特种植系统及配套的种植体,种植修复完成后对患者进行1年的随访,采用临床检查、X射线评价种植体和骨组织结合成功率。结果与结论:全牙弓式修复组种植成功率为100%,分段式修复组种植成功率为98%,两组间比较差异无显著性意义;全牙弓式修复组修复成功率为97%,分段式修复组修复成功率为98%,两组间比较差异无显著性意义;两组种植后三四个月及修复完成后12个月的骨吸收情况无差异;两组患者对种植义齿的咀嚼功能恢复、固定效果、主观舒适度、发音均比较满意,组间比较差异无显著性意义(P>0.05),但全牙弓式修复组的美观评价、维护方便性及总满意度明显高于分段式修复组(P 0.05). The successful restoration rates were 96.5% and 98% in the two groups, respectively, with no significant difference (P > 0.05). Bone resorption showed no difference between the two groups at 3-4 months after implantation or at 12 months after restoration. Patients in the two groups were al satisfied with masticatory function, fixed effect, subjective comfort and pronunciation are satisfactory, and there was no statisticaly significant difference (P > 0.05). However, beautiful evaluation, maintenance convenience and total satisfaction were significantly higher in the ful-arch group than the sectional repair group (P < 0.05). These findings suggest that both ful-arch

  2. Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

    Directory of Open Access Journals (Sweden)

    Marcio Rodrigues de Almeida

    2015-06-01

    Full Text Available OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB. Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB. Cone-beam computed tomography (CBCT scans and a 3D program (Dolphin assessed changes in transversal width of buccal bone (TWBB and buccal bone thickness (BBT before (T1 and 7 months after treatment onset (T2. Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone.

  3. Using biomechanical calculation and experimental measurement to study the relationship between the load and the changes in the shape of the arch-dental shape memory connector%弓齿形状记忆接骨器记忆生物力学计算和实验力学测定

    Institute of Scientific and Technical Information of China (English)

    苏佳灿; 张春才; 禹宝庆; 薛召军; 吴建国; 丁祖泉

    2005-01-01

    BACKGROUND: The biomechanical features of arch-dental shape memory connector designed for fractures in pelvis or the parts adjacent to joints are analyzed through biomechanical calculation and experimental measurements.OBJECTIVE: To explore the relationship between the changes in shape of arch-dental shape memory connector and the load on it.DESIGN: Both biomechanical calculation and the experimental measurement were conducted for mutual supplementation and confirmation.SETTING: The Orthopedic Department of Changhai Hospital Affiliated to the Second Military Medical University of Chinese PLA and the Life Science and Bioengineering College of Tongji University.MATERIALS:The trial was conducted from at Shanghai Changhai Hospital and Life Science Laboratory of Tongji University from April 2002 to April 2004. The subjects were arch-dental shape memory connectors.METHODS: We calculated the stress in and around the fracture face produced by arch-dental shape memory connector according to Moire principle and we also measured the changes in the shape of arch-dental shape memory connector. The relationship between load and the changes in the shape of arch-dental shape memory connector was explored.MAIN OUTCOME MEASURES: To explore whether the results of biomechanical calculation and those of the experimental measurement are consistent.RESULTS: Biomechanical calculation found that the relationship between the load (P) and the displacement(δ) in arch-dental shape memory connector was P = 13.69δ. The experimental measurement found that the load on the connector and the displacement were in a linear relationship.CONCLUSION: The relationship between the load and the displacement in arch-dental shape memory connector was linear within its elastic range and the biomechanical calculation results were consistent with the results of the experimental measurement.%背景:通过记忆生物力学计算和实验测定,分析骨盆骨折和近关节部位弓齿形状记忆合金接骨

  4. 单颌牙弓夹板+颌内钢丝结扎法治疗下颌骨正中骨折16例%Single Maxillary Dental Arch Splint+Jaw Steel Wire Ligation in Treatment of 12 Cases of Fracture of Mandibular Median

    Institute of Scientific and Technical Information of China (English)

    潘树矿; 陆开睿

    2015-01-01

    目的探讨单纯性下颌骨正中骨折的非手术治疗方式。方法应用单颌牙弓夹板和颌内钢丝结扎对下颌骨骨折处进行固定制动4w,为下颌骨正中骨折的愈合创造固定的外部条件。结果16例下颌骨正中骨折的患者4 w后拆除牙弓夹板,骨折断端愈合良好,咬合关系恢复正常。结论单颌牙弓夹板和颌内钢丝结扎治疗单纯性下颌骨正中骨折,能对骨折处有效的制动,有利于口腔卫生的保持,避免二次手术拆除内固定所用的钛板,经济实用。%Objective To study the non operation treatment of simple mandibular fracture.Methods Applicationofsinglemaxil arydental arch splint and intermaxil ary wiring on mandibular fracture were fixed brake 4 weeks, healing of mandibular fracture fixation for the creation of the external conditions. Results 16 cases of mandibular fractures in patients with the 4 week after removal of dental arch splint broken ends of fracture healing, good, normal occlusal relationship. Conclusion Single maxil ary dental arch splint and jaw steel wire ligation in the treatment of median simple mandible fracture, fracture is ef ective to brake, is conducive to maintaining oral hygiene, avoid titanium plate two times operation removal of internal fixation using, economical and practical.

  5. Avaliação das alterações na distância intercaninos do arco inferior em pacientes com má oclusão de Classe I tratados ortodonticamente Intercanine width changes in the mandibular arch of Class I malocclusion patients orthodontically treated

    Directory of Open Access Journals (Sweden)

    Patricia Regina Rizzo Araújo

    2007-04-01

    recidiva na medida feita na ponta da cúspide do que na da face vestibular após a remoção das contenções, indicando que houve uma inclinação dos caninos para lingual.INTRODUCTION: Intercanine width changes in the mandibular arch during orthodontic treatment are considered unstable. AIM AND METHODS: In order to observe the post treatment alterations in the lower intercanine width, 30 patients with Class I malocclusion were selected from the files of the graduate orthodontic clinic of the Catholic University of Minas Gerais based on the availability of records. The measurements were made on study models, taken in two areas (cuspid tip and buccal surface and in three different periods of time: T1 (pre treatment; T2 (post treatment and T3 (at least one year out of retention. RESULTS AND CONCLUSIONS: There was a significant increase in the intercanine width during treatment and a reduction in the post retention period at the cuspid tip and the buccal surface. When the area of measurement was considered, there was no difference between T3 and T1 at the cuspid tip. At buccal surface it was significantly greater in T3 than in T13. There were no statistical differences in the intercanine width related to gender and time out of retention. The extraction group showed a significantly greater increase in the intercanine width than the non extraction group in the cuspid tip and in the buccal surface. The extraction group showed a significant greater reduction of the intercanine width measured at the cuspid tip when compared to measurements at the buccal surface. The extraction cases were more stable than the non extraction cases considering the buccal surface. Considering the type of movement used for canine expansion, the translation cases were more stable with measurements at buccal surface than at cuspid tip, indicating a lingual inclination of the crowns of the canines in the post retention period.

  6. Glossary to ARCH (GARCH)

    DEFF Research Database (Denmark)

    Bollerslev, Tim

    The literature on modeling and forecasting time-varying volatility is ripe with acronyms and abbreviations used to describe the many different parametric models that have been put forth since the original linear ARCH model introduced in the seminal Nobel Prize winning paper by Engle (1982......).  The present paper provides an easy-to-use encyclopedic reference guide to this long list of ARCH acronyms.  In addition to the acronyms associated with specific parametric models, I have also included descriptions of various abbreviations associated with more general statistical procedures and ideas...

  7. Glossary to ARCH (GARCH)

    DEFF Research Database (Denmark)

    Bollerslev, Tim

    The literature on modeling and forecasting time-varying volatility is ripe with acronyms and abbreviations used to describe the many different parametric models that have been put forth since the original linear ARCH model introduced in the seminal Nobel Prize winning paper by Engle (1982......).  The present paper provides an easy-to-use encyclopedic reference guide to this long list of ARCH acronyms.  In addition to the acronyms associated with specific parametric models, I have also included descriptions of various abbreviations associated with more general statistical procedures and ideas...

  8. Electrothermally Tunable Arch Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2017-03-18

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of electrothermally actuated microelectromechanical arch beams. The beams are made of silicon and are intentionally fabricated with some curvature as in-plane shallow arches. An electrothermal voltage is applied between the anchors of the beam generating a current that controls the axial stress caused by thermal expansion. When the electrothermal voltage increases, the compressive stress increases inside the arch beam. This leads to an increase in its curvature, thereby increasing its resonance frequencies. We show here that the first resonance frequency can increase monotonically up to twice its initial value. We show also that after some electrothermal voltage load, the third resonance frequency starts to become more sensitive to the axial thermal stress, while the first resonance frequency becomes less sensitive. These results can be used as guidelines to utilize arches as wide-range tunable resonators. Analytical results based on the nonlinear Euler Bernoulli beam theory are generated and compared with the experimental data and the results of a multi-physics finite-element model. A good agreement is found among all the results. [2016-0291

  9. Mixing properties of ARCH and time-varying ARCH processes

    CERN Document Server

    Fryzlewicz, Piotr; 10.3150/10-BEJ270

    2011-01-01

    There exist very few results on mixing for non-stationary processes. However, mixing is often required in statistical inference for non-stationary processes such as time-varying ARCH (tvARCH) models. In this paper, bounds for the mixing rates of a stochastic process are derived in terms of the conditional densities of the process. These bounds are used to obtain the $\\alpha$, 2-mixing and $\\beta$-mixing rates of the non-stationary time-varying $\\operatorname {ARCH}(p)$ process and $\\operatorname {ARCH}(\\infty)$ process. It is shown that the mixing rate of the time-varying $\\operatorname {ARCH}(p)$ process is geometric, whereas the bound on the mixing rate of the $\\operatorname {ARCH}(\\infty)$ process depends on the rate of decay of the $\\operatorname {ARCH}(\\infty)$ parameters. We note that the methodology given in this paper is applicable to other processes.

  10. The assessment of crowding without the need to record arch perimeter. Part I: Arches with acceptable alignment.

    Science.gov (United States)

    Battagel, J M

    1996-05-01

    A simplified, mathematically determined technique for calculating arch perimeter (the overlap method) is described and its validity in determining an accurate assessment of crowding is tested. Indices, expressed in millimetres of crowding or spacing, were computed for both the whole arch and the labial segment alone. Study casts of 36 individuals with clinically acceptable lower arches were used to validate the method. The degree of crowding or spacing calculated was compared with a "clinical' assessment of each arch, in which the irregularity was measured directly using a steel ruler. Various calculation schemes were tested. Depending on exactly how the overlap was determined, the results varied slightly. Although the arches showed acceptable alignment, it was preferable to include a strategy for normalizing the positions of any rotated teeth before the overlaps were calculated. Repositioning any bucco-lingually displaced teeth into the line of the arch, however, was not useful. For the complete arch good agreement with the clinical assessment was reached on 31 occasions and for the labial segment, all but one appraisals were within 0.5 mm of each other. In the remaining instances (five complete arches and one labial segment), the degree of crowding or spacing was between 0.5 and 1 mm of the clinical assessment. Considering that clinical measurement of minor degrees of crowding and spacing cannot be precise, these results were considered acceptable. The method was easy to use, relying only on the recording of mesio-distal tooth widths and was acceptably reproducible. The technique would therefore appear to provide a valid yet simple research tool with which to record the degree of crowding. Its ability to cope with irregular and crowded arches will be the subject of a subsequent review.

  11. Oral breathing and dental malocclusions.

    Science.gov (United States)

    Zicari, A M; Albani, F; Ntrekou, P; Rugiano, A; Duse, M; Mattei, A; Marzo, G

    2009-06-01

    Aim of the present study was to evaluate existing correlations between oral breathing and dental malocclusions. The study was conducted on a paediatric group of 71 oral breathers selected at the Allergology and Paediatric Immunology Department of Umberto I General Hospital, University of Rome "La Sapienza" (Italy). The children were selected based on inclusion/exclusion criteria. Children aged 6 to 12 years with no history of craniofacial malformations or orthodontic treatment were included. The results were compared with a control group composed of 71 patient aged 6 to 12 years with nasal breathing. After their medical history was recorded, all patients underwent orthodontic/otolaryngological clinical examinations. The following diagnostic procedures were then performed: latero-lateral projection teleradiography, orthopantomogram, dental impressions, anterior rhinomanometry before and after administering a local vasoconstrictor, nocturnal home pulse oximetry (NHPO) recording, spirometry test, skin prick test, study cast evaluation and cephalometric analysis following Tweed's principles. The intraoral examination assessed: dental class type, overbite, overjet, midlines, crossbite, and presence of parafunctional oral habits such as atypical swallowing, labial incompetence, finger sucking and sucking of the inner lip. Evaluation of the study casts involved arch perimeter and transpalatal width assessment, and space analysis. The results showed a strong correlation between oral breathing and malocclusions, which manifests itself with both dentoskeletal and functional alterations, leading to a dysfunctional malocclusive pattern. According to the authors' results, dysfunctional malocclusive pattern makes it clear that the association between oral breathing and dental malocclusions represents a self-perpetuating vicious circle in which it is difficult to establish if the primary alteration is respiratory or maxillofacial. Regardless, the problem needs to be addressed and

  12. The ARCHES Project

    Science.gov (United States)

    Motch, C.; Arches Consortium

    2015-09-01

    The Astronomical Resource Cross-matching for High Energy Studies (ARCHES) project is a FP7-Space funded programme started in 2013 and involving the Observatoire Astronomique de Strasbourg including the CDS (France), the Leibniz- Institut für Astrophysik Potsdam (Germany), the University of Leicester (UK), the Universidad de Cantabria (IFCA, Spain) and the Instituto Nacional de Tecnica Aeroespacial (Spain). ARCHES will provide the international astronomical community with well-characterised multi-wavelength data in the form of spectral energy distributions (SEDs) for large samples of objects extracted from the 3XMM X-ray catalogue of serendipitous sources. The project develops new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues and a multi-wavelength finder for clusters of galaxies. SEDs are based on an enhanced version of the 3XMM catalogue and on a careful selection of the most relevant multi-wavelength archival catalogues. In order to ensure the largest audience, SEDs will be distributed to the international community through CDS services and through the Virtual Observatory. These enhanced resources are tested in the framework of several science cases. More information may be found at http://www.arches-fp7.eu/

  13. Diagnostic Value of Manual and Computerized Methods of Dental Casts Analysis

    OpenAIRE

    H. Rahimi; M. Katchooi; Tehranchi, A.; M. Nouri; Massudi, R

    2009-01-01

    Objective: The aim of this study was to evaluate the validity of computerized and manual methods of dental cast analysis.Materials and Methods: Twenty set-ups of upper and lower casts using artificial teeth corresponding to various malocclusions were created for a diagnostic in vitro study. Values of tooth size were calculated from the isolated artificial teeth out of the set-ups, results were considered as a gold standard for the tooth size. Arch width was calculated from the existing set-up...

  14. Clinical study on correction of maxillary dental crowding with Smart clip self-ligating system%应用Smart clip自锁托槽矫治上颌牙列拥挤的临床研究

    Institute of Scientific and Technical Information of China (English)

    王海燕; 李琥

    2012-01-01

    目的:探讨Smart clip自锁托槽矫治上颌牙列拥挤病例的牙弓变化特点.方法:选取20例上牙轻中度拥挤的患者,不拔牙矫治,使用Smart clip自锁托槽排齐牙列,在治疗前和上牙排齐时分别进行模型测量,对比分析治疗前后上颌牙弓宽度、牙弓长度及周长的变化,应用SPSS12.0统计软件分析处理数据.结果:排齐后与治疗前阶段相比,上颌牙弓长度、周长、前磨牙间宽度和第一磨牙间宽度均显著增加,尖牙间宽度和第二磨牙间宽度无显著变化.结论:应用Smart clip自锁托槽系统排齐和整平上颌轻中度拥挤牙列,上颌牙弓宽度、牙弓长度及周长均显著增大,增加不拔牙矫治可能.%Objective To clarify changes in the dental arch on Nonextraction correction of maxillary dental crowding withSmart clip self-ligating system. Methods The Smart clip self-ligating system was used in 20 patients with mild andmoderate crowding in the maxillary arch.Models of the maxillary arch were taken before treatment and at the end ofleveling and aligning phase.Width,depth and perimeter of the dental arch were measured on the pre -treatment andpost-treatment models.All data were analyzed by SPSS12.0 software. Results Compared with pre-treatment,on thepost -treatment statistically significant increases were recorded in depth,perimeter and premolar widths and the firstmolar widths.No significant changes were found in the cuspid width and the the second molar width. ConclusionDuring the initial phase of leveling and aligning, the Smart clip self-ligating system produces significant increases in thedental arch width and depth and perimeter of the maxillary arch.

  15. Double arch mirror study

    Science.gov (United States)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  16. The ARCHES project

    CERN Document Server

    Motch, C; Genova, F; Esteban, F Jiménez-; López, M; Michel, L; Mingo, B; Mints, A; Gómez-Morán, A Nebot; Pineau, F -X; Rosen, S; Sanchez, E; Schwope, A; Solano, E; Watson, M

    2016-01-01

    ARCHES (Astronomical Resource Cross-matching for High Energy Studies) is a FP7-Space funded project whose aim is to provide the international astronomical community with well-characterised multi-wavelength data in the form of spectral energy distributions (SEDs) for large samples of objects extracted from the 3XMM DR5 X-ray catalogue of serendipitous sources. The project has developed new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues for unresolved sources and a multi-wavelength finder for clusters of galaxies for extended sources. These enhanced resources have been tested in the framework of several science cases.

  17. Comparison of conventional study model measurements and 3D digital study model measurements from laser scanned dental impressions

    Science.gov (United States)

    Nugrahani, F.; Jazaldi, F.; Noerhadi, N. A. I.

    2017-08-01

    The field of orthodontics is always evolving,and this includes the use of innovative technology. One type of orthodontic technology is the development of three-dimensional (3D) digital study models that replace conventional study models made by stone. This study aims to compare the mesio-distal teeth width, intercanine width, and intermolar width measurements between a 3D digital study model and a conventional study model. Twelve sets of upper arch dental impressions were taken from subjects with non-crowding teeth. The impressions were taken twice, once with alginate and once with polivinylsiloxane. The alginate impressions used in the conventional study model and the polivinylsiloxane impressions were scanned to obtain the 3D digital study model. Scanning was performed using a laser triangulation scanner device assembled by the School of Electrical Engineering and Informatics at the Institut Teknologi Bandung and David Laser Scan software. For the conventional model, themesio-distal width, intercanine width, and intermolar width were measured using digital calipers; in the 3D digital study model they were measured using software. There were no significant differences between the mesio-distal width, intercanine width, and intermolar width measurments between the conventional and 3D digital study models (p>0.05). Thus, measurements using 3D digital study models are as accurate as those obtained from conventional study models

  18. Maxillary Arch Dimensions and Spectral Characteristics of Children with Cleft Lip and Palate Who Produce Middorsum Palatal Stops

    Science.gov (United States)

    Zajac, David J.; Cevidanes, Lucia; Shah, Sonam; Haley, Katarina L.

    2012-01-01

    Purpose: The purpose of this study was twofold: (a) to determine maxillary arch dimensions of children with repaired cleft lip and palate (CLP) who produced middorsum palatal stops and (b) to describe some spectral characteristics of middorsum palatal stops. Method: Maxillary arch width, length, and height dimensions and first spectral moments of…

  19. Maxillary Arch Dimensions and Spectral Characteristics of Children with Cleft Lip and Palate Who Produce Middorsum Palatal Stops

    Science.gov (United States)

    Zajac, David J.; Cevidanes, Lucia; Shah, Sonam; Haley, Katarina L.

    2012-01-01

    Purpose: The purpose of this study was twofold: (a) to determine maxillary arch dimensions of children with repaired cleft lip and palate (CLP) who produced middorsum palatal stops and (b) to describe some spectral characteristics of middorsum palatal stops. Method: Maxillary arch width, length, and height dimensions and first spectral moments of…

  20. Applicability of Moyers′ and Tanaka-Johnston′s mixed dentition analyses for predicting canine and premolar widths in south Indian population - A cross sectional study

    Directory of Open Access Journals (Sweden)

    Rekhalakshmi Kamatham

    2017-01-01

    Full Text Available Aim: To test the applicability of Moyers’ and Tanaka–Johnston’s (TJ mixed dentition analyses in predicting canines (C and premolars (Ps dimensions in South Indian population. Materials and Methods: A total of 100 boys and 101 girls in the age range of 11–15 years were recruited into the study. Maxillary and mandibular arch impressions were made and poured with dental stone. The maximum mesio-distal widths of mandibular central and lateral incisors, maxillary and mandibular C and Ps were measured. The predicted values of C and Ps obtained using Moyers’ and TJ methods were correlated and compared with the actual tooth sizes using Pearson correlation test and paired t test, respectively. Results: Moderate positive correlations were observed between the actual measurements and the predicted values obtained using both TJ and Moyers’ methods, irrespective of the gender. However, the validity, as tested using paired t test showed no applicability of TJ and Moyers’ (35 and 75% methods. On the other hand, Moyers’ 50% was applicable for both the arches in boys and 65% for girls only in the maxillary arch. Conclusion: TJ and Moyers’ methods cannot be applied in the present population (Southeast India; hence, population adjusted regression equations have to be formulated.

  1. Semi- and Nonparametric ARCH Processes

    Directory of Open Access Journals (Sweden)

    Oliver B. Linton

    2011-01-01

    Full Text Available ARCH/GARCH modelling has been successfully applied in empirical finance for many years. This paper surveys the semiparametric and nonparametric methods in univariate and multivariate ARCH/GARCH models. First, we introduce some specific semiparametric models and investigate the semiparametric and nonparametrics estimation techniques applied to: the error density, the functional form of the volatility function, the relationship between mean and variance, long memory processes, locally stationary processes, continuous time processes and multivariate models. The second part of the paper is about the general properties of such processes, including stationary conditions, ergodic conditions and mixing conditions. The last part is on the estimation methods in ARCH/GARCH processes.

  2. Using ArchE in the Classroom: One Experience

    Science.gov (United States)

    2007-09-01

    displaying the new itinerary The team initially adopted the Model-View-Controller ( MVC ) architecture as the top-level architecture . The...CMU/SEI-2007-TN-001 Software Architecture Technology Initiative Unlimited distribution subject to the copyright. This report was prepared...SOFTWARE ENGINEERING INSTITUTE | v vi | CMU/SEI-2007-TN-001 Abstract The Architecture Expert (ArchE) tool serves as a software architecture

  3. Accuracy and reproducibility of dental measurements on tomographic digital models: a systematic review and meta-analysis.

    Science.gov (United States)

    Ferreira, Jamille B; Christovam, Ilana O; Alencar, David S; da Motta, Andréa F J; Mattos, Claudia T; Cury-Saramago, Adriana

    2017-04-26

    The aim of this systematic review with meta-analysis was to assess the accuracy and reproducibility of dental measurements obtained from digital study models generated from CBCT compared with those acquired from plaster models. The electronic databases Cochrane Library, Medline (via PubMed), Scopus, VHL, Web of Science, and System for Information on Grey Literature in Europe were screened to identify articles from 1998 until February 2016. The inclusion criteria were: prospective and retrospective clinical trials in humans; validation and/or comparison articles of dental study models obtained from CBCT and plaster models; and articles that used dental linear measurements as an assessment tool. The methodological quality of the studies was carried out by Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A meta-analysis was performed to validate all comparative measurements. The databases search identified a total of 3160 items and 554 duplicates were excluded. After reading titles and abstracts, 12 articles were selected. Five articles were included after reading in full. The methodological quality obtained through QUADAS-2 was poor to moderate. In the meta-analysis, there were statistical differences between the mesiodistal widths of mandibular incisors, maxillary canines and premolars, and overall Bolton analysis. Therefore, the measurements considered accurate were maxillary and mandibular crowding, intermolar width and mesiodistal width of maxillary incisors, mandibular canines and premolars, in both arches for molars. Digital models obtained from CBCT were not accurate for all measures assessed. The differences were clinically acceptable for all dental linear measurements, except for maxillary arch perimeter. Digital models are reproducible for all measurements when intraexaminer assessment is considered and need improvement in interexaminer evaluation.

  4. Dental Implants.

    Science.gov (United States)

    Griggs, Jason A

    2017-10-01

    Systematic reviews of literature over the period between 2008 and 2017 are discussed regarding clinical evidence for the factors affecting survival and failure of dental implants. The factors addressed include publication bias, tooth location, insertion torque, collar design, implant-abutment connection design, implant length, implant width, bone augmentation, platform switching, surface roughness, implant coatings, and the use of ceramic materials in the implant body and abutment. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. A Foot-Arch Parameter Measurement System Using a RGB-D Camera

    Directory of Open Access Journals (Sweden)

    Sungkuk Chun

    2017-08-01

    Full Text Available The conventional method of measuring foot-arch parameters is highly dependent on the measurer’s skill level, so accurate measurements are difficult to obtain. To solve this problem, we propose an autonomous geometric foot-arch analysis platform that is capable of capturing the sole of the foot and yields three foot-arch parameters: arch index (AI, arch width (AW and arch height (AH. The proposed system captures 3D geometric and color data on the plantar surface of the foot in a static standing pose using a commercial RGB-D camera. It detects the region of the foot surface in contact with the footplate by applying the clustering and Markov random field (MRF-based image segmentation methods. The system computes the foot-arch parameters by analyzing the 2/3D shape of the contact region. Validation experiments were carried out to assess the accuracy and repeatability of the system. The average errors for AI, AW, and AH estimation on 99 data collected from 11 subjects during 3 days were −0.17%, 0.95 mm, and 0.52 mm, respectively. Reliability and statistical analysis on the estimated foot-arch parameters, the robustness to the change of weights used in the MRF, the processing time were also performed to show the feasibility of the system.

  6. Prediction of Mesiodistal Width of Unerupted Lateral Incisors, Canines and Premolars in Orthodontic Patients in Early Mixed Dentition Period

    Science.gov (United States)

    Toodehzaeim, Mohammad Hossein; Haerian, Alireza

    2016-01-01

    Objectives: Proper diagnosis and prevention of malocclusion are superior to treatment. Discrepancy between arch length and tooth size in mixed dentition period is a condition requiring timely diagnosis. Estimating the mesiodistal width of unerupted teeth according to the size of erupted ones can lead to earlier diagnosis of malocclusion. On the other hand, the best timing for serial extractions is before the eruption of lateral incisors. The aim of this study was to present prediction formulas for mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population based on the width of erupted permanent mandibular central incisors and maxillary first molars. Materials and Methods: A total of 120 dental models (60 males, 60 females) of orthodontic patients between 11–25 years were evaluated in Yazd city. The measurements were made by a digital caliper on the widest mesiodistal width of teeth at the interproximal contacts. Data were analyzed to calculate the prediction equation. Results: The prediction equation in the upper jaw was y=0.57x+10.82 for males, y=0.7x+6.37 for females and y=0.64x+8.46 for both sexes. The equation for the lower jaw was y=0.76x+2.86 for males, y=0.74x+3.53 for females and y=0.77x+2.7 for both sexes. Conclusions: The prediction equations suggested in this study can predict the mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population in early mixed dentition period without taking radiographs. PMID:28243298

  7. Accuracy and efficiency of full-arch digitalization and 3D printing: A comparison between desktop model scanners, an intraoral scanner, a CBCT model scan, and stereolithographic 3D printing.

    Science.gov (United States)

    Wesemann, Christian; Muallah, Jonas; Mah, James; Bumann, Axel

    2017-01-01

    The primary objective of this study was to compare the accuracy and time efficiency of an indirect and direct digitalization workflow with that of a three-dimensional (3D) printer in order to identify the most suitable method for orthodontic use. A master model was measured with a coordinate measuring instrument. The distances measured were the intercanine width, the intermolar width, and the dental arch length. Sixty-four scans were taken with each of the desktop scanners R900 and R700 (3Shape), the intraoral scanner TRIOS Color Pod (3Shape), and the Promax 3D Mid cone beam computed tomography (CBCT) unit (Planmeca). All scans were measured with measuring software. One scan was selected and printed 37 times on the D35 stereolithographic 3D printer (Innovation MediTech). The printed models were measured again using the coordinate measuring instrument. The most accurate results were obtained by the R900. The R700 and the TRIOS intraoral scanner showed comparable results. CBCT-3D-rendering with the Promax 3D Mid CBCT unit revealed significantly higher accuracy with regard to dental casts than dental impressions. 3D printing offered a significantly higher level of deviation than digitalization with desktop scanners or an intraoral scanner. The chairside time required for digital impressions was 27% longer than for conventional impressions. Conventional impressions, model casting, and optional digitization with desktop scanners remains the recommended workflow process. For orthodontic demands, intraoral scanners are a useful alternative for full-arch scans. For prosthodontic use, the scanning scope should be less than one quadrant and three additional teeth.

  8. Reliability of permanent mandibular first molars and incisors widths as predictor for the width of permanent mandibular and maxillary canines and premolars

    Directory of Open Access Journals (Sweden)

    Madhulika Mittar

    2012-01-01

    Full Text Available Aim: Preventive measures are necessary to prevent a potential irregularity from progressing into a more severe malocclusion. The determination of the tooth size-arch length discrepancy in mixed dentition requires an accurate prediction of the mesiodistal widths of the unerupted permanent teeth. Materials and Methods: For the study, 200 subjects in the age group of 16-25 years were selected from various colleges of M. M. University. The mesiodistal width of permanent mandibular incisors, first molars, canines and premolars of both arches were measured on the subject cast using an electronic digital caliper. Statistical analysis showed a significant difference between mesiodistal tooth widths of males and females. Linear regression equation was determined to predict the sum of mandibular and maxillary permanent canines and premolars using mandibular first molars plus the four mandibular incisors as predictors. Results: There was no significant difference between the actual and predicted width of sum of permanent canines and premolars using regression equations. The predicted widths of both arches using Tanaka and Johnston equations showed significant differences. Determined regression equations for males were accurate in male samples and determined regression equation for females were accurate in female samples for both arches.

  9. Simplified zygomatic arch radiographic technique to overcome the drawback of jug handle view

    Directory of Open Access Journals (Sweden)

    Siddana Gouda Siddana

    2014-01-01

    Full Text Available Introduction: The imaging of the zygomatic arch is very important in the diagnosis and management of zygomatic arch fractures. It is accomplished by jug handle radiography (a variation of the submentovertex view and sometimes with modifications like the tangential or tea cup projection. For these techniques, the patient has to be positioned in a way which makes it non-applicable in cases having cervical injuries or suspected cervical injuries. Aims and Objectives: To devise a new approach with which the image of the zygomatic arch can be obtained with normal head position, in either sitting or supine position, using a dental X-ray machine and an occlusal film, which can even be used in patients with cervical injuries or suspected cervical injuries, without any complications. Materials and Methods: The present approach requires a dental X-ray machine and an occlusal X-ray film thereby eliminating the need for additional equipment like a general X-ray machine and extraoral film cassette. This approach can be carried out in a conventional dental setup to rule out zygomatic arch fractures. Conclusion: This technique can be applied in patients having cervical injuries or suspected cervical injuries, thus overcoming the drawback of the jug handle view, and is easy to master. This technique can be used in a conventional dental setup and holds good with the ALARA (as low as reasonably achievable principle of radiation protection and safety.

  10. A technique to stabilize record bases for Gothic arch tracings in patients with implant-retained complete dentures.

    Science.gov (United States)

    Raigrodski, A J; Sadan, A; Carruth, P L

    1998-12-01

    Clinicians have long expressed concern about the accuracy of the Gothic arch tracing for recording centric relation in edentulous patients. With the use of dental implants to assist in retaining complete dentures, the problem of inaccurate recordings, made for patients without natural teeth, can be significantly reduced. This article presents a technique that uses healing abutments to stabilize the record bases so that an accurate Gothic arch tracing can be made.

  11. Theory of Arched Structures Strength, Stability, Vibration

    CERN Document Server

    Karnovsky, Igor A

    2012-01-01

    Theory of Arched Structures: Strength, Stability, Vibration presents detailed procedures for analytical analysis of the strength, stability, and vibration of arched structures of different types, using exact analytical methods of classical structural analysis. The material discussed is divided into four parts. Part I covers stress and strain with a particular emphasis on analysis; Part II discusses stability and gives an in-depth analysis of elastic stability of arches and the role that matrix methods play in the stability of the arches; Part III presents a comprehensive tutorial on dynamics and free vibration of arches, and forced vibration of arches; and Part IV offers a section on special topics which contains a unique discussion of plastic analysis of arches and the optimal design of arches.

  12. Arch bridges – unlocking their potential

    OpenAIRE

    Long, Adrian; Nanukuttan, Sreejith

    2016-01-01

    Arch bridges are strong, durable, aesthetically pleasing and require little maintenance but very few have been built since the early 1900s. However, this trend has changed as more than 60 FlexiArch bridges have been installed since the system was launched in 2007. The FlexiArch uses precast concrete voussoirs, requires neither corrodible reinforcement, nor centring, can be installed in hours and is contractor friendly. Details of this innovative method of construction and installation of arch...

  13. Avaliação da profundidade do palato e das dimensões do arco dentário superior em indivíduos com má oclusão e diferentes tipos faciais Evaluation of palatine depth and dimensions of the upper dental arch in patients with malocclusion and different facial types

    Directory of Open Access Journals (Sweden)

    Andrea Esteves

    2007-01-01

    evaluate palatine depth and dimensions of the upper dental arch in patients with malocclusion and different facial types. METHODS: The sample was constituted of profile cephalograms and dental casts of 135 individuals, 67 females and 68 males, with age between 12 to 21 years and malocclusions: Class I (n = 45, Class II (n = 45 and Class III (n = 45, Angle. The sample was divided in three groups, according to the facial type: brachyfacial (n = 45, mesofacial (n = 45 and dolichofacial (n = 45. The transversal dimensions (intercuspids and inter-first molars distances and upper dental arch length were obtained with auxiliary of digital caliper. In order, to obtain palatine depth measurement was used a special equipment developed and adapted to the digital caliper. RESULTS AND CONCLUSION: Based on our results, we concluded that: (1 no statistically significant differences between these measurements were found considering the facial types, except for the palatine depth, that was smaller in brachyfacial group (18.18mm than dolichofacial group (19.52mm; (2 according to sex, only two variables, the depth palatine and inter-first molar distance, demonstrated statistically significant differences, that appeared to be bigger in males than females; (3 according to the malocclusion, statistically significant differences between these measurements were found only to the upper dental arch length, that was bigger in Class II group (31.23mm than Class III group (29.64mm.

  14. A simplified protocol for the immediate loading of the edentulous arch.

    Science.gov (United States)

    Apfel, Paul S; Kopman, Jeffrey S

    2006-01-01

    Restoring dentitions with dental implants is an extremely gratifying procedure for the dental professional. However, the traditional approach of delayed loading requires surgical, prosthetic and patient management gymnastics, often necessitating extended treatment over one year, with multiple relines of fixed provisional restorations or even long periods with removable prostheses. The purpose of this article is to outline a simplified protocol for the immediate loading of the edentulous arch. By adhering to this protocol, the dental team can provide patients with an immediate functional, esthetic and fixed restoration, thereby avoiding the multitude of issues associated with delayed loading and enhancing patient satisfaction.

  15. Estudo do relacionamento ântero-posterior entre os arcos dentários decíduos, de crianças nipo-brasileiras, dos dois aos seis anos de idade Study of the anteroposterior relationship between deciduous dental arches of Japanese-Brazilian children, from 2 to 6 years of age

    Directory of Open Access Journals (Sweden)

    Dirce Yamada Kataoka

    2006-10-01

    Full Text Available OBJETIVO: verificar as prevalências dos diferentes tipos de relacionamentos ântero-posteriores entre os arcos dentários decíduos, bem como o possível dimorfismo sexual, em crianças nipo-brasileiras na faixa etária dos dois aos seis anos de idade. METODOLOGIA: foram avaliadas por inspeção visual 310 crianças nipo-brasileiras, matriculadas em 19 escolas do estado de São Paulo, sendo 154 do gênero masculino e 156 do feminino. Os resultados foram submetidos ao teste do qui-quadrado e revelaram ausência de dimorfismo sexual para a maioria dos relacionamentos analisados, permitindo apresentar os resultados conjuntamente para ambos os gêneros. RESULTADOS: as prevalências dos relacionamentos entre os segundos molares decíduos foram: 47,4% para o degrau mesial, 41,3% para o plano terminal reto, 5,5% para o degrau distal e 5,8% para os casos com assimetrias. Para os relacionamentos entre os caninos decíduos, conforme Foster e Hamilton, constataram-se prevalências de 77,4% para a Classe 1, 6,8% para a Classe 2, 6,8% para a Classe 3 e 9% para as relações assimétricas. Apenas a Classe 2 apresentou dimorfismo sexual, sendo de 3,9% para o feminino e de 9,7% para o masculino. Quanto à sobressaliência verificaram-se prevalências de 71,3% para a normal, 14,2% para a aumentada, 7,4% para a mordida cruzada anterior e 7,1% para a mordida topo-a-topo. RESULTADOS: concluiu-se que a maioria das crianças nipo-brasileiras avaliadas neste estudo, apresentaram um relacionamento ântero-posterior normal entre os arcos decíduos, merecendo atenção uma ligeira tendência para o desenvolvimento da Classe 3.AIM: the purpose of this cross-sectional study was to verify the prevalences of different types of anteroposterior relationships between deciduous dental arches and its possible sexual dimorphism, in Japanese-Brazilian children from 2 to 6 years of age. METHODS: a total of 310 Japanese-Brazilian children from 19 schools in São Paulo, Brazil

  16. Experiment Study on Normal Section Bearing Capacity of Masonry Arch?Bridge Reinforced with Composite Arch Ring%复合拱圈加固圬工拱桥正截面承载力试验研究

    Institute of Scientific and Technical Information of China (English)

    乔文靖; 孙克东; 李成华

    2016-01-01

    In order to research on normal section bearing capacity of masonry arch bridge that is strengthened by composite arch ring under cracks of original arch ring,the three sectional models of masonry arch bridge strengthened by composite arch circle are designed,considering the cracks of original arch ring and the mechanical properties of different materials,numerical simulation and experimental research are carried out based on common stress and deformation coordination between the original arch ring and reinforced layer.The results show:When the crack width is 1/4 original arch width,the bearing capacity is 14.5% less than the non crack arch segment;When the crack width is 1/2 original arch width,the bearing capacity is 3 7 .3% less than the non crack arch segment;The bearing capacity decreases in proportion of the increased crack width.%为了研究原拱圈在裂缝作用下,复合拱圈加固圬工拱桥的正截面承载力计算问题,建立了3个复合拱圈加固圬工拱桥节段模型,考虑原拱圈的裂缝和不同材料的力学性能,基于原拱圈和加固层共同受力和协调变形,进行了数值模拟和试验研究.结果表明:当裂缝宽度为原拱圈宽度1/4时,实测承载力比无裂缝拱段减少了14.5%;当裂缝宽度为原拱圈宽度1/2时,实测承载力比无裂缝拱段减少了37.3%,裂缝增大使承载力成比例减小.

  17. Cambios esqueléticos, dentales y faciales de la maloclusión clase III esquelética tratada con la filosofía de MEAW (Multiloop Edgewise Arch Wire: descriptivo restrospectivo

    Directory of Open Access Journals (Sweden)

    Ángela Anyur García Bernal

    2012-11-01

    Full Text Available Antecedentes: uno de los problemas más complejos del diagnósticoy tratamiento de las maloclusiones lo constituye la corrección de laclase III esquelética. Objetivo: determinar los cambios esqueléticos,dentales y faciales de la maloclusión clase III esquelética tratadacon la filosofía Edgewise Multiloop (MEAW, en pacientes queasistieron a una clínica odontológica privada entre marzo de 2009a septiembre de 2012. Métodos: se realizó un estudio descriptivoretrospectivo, donde se analizaron los registros clínicos de sietepacientes con diagnóstico de maloclusión clase III esquelética.Se evaluaron las variables edad, género, medidas cefalométricasiniciales y finales en radiografías y fotografías laterales. Resultados:los pacientes de ángulo alto fueron 60% mujeres, con edad mediade 21,8 años (DE± 7,25. El ángulo de la convejidad pasó de 10,58° a16,4°; el Indicador de Displasia Antero-Posterior (APDI disminuyóde 96,7° a 91,0°; el Plano Palatino (PP aumentó de 114,3°a 115,4° yel plano oclusal aumentó la inclinación de 17,8°a 24,7°. El promediode tiempo en el tratamiento fue de 19,4 meses. Conclusiones: lafilosofía MEAW es una alternativa terapéutica de camuflaje en eltratamiento de las maloclusiones clase III esquelética.

  18. ON THE CYTOTOXICITY OF ORTHODONTIC ARCHES IN HUMAN FIBROBLAST CULTURES

    Directory of Open Access Journals (Sweden)

    Liliana-Gabriela HALIŢCHI

    2015-12-01

    Full Text Available The present study analyzes the orthodontic nickel-titanium alloy with orthodontic shape memory (Niti GAC arches, Nitinol 3M arches, Beta Titanium 3M arches from the viewpoint of its cytotoxicity. Apart from the intrinsic toxicity of the metals upon cells, corrosion may dramatically alter the behaviour of alloys, as evidenced by the in vitro and in vivo studies developed in the field. Due to the high and variable nickel content, its is possible that, at least theoretically, the released ions should produce – as a result of intraoral corrosion – secondary effects, which makes necessary to assert the cytotoxicity of NiTi alloys prior to their safe utilizationor in the oral cavity of children and young patients. Evaluation of cell morphology and determination of cell viability, following exposure to the 3 types of orthodontic materials, evidenced no toxic reactions. Several problems are still to be elucidated, related to the consequences of the surface conditions, of the dissolution and in vivo release of the nickel ions after a longer treatment, of the accumulations of ion traces, of the response of the dental-periodontal tissues, of the effects manifested at cell and molecular level. Apart from the intrisic toxicity of metals upon cells, corrosion may dramatically influence the behaviour of alloys under in vitro conditions, comparatively with the in vivo ones, the nitinol samples being biologically safe.

  19. Dental Fluorosis

    Science.gov (United States)

    ... have been broadly termed dental fluorosis. What is dental fluorosis? Dental fluorosis is a condition that causes ... less than 2 milligrams per liter. What causes dental fluorosis? Dental fluorosis is caused by taking in ...

  20. Dental Amalgam

    Science.gov (United States)

    ... Products and Medical Procedures Dental Devices Dental Amalgam Dental Amalgam Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Dental amalgam is a dental filling material which is ...

  1. Comparison between different plantar arch

    OpenAIRE

    2009-01-01

    The longitudinal plantar arch (LPA) perform biomechanics functions in the foot. The aim of this study was to compare the relationship between different index to measure the LPA of the foot. The arc index, Staheli index, Viladot classification and Feiss line were compared. In the transversal study, the experimental samples were soccer players females with age between 13 to 19 years. The measure were performed by plantigraphy, with out Feiss line. Although non significant the higher agreement w...

  2. Level Width Broaden Effect

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Shang

    2004-01-01

    In fitting the double-differential measurements thelevelwidth broadening effect should be taken into account properly due to Heisenberg uncertainty.Besides level width broadening effect the energy resolution in the measurements is also needed in this procedure.In general,the traditional normal Gaussian expansion is employed.However,the research indicates that to do so in this way the energy balance could not hold.For this reason,the deformed Gaussian expansion functions with exponential form for both the single energy point and continuous spectrum are introduced,with which the normalization and energy balance conditions could hold exactly in the analytical form.

  3. The influence of foot orthoses on foot mobility magnitude and arch height index in adults with flexible flat feet.

    Science.gov (United States)

    Sheykhi-Dolagh, Roghaye; Saeedi, Hassan; Farahmand, Behshid; Kamyab, Mojtaba; Kamali, Mohammad; Gholizadeh, Hossein; Derayatifar, Amir A; Curran, Sarah

    2015-06-01

    Flexible flat foot is described as a reduction in the height of the medial longitudinal arch and may occur from abnormal foot pronation. A foot orthosis is thought to modify and control excessive pronation and improve arch height. To compare the immediate effect of three types of orthoses on foot mobility and the arch height index in subjects with flexible flat feet. A quasi-experimental study. The dorsal arch height, midfoot width, foot mobility and arch height index were assessed in 20 participants with flexible flat feet (mean age = 23.2 ± 3 years) for three different foot orthosis conditions: soft, semi-rigid and rigid University of California Biomechanics Laboratory (UCBL). Maximum midfoot width at 90% with arch mobility in the coronal plane was shown in the semi-rigid orthosis condition. The semi-rigid orthosis resulted in the highest mean foot mobility in 90% of weight bearing, and the rigid orthosis (UCBL) had the lowest mean foot mobility. The soft orthosis resulted in foot mobility between that of the rigid and the semi-rigid orthosis. UCBL orthosis showed the highest arch height index, and the semi-rigid orthosis showed the lowest mean arch height index. Due to its rigid structure and long medial-lateral walls, the UCBL orthosis appears to limit foot mobility. Therefore, it is necessary to make an orthosis that facilitates foot mobility in the normal range of the foot arch. Future studies should address the dynamic mobility of the foot with using various types of foot orthoses. Although there are many studies focussed on flat foot and the use of foot orthoses, the mechanism of action is still unclear. This study explored foot mobility and the influence of foot orthoses and showed that a more rigid foot orthosis should be selected based on foot mobility. © The International Society for Prosthetics and Orthotics 2014.

  4. Revisiting impressions using dual-arch trays.

    Science.gov (United States)

    Small, Bruce W

    2012-01-01

    Making routine perfect impressions is the goal of any restorative dentist. Using dual-arch trays is an easy, repeatable way to accomplish that goal, as long as each step is done before the next and each step is performed perfectly. This column reviewed several articles that support the metal dual-arch concept and provided some clinical tips that might help restorative dentists. The dual-arch technique does have its limits and is meant for one or two teeth in a quadrant when there are other teeth to occlude with. Also, if the case involves anterior guidance, a full-arch impression maybe advisable.

  5. Evaluation of the Occlusion and Arch Dimensions in the Primary Dentition of an Iranian Population

    Directory of Open Access Journals (Sweden)

    Maryam Talebi

    2013-12-01

    Full Text Available Introduction: The objective of this study was to gather information about normal occlusion and arch dimensions in the primary teeth of the children belonging to an Iranian population. Methods: This descriptive cross-sectional study was performed on 68 children from the city of Mashhad in the 3-5 age range. Dental arch dimensions, interrelationships of primary canine and second molars, overbite and overjet were evaluated. Results: Primate space was observed on both sides of the arch in 82.2% of the subjects. The most prevalent type of primary molar relationship was flush terminal plane (52.1% followed by distal step (31.3% and then mesial step (16.7%. The primary canine relationship was ranked in the descending order of prevalence as Class I (77.1%, Class II (13.5%, end-to-end (5.2% and Class III (4.2%. Normal overbite and normal overjet was observed in 50% and 81.3% of cases, respectively. Conclusion: This study provides an insight into the dental arch dimensions, occlusion, spacing and crowding in primary dentition in Iranian children. In most of the cases, primate space and flush terminal plane were observed.

  6. Evaluation of the Occlusion and Arch Dimensions in the Primary Dentition of an Iranian Population

    Directory of Open Access Journals (Sweden)

    Maryam Talebi

    2013-01-01

    Full Text Available Introduction: The objective of this study was to gather information about normal occlusion and arch dimensions in the primary teeth of the children belonging to an Iranian population. Methods: This descriptive cross-sectional study was performed on 68 children from the city of Mashhad in the 3-5 age range. Dental arch dimensions, interrelationships of primary canine and second molars, overbite and overjet were evaluated. Results: Primate space was observed on both sides of the arch in 82.2% of the subjects. The most prevalent type of primary molar relationship was flush terminal plane (52.1% followed by distal step (31.3% and then mesial step (16.7%. The primary canine relationship was ranked in the descending order of prevalence as Class I (77.1%, Class II (13.5%, end-to-end (5.2% and Class III (4.2%. Normal overbite and normal overjet was observed in 50% and 81.3% of cases, respectively. Conclusion: This study provides an insight into the dental arch dimensions, occlusion, spacing and crowding in primary dentition in Iranian children. In most of the cases, primate space and flush terminal plane were observed.

  7. Tympanic ossicles and pharyngeal arches.

    Science.gov (United States)

    Whyte, J; Cisneros, A; Yus, C; Fraile, J; Obón, J; Vera, A

    2009-02-01

    We have performed a study on 11 human embryos regarding the development of the tympanic ossicles and their relationship with the first pharyngeal arch. After performing measurements to date the embryos and foetuses chronologically, we performed a meticulous dissection of the temporal bones. Subsequently, they were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in 7-mm sequences and stained with Martin's trichrome technique. In the 21- and 24-mm cranium-raquis (CR) length human embryos, we have observed the head of the malleus and the body of the incus close to Meckel's cartilage, in addition to the handle of the malleus, the long limb of the incus and the stapes. Between them there was a mesenchymal band inside the primordium of the tympanic cavity. In the 27-mm CR embryo, the various components of the malleus and incus were fusing, and in the 30-mm CR embryo the union was complete. From our observations, we can conclude that the malleus and the incus are derived from the first and second pharyngeal arches.

  8. Thirty-two-year follow-up study of Herbst therapy: a biometric dental cast analysis.

    Science.gov (United States)

    Pancherz, Hans; Bjerklin, Krister; Lindskog-Stokland, Birgitta; Hansen, Ken

    2014-01-01

    The aim of this study was to analyze the very long-term effects of Herbst treatment on tooth position and occlusion. Fourteen patients from a sample of 22 with Class II Division 1 malocclusions consecutively treated with the banded Herbst appliance were reexamined 32 years after therapy. Dental casts were analyzed from before (T1) and after (T2) treatment, and at 6 years (T3) and 32 years (T4) after treatment. Minor changes in maxillary and mandibular dental arch perimeters and arch widths were seen during treatment (T1-T2) and posttreatment (T2-T4). Mandibular incisor irregularity remained, on average, unchanged from T1 to T2 but increased continuously during the 32-year follow-up period (T2-T4). Class II molar and canine relationships were normalized in most patients from T1 to T2. During the early posttreatment period (T2-T3), there was a minor relapse; during the late posttreatment period (T3-T4), molar and canine relationships remained, on average, unchanged. Overjet and overbite were reduced to normal values in all subjects during treatment (T1-T2). After treatment (T2-T4), overjet remained, on average, unchanged, but overbite increased insignificantly. Thirty-two years after Herbst therapy, overall, acceptable long-term results were seen. Stability was found in 64% of the patients for sagittal molar relationships, in 14% for sagittal canine relationships, in 86% for overjet, and in 86% for overbite. A Class II relapse seemed to be caused by an unstable interdigitation of the occluding teeth, a persisting oral habit, or an insufficient retention regimen after treatment. Most posttreatment changes occurred during the first 6 years after treatment. After the age of 20 years, only minor changes were noted. Long-term posttreatment changes in maxillary and mandibular dental arch perimeters and widths as well as in mandibular incisor irregularity seemed to be independent of treatment and a result of physiologic dentoskeletal changes throughout adulthood. Copyright

  9. Research of air-cushion isolation effects on high arch dam reservoir

    Science.gov (United States)

    Zhang, Shao-Jie; Chen, Jiang; Zhang, Yuan-Ze; Liu, Hao-Wu

    2011-10-01

    A three-dimensional (3D) finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account. In this model, the displacement formulation in Lagrange method, pressure formulation in Euler method, nonlinear contact model based on Coulomb friction law are applied to the air-cushion, reservoir and contraction joint domain, respectively. The dynamic response of Jinping I arch dam with a height of 305 m is analyzed using the seismic records of the Wenchuan Earthquake in 2008. Numerical results show that the air-cushion isolation reduces significantly the hydrodynamic pressure as well as the opening width for the contraction joints of high arch dam.

  10. The significance of biometric parameters in determining anterior teeth width

    Directory of Open Access Journals (Sweden)

    Strajnić Ljiljana

    2013-01-01

    Full Text Available Background/Aim. An important element of prosthetic treatment of edentulous patients is selecting the size of anterior artificial teeth that will restore the natural harmony of one’s dentolabial structure as well as the whole face. The main objective of this study was to determine the correlation between the inner canthal distance (ICD and interalar width (IAW on one side and the width of both central incisors (CIW, the width of central and lateral incisors (CLIW, the width of anterior teeth (ATW, the width between the canine cusps (CCW, which may be useful in clinical practice. Methods. A total of 89 subjects comprising 23 male and 66 female were studied. Their age ranged from 19 to 34 years with the mean of 25 years. Only the subjects with the preserved natural dentition were included in the sample. All facial and intraoral tooth measurements were made with a Boley Gauge (Buffalo Dental Manufacturing Co., Brooklyn NY, USA having a resolution of 0.1mm. Results. A moderate correlation was established between the interalar width and combined width of anterior teeth and canine cusp width (r = 0.439, r = 0.374. A low correlation was established between the inner canthal distance and the width of anterior teeth and canine cusp width (r = 0.335, r = 0.303. The differences between the two genders were highly significant for all the parameters (p < 0.01. The measured facial distances and width of anterior teeth were higher in men than in women. Conclusion. The results of this study suggest that the examined interalar width and inner canthal distance cannot be considered reliable guidelines in the selection of artificial upper anterior teeth. However, they may be used as a useful additional factor combined with other methods for objective tooth selection. The final decision should be made while working on dentures fitting models with the patient’s consent.

  11. Fixation of a severely resorbed mandible for complete arch screw-retained rehabilitation: A clinical report.

    Science.gov (United States)

    Fabris, Vinicius; Bacchi, Atais

    2016-05-01

    Severely resorbed mandibles with placed endosteal dental implants can fracture. Therefore, techniques to reduce the risk or minimize the consequences of these fractures are needed. This clinical report presents a technique for placing a titanium plate in a severely resorbed mandible subjected to complete-arch implant therapy. The titanium plate is placed in the same surgical procedure as the implants, allowing immediate implant loading. This technique provides safe implant-supported treatment for patients with severe mandibular resorption.

  12. Clinical trial investigating success rates for polyether and vinyl polysiloxane impressions made with full-arch and dual-arch plastic trays.

    Science.gov (United States)

    Johnson, Glen H; Mancl, Lloyd A; Schwedhelm, E Ricardo; Verhoef, Douglas R; Lepe, Xavier

    2010-01-01

    Success rates for making fixed prosthodontic impressions based on material and tray selection are not known. The purpose of this clinical study was to compare first impression success rates for 2 types of impression material and 2 impression tray systems. Dual-viscosity impressions were made with a vinyl polysiloxane (VPS) (Aquasil Ultra Monophase/Aquasil Ultra XLV) and a polyether (PE) (Impregum Penta Soft HB/Impregum Garant Soft LB) impression material. The first impression made was evaluated for success or failure using developed criteria. Fifty senior dental students participated. The type of impression material alternated for each new patient. A full-arch perforated plastic (President Tray) or a plastic dual-arch impression tray (Tri-Bite) was used based on clinical guidelines. Impression success rates were compared using logistic regression, fitted using the method of generalized estimating equations (alpha=.05). One hundred ninety-one impressions were evaluated, and the overall success rate was 61% for VPS and 54% for PE (P=.39). Additional regression analyses, adjusted for potential confounders, did not indicate a difference between the 2 systems (P=.35). There was little difference in success rates between the 2 materials when a full-arch tray was used (50% versus 49% success, P=.89), whereas a larger difference was apparent with the use of dual-arch trays (70% success with VPS versus 58% success with PE, P=.21). The most common critical defect was located on the preparation finish line (94%), and the most common operator error was inadequate gingival displacement (15%). There was little difference in success rates between VPS and PE when full-arch impression trays were used, but there was greater success when using VPS with dual-arch trays. For single teeth, the trend favored VPS, but when more than one prepared tooth per impression was involved, the success rate was higher for PE. Copyright 2010 The Editorial Council of the Journal of Prosthetic

  13. 3D space analysis of dental models

    Science.gov (United States)

    Chuah, Joon H.; Ong, Sim Heng; Kondo, Toshiaki; Foong, Kelvin W. C.; Yong, Than F.

    2001-05-01

    Space analysis is an important procedure by orthodontists to determine the amount of space available and required for teeth alignment during treatment planning. Traditional manual methods of space analysis are tedious and often inaccurate. Computer-based space analysis methods that work on 2D images have been reported. However, as the space problems in the dental arch exist in all three planes of space, a full 3D analysis of the problems is necessary. This paper describes a visualization and measurement system that analyses 3D images of dental plaster models. Algorithms were developed to determine dental arches. The system is able to record the depths of the Curve of Spee, and quantify space liabilities arising from a non-planar Curve of Spee, malalignment and overjet. Furthermore, the difference between total arch space available and the space required to arrange the teeth in ideal occlusion can be accurately computed. The system for 3D space analysis of the dental arch is an accurate, comprehensive, rapid and repeatable method of space analysis to facilitate proper orthodontic diagnosis and treatment planning.

  14. A quantitative method for defining high-arched palate using the Tcof1(+/-) mutant mouse as a model.

    Science.gov (United States)

    Conley, Zachary R; Hague, Molly; Kurosaka, Hiroshi; Dixon, Jill; Dixon, Michael J; Trainor, Paul A

    2016-07-15

    The palate functions as the roof of the mouth in mammals, separating the oral and nasal cavities. Its complex embryonic development and assembly poses unique susceptibilities to intrinsic and extrinsic disruptions. Such disruptions may cause failure of the developing palatal shelves to fuse along the midline resulting in a cleft. In other cases the palate may fuse at an arch, resulting in a vaulted oral cavity, termed high-arched palate. There are many models available for studying the pathogenesis of cleft palate but a relative paucity for high-arched palate. One condition exhibiting either cleft palate or high-arched palate is Treacher Collins syndrome, a congenital disorder characterized by numerous craniofacial anomalies. We quantitatively analyzed palatal perturbations in the Tcof1(+/-) mouse model of Treacher Collins syndrome, which phenocopies the condition in humans. We discovered that 46% of Tcof1(+/-) mutant embryos and new born pups exhibit either soft clefts or full clefts. In addition, 17% of Tcof1(+/-) mutants were found to exhibit high-arched palate, defined as two sigma above the corresponding wild-type population mean for height and angular based arch measurements. Furthermore, palatal shelf length and shelf width were decreased in all Tcof1(+/-) mutant embryos and pups compared to controls. Interestingly, these phenotypes were subsequently ameliorated through genetic inhibition of p53. The results of our study therefore provide a simple, reproducible and quantitative method for investigating models of high-arched palate.

  15. Study on Structure of Arched Longitudinal Beams of Deep Water Wharf

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate large tonnage vessels, wharves should be constructed in deep water gradually. However, conventional high-pile and beam-slab structures are hard to meet the requirements of large deep-water wharf. According to arch's stress characteristics, a new type of wharf with catenary arched longitudinal beams is presented in this paper. The new wharf structure can make full use of arch's overhead crossing and reinforced concrete compression resistance, improve the interval between transverse bents greatly, and decrease underwater construction quantity. Thus, the construction cost cab be reduced. Take the third phase project of the Yangshan Deep-water Port for example, comparative analysis on catenary arched longitudinal beams and conventional longitudinal beams has been made. The result shows that with the same wharf length and width, the same loads and same longitudinal beam moment, catenary arch structure can improve the interval between bents up to 28 m, decrease the number of piles and underwater construction quantity.

  16. Persistent fifth arch anomalies - broadening the spectrum to include a variation of double aortic arch vascular ring

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Beverley; Chan, Frandics [Stanford Children' s Hospital and Stanford University, Department of Radiology, Stanford, CA (United States); Hanneman, Kate [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada)

    2016-12-15

    Fifth arch anomalies are rare and complex and frequently misdiagnosed or mistaken for other entities. We report a double arch vascular ring that is thought to consist of right fourth arch and left fifth arch components, a previously undescribed persistent fifth arch variant. The currently recognized spectrum and classification of fifth arch vascular anomalies are expanded along with illustrative images to justify the proposed changes. Reviewing and expanding the classification of fifth arch anomalies to include a double arch ring variant will promote recognition, correct diagnosis and appropriate management of these anomalies. (orig.)

  17. Nonlinear Dynamics of Electrostatically Actuated MEMS Arches

    KAUST Repository

    Al Hennawi, Qais M.

    2015-05-01

    In this thesis, we present theoretical and experimental investigation into the nonlinear statics and dynamics of clamped-clamped in-plane MEMS arches when excited by an electrostatic force. Theoretically, we first solve the equation of motion using a multi- mode Galarkin Reduced Order Model (ROM). We investigate the static response of the arch experimentally where we show several jumps due to the snap-through instability. Experimentally, a case study of in-plane silicon micromachined arch is studied and its mechanical behavior is measured using optical techniques. We develop an algorithm to extract various parameters that are needed to model the arch, such as the induced axial force, the modulus of elasticity, and the initially induced initial rise. After that, we excite the arch by a DC electrostatic force superimposed to an AC harmonic load. A softening spring behavior is observed when the excitation is close to the first resonance frequency due to the quadratic nonlinearity coming from the arch geometry and the electrostatic force. Also, a hardening spring behavior is observed when the excitation is close to the third (second symmetric) resonance frequency due to the cubic nonlinearity coming from mid-plane stretching. Then, we excite the arch by an electric load of two AC frequency components, where we report a combination resonance of the summed type. Agreement is reported among the theoretical and experimental work.

  18. Interalar width as a guide in denture tooth selection.

    Science.gov (United States)

    Hoffman, W; Bomberg, T J; Hatch, R A

    1986-02-01

    This study was undertaken to determine the relationship of the IAW, measured between at the widest dimension of the alae of the nose, and two other measurements of maxillary anterior teeth. The other measurements, both of which are significant in the selection and arrangement of artificial teeth used in complete dentures, were the ICTW and the ARCD measured from the distal surface of the maxillary canine on one side of the arch to the distal surface of the canine on the opposite side of the arch. No distinction was made between either the sex or the age of the subjects. The mean ICTW of 35.35 mm was 3% greater than the mean IAW of 34.28 mm. The mean ARCD of 44.85 mm was 31% greater than the mean IAW of 34.28 mm. This mean ARCD compares favorably (less than 1 mm difference) with a constructed ARCD of 45.8 mm from a tooth dimension study by Shillingburg et al. The ARCD was 44.85 mm. This measurement had not been made in the previous study examining the relationship of interalar distance to ICTW. When the IAW was plotted against the intercanine cusp tip width, a fairly strong correlation coefficient of 0.413 was exhibited. A weaker but definite correlation coefficient of 0.217 was observed when the interalar width plotted against the circumferential arc distance from distal surface to distal surface of the maxillary canines.

  19. [Biomechanical study on dento-alveolar arch forces].

    Science.gov (United States)

    Onu, Brînduşa; Burlui, V

    2009-01-01

    This study has two major objectives. The first one is to draw attention in an original device especially conceived and designed to measure bite force; the second purpose of the study is represented by proper measurements of individual bite force during bilateral clenching for two lots of patients using this device and comparing the outcomes to those of other similar studies, in order to prove its practical utility. 62 young (20-35 years of age) healthy patients were tested: 35 fully dentured subjects in control group and 27 subjects with various single unit treated edentation, in test group. The two potentiometers from the lateral side of the device are connected to a computer which would measure, register and interpret the outcomes during three different sessions of clenching for each patient. Measured values showed that the mean maximum bilateral bite force in patients with no edentation was, in all cases, higher than in patients with single unit treated edentation for all three sessions. Because the device allows simultaneous bilateral registration of the bite force, during the same session, it is obvious that it can measure also the asymmetry between left and right dental hemi-arches. Therefore, in control group, mean values found in left side were higher (369.36N - 399.75N) than right side (352.18N - 392.15N); an opposite situation was found in test group: higher values were found in right side (313.75N - 329.43N) comparing to left side (310.54N -321.53N). The device proved to be usefull not only for measuring bite force in one region of dental arches, but it is designed to simultaneous register parameters from various regions; the values obtained in this study are similar to those reported by others authors who used more sophisticated devices, so that this simple device proves its usefulness.

  20. Mycotic Aneurysm of the Aortic Arch

    Directory of Open Access Journals (Sweden)

    Ji Hye Seo

    2014-08-01

    Full Text Available A mycotic aneurysm of the thoracic aorta is rare. We report a case of mycotic aneurysm that developed in the aortic arch. An 86-year-old man was admitted with fever and general weakness. Blood culture yielded methicillin-resistant Staphylococcus aureus. Chest X-ray showed an enlarged aortic arch, and computed tomography scan revealed an aneurysm in the aortic arch. The patient was treated only with antibiotics and not surgically. The size of the aneurysm increased rapidly, resulting in bronchial obstruction and superimposed pneumonia. The patient died of respiratory failure.

  1. In-Plane Elastic Buckling of Arch

    Institute of Scientific and Technical Information of China (English)

    剧锦三; 郭彦林

    2002-01-01

    The in-plane elastic buckling behavior of arches is investigated using a new finite-element approach for the nonlinear analysis. The linear buckling, nonlinear primary buckling, and secondary bifurcation buckling behavior of arches are compared taking into account the large deformation and the effects of initial geometric imperfections or perturbations. The theoretical investigation emphasizes the nonlinear secondary bifurcation buckling behavior for a full span uniformly distributed load. The efficiency of compact method for tracing secondary buckling path is shown through several examples. Finally, a new structural design, which prevents the secondary bifurcation buckling by adding some crossed cables across the arch, is proposed to improve the limit load carrying capacity.

  2. Radiographic signs and diagnosis of dental disease.

    Science.gov (United States)

    Bellows, J

    1993-08-01

    Dental radiographs are critical for the complete assessment and treatment of dental diseases. Dental radiography is commonly used to evaluate congenital dental defects, periodontal disease, orthodontic manipulations, oral tumors, endodontic treatments, oral trauma, and any situation where an abnormality is suspected. Although standard radiographic equipment and film can be used to produce dental radiographs, dental X-ray equipment and film provide superior quality images and greater convenience of animal patient positioning. An understanding of normal dental radiographic anatomy is important when interpreting dental radiographs. Stage III periodontitis is the earliest stage of periodontal disease at which radiographic abnormalities become apparent. Bone loss associated with periodontal disease can be classified as either horizontal or vertical. Periapical radiolucencies can represent granulomas, cysts, or abscesses, whereas periapical radiodensities may represent sclerotic bone or condensing osteitis. Lytic lesions of the bone of the jaw often represent oral neoplasms. Neoplasms also can displace or disrupt teeth in the dental arch. Resorptive lesions can be external or internal and appear as radiolucent areas involving the external surface of the root or the pulp cavity, respectively. Feline dental resorptive lesions, also known as odontoclastic resorptions, are a specific form of dental resorptive lesions unique to cats.

  3. Development and evaluation of a digital dental modeling method based on grating projection and reverse engineering software.

    Science.gov (United States)

    Zhou, Qin; Wang, Zhenzhen; Chen, Jun; Song, Jun; Chen, Lu; Lu, Yi

    2016-01-01

    For reasons of convenience and economy, attempts have been made to transform traditional dental gypsum casts into 3-dimensional (3D) digital casts. Different scanning devices have been developed to generate digital casts; however, each has its own limitations and disadvantages. The purpose of this study was to develop an advanced method for the 3D reproduction of dental casts by using a high-speed grating projection system and noncontact reverse engineering (RE) software and to evaluate the accuracy of the method. The methods consisted of 3 main steps: the scanning and acquisition of 3D dental cast data with a high-resolution grating projection system, the reconstruction and measurement of digital casts with RE software, and the evaluation of the accuracy of this method using 20 dental gypsum casts. The common anatomic landmarks were measured directly on the gypsum casts with a Vernier caliper and on the 3D digital casts with the Geomagic software measurement tool. Data were statistically assessed with the t test. The grating projection system had a rapid scanning speed, and smooth 3D dental casts were obtained. The mean differences between the gypsum and 3D measurements were approximately 0.05 mm, and no statistically significant differences were found between the 2 methods (P>.05), except for the measurements of the incisor tooth width and maxillary arch length. A method for the 3D reconstruction of dental casts was developed by using a grating projection system and RE software. The accuracy of the casts generated using the grating projection system was comparable with that of the gypsum casts. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  4. Determinant factors of Yemeni maxillary arch dimensions

    Directory of Open Access Journals (Sweden)

    Nabil Muhsen Al-Zubair

    2015-01-01

    Conclusion: Measurements of palatal depth and relationships of the canines to one another and to other teeth thus had the widest ranges, implying that these dimensions are the strongest determinants of maxillary arch size.

  5. CORRECTION OF ALVEOLAR ARCH MALALIGNMENT AFTER TOTAL CORRECTION IN UNILATERAL AND BILATERAL GR III CLEFTS

    Directory of Open Access Journals (Sweden)

    Mohana Rao

    2015-06-01

    Full Text Available AIMS AND OBJECTIVES: Aim of this study is to document and analyse the pre - operative and postoperative alveolar arch impressions . MATERIALS AND METHODS: 20 cases of both unilateral and bilateral GR III clefts selected for this study. These pati ents were operated at the age of not less than 9 months, preferably below the age of 18 months. Below the age of 9 months general condition of these children may not cope up the duration of general anesthesia and amount of surgical trauma. After intubating the patient preoperatively, with the help of custom made metal arch plates, at first, Medical grade Alginate material with optimal hydration used to get negative impression, from these , positive impressions were obtained by the use of optimally hydrated m edical grade stone powder routinely used by dental surgeons. These positive impressions along with negative impression s and metal plates allowed to settle down for 10 hours undisturbed, after that positive impressions retrieved carefully without breaking a nd stored for analysis. Similarly postoperative impressions were taken after a gap of 2 years in the same manner like that of pre - operative ones under general anesthesia. Both impressions w ere compared and analysis was done regarding alveolar arch malalign ment, asymmetry and arch collapse correction. RESULTS & CONCLUSION: The status of the alveolar arch after single stage operation for cleft lip and palate in the unilateral cleft was much improved and there was considerable correction of the arch collapse a s well; in the bilateral cleft the correction of the premaxillary protrusion was better appreciated than the degree of correction of the alveolar gap.

  6. Correlação entre padrão facial e relação sagital entre os arcos dentários no estágio de dentadura decídua: considerações epidemiológicas Correlation between facial pattern and sagittal relationship between dental arches in deciduous dentition: epidemiological considerations

    Directory of Open Access Journals (Sweden)

    Omar Gabriel da Silva Filho

    2008-02-01

    Full Text Available OBJETIVO: A inter-relação oclusão e morfologia facial é fundamental para o diagnóstico e planejamento em ortodontia, bem como para determinação do prognóstico de tratamento. De um modo geral, a relação sagital entre os arcos dentários (Classe tende a refletir o comportamento sagital do esqueleto facial (Padrão. O presente trabalho avalia a correlação entre as características morfológicas sagitais da face (Padrão e da oclusão (Classe no estágio de dentadura decídua. METODOLOGIA: A amostra foi composta por 2009 crianças, entre 03 e 06 anos de idade, no período de dentadura decídua completa, de 20 pré-escolas do Município de Bauru - SP. Os resultados demonstraram uma correlação estreita entre o Padrão facial e a Classe. No Padrão I predominou a Classe I (62,99%, seguida pela Classe II (35,82% e Classe III (1,18%. No Padrão II, a Classe II foi predominante (81,35% acompanhada de uma incidência baixa de Classe I (18,64%. No Padrão III, a Classe III estava presente em 50% das crianças, seguida pela Classe I, em 48,64%, e Classe II, em 1,35%. RESULTADOS: A expectativa se comprovou. Há uma tendência da Classe acompanhar o Padrão, desde o estágio de dentadura decídua. Isso foi mais explícito no Padrão II. Os resultados também esclarecem que a oclusão guarda alguma independência em relação ao Padrão. CONCLUSÃO: A maior heterogeneidade na distribuição das Classes ficou para os Padrões I e III. No Padrão II, as Classes se comportaram de forma mais homogênea, com mais de 80% das crianças exibindo Classe II.The interrelationship between occlusion and facial morphology is fundamental for diagnosis and planning in Orthodontics. In general, the sagittal relationship between dental arches (Class tends to reflect the sagittal position of facial skeleton (Pattern. This current paper assesses the correlation between sagittal facial morphological characteristics (Pattern and occlusion (Class in deciduous dentition

  7. Distúrbios craniomandibulares em pacientes edentados unilaterais inferiores com e sem próteses parciais removíveis (PPR: um estudo transversal utilizando o índice craniomandibular Craniomandibular disorders in unilateral lower free end dental arch subjects with and without removable partial dentures (RPD: a cross sectional study using the craniomandibular index (CMI

    Directory of Open Access Journals (Sweden)

    Carlos GIL

    1998-04-01

    following a score methodology according to clinical history, examination and study models. The following groups were observed: a 34 patients wearing removable partial dentures (RPD with unilateral absence of teeth (Kennedy’s Class II; b 34 patients not wearing removable partial dentures with unilateral absence of teeth, and c 34 patients with complete dental arches. All subjects in this survey presented some degree of pain or muscle discomfort. The results showed statistically significant differences between the three groups: the non RPD, partially edentulous subjects, with absence of teeth for more than 5 years had the worst degree of severity of signs and symptoms of CMD. It was concluded that the main signs and symptoms can be reliably evaluated utilizing this (CMI score methodology.

  8. Complete interruption of the aortic arch

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Hak; Park, In Kyu; Lee, Won Hwa; Kim, Yong Joo; Kang, Duk Sik; Lee, Jong Tae [Kyungpook National University College of Medicine, Taegu (Korea, Republic of)

    1984-09-15

    Complete interrupture of the aortic arch is one of the least common cardiac malformation. In this condition, continuity between the ascending and descending protions of the aorta is not present, and the descending aorta is supplied through a reversing patent ductus arteriosus. In the majority of the patients a ventricular septal defect is present. Authors have experienced a case of the complete interruption of aortic arch, interruption between the left carotid and the left subclavian artery.

  9. Fractionally Integrated Models With ARCH Errors

    OpenAIRE

    Hauser, Michael A.; Kunst, Robert M.

    1993-01-01

    Abstract: We introduce ARFIMA-ARCH models which simultaneously incorporate fractional differencing and conditional heteroskedasticity. We develop the likelihood function and a numerical estimation procedure for this model class. Two ARCH models - Engle- and Weiss-type - are explicitly treated and stationarity conditions are derived. Finite-sample properties of the estimation procedure are explored by Monte Carlo simulation. An application to the Standard & Poor 500 Index indicates existence o...

  10. Highly Tunable Electrothermally Actuated Arch Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of electrothermally actuated MEMS arch beams. The beams are made of silicon and are intentionally fabricated with some curvature as in-plane shallow arches. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and results of a multi-physics finite-element model. A good agreement is found among all the results. The electrothermal voltage is applied between the anchors of the clamped-clamped MEMS arch beam, generating a current that passes through the MEMS arch beam and controls its axial stress caused by thermal expansion. When the electrothermal voltage increases, the compressive stress increases inside the arch beam. This leads to increase in its curvature, thereby increases the resonance frequencies of the structure. We show here that the first resonance frequency can increase up to twice its initial value. We show also that after some electro-thermal voltage load, the third resonance frequency starts to become more sensitive to the axial thermal stress, while the first resonance frequency becomes less sensitive. These results can be used as guidelines to utilize arches as wide-range tunable resonators.

  11. The growth of foot arches and influencing factors

    OpenAIRE

    Ferial Hadipoetro Idris

    2016-01-01

    Background Foot arches are important components for body sup- port. Foot arch deformity caused by growth abnormalities cause serious limitations in daily activities. Objectives To determine the patterns of foot arch growth, factors influencing foot arch growth, and the timing for intervention in er- rant growth patterns. Methods A cross-sectional study evaluated the foot arches of chil- dren aged 0-18 years according to age and sex. Subjects included had no evidence of...

  12. Probabilistic Analysis of Crack Width

    Directory of Open Access Journals (Sweden)

    J. Marková

    2000-01-01

    Full Text Available Probabilistic analysis of crack width of a reinforced concrete element is based on the formulas accepted in Eurocode 2 and European Model Code 90. Obtained values of reliability index b seem to be satisfactory for the reinforced concrete slab that fulfils requirements for the crack width specified in Eurocode 2. However, the reliability of the slab seems to be insufficient when the European Model Code 90 is considered; reliability index is less than recommended value 1.5 for serviceability limit states indicated in Eurocode 1. Analysis of sensitivity factors of basic variables enables to find out variables significantly affecting the total crack width.

  13. A deterministic width function model

    Directory of Open Access Journals (Sweden)

    C. E. Puente

    2003-01-01

    Full Text Available Use of a deterministic fractal-multifractal (FM geometric method to model width functions of natural river networks, as derived distributions of simple multifractal measures via fractal interpolating functions, is reported. It is first demonstrated that the FM procedure may be used to simulate natural width functions, preserving their most relevant features like their overall shape and texture and their observed power-law scaling on their power spectra. It is then shown, via two natural river networks (Racoon and Brushy creeks in the United States, that the FM approach may also be used to closely approximate existing width functions.

  14. 正畸弓丝形态的研究进展%Research prowess on the arch form in orthodontics

    Institute of Scientific and Technical Information of China (English)

    张林; 段沛沛

    2012-01-01

    在正畸临床治疗过程中,弓丝形态的设计和应用至关重要,其不仅关系到正畸治疗效果,而且对治疗周期、治疗后的稳定性等有着重要影响.不正确的弓丝形态的应用容易造成牙弓、牙槽弓、基骨弓形态的不一致,从而可能引起口颌肌系统功能不协调,容易导致复发.很多学者对怎样确定正确的正畸弓丝形态进行了大量研究,包括寻找适合大多数患者的理想弓形以及适合于个别患者的个体(牙合)弓形.本文将对标准理想牙弓形态以及个体(牙合)牙弓形态的拟合理论、应用现状以及优缺点作一综述.%The size and shape of the arch wire used in orthodontic treatment have considerable implications on the treatment effect, treatment cycle and the stability of the dentition. Using improper arch wire may cause mismatching of shape among dental arch, alveolar arch and basal arch, affecting the equilibrium of teeth between tongue and circumoral muscle forces. This always leads to relapse. Arch form relative to orthodontic therapy has been examined in various studies, including the classic and individual arch wire form. The aim of the article is to give a review on the relevant researches about the combination of the classic and individual arch wire form. The theory, practical applications and problems of these methods are described.

  15. Dental Emergencies

    OpenAIRE

    Domb, Ivor

    1982-01-01

    Emergency dental problems can result from trauma, dental pathology, or from dental treatment itself. While the physician can treat many instances of dental trauma, the patient should see a dentist as soon as possible so that teeth can be saved. Emergency treatment of dental pathology usually involves relief of pain and/or swelling. Bleeding is the most frequent post-treatment emergency. The physician should be able to make the patient comfortable until definitive dental treatment can be avail...

  16. Immediate loading of immediate mandibular implants with a full-arch fixed prosthesis: a preliminary study.

    Science.gov (United States)

    Peñarrocha, Miguel; Boronat, Araceli; Garcia, Berta

    2009-06-01

    To determine the survival of immediate dental implants with immediate loading in the partially edentulous mandible, by use of a full-arch screw-retained provisional restoration. Patients who were partially edentulous in the mandible with indications for extraction of the remaining teeth and with a minimum follow-up of 12 months after implant placement were included in the study. They were treated in chronologic order by the insertion of 6 Defcon dental implants (Impladent, Sentmenat, Spain) subjected to immediate loading (4 interforaminal and 2 posterior placements). Implants with a minimum primary stability of 60 implant stability quotient were loaded. All resin screw-retained prostheses were inserted and loaded with fully functional occlusion within 24 hours of implant placement. Eleven patients were treated with immediate implants, although 2 patients were excluded from the study for having an implant stability quotient value below 60 in at least one of the implants after surgery and did not undergo restoration with immediate loading. Fifty-four implants were placed in 9 partially edentulous patients with immediate loading with a full-arch screw-fixed prosthesis. The patients wore this provisional prosthesis during the healing period (2 months) without complication and with a high level of comfort. The survival rate of the implants was 100% at 12 months of follow-up. Immediate mandibular loading with immediate full-arch implant-supported and screw-retained restorations is a viable treatment alternative, yielding a 100% success rate in this small series of patients.

  17. Dental Procedures.

    Science.gov (United States)

    Ramponi, Denise R

    2016-01-01

    Dental problems are a common complaint in emergency departments in the United States. There are a wide variety of dental issues addressed in emergency department visits such as dental caries, loose teeth, dental trauma, gingival infections, and dry socket syndrome. Review of the most common dental blocks and dental procedures will allow the practitioner the opportunity to make the patient more comfortable and reduce the amount of analgesia the patient will need upon discharge. Familiarity with the dental equipment, tooth, and mouth anatomy will help prepare the practitioner for to perform these dental procedures.

  18. Right circumflex retro-oesophageal aortic arch with coarctation of a high-positioned right arch

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Kyung-Sik; Yong, Hwan Seok; Woo, Ok Hee; Kang, Eun-Young [Korea University Guro Hospital, Department of Radiology, Seoul (Korea); Lee, Joo-Won [Korea University Guro Hospital, Department of Paediatrics, Seoul (Korea)

    2007-06-15

    We present a rare case of right circumflex retro-oesophageal aortic arch with coarctation of a high-positioned right arch. A 7-month-old boy presented with a cardiac murmur. Cardiac situs was normal and there was no evidence of an intracardiac shunt or patent ductus arteriosus. MR aortography revealed a right aortic arch that was high-positioned, tortuous and narrowed. This right aortic arch crossed the midline behind the oesophagus and continued as a left-sided descending aorta. The left common carotid and subclavian arteries arose from a large branching vascular structure that derived from the top of the left-sided descending aorta. The right common carotid artery arose from the ascending aorta. The proximal portion of the right common carotid artery showed very severe stenosis and poststenotic dilatation. The right subclavian artery originated distal to the narrowed and tortuous segment of the aortic arch. (orig.)

  19. Arch Index: An Easier Approach for Arch Height (A Regression Analysis

    Directory of Open Access Journals (Sweden)

    Hironmoy Roy

    2012-04-01

    Full Text Available Background: Arch-height estimation though practiced usually in supine posture; is neither correct nor scientific as referred in literature, which favour for standing x-rays or arch-index as yardstick. In fact the standing x-rays can be excused for being troublesome in busy OPD, but an ink-footprint on simple graph-sheet can be documented, as it is easier, cheaper and requires almost no machineries and expertisation. Objective: So this study aimed to redefine the inter-relationship of the radiological standing arch-heights with the arch-index for correlation and regression so that from the later we can derive the radiographical standing arch-height values indirectly, avoiding the actual maneuver. Methods: The study involved 103 adult subjects attending at a tertiary care hospital of North Bengal. From the standing x-rays of foot, the standing navicular, talar heights were measured, and ‘normalised’ with the foot length. In parallel foot-prints also been obtained for arch-index. Finally variables analysed by SPSS software. Result: The arch-index showed significant negative correlations and simple linear regressions with standing navicular height, standing talar height as well as standing normalised navicular and talar heights analysed in both sexes separately with supporting mathematical equations. Conclusion: To measure the standing arch-height in a busy OPD, it is wise to have the foot-print first. Arch-index once get known, can be put in the equations as derived here, to predict the preferred standing arch-heights in either sex.

  20. Correlation between interalar width and intercommisural width against mesiodistal width of central upper incisor in Buginese tribe

    Directory of Open Access Journals (Sweden)

    Bahruddin Thalib

    2016-04-01

    Full Text Available Various types of anatomical landmarks of the face should match its proportions with the size of the teeth which is the interalar width, intercomissural width, interpupillary width, Intercanthal width, and byzigomatic width. Some of face landmarks can be used as a guide in the selection of anterior teeth in complete denture, especially if the pre extraction record such as radiography image, extracted teeth, model study, the remaining teeth, face shape, and the shape of the curved jaw have been lost. The objective of this study was to evaluate the correlation between interalar width and intercommisural width against mesiodistal incisivus centralis width in a group of Buginese tribe. Ninety nine Buginese tribe subjects aged 17-25 were selected. The interalar width, intercommisural width, and mesiodistal incisor centralis teeth were measured using caliper about three times for accuracy and precision. Mean of interalar width and mesiodistal incisor centralis maxilla width in males more width than females (p0.05. The degree of correlation between interalar width against mesiodistal incisor centralis maxilla width was 0.030, -0.246, 0,225 in Buginese tribe, males, and females (p>0.05. : The degree of correlation between intercommisural width against  mesiodistal incisor centralis maxilla width in Buginese tribe was 0,054, 0,013, 0,153 in Buginese tribe, males, and females (p>0.05. The degree of correlation between interalar width and intercommisural width was 0.301 and 0.356 in Buginese tribe and males (p0.05. In conclusion, there is no significant correlation between interalar width and intercommisural width against mesiodistal incisor centralis maxilla width in a group of Buginese tribe. Interalar width and intercommisural width  directly proportional to mesiodistal incisor centralis maxilla in a group of Buginese tribe. Interalar width and intercommisural width  inversely proportional to mesiodistal incisor centralis maxilla in males and directly

  1. Integration of digital dental casts in cone-beam computed tomography scans

    NARCIS (Netherlands)

    Rangel, F.A.; Maal, T.J.J.; Berge, S.J.; Kuijpers-Jagtman, A.M.

    2012-01-01

    Cone-beam computed tomography (CBCT) is widely used in maxillofacial surgery. The CBCT image of the dental arches, however, is of insufficient quality to use in digital planning of orthognathic surgery. Several authors have described methods to integrate digital dental casts into CBCT scans, but all

  2. Tubular Steel Arch Stabilized by Textile Membranes

    Directory of Open Access Journals (Sweden)

    Ondrej Svoboda

    2016-10-01

    Full Text Available Tubular steel arch supporting textile membrane roofing is investigated experimentally and numerically. The stabilization effects of the textile membrane on in-plane and out-of-plane behavior of the arch is of primary interest. First a model of a large membrane structure tested in laboratory is described. Prestressed membranes of PVC coated polyester fabric Ferrari® Précontraint 702S were used as a currently standard and excellent material. The test arrangement, loading and resulting load/deflection values are presented. The supporting structure consisted of two steel arch tubes, outer at edge of the membrane and inner supporting interior of the membrane roofing. The stability and strength behavior of the inner tube under both symmetrical and asymmetrical loading was monitored and is shown in some details. Second the SOFiSTiK software was employed to analyze the structural behavior in 3D, using geometrically nonlinear analysis with imperfections (GNIA. The numerical analysis, FE mesh sensitivity, the membrane prestressing and common boundary conditions are validated by test results. Finally a parametrical study concerning stability of mid arch with various geometries in a membrane structure with several supporting arches is presented, with recommendations for a practical design.

  3. Biological width: No violation zone

    Directory of Open Access Journals (Sweden)

    Ashu Sharma

    2012-01-01

    Full Text Available Maintenance of gingival health is one of the keys for the longevity of teeth, as well as for the longevity of restorations. The concept of Biologic width has been widely described by periodontists and restorative dentists. An adequate understanding of relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function and esthetics, and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width and indications and applications of surgical crown lengthening. These violations lead to complications like gingival inflammation, alveolar bone loss and improper fit of the restorative component. This review gives the wide aspect of the complex question of biologic width and represents an attempt to answer some of the demands in relation to it. The article also discusses the possible methods to assess biologic width, problems that occur after improper margin placement in the periodontium and the alternative procedures for prevention of biological width violation.

  4. A unique variation of superficial palmar arch

    Directory of Open Access Journals (Sweden)

    Jiji PJ

    2009-09-01

    Full Text Available We present a unique variation in the arterial pattern of superficial palmar arch in which it was completed by one of the large terminal branches of radial artery. The origin of the arteria radialis indicis was also peculiar that it was arising from the communicating branch of the radial artery and further reinforced by the first dorsal metacarpal artery that joined it after reaching the volar aspect. Pertinent anatomical knowledge regarding the variations of the palmar arch is significant for the purposes of microvascular repairs and re-implantations.

  5. The characteristics of the arch form of skeletal Class Ⅲ malocclusion%骨性Ⅲ类错(牙合)患者牙弓形态特征分析

    Institute of Scientific and Technical Information of China (English)

    孙留振; 范向飞; 肖丹娜; 高辉

    2012-01-01

    Objective To study the characteristics of the arch form of skeletal Class ffl malocclusion and provide references for diagnosis and treatment plan. Methods 7 indexes in dental casts of 47 patients with skeletal Class ffl malocclusion and 50 individuals with normal occlusion were measured respectively. And differences between corresponding upper and lower measurements were calculated. Independent samples (-test was employed for comparing between the two groups by SPSS 17.0. Results Compared with normal occlusion sample, Class 0 malocclusion group had smaller anterior segment lengths and larger canine angles (P<0.05). Differences between upper and lower first pre-molar widths were larger in males with skeletal Class Iff malocclusion. And differences between upper and lower anterior segment lengths were smaller in males with skeletal Class M malocclusion (P<0.05). Conclusion Arch widths of patients with skeletal Class ID malocclusion are basically normal. The lengths of anterior segment are smaller and the anterior arch forms are straighter.%目的 探讨骨性Ⅲ类错(牙合)患者的牙弓形态特征,为临床诊断和治疗提供理论依据.方法 选择骨性Ⅲ类错(牙合)患者47例为实验组,个别正常(牙合)50例为对照组,在石膏模型上测量与牙弓形态特征相关的7个项目,计算上下颌相应测量项目之差,采用SPSS 17.0软件对数据进行独立样本t检验.结果 实验组的上颌牙弓前段长度小于对照组,上颌尖牙角大于对照组(P<05);男性实验组的上下颌第一前磨牙间宽度之差大于对照组,牙弓前段长度之差小于对照组(P<0.05).结论 骨性Ⅲ类错(牙合)患者的牙弓宽度基本正常,但牙弓前段长度不足,且前段弓形较为平直.

  6. CD(4) has bounded width

    CERN Document Server

    Carvalho, Catarina; Marković, Petar; Maróti, Miklós

    2007-01-01

    We prove that the constraint languages invariant under a short sequence of J\\'onsson terms (containing at most three non-trivial ternary terms) are tractable by showing that they have bounded width. This improves the previous result by Kiss and Valeriote and presents some evidence that the Larose-Zadori conjecture holds in the congruence-distributive case.

  7. Educational material of dental anatomy applied to study the morphology of permanent teeth.

    Science.gov (United States)

    Siéssere, Selma; Vitti, Mathias; de Sousa, Luiz Gustavo; Semprini, Marisa; Regalo, Simone Cecílio Hallak

    2004-01-01

    The purpose of this report is to present educational material that would allow the dental student to learn to easily identify the morphologic characteristics of permanent teeth, and how they fit together (occlusion). In order to do this, macro models of permanent teeth with no attrition were carved in wax and later molded with alginate. These molds were filled with plaster, dental stone and/or cold-cured acrylic resin. The large individual dental stone tooth models were mounted on a wax base, thus obtaining maxillary and mandibular arches which were occluded. These dental arches were molded with plaster or dental stone. The authors suggest that these types of macro models allow an excellent visualization of the morphologic characteristics of permanent teeth and occlusion. Dental students are able to carve the permanent dentition in wax with great facility when they can observe macro models.

  8. Contribution of the transverse arch to foot stiffness in humans

    OpenAIRE

    Yawar, Ali; Korpas, Lucia; Lugo-Bolanos, Maria; Mandre, Shreyas; Venkadesan, Madhusudhan

    2017-01-01

    Stiffness of the human foot is central to its mechanical function, such as elastic energy storage and propulsion. Its doubly-arched structure, manifested as longitudinal and transverse arches, is thought to underlie the stiff nature. However, previous studies have focused solely on the longitudinal arch, and little is known about whether and how the transverse arch impacts the foot's stiffness. The common observation that a flexible currency bill significantly stiffens upon curling it transve...

  9. Average radiation widths and the giant dipole resonance width

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Thielemann, F.K.

    1982-11-01

    The average E1 radiation width can be calculated in terms of the energy Esub(G) and width GAMMAsub(G) of the Giant Dipole Resonance (GDR). While various models can predict Esub(G) quite reliably, the theoretical situation regarding ..lambda..sub(G) is much less satisfactory. We propose a simple phenomenological model which is able to provide GAMMAsub(G) values in good agreement with experimental data for spherical or deformed intermediate and heavy nuclei. In particular, this model can account for shell effects in GAMMAsub(G), and can be used in conjunction with the droplet model. The GAMMAsub(G) values derived in such a way are used to compute average E1 radiation widths which are quite close to the experimental values. The method proposed for the calculation of GAMMAsub(G) also appears to be well suited when the GDR characteristics of extended sets of nuclei are required, as is namely the case in nuclear astrophysics.

  10. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2015-01-01

    A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge...... the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The number of post-tensioning......, and gives a large positive bending moment below the load and a smaller negative bending moment in the unloaded side. When the Pearl-Chain Bridge concept is compared to other pre-fabricated arch bridge solutions we find a number of advantages when using Pearl-Chain Bridges: Straight elements, combination...

  11. Assembly and lifting of Pearl-Chain arches

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Viebæk, N.E.

    2015-01-01

    Pearl-Chain arches were invented at the Technical University of Denmark in cooporation with the company Abeo A/S. The system uses specially designed, pre-fabricated concrete elements that are post-tensioned together into an arch shape, which is then lifted into place. The arches can be used both...

  12. Dilatation of the aneurysmal sac after total arch replacement.

    Science.gov (United States)

    Watanuki, Hirotaka; Ogino, Hitoshi; Matsuda, Hitoshi; Minatoya, Kenji; Sasaki, Hiroaki; Fukuda, Tetsuya; Kitamura, Soichiro

    2008-02-01

    In our institution, total arch replacement for distal arch aneurysms is performed through a median sternotomy with antegrade selective cerebral perfusion. The distal anastomosis to the completely transected descending aorta is made through the aneurysmal sac. We report on three interesting cases presenting late dilatation of the aneurysmal sac due to collateral flow after total arch replacement.

  13. Hybrid Exotic Meson Decay Width

    CERN Document Server

    Cook, M S

    2005-01-01

    We present results of a decay width calculation for a hybrid exotic meson(h, JPC=1-+) in the decay channel h to pi+a1. This calculation uses quenched lattice QCD and Luescher's finite box method. Operators for the h and pi+a1 states are used in a correlation matrix which was expanded by varying the smearing and fuzzing levels at source and sink points. Scattering phase shifts for a discrete set of relative pi+a1 momenta are determined using eigenvalues of the correlation matrix and formulae derived by Luescher. The phase shift data is very sparse, but fits to a Breit-Wigner model are made, resulting in a decay width of about 80 MeV.

  14. On the maximal diphoton width

    CERN Document Server

    Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo

    2016-01-01

    Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

  15. Using a Visible Light-Polymerized Resin to Fabricate an Interim Partial Removable Dental Prosthesis.

    Science.gov (United States)

    Segal, Aaron; Yu, Hui Wen; Elkassaby, Heba

    2017-02-01

    An interim partial removable dental prosthesis (RDP) is any dental prosthesis that replaces some teeth in a partially dentate arch designed to enhance esthetics, stabilization, and/or function for a limited period of time, after which it is to be replaced by a definitive dental prosthesis. This article describes a technique that uses a visible light-polymerized (VLP) resin as the base material for an interim partial RDP. This technique can be easily accomplished in a dental office or laboratory and results in a predictable dental prosthesis. This technique eliminates the need for laboratory processing.

  16. 上颌异位尖牙埋伏阻生的辅弓矫治%The treatment of canine ectopic eruption with the auxiliary arch fragment

    Institute of Scientific and Technical Information of China (English)

    王德顺; 高益林; 谢小飞; 田瑞雪

    2011-01-01

    Objective To explore the treatment method of the vertical loop of auxiliary arch fragment in canine ectopic eruption with fixed orthodontic technique. Methods In 6 cases of ectopic maxillary canine a fixed orthodontic technique is used with the vertical loop of auxiliary arch fragment support. Results 6 cases of ectopic canine with the vertical loop of auxiliary arch fragment support have been aligned into the dental arch in about 12 months. Conclusion The ectopic canine can be aligned completely into the dental arch by means of the orthodontic technique without the tooth extraction.%目的:探讨垂直曲式的片段辅弓应用在尖牙异位萌出的固定矫治方法.方法:对6例上颌异位尖牙用垂直曲式的片段辅弓支持下,固定正畸技术进行矫治.结果:6例在片段辅弓固定矫治器支持下,12个月左右异位尖牙进入牙弓排齐.结论:上颌异位尖牙通过正畸技术完全能排入正常牙列,不需拔除.

  17. About Dental Amalgam Fillings

    Science.gov (United States)

    ... and Medical Procedures Dental Devices Dental Amalgam About Dental Amalgam Fillings Share Tweet Linkedin Pin it More ... should I have my fillings removed? What is dental amalgam? Dental amalgam is a dental filling material ...

  18. Dental Implant Surgery

    Science.gov (United States)

    ... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, ... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, ...

  19. Mandibular arch orthodontic treatment stability using passive self-ligating and conventional systems in adults: A randomized controlled trial

    Science.gov (United States)

    Wey, Mang Chek; Othman, Siti Adibah

    2017-01-01

    Objective This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods Fortyseven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age 21.58 ± 2.94 years) were randomized into two groups to receive either passive self-ligating (Damon® 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention. PMID:28127535

  20. Dental Sealants

    Science.gov (United States)

    ... Dates Electronic Submission of Applications Grants 101 (How to Write a Grant) Questions and Answers Grant Writing Tips ... offers strategies for providing oral care. NIDCR > Data & Statistics > Find Data by Topic > Dental Sealants Dental Sealants ...

  1. Dental Assistants

    Science.gov (United States)

    ... Z INDEX | OOH SITE MAP | EN ESPAÑOL Healthcare > Dental Assistants PRINTER-FRIENDLY EN ESPAÑOL Summary What They ... of workers and occupations. What They Do -> What Dental Assistants Do About this section Assistants prepare and ...

  2. Dental sealants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000779.htm Dental sealants To use the sharing features on this ... case a sealant needs to be replaced. How Dental Sealants are Applied Your dentist applies sealants on ...

  3. Dental cavities

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001055.htm Dental cavities To use the sharing features on this page, please enable JavaScript. Dental cavities are holes (or structural damage) in the ...

  4. DENTAL MATERIALS.

    Science.gov (United States)

    The study deals with the determination of characteristic physical and mechanical properties of restorative dental materials, and effect of...manipulative variables on these properties. From the study an entirely new dental gold inlay casting technic was developed, based on the principle of...controlled water added hygroscopic technic. The method has had successful dental applications and is a recognized method of dental inlay casting procedure

  5. Evaluation of senior Brazilian dental students about mouth preparation and removable partial denture design.

    Science.gov (United States)

    Neto, Arcelino Farias; Duarte, Antônio Ricardo Calazans; Shiratori, Fábio Kenji; de Alencar e Silva Leite, Pedro Henrique; Rizzatti-Barbosa, Célia Marisa; Bonachela, Wellington Cardoso

    2010-11-01

    This study aimed to evaluate the knowledge of senior dental students about mouth preparation and removable partial denture (RPD) design. Two hundred sixty-six senior students from eleven dental schools in the State of São Paulo, Brazil, comprised the sample. The subjects examined two partially edentulous casts mounted on a semiadjustable articulator, answered a questionnaire regarding the treatment plan, and drew the RPD design. The casts consisted of Kennedy Class III, modification 1 maxillary arch and Class II mandibular arch. Ninety percent of the students believed that mouth preparation should be performed although no one was able to name all necessary procedures. For the maxillary arch, 12 percent of the denture designs were completely appropriate, 51 percent were partially appropriate, and 37 percent were inappropriate. For the mandibular arch, the results were 3 percent, 40 percent, and 57 percent, respectively.

  6. Geometrical Nonlinearity Analysis of the Steel Network Arch Bridges

    Directory of Open Access Journals (Sweden)

    Sigutė Žilėnaitė

    2016-12-01

    Full Text Available Arch bridges are one of the popular, oldest and graceful bridges which are being built in zones of the city and out of the city. However arches becomes especially sensitive to their buckling response due to dominated compressive force in the arch. In order to ensure stability conditions of the individual arch and arch bridges, it is estimated not just geometrical factor of arch, residual stress, work conditions, geometric imperfections but geometrical nonlinearity too. Geometric nonlinearity especially dominates in many times static indeterminable systems such as network arch bridges. However there are a few represents of estimation of geometric nonlinearity of the new construction form of the arch bridges created in a middle of 20th century. This paper represents estimation of geometric nonlinearity with numerical method of the steel arch bridges with vertical hangers and network arch bridges. There are determined stress-strain law and principal behavior of the steel network arch bridges under symmetric and asymmetric pedestrian loadings.

  7. In-plane elastic stability of fixed parabolic shallow arches

    Institute of Scientific and Technical Information of China (English)

    CAI JianGuo; FENG Jian; CHEN Yao; HUANG LiFeng

    2009-01-01

    The nonlinear behavior of fixed parabolic shallow arches subjected to a vertical uniform load is inves-tigated to evaluate the in-plane buckling load. The virtual work principle method is used to establish the non-linear equilibrium and buckling equations. Analytical solutions for the non-linear in-plane sym-metric snap-through and antisymmetric bifurcation buckling loads are obtained. Based on the least square method, an approximation for the symmetric buckling load of fixed parabolic arch is proposedto simplify the solution process. And the relation between modified slenderness and buckling modes are discussed. Comparisons with the results of finite element analysis demonstrate that the solutions are accurate. A cable-arch structure is presented to improve the in-plane stability of parabolic arches. The comparison of buckling loads between cable-arch systems and arches only show that the effect of cables becomes more evident with the increase of arch's modified slenderness.

  8. Masses, widths, and leptonic widths of the higher upsilon resonances

    Energy Technology Data Exchange (ETDEWEB)

    Lovelock, D.M.J.; Horstkotte, J.E.; Klopfenstein, C.; Lee-Franzini, J.; Romero, L.; Schamberger, R.D.; Youssef, S.; Franzini, P.; Son, D.; Tuts, P.M.

    1985-02-04

    The masses, total widths, and leptonic widths of three triplet s-wave bb-bar states UPSILON(4S), UPSILON(5S), and UPSILON(6S) are determined from measurements of the e/sup +/e/sup -/ annihilation cross section into hadrons for 10.55

  9. Influence of deciduous canine extractions on incisor alignment, dental arch dimensions and dental fear

    OpenAIRE

    Sjögren, Anders

    2011-01-01

    Interception of crowding, by extraction of deciduous and permanent teeth, to eliminate or at least facilitate orthodontic treatment has a long tradition. This treatment procedure, know as “guided eruption” or “serial extraction” was re-introduced by Robert Hotz and Birger Kjellgren in 1947-48. The sequential extraction procedure begins with the removal of the deciduous canines in the early mixed dentition and additional extractions of deciduous first molars and permanent bicusp...

  10. Spreading widths of doorway states

    Energy Technology Data Exchange (ETDEWEB)

    De Pace, A., E-mail: depace@to.infn.i [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Molinari, A. [Dipartimento di Fisica Teorica dell' Universita di Torino, via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Weidenmueller, H.A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

    2011-01-01

    As a function of energy E, the average doorway strength function S(E)-bar of a doorway state is commonly assumed to be Lorentzian in shape and characterized by two parameters, the peak energy E{sub 0} and the spreading width {Gamma}{sup {down_arrow}}. The simple picture is modified when the density of background states that couple to the doorway state changes significantly in an energy interval of size {Gamma}{sup {down_arrow}}. For that case we derive an approximate analytical expression for S(E)-bar. We test our result successfully against numerical simulations. Our result may have important implications for shell-model calculations.

  11. N-Widths and Average Widths of Besov Classes in Sobolev Spaces

    Institute of Scientific and Technical Information of China (English)

    Gui Qiao XU; Yong Sheng SUN; Yong Ping LIU

    2006-01-01

    In this paper, we consider the n-widths and average widths of Besov classes in the usual Sobolev spaces. The weak asymptotic results concerning the Kolmogorov n-widths, the linear n-widths,the Gel'fand n-widths, in the Sobolev spaces on Td, and the infinite-dimensional widths and the average widths in the Sobolev spaces on Rd are obtained, respectively.

  12. Evolution Characteristic Analysis of Pressure-arch of a Double-arch Tunnel in Water-rich Strata

    Directory of Open Access Journals (Sweden)

    C. L. Li

    2016-03-01

    Full Text Available It is of importance to analyze the morphological characterization, the evolution process and the skewed effect of pressure-arch of a double-arch tunnel in the water-rich strata. Taking a buried depth 80 m double-arch tunnel as an example, a computational model of the double-arch tunnel was built by using FLAC3D technique. Then considering some aspects including groundwater conditions, tunnel depth, construction sequences and permeability coefficients, the coupling effect of stress field and seepage field in the pressure-arch of the double-arch tunnel was analyzed. The results show that the thickness of the pressure-arch induced by step-by-step excavation and display a step-descent skewed distribution from the left to the right of the double-arch tunnel. The permeability coefficient has a significant influence on the shape and the skewed effect of the pressure arch. The excavation of the bench method has a better arching condition than that of the expanding method. The abtained results provide a basic reference for the rock reinforcement design and safety construction of double-arch tunnels in the water-rich strata.

  13. Multislice CT angiography of interrupted aortic arch

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dong Hyun; Goo, Hyun Woo [Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea); Seo, Dong-Man; Yun, Tae-Jin; Park, Jeong-Jun [Asan Medical Center, University of Ulsan College of Medicine, Department of Paediatric Cardiac Surgery, Seoul (Korea); Park, In-Sook; Ko, Jae Kon; Kim, Young Hwee [Asan Medical Center, University of Ulsan College of Medicine, Department of Paediatric Cardiology, Seoul (Korea)

    2008-01-15

    Interrupted aortic arch (IAA) is defined as complete luminal and anatomic discontinuity between the ascending and descending aorta. Because almost all patients with IAA become critically ill during the neonatal period, they should undergo urgent corrective surgery. This clinical urgency necessitates a fast and accurate noninvasive diagnostic method. Although echocardiography remains the primary imaging tool for this purpose, it is not always sufficient for planning surgical correction of IAA, principally due to a limited acoustic window and the inexperience of imagers. In this context, multislice CT angiography is regarded as an appropriate imaging technique complementary to echocardiography because it is fast, accurate, and objective for the diagnosis of IAA. In this article we describe what cardiac radiologists should know about IAA in their clinical practice, including clinicopathological features, CT features with contemporary surgical methods and postoperative complications, and differentiation from coarctation of the aorta and aortic arch atresia. (orig.)

  14. [Dental anatomy of dogs].

    Science.gov (United States)

    Sarkisian, E G

    2014-12-01

    The aim of the research was to investigate dog teeth anatomy as animal model for study of etiopathogenesis of caries disease and physiological tooth wear in human. After examining the dog's dental system, following conclusions were drawn: the dog has 42 permanent teeth, which are distributed over the dental arches not equally, and so the upper dentition consists of 20, and the lower of 22 teeth. The largest are considered upper fourth premolar and lower first molars, which are called discordant teeth. Between discordant teeth and fangs a dog has an open bite, which is limited to the top and bottom conical crown premolar teeth. Thus, in the closed position of the jaws, behind this occlusion is limited by discordant teeth, just in contact are smaller in size two molars. Only large dog's molars in a valid comparison can be likened to human molars, which allows us to use them in an analog comparison between them with further study of the morphological features ensure durability short-crown teeth and their predisposition to caries.

  15. Recurrent Pneumonia due to Double Aortic Arch

    Directory of Open Access Journals (Sweden)

    I. Sedighi

    2012-04-01

    Full Text Available Introduction: Pneumonia is one of the most common infections during childhood. In children with recurrent bacterial pneumonia complete evaluation for underlying factors is necessary. The most common underlying diseases include: antibody deficiencies , cystic fibrosis , tracheoesophageal fistula and increased pulmonary blood flow. Vascular ring and its pressure effect is a less common cause of stridor and recurrent pneumonia. Congenital abnormalities in aortic arch and main branches which form vascular ring around esophagus and trachea with variable pressure effect cause respiratory symptoms such as stridor , wheezing and recurrent pneumoniaCase Report: A 2 year old boy was admitted in our hospital with respiratory distress and cough . Chest x-Ray demonstrated right lobar pneumonia. He had history of stridor and wheezing from neonatal period and hospitalization due to pneumonia for four times. The patient received appropriate antibiotics. Despite fever and respiratory distress improvement, wheezing continued. Review of his medical documents showed fixed pressure effect on posterior aspect of esophagus in barium swallow. In CT angiography we confirmed double aortic arch.Conclusion: Double aortic arch is one of the causes of persistant respiratory symptom and recurrent pneumonia in children for which fluoroscopic barium swallow is the first non-invasive diagnostic method.(Sci J Hamadan Univ Med Sci 2012;19(1:70-74

  16. Correction parameters in conventional dental radiography for dental implant

    Directory of Open Access Journals (Sweden)

    Barunawaty Yunus

    2009-12-01

    Full Text Available Background: Radiographic imaging as a supportive diagnostic tool is the essential component in treatment planning for dental implant. It help dentist to access target area of implant due to recommendation of many inventions in making radiographic imaging previously. Along with the progress of science and technology, the increasing demand of easier and simpler treatment method, a modern radiographic diagnostic for dental implant is needed. In fact, Makassar, especially in Faculty of Dentistry Hasanuddin University, has only a conventional dental radiography. Researcher wants to optimize the equipment that is used to obtain parameters of the jaw that has been corrected to get accurate dental implant. Purpose: This study aimed to see the difference of radiographic imaging of dental implant size which is going to be placed in patient before and after correction. Method: The type of research is analytical observational with cross sectional design. Sampling method is non random sampling. The amount of samples is 30 people, male and female, aged 20–50 years old. The correction value is evaluated from the parameter result of width, height, and thick of the jaw that were corrected with a metal ball by using conventional dental radiography to see the accuracy. Data is analyzed using SPSS 14 for Windows program with T-test analysis. Result: The result that is obtained by T-Test analysis results with significant value which p<0.05 in the width and height of panoramic radiography technique, the width and height of periapical radiography technique, and the thick of occlusal radiography technique before and after correction. Conclusion: It can be concluded that there is a significant difference before and after the results of panoramic, periapical, and occlusal radiography is corrected.

  17. Effectiveness of a lower lingual arch as a space holding device.

    Science.gov (United States)

    Owais, A I; Rousan, M E; Badran, S A; Abu Alhaija, E S

    2011-02-01

    The aims of this study were to evaluate the effectiveness of a lower lingual holding arch (LLHA) in maintaining arch length, and to compare the effectiveness of two LLHAs made of two different gauges (0.9 and 1.25 mm) of stainless steel (SS) wire. The sample comprised 44 subjects (24 males and 20 females) who for various reasons attended orthodontic clinics at Jordan University of Science and Technology Dental Teaching Center. The subjects were randomly divided into two treatment groups. The first group contained 20 subjects (12 males/8 females, average age 10.76 ± 0.75 years). The LLHA used in this group was made of 0.9 mm SS wire. The second group comprised 24 subjects (12 males/12 females, average age 10.57 ± 0.54 years). The LLHA used in this group was made of 1.25 mm SS wire. The third group consisted of 23 subjects (15 males/8 females, average age 10.63 ± 0.66 years) who served as the control. The records consisted of lateral cephalograms, dental pantomograms, and study casts. Paired t-test, analysis of variance, and chi-square tests were used to determine whether significant differences existed between the groups. In both treatment groups, the lower incisors proclined and moved forward, and space loss of the lower primary second molar occurred. The LLHA made of 0.9 mm SS was superior to that made of 1.25 mm SS in terms of arch length preservation.

  18. Immediate loading with fixed full-arch prostheses in the maxilla: Review of the literature

    Science.gov (United States)

    Peñarrocha-Oltra, David; Covani, Ugo; Peñarrocha-Diago, Miguel

    2014-01-01

    conventional loading procedures. Key words:Immediate loading, full-arch, dental implants, loading protocols. PMID:24880445

  19. Mesiodistal width and proximal enamel thickness of maxillary first bicuspids

    Directory of Open Access Journals (Sweden)

    Aurélio de Carvalho Macha

    2010-03-01

    Full Text Available This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left, selected from white patients (mean age: 23.7 ± 4.2 years, who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (α = 0.05. The mesiodistal crown width mean values found were 7.51 mm (± 0.54 on the right side and 7.53 mm (± 0.35 on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18. The mean values for the mesial surfaces were 1.08 mm (± 0.14 and 1.19 mm (± 0.25, on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

  20. Accuracy of impressions obtained with dual-arch trays.

    Science.gov (United States)

    Wöstmann, Bernd; Rehmann, Peter; Balkenhol, Markus

    2009-01-01

    This study aimed to analyze the accuracy resulting from dual-arch impressions when compared to conventional impressions in complex preparations (ie, inlay and partial crown). One hundred eighty impressions were made using two different dual-arch trays; conventional trays served as the control. The accuracy of the dies obtained (Fuji-Rock EP, GC Europe) was assessed indirectly from the change of 59 transversal dimensions. Statistical analysis (t test, analysis of variance) revealed that less rigid dual-arch trays performed better than rigid ones. Though the inlay preparation was more difficult to reproduce with dual-arch trays, it can be concluded that the accuracy obtainable with nonrigid dual-arch trays is comparable to impressions taken from full-arch trays.

  1. Asymptotics of the QMLE for General ARCH(q) Models

    DEFF Research Database (Denmark)

    Kristensen, Dennis; Rahbek, Anders Christian

    2009-01-01

    Asymptotics of the QMLE for Non-Linear ARCH Models Dennis Kristensen, Columbia University Anders Rahbek, University of Copenhagen Abstract Asymptotic properties of the quasi-maximum likelihood estimator (QMLE) for non-linear ARCH(q) models -- including for example Asymmetric Power ARCH and log......-ARCH -- are derived. Strong consistency is established under the assumptions that the ARCH process is geometrically ergodic, the conditional variance function has a finite log-moment, and finite second moment of the rescaled error. Asymptotic normality of the estimator is established under the additional assumption...... that certain ratios involving the conditional variance function are suitably bounded, and that the rescaled errors have little more than fourth moment. We verify our general conditions, including identification, for a wide range of leading specific ARCH models....

  2. In-plane elastic stability of fixed parabolic shallow arches

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The nonlinear behavior of fixed parabolic shallow arches subjected to a vertical uniform load is inves- tigated to evaluate the in-plane buckling load. The virtual work principle method is used to establish the non-linear equilibrium and buckling equations. Analytical solutions for the non-linear in-plane sym- metric snap-through and antisymmetric bifurcation buckling loads are obtained. Based on the least square method, an approximation for the symmetric buckling load of fixed parabolic arch is proposed to simplify the solution process. And the relation between modified slenderness and buckling modes are discussed. Comparisons with the results of finite element analysis demonstrate that the solutions are accurate. A cable-arch structure is presented to improve the in-plane stability of parabolic arches. The comparison of buckling loads between cable-arch systems and arches only show that the effect of cables becomes more evident with the increase of arch’s modified slenderness.

  3. Space maintenance in a child dental care program.

    Science.gov (United States)

    Hill, C J; Sorenson, H W; Mink, J R

    1975-04-01

    Five types of space maintainers were placed in 196 children participating in an extensive dental care program during a four-year study. Children with space maintainers were examined at six-month intervals. During the study, some sort of difficulty was encountered with 43% of the appliances inserted. The most common problem encountered was lost or missing appliances. Sixteen appliances had broken arch wires or loop wires; only ten broken bands were noted. Anther problem was distortion of arch wires. Suggestions are made for possible modifications in the space maintainers to reduce the incidence of problems.

  4. 14 CFR 121.115 - Route width.

    Science.gov (United States)

    2010-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  5. Clique-width of unit interval graphs

    OpenAIRE

    Lozin, Vadim V.

    2007-01-01

    The clique-width is known to be unbounded in the class of unit interval graphs. In this paper, we show that this is a minimal hereditary class of unbounded clique-width, i.e., in every hereditary subclass of unit interval graphs the clique-width is bounded by a constant.

  6. Aortic arch blunt injury in front-seat passenger.

    Science.gov (United States)

    Türkmen, Nursel; Eren, Bülent; Aydin, Şule Akköse

    2013-10-01

    Aortic arch blunt injury has highly lethal nature. Because the physical examination findings are subtle, immediate medical evaluation is very important. The case was a 72-year-old woman. Massive haemorrhage in the left haemotorax, contusion area in the left lung and a traumatic transection of the distal aortic arch was observed during autopsy. We described intersting autopsy case of aortic arch blunt injury.

  7. Critical thrombotic obstruction of transverse aortic arch in a neonate

    Directory of Open Access Journals (Sweden)

    Karunakar Vadlamudi

    2015-01-01

    Full Text Available A 3-day-old neonate presented with features suggestive of coarctation of aorta. Echocardiography showed a large organized thrombus in the transverse arch causing obstruction to theaortic arch and carotids with partial recanalization. Patient underwent surgical thromboendarterectomy with arch reconstruction. The evaluation did not reveal any hematological abnormalities and suspected to be due to fetal thromboembolism. Patient improved well, and no neurological deficits were observed during follow-up.

  8. An Electrostatically Actuated MEMS Arch Band-Pass Filter

    Directory of Open Access Journals (Sweden)

    Hassen M. Ouakad

    2013-01-01

    Full Text Available This work presents an investigation of the dynamics of micromachined arches resonators and their potential to be utilized as band-pass filters. The arches are actuated by a DC electrostatic load superimposed to an AC harmonic load. The dynamic response of the arch is studied analytically using a Galerkin-based reduced-order model when excited near its fundamental and third natural frequencies. Several simulation results are presented demonstrating interesting jumps and snap-through behavior of the arches and their attractive features for uses as band-pass filters, such as their sharp roll-off from pass bands to stop bands and their flat response.

  9. Right aortic arch with coarctation in Chinese children

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Zhu; Aimin, Sun [Shanghai Children' s Medical Center, Department of Radiology, Shanghai (China)

    2008-05-15

    Because of the rarity of right aortic arch coarctation there are few reports of large groups of patients. To characterize the frequency and type of right aortic arch coarctation in a large group of pediatric patients. From June 1997 through May 2007, 11,276 consecutive children with congenital heart disease underwent multidetector CT (MDCT), MRI or angiocardiography examination. All children with a right aortic arch or coarctation were reviewed. Right aortic arch coarctation was found in 11 children representing 0.1% of the total group of 11,276 children, 1.7% of 658 children with native coarctations and 2.3% of 473 children with a right aortic arch. Among the 11 patients, 6 had long-segment narrowing and 7 had an aberrant left subclavian artery. MDCT, MRI and angiocardiography are reliable imaging techniques for the diagnosis of right aortic arch and coarctation. Our findings showed that the pattern of right aortic arch coarctation was different from that of left aortic arch coarctation, suggesting that they are different etiological entities. The pivotal role possibly played by flow dynamics in the development of right aortic arch coarctation is discussed. (orig.)

  10. Mathematical model of a moment-less arch.

    Science.gov (United States)

    Lewis, W J

    2016-06-01

    This paper presents a mathematical model for predicting the geometrical shapes of rigid, two-pin, moment-less arches of constant cross section. The advancement of this work lies in the inclusion of arch self-weight and the ability to produce moment-less arch forms for any span/rise ratio, and any ratio of uniformly distributed load per unit span, w, to uniformly distributed arch weight per unit arch length, q. The model is used to derive the shapes of two classical 'moment-less' arch forms: parabolic and catenary, prior to demonstrating a general case, not restricted by the unrealistic load assumptions (absence of q, in the case of a parabolic form, or no w, in the case of a catenary arch). Using the same value of span/rise ratio, and w/q>1, the behaviour of the moment-less and parabolic arches under permanent loading, (w+q), is analysed. Results show the former to be developing much lower stresses than its parabolic rival, even when there are relatively small differences in the two geometries; for a medium span/rise ratio of 4 and w/q=2, differences in the parabolic and moment-less arch geometries would, in practical terms, be viewed as insignificant, but the stresses in them are different.

  11. Palindromic widths of nilpotent and wreath products

    Indian Academy of Sciences (India)

    Valeriy G Bardakov; Oleg V Bryukhanov; Krishnendu Gongopadhyay

    2017-02-01

    We prove that the nilpotent product of a set of groups $A_1, \\ldots , A_s$ has finite palindromic width if and only if the palindromic widths of $A_i$, $i = 1, \\ldots , s$, are finite. We give a new proof that the commutator width of $F_n \\wr K$ is infinite, where $F_n$ is a free group of rank $n\\geq 2$ and $K$ is a finite group. This result, combining with a result of Fink [9] gives examples of groups with infinite commutator width but finite palindromic width with respect to some generating set.

  12. [Single coronary artery and right aortic arch].

    Science.gov (United States)

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Coronary anomalies are mostly asymptomatic and diagnosed incidentally during coronary angiography or echocardiography. However, they must be taken into account in the differential diagnosis of angina, dyspnea, syncope, acute myocardial infarction or sudden death in young patients. The case is presented of two rare anomalies, single coronary artery originating from right sinus of Valsalva and right aortic arch, in a 65 year-old patient with atherosclerotic coronary artery disease treated percutaneously. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  13. A Functional Version of the ARCH Model

    CERN Document Server

    Hormann, Siegfried; Reeder, Ron

    2011-01-01

    Improvements in data acquisition and processing techniques have lead to an almost continuous flow of information for financial data. High resolution tick data are available and can be quite conveniently described by a continuous time process. It is therefore natural to ask for possible extensions of financial time series models to a functional setup. In this paper we propose a functional version of the popular ARCH model. We will establish conditions for the existence of a strictly stationary solution, derive weak dependence and moment conditions, show consistency of the estimators and perform a small empirical study demonstrating how our model matches with real data.

  14. A Binomial Integer-Valued ARCH Model.

    Science.gov (United States)

    Ristić, Miroslav M; Weiß, Christian H; Janjić, Ana D

    2016-11-01

    We present an integer-valued ARCH model which can be used for modeling time series of counts with under-, equi-, or overdispersion. The introduced model has a conditional binomial distribution, and it is shown to be strictly stationary and ergodic. The unknown parameters are estimated by three methods: conditional maximum likelihood, conditional least squares and maximum likelihood type penalty function estimation. The asymptotic distributions of the estimators are derived. A real application of the novel model to epidemic surveillance is briefly discussed. Finally, a generalization of the introduced model is considered by introducing an integer-valued GARCH model.

  15. Three-dimensional measurement of foot arch in preschool children

    Directory of Open Access Journals (Sweden)

    Chang Hsun-Wen

    2012-09-01

    Full Text Available Abstract Background The prevalence of flexible flatfoot is high among preschool-aged children, but the effects of treatment are inconclusive due to the unclear definitions of normal flatfoot. To date, a universally accepted evaluation method of the foot arch in children has not been completely established. Our aims of this study were to establish a new method to evaluate the foot arch from a three dimensional perspective and to investigate the flexibility of the foot arch among children aged from two to six. Methods A total of 44 children aged from two to six years of age were put into five age groups in this study. The navicular height was measured with one leg standing, and both feet were scanned separately in both sitting and one leg standing positions to compute the foot arch volume. The arch volume index, which represents the ratio of the difference in volume between sitting and one leg standing positions to the volume when sitting was calculated to demonstrate the flexibility of the foot arch. The differences of measured parameters between each aged group were analyzed by one-way ANOVA. Results The arch volumes when sitting and standing were highly correlated with the navicular height. The navicular height ranged from 15.75 to 27 mm, the arch volume when sitting ranged from 6,223 to 11,630 mm3, and the arch volume when standing from 3,111 to 7,848 mm3 from two to six years of age. The arch volume index showed a declining trend as age increased. Conclusion This study is the first to describe the foot arch with volume perspective in preschool-aged children. The foot arch volume was highly correlated with the navicular height. Research results show both navicular height index and arch volume index gradually increase with age from two to six. At the same time the arch also becomes rigid with age from two to six. These results could be applied for clinical evaluation of the foot arch and post-treatment evaluation.

  16. Dental Hygienist.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of dental hygienist, lists technical competencies and competency builders for 13 units pertinent to the health technologies cluster in general and 9 units specific to the occupation of dental hygienist. The following skill areas are covered in…

  17. Isolated right aortic arch: Antenatal evaluation

    Directory of Open Access Journals (Sweden)

    Ali Babacan

    2015-06-01

    Full Text Available Aortic arch abnormalities are the least frequently prenatally diagnosed congenital cardiac abnormalities. Right aortic arch (RAA identified in prenatal period is associated frequently with other cardiac/non-cardiac malformations, notably tracheal or esophageal compression and microdeletions 22q11. Intrauterine and postnatal survey of the fetus depends on these anomalies and their effects. Aortic arc variations, particularly RAA, can be diagnosed accurately by fetal echocardiography. Elaborated fetal cardiac and extracardiac evaluation should be undertaken in all cases of RAA by using Doppler ultrasound. Also cytogenetic testing for 22q11 microdeletions should be considered carefully. Nonetheless, it should be kept in mind that isolated RAA has a good prognosis, and in the majority of the patients, it is an asymptomatic vascular variant with a relatively low risk for chromosomal anomaly. In this paper with this case, we aim to evaluate the prenatal findings, associated conditions and prognosis of prenatally detected RAA anomalies in the light of literatures. J Clin Exp Invest 2015; 6 (2: 192-195

  18. Blood flow characteristics in the aortic arch

    Science.gov (United States)

    Prahl Wittberg, Lisa; van Wyk, Stevin; Mihaiescu, Mihai; Fuchs, Laszlo; Gutmark, Ephraim; Backeljauw, Philippe; Gutmark-Little, Iris

    2012-11-01

    The purpose with this study is to investigate the flow characteristics of blood in the aortic arch. Cardiovascular diseases are associated with specific locations in the arterial tree. Considering atherogenesis, it is claimed that the Wall Shear Stress (WSS) along with its temporal and spatial gradients play an important role in the development of the disease. The WSS is determined by the local flow characteristics, that in turn depends on the geometry as well as the rheological properties of blood. In this numerical work, the time dependent fluid flow during the entire cardiac cycle is fully resolved. The Quemada model is applied to account for the non-Newtonian properties of blood, an empirical model valid for different Red Blood Cell loading. Data obtained through Cardiac Magnetic Resonance Imaging have been used in order to reconstruct geometries of the the aortic arch. Here, three different geometries are studied out of which two display malformations that can be found in patients having the genetic disorder Turner's syndrome. The simulations show a highly complex flow with regions of secondary flow that is enhanced for the diseased aortas. The financial support from the Swedish Research Council (VR) and the Sweden-America Foundation is gratefully acknowledged.

  19. Level-ARCH Short Rate Models with Regime Switching

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    This paper introduces regime switching volatility into level- ARCH models for the short rates of the US, the UK, and Germany. Once regime switching and level effects are included there are no gains from including ARCH effects. It is of secondary importance exactly how the regime switching...

  20. Defect in Posterior Arch of Atlas in Myelomeningocele

    NARCIS (Netherlands)

    G. Blaauw (Gerhard)

    1971-01-01

    textabstractThe posterior arches of the cervical vertebrae of 30 children who died with a myelomeningocele in the lower thoracic, lumbar or sacral region were examined; in 70 per cent of these cases a defect was found in the posterior arch of the atlas, which was bridged by a firm fibrous band. Alté

  1. Modelling subset multivariate ARCH model via the AIC principle

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper we consider the problem of identifying a parsimonious subset multivariate ARCH model based on the AIC principle. The proposed approach can reduce the number of parameters in the final ARCH specification and allows for non-constant correlations between the components. Some simulation results illustrate the viability of the proposed procedure.

  2. Defect in Posterior Arch of Atlas in Myelomeningocele

    NARCIS (Netherlands)

    G. Blaauw (Gerhard)

    1971-01-01

    textabstractThe posterior arches of the cervical vertebrae of 30 children who died with a myelomeningocele in the lower thoracic, lumbar or sacral region were examined; in 70 per cent of these cases a defect was found in the posterior arch of the atlas, which was bridged by a firm fibrous band. Alté

  3. Double aortic arch and nasogastric tubes: A fatal combination

    Institute of Scientific and Technical Information of China (English)

    Julia Massaad; Kelly Crawford

    2008-01-01

    Double aortic arch is a common form of complete vascular ring that encircles both the trachea and the esophagus, and presents with various respiratory and esophageal symptoms, usually in the pediatric population.We present a case of double aortic arch in an adult patient that manifested as massive upper gastrointestinal bleeding after prolonged nasogastric intubation.

  4. Adult presentation with vascular ring due to double aortic arch.

    Science.gov (United States)

    Kafka, Henryk; Uebing, Anselm; Mohiaddin, Raad

    2006-11-01

    This is a case report on the use of cardiovascular magnetic resonance imaging to diagnose vascular ring due to double aortic arch in an adult presenting with an abnormal chest X-ray. The experience in this case and the literature review identify the benefits of using cardiovascular magnetic resonance imaging to clarify complex aortic arch anatomy.

  5. Twin - Arch technique. Revival of the "edgewise -Technique"?

    Directory of Open Access Journals (Sweden)

    Jacob Karp

    2012-01-01

    The SNB – Bracket brings a new dimension into the orthodontic world which is most apparent in extraction cases. Its Teflon – like material has a very low friction coefficient thus, reducing the treatment time considerably. Through the use of low dimensioned arch wires, the Twin – Arch Technique becomes a Light – wire system and simultaneously provides good anchorage and torque control.

  6. Full-scale load tests of Pearl-Chain arches

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2017-01-01

    , pre-fabricated, composite, lightweight, concrete deck elements (SL-Decks), that are post-tensioned together into an arch shape. The two Pearl-Chain arches, each with a span of 13m and a rise of 1m, were placed on a post tensioned bearing plate prepared in advance. The aches are tested with load...

  7. Class III correction using an inter-arch spring-loaded module.

    Science.gov (United States)

    Vanlaecken, Robert; Williams, Michael O; Razmus, Thomas; Gunel, Erdogan; Martin, Chris; Ngan, Peter

    2014-05-02

    A retrospective study was conducted to determine the cephalometric changes in a group of Class III patients treated with the inter-arch spring-loaded module (CS2000®, Dynaflex, St. Ann, MO, USA). Thirty Caucasian patients (15 males, 15 females) with an average pre-treatment age of 9.6 years were treated consecutively with this appliance and compared with a control group of subjects from the Bolton-Brush Study who were matched in age, gender, and craniofacial morphology to the treatment group. Lateral cephalograms were taken before treatment and after removal of the CS2000® appliance. The treatment effects of the CS2000® appliance were calculated by subtracting the changes due to growth (control group) from the treatment changes. All patients were improved to a Class I dental arch relationship with a positive overjet. Significant sagittal, vertical, and angular changes were found between the pre- and post-treatment radiographs. With an average treatment time of 1.3 years, the maxillary base moved forward by 0.8 mm, while the mandibular base moved backward by 2.8 mm together with improvements in the ANB and Wits measurements. The maxillary incisor moved forward by 1.3 mm and the mandibular incisor moved forward by 1.0 mm. The maxillary molar moved forward by 1.0 mm while the mandibular molar moved backward by 0.6 mm. The average overjet correction was 3.9 mm and 92% of the correction was due to skeletal contribution and 8% was due to dental contribution. The average molar correction was 5.2 mm and 69% of the correction was due to skeletal contribution and 31% was due to dental contribution. Mild to moderate Class III malocclusion can be corrected using the inter-arch spring-loaded appliance with minimal patient compliance. The overjet correction was contributed by forward movement of the maxilla, backward and downward movement of the mandible, and proclination of the maxillary incisors. The molar relationship was corrected by mesialization of the

  8. Seismic multi-arch structures in East China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In previous papers (Wencai, 2002, 2003), the author has analyzed the deep seismic reflection profiles along some of the Mesozoic plutons in East China, and has pointed out that the crustal structures around these intrusions usually correlate with a special seismic fabric called the seismic multi-arch structure. This paper will continue to show main characteristics of the seismic multi-arch structures and discuss their relationship with mantle-origin magmatism and the lithospheric thinning process. Calibration of seismic reflectors in Chinese continental drilling sites shows that small-scale arch-like reflectors can be generated by fractured eclogites or other plutons, they do not belong to the multi-arch structure specially discussed in the paper. The multi-arch structure is characterized by several arch-like reflectors distributed in both the upper and lower crust with granitoid plutons or stocks exposed on the surface, which do not have obvious negative Europium anomalies. Based on the distribution pattern of arch reflectors, the multi-arch magmatic structures can be divided into three main types, namely the simple vertical combination type, the spread arch magmatic structure and the arch-bouquet structure. All of them correlate to mantle-origin magmatism, but occur in different places. The spread arch magmatic structures occur within a Mesozoic/Cenozoic rift zone with very thin and hot lithosphere. The vertical combination type of the multi-arch structures occurred near the rift zones where lithosphere was thin and hot. The arch-bouquet magmatic structures occur far from the rift zones where the lithosphere is not hot. The continental rifting acted as the late episode of the lithospheric thinning process seeing that the rift zones usually coincide with the thinnest parts of the lithosphere in East China. In different locations within the lithospheric thinning areas, mantle-origin magmatic activities have different characteristics, which might generate different

  9. Left testicular artery arching over the ipsilateral renal vein

    Institute of Scientific and Technical Information of China (English)

    Munekazu Naito; Hayato Terayama; Yoichi Nakamura; Shogo Hayashi; Takayoshi Miyaki; Masahiro Itoh

    2006-01-01

    Aim: To report two cases of the left testicular artery arching over the left renal vein (LRV) before running downward to the testis. Methods: The subjects were obtained from two Japanese cadavers. During the student course of gross-anatomical dissection, the anatomical relationship between the testicular vessels and the renal vein was specifically observed. Results: The arching left testicular artery arose from the aorta below the LRV and made a loop around the LRV, which appeared to be mildly compressed between the arching artery and the psoas major muscle.Conclusion: Clinically, compression of the LRV between the abdominal aorta and the superior mesenteric artery occasionally induces LRV hypertension, resulting in varicocele, orthostatic protenuria and hematuria. Considering that the incidence of a left arching testicular artery is higher than that of a right one, an arching left artery could be an additional cause of LRV hypertension.

  10. Atlantoaxial stabilization using multiaxial C-1 posterior arch screws.

    Science.gov (United States)

    Donnellan, Michael B; Sergides, Ioannis G; Sears, William R

    2008-12-01

    The authors present a novel technique of atlantoaxial fixation using multiaxial C-1 posterior arch screws. The technique involves the insertion of bilateral multiaxial C-1 posterior arch screws, which are connected by crosslinked rods to bilateral multiaxial C-2 pars screws. The clinical results are presented in 3 patients in whom anomalies of the vertebral arteries, C-1 lateral masses, and/or posterior arch of C-1 presented difficulty using existing fixation techniques with transarticular screws, C-1 lateral mass screws, or posterior wiring. The C-1 posterior arch screws achieved solid fixation and their insertion appeared to be technically less demanding than that of transarticular or C-1 lateral mass screws. This technique may reduce the risk of complications compared with existing techniques, especially in patients with anatomical variants of the vertebral artery, C-1 lateral masses, or C-1 posterior arch. This technique may prove to be an attractive fixation option in patients with normal anatomy.

  11. Effect of Obesity on Arch Index in Young Adults

    Directory of Open Access Journals (Sweden)

    Sneha Sameer Ganu

    2013-01-01

    Full Text Available Background: Excessive increases in weight bearing forces caused by obesity may negatively affect the lower limbs and feet but minimal research has examined the long-term loading effects of obesity on the musculoskeletal system, particularly in reference to the feet. Objectives: The purpose of the study was to investigate the effect of obesity on medial longitudinal arch of foot in young adults. Method: 60 subjects, 30 obese & 30 non obese were assessed for height & weight using standard technique. Radiographic images under static condition were used for calculating the arch index. Result: The arch index of obese subjects was significantly lower than the non obese subjects & there is a negative correlation between the BMI & the arch index. Conclusion: These results suggests that obesity lowers the medial longitudinal arch of foot.

  12. Approximation Algorithms for Directed Width Parameters

    CERN Document Server

    Kintali, Shiva; Kumar, Akash

    2011-01-01

    Treewidth of an undirected graph measures how close the graph is to being a tree. Several problems that are NP-hard on general graphs are solvable in polynomial time on graphs with bounded treewidth. Motivated by the success of treewidth, several directed analogues of treewidth have been introduced to measure the similarity of a directed graph to a directed acyclic graph (DAG). Directed treewidth, D-width, DAG-width, Kelly-width and directed pathwidth are some such parameters. In this paper, we present the first approximation algorithms for all these five directed width parameters. For directed treewidth and D-width we achieve an approximation factor of O(sqrt{logn}). For DAG-width, Kelly-width and directed pathwidth we achieve an O({\\log}^{3/2}{n}) approximation factor. Our algorithms are constructive, i.e., they construct the decompositions associated with these parameters. The width of these decompositions are within the above mentioned factor of the corresponding optimal width.

  13. Width Distributions for Convex Regular Polyhedra

    CERN Document Server

    Finch, Steven R

    2011-01-01

    The mean width is a measure on three-dimensional convex bodies that enjoys equal status with volume and surface area [Rota]. As the phrase suggests, it is the mean of a probability density f. We verify formulas for mean widths of the regular tetrahedron and the cube. Higher-order moments of f_tetra and f_cube have not been examined until now. Assume that each polyhedron has edges of unit length. We deduce that the mean square width of the regular tetrahedron is 1/3+(3+sqrt(3))/(3*pi) and the mean square width of the cube is 1+4/pi.

  14. The width of 5-dimensional prismatoids

    CERN Document Server

    Matschke, Benjamin; Weibel, Christophe

    2012-01-01

    Santos' construction of counter-examples to the Hirsch conjecture is based on the existence of prismatoids of dimension d of width greater than d. The case d=5 being the smallest one in which this can possibly occur, we here study the width of 5-dimensional prismatoids, obtaining the following results: - There are 5-prismatoids of width six with only 25 vertices, versus the 48 vertices in Santos' original construction. This leads to lowering the dimension of the non-Hirsch polytopes from 43 to only 20. - There are 5-prismatoids with n vertices and width \\Omega(n^(1/2)) for arbitrarily large n.

  15. Diagnostic methods for assessing maxillary skeletal and dental transverse deficiencies: A systematic review

    Science.gov (United States)

    Sawchuk, Dena; Currie, Kris; Vich, Manuel Lagravere; Palomo, Juan Martin

    2016-01-01

    Objective To evaluate the accuracy and reliability of the diagnostic tools available for assessing maxillary transverse deficiencies. Methods An electronic search of three databases was performed from their date of establishment to April 2015, with manual searching of reference lists of relevant articles. Articles were considered for inclusion if they reported the accuracy or reliability of a diagnostic method or evaluation technique for maxillary transverse dimensions in mixed or permanent dentitions. Risk of bias was assessed in the included articles, using the Quality Assessment of Diagnostic Accuracy Studies tool-2. Results Nine articles were selected. The studies were heterogeneous, with moderate to low methodological quality, and all had a high risk of bias. Four suggested that the use of arch width prediction indices with dental cast measurements is unreliable for use in diagnosis. Frontal cephalograms derived from cone-beam computed tomography (CBCT) images were reportedly more reliable for assessing intermaxillary transverse discrepancies than posteroanterior cephalograms. Two studies proposed new three-dimensional transverse analyses with CBCT images that were reportedly reliable, but have not been validated for clinical sensitivity or specificity. No studies reported sensitivity, specificity, positive or negative predictive values or likelihood ratios, or ROC curves of the methods for the diagnosis of transverse deficiencies. Conclusions Current evidence does not enable solid conclusions to be drawn, owing to a lack of reliable high quality diagnostic studies evaluating maxillary transverse deficiencies. CBCT images are reportedly more reliable for diagnosis, but further validation is required to confirm CBCT's accuracy and diagnostic superiority. PMID:27668196

  16. Dental OCT

    Science.gov (United States)

    Wilder-Smith, Petra; Otis, Linda; Zhang, Jun; Chen, Zhongping

    This chapter describes the applications of OCT for imaging in vivo dental and oral tissue. The oral cavity is a diverse environment that includes oral mucosa, gingival tissues, teeth and their supporting structures. Because OCT can image both hard and soft tissues of the oral cavity at high resolution, it offers the unique capacity to identity dental disease before destructive changes have progressed. OCT images depict clinically important anatomical features such as the location of soft tissue attachments, morphological changes in gingival tissue, tooth decay, enamel thickness and decay, as well as the structural integrity of dental restorations. OCT imaging allows for earlier intervention than is possible with current diagnostic modalities.

  17. Lymphoepithelial cyst in the palatoglossus arch

    Directory of Open Access Journals (Sweden)

    Evanice Maria Marçal Vieira

    2012-12-01

    Full Text Available The objective of this study was to describe a case of a lymphoepithelial cyst in the palatoglossus arch. A 16-years-old black man said that he was observed a lesion in his mouth. On the physical exam, a pedicled, consistent, smooth surface 1.5 x 1 cm lesion, similar in color to the adjacent mucosa, was found. The lesion was surgically removed and the microscopic exam showed mucosal fragments with pedicled lesion; the cystic cavity sometimes lined with pseudostratified cylindrical epithelium and others with stratified squamous flat interface of the epithelium. Around the cyst, a well-delimited mass of lymphoid tissue, presenting lymphoid follicles, was also seen. Lymphoepithelial cyst has clinical characteristics similar to those of others lesions that occur in the oral cavity. The diagnosis should be based on conservative biopsy, with total removal of lesion.

  18. Accuracy in dental medicine, a new way to measure trueness and precision.

    Science.gov (United States)

    Ender, Andreas; Mehl, Albert

    2014-04-29

    Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 ± 1.1 µm for trueness and 1.6 ± 0.6 µm for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 ± 2.2 µm, precision: 12.5 ± 2.5 µm) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes.

  19. Comparison of temporary anchorage devices and transpalatal arch-mediated anchorage reinforcement during canine retraction

    Science.gov (United States)

    Kecik, Defne

    2016-01-01

    Objective: The purpose of this study was to compare the dental and skeletal effects of canine retraction using conventional anchorage reinforcement systems and comparing them with the usage of TADs. Materials and Methods: The sample consisted of 50 patients having Class I malocclusions with bimaxillary protrusion indicated for first premolar extraction, and allocated into two groups. The first group consisted of 25 patients with a mean age of 18,7 years (min:14, max:22 years, 16 girls and 9 boys) that TADs were applied as an anchorage mechanic between attached gingiva of upper second premolar and first molar teeth. The second group consisted of 25 patients with a mean age of 19,4 years (min:15, max:23 years, 14 girls and 11 boys) that conventional molar anchorage with Transpalatal arch (TPA) was applied for the anchorage mechanics against canine retraction. Results: The results showed that mean mesial movement and the tipping of the first molars in TAD group between T0 - T1 were insignificant (P > 0,05), however in the TPA group were significant (P0,05). Conclusion: Although TPA is a useful appliance, it doesn't provide an effective anchorage control on anteroposterior movement maxillary first molar teeth concerning first premolar extraction treatment. TADs are more convenient to provide absolute anchorage during maxillary canine retraction in contrast to transpalatal arch. PMID:28042267

  20. 14 CFR 121.95 - Route width.

    Science.gov (United States)

    2010-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  1. Constant Width Planar Computation Characterizes ACC0

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt

    2006-01-01

    We obtain a characterization of ACC0 in terms of a natural class of constant width circuits, namely in terms of constant width polynomial size planar circuits. This is shown via a characterization of the class of acyclic digraphs which can be embedded on a cylinder surface in such a way that all...

  2. Constant Width Planar Computation Characterizes ACC0

    DEFF Research Database (Denmark)

    Hansen, K.A.

    2004-01-01

    We obtain a characterization of ACC 0 in terms of a natural class of constant width circuits, namely in terms of constant width polynomial size planar circuits. This is shown via a characterization of the class of acyclic digraphs which can be embedded on a cylinder surface in such a way that all...

  3. A Niche Width Model of Optimal Specialization

    NARCIS (Netherlands)

    Bruggeman, Jeroen; Ó Nualláin, Breanndán

    2000-01-01

    Niche width theory, a part of organizational ecology, predicts whether “specialist” or “generalist” forms of organizations have higher “fitness,” in a continually changing environment. To this end, niche width theory uses a mathematical model borrowed from biology. In this paper, we first loosen th

  4. 7 CFR 29.1085 - Width.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Width. 29.1085 Section 29.1085 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Heavy Fleshy Medium Thin Oil Lean Oily Rich Color intensity Pale Weak Moderate Strong Deep. Width...

  5. Relationship between width and length ratios of upper anterior teeth in young Chilean population.

    Directory of Open Access Journals (Sweden)

    Jorge Troncoso-Pazos

    2017-08-01

    Full Text Available Introduction: Knowledge about the size and proportion of upper anterior teeth allows dental rehabilitation taking into consideration the local parameters of a population. The aim of this research is to determine the width, length and the relationship between width and length of central incisor, lateral incisor and canine teeth in both sexes in young Chilean population. Methodology: A cross-sectional study was performed. Study subjects included 187 dentistry students from two Chilean cities (mean age 21.35±2.7 years, 52.9% men. The teeth width and height were measured and the width/height ratio was calculated. Differences in measurements according to sex was analyzed (p<0.05; STATA v.10.0. Results: The width and height of the teeth were statistically and proportionally larger in men (p<0.05. The width/height ratio of lateral and canine incisors was significantly higher in women (p<0.05. Conclusion: In a sample of young Chileans, upper anterior teeth were longer and wider in men. However, the width/height ratio of teeth was found to be significantly higher in women.

  6. Dental Fusion: Report on a Clinical Case

    OpenAIRE

    Colorado Vélez, Carlos

    2014-01-01

    Fusion is defined as the partial or complete union of two or more teeth during their development; it can occur between normal teeth or between a normal tooth and a supernumerary tooth. This anomaly can be unilateral or bilateral and can affect any teeth, although deciduous teeth are more frequently damaged. It can also affect the patient’s appearance, cause changes in the dental arch space, lead to cavities and affect periodontal structures. This article presents the case of 13-year-old who c...

  7. Occlusal considerations for dental implant restorations.

    Science.gov (United States)

    Bergmann, Ranier H

    2014-01-01

    When placed, dental implants are put into an ever-changing oral environment in which teeth can continue to migrate. Yet, the implants themselves are ankylosed. This can lead to occlusal instability. Teeth may continue to erupt, leaving the implants in infraocclusion. Teeth may move mesially away from an implant, requiring modification to close an open contact point. Friction in the connection between teeth and implants can lead to intrusion of teeth and damage to the periodontal attachment apparatus. Implant occlusion with shallow incisal guidance minimizes lateral and tipping forces. Cross-arch stabilization allows the best distribution of occlusal forces. The choice of restorative materials influences long-term occlusal stability.

  8. 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 ...

  9. Infant dental care (image)

    Science.gov (United States)

    ... sugar water. As the child grows, establishing proper dental hygiene will promote healthy teeth and gums which are essential to overall good health. Poor dental development, dental disease, and dental trauma can result ...

  10. Image Processing Techniques for Assessment of Dental Trays

    Science.gov (United States)

    2007-11-02

    Dimensional Tooth Movement During Orthodontic Treatment�, IEEE Transactions on Biomedical Engineering, Vol. 38, no 4, pp. 360-365, April 1991. [2...in a Complete Dental Arch Cast�, The Journal of Prosthetic Dentistry, Vol 61, no 1, pp. 54-58, January 1989. [3] Saunders, W. P., Sharkey, S. W...Polyvinyl Siloxane Impression Material�, Journal of Dentistry, Vol. 19, no. 5, pp. 283-289, October 1991. [4] Johnson, G.H., Craig, R. G., �Accuracy

  11. Immediate placement of dental implants in the mandible

    Directory of Open Access Journals (Sweden)

    Gurkar Haraswarupa Puttaraju

    2013-01-01

    Full Text Available This case describes extraction of teeth in the mandibular arch, i.e., 41 42 43 44 45 51 52 53 54 55 56 57 58 (grade two mobility, followed by immediate placement of four dental implants (3i biomet, two in the 45 55 region and two dental implants in 12 21 region. A prefabricated provisional mandibular denture was immediately placed. The purpose of immediate placement was to aid the patient resume his professional duties the next day itself along with esthetic and functional comfort, psychological well-being and most importantly preserving the remaining tissue in a healthy condition.

  12. Diagnostic Value of Manual and Computerized Methods of Dental Casts Analysis

    Directory of Open Access Journals (Sweden)

    H. Rahimi

    2009-06-01

    Full Text Available Objective: The aim of this study was to evaluate the validity of computerized and manual methods of dental cast analysis.Materials and Methods: Twenty set-ups of upper and lower casts using artificial teeth corresponding to various malocclusions were created for a diagnostic in vitro study. Values of tooth size were calculated from the isolated artificial teeth out of the set-ups, results were considered as a gold standard for the tooth size. Arch width was calculated from the existing set-ups on the dentins.Impressions were taken of the casts with alginate and duplicated with dental stone. Models were measured with digital caliper manually. Then images were taken from the occlusal views of the casts by a digital camera. Measurements were done on digital images with the AutoCAD software.The results of the computerized and manual methods were compared with the gold standard.Intra class correlation coefficient of reliability was used to measure the accuracy ofthe methods and the Friedman technique used to evaluate the significance of differences.Results: Results indicated that all measurements were highly correlated, e.g. gold standard and manual (0.9613-0.9991, gold standard and computerized (0.7118-0.9883, manual and computerized (0.6734-0.9914. Statistically significant differences were present between these methods (P<0.05, but they proved not to be clinically significant.Conclusion: Manual measurement is still the most accurate method when compared to the computerized measurements and the results of measurement by computer should be interpreted with caution.

  13. Dental Occlusion and Ophthalmology: A Literature Review

    Science.gov (United States)

    Marchili, Nicola; Ortu, Eleonora; Pietropaoli, Davide; Cattaneo, Ruggero; Monaco, Annalisa

    2016-01-01

    Stomatognathic system is strictly correlated to other anatomical regions; many studies investigated relationship between temporomandibular joint and posture, several articles describe cranio-facial pain from dental causes, such as trigger points. Until now less interest has been given to connections between dental occlusion and ophthalmology, even if they are important and involving. Clinical experience in dental practice claims that mandibular latero-deviation is connected both to eye dominance and to defects of ocular convergence. The trigeminal nerve is the largest and most complex of the twelve cranial nerves. The trigeminal system represents the connection between somitic structures and those derived from the branchial arches, collecting the proprioception from both somitic structures and oculomotor muscles. The intermedius nucleus of the medulla is a small perihypoglossal brainstem nucleus, which acts to integrate information from the head and neck and relays it on to the nucleus of the solitary tract where autonomic responses are generated. This intriguing neurophysiological web led our research group to investigate anatomical and functional associations between dental occlusion and vision. In conclusion, nervous system and functional pathways strictly connect vision and dental occlusion, and in the future both dentists and oculists should be more and more aware of this correlation for a better diagnosis and therapy. PMID:27733873

  14. Articulated dental cast analysis of asymptomatic and symptomatic populations

    Science.gov (United States)

    Cordray, Frank E

    2016-01-01

    Dental instrumentation has long provided insight into the mechanism of musculo-skeletal function of the gnathic system. While large population studies associate dental arch displacement (DAD), especially laterally, with symptoms, mandibular condyle displacement (CD) resulting from DAD has not been targeted as possibly etiologic in the production of common muscle contraction headache (CMCH) and temporo-mandibular dysfunction (TMD). The objective was to evaluate the three-dimensional nature of DAD and CD between the seated condylar position (SCP) and the intercuspal position (ICP) and to compare results derived from large deprogrammed asymptomatic and symptomatic populations. A total of 1 192 sets of dental casts collected from asymptomatic and symptomatic populations were articulated in the SCP. The initial occlusal contact, DAD, and condylar displacement were evaluated for frequency, direction, and magnitude of displacement between the SCP and ICP. The data revealed significant displacement between the SCP and ICP of the condyles (displaced most frequently inferior (down) and posterior (distal)) and substantially increased frequency and magnitude of displacement of the dental arches (with posterior premature occlusal contacts, increased overjet, decreased overbite, midline differences, and occlusal classification changes) in symptomatic subjects. These discrepancies were statistically significant and clinically significant. The data support the concept of increased DAD and CD with dysfunction. Transverse condylar displacement, commonly presenting with dental cross bite, may be associated with CMCH and TMD. Displacement of the mandibular condyle may be an etiologic factor in CMCH and dysfunction of the temporo-mandibular joint. PMID:27357324

  15. Young adult patient with two palatally maxillary impacted canines and forced traction on rigid arches of stabilization. Case report

    Science.gov (United States)

    MUCEDERO, M.; PEZZUTO, C.; ROZZI, M.; RICCHIUTI, M.R.; COZZA, P.

    2016-01-01

    SUMMARY Objective Young adult patient treated for impaction of two maxillary canines. Methods C.S., 15 years, female. Diagnostic evaluation by clinical and radiographic examinations shows permanent dentition with persistence of 5.3 and 6.3, impaction of 1.3 and 2.3, dento-skeletal Cl I malocclusion, normodivergence of bone bases. Analysis of TC dentalscan confirms the palatal impaction of 1.3 and 2.3. The treatment plan provided an orthodontic-surgical approach for adequate space management in dental arch, evaluation of eruption movements, choice of anchorage device, surgical exposure and application of the brackets. Results Deciduous canines have been extracted and an edgewise appliance with rigid rectangular full thickness archwires has been used to align the arches and to obtain maximum anchorage during the forced traction. The surgical phase, for exposure of 1.3 and 2.3 respectively, performed an open technique by excisional uncovering and a close technique by a repositioned flap. The case has been finalized for the achievement of the right occlusal keys. Conclusion The possibility to choose the surgical technique depending on the intraosseous position of impacted teeth in association to the edgewise therapy with full thickness arches allows to realize an effectiveness surgical-orthodontic approach for the forced traction of impacted teeth in a favourable position. PMID:28042427

  16. A comparative study of inter-abutment distance of dies made from full arch dual-arch impression trays with those made from full arch stock trays: An in vitro study

    Directory of Open Access Journals (Sweden)

    Reddy Jagan

    2009-01-01

    Full Text Available Objectives: The dual-arch impression technique is convenient in that it makes the required maxillary and mandibular impressions, as well as the inter-occlusal record in one procedure. The accuracy of inter-abutment distance in dies fabricated from dual-arch impression technique remains in question because there is little information available in the literature. Materials and Methods: This study was conducted to evaluate the accuracy of inter-abutment distance in dies obtained from full arch dual-arch trays with those obtained from full arch stock metal trays. Results and Conclusion: The metal dual-arch trays showed better accuracy followed by the plastic dual-arch and stock dentulous trays, respectively, though statistically insignificant. The pouring sequence did not have any effect on the inter-abutment distance statistically, though pouring the non-working side of the dual-arch impression first showed better accuracy.

  17. Overjet at the anterior and posterior segments: three-dimensional analysis of arch coordination.

    Science.gov (United States)

    Kook, Yoon-Ah; Bayome, Mohamed; Park, Soo-Byung; Cha, Bong-Kuen; Lee, Young-Wuk; Baek, Seung-Hak

    2009-05-01

    To compare the amounts of anatomical overjet measured from facial axis (FA) points with the amounts of bracket overjet measured from bracket slot center (BSC) points. The samples consisted of 27 subjects with normal occlusion whose models were fabricated with a three-dimensional (3D) scanner and the 3Txer program (Orapix Co Ltd, Seoul, Korea). 3D virtual brackets (0.022'' Slot, MBT setup, 3M Unitek, Monrovia, Calif) constructed with a 3D-CAD program were placed on an FA point with the 3Txer program. The arch dimension and the amounts of overjet from FA and BSC points were measured. Paired t-tests and analysis of variance (ANOVA) tests were used for statistical analysis. No significant difference in arch width and depth was observed between FA and BSC points. Although the amounts of overjet measured from FA points showed homogenous distribution, a tendency to decrease from the anterior segment (2.3 mm) to the posterior one (2.0 mm) was noted. However, the amounts of overjet measured from BSC points were variable, especially in the premolar and molar areas. Significant discrepancies in the amounts of overjet in most of the areas between FA and BSC points (more than P overjet measured from BSC points was 3 mm through the whole segments and that distribution of the amounts of overjet from BSC points was the same as that from FA points were rejected.

  18. 激光扫描法建立三维数字化牙颌模型的准确性和可靠性评价%Evaluation of accuracy and reproducibility of 3D digital dental models with laser scanning

    Institute of Scientific and Technical Information of China (English)

    胡心怡; 法晨; 潘晓岗

    2015-01-01

    目的 研究应用激光扫描法建立三维数字化牙颌模型的准确性和可靠性评价.方法 选择正畸治疗患者的石膏模型24副,采用激光扫描法对石膏模型进行扫描,建立三维数字化牙颌模型,并对其牙冠宽度、牙冠高度、牙弓宽度和牙弓长度进行测量,与手工测得的结果进行比较分析.结果 石膏模型和数字化模型所有测量项目的一致性相关系数中,除双侧上颌第一前磨牙颊尖顶之间的距离(CCC=0.6307)和上颌中切牙近中接触点到右侧第一磨牙远中接触点的距离2项测量指标结果(CCC=0.6571)良好外,其余指标的一致性都比较接近(CCC﹥0.7).所有测量项目的均数差在0.017~0.862mm之间,平均为0.104mm, D%﹤5%,部分指标存在统计学差异,但不具有临床意义.结论 基于激光扫描技术重建的三维数字化牙颌模型中,牙冠宽度和牙冠高度的准确性高,牙弓长度其次,牙弓宽度的准确性较低.%Objective To evaluate the accuracy and reproducibility of the 3D digital dental models prepared using laser scanning technique. Methods 24 plaster models of orthodontic patients were selected and the digital models were constructed by laser scanning, and then the width and height of crown, the length and width of dental arch were measured. The data was compared with those obtained by manual measurement. Results The concordance correlation coefficient (CCC) of all these measurements were quite good (CCC>0.7) except DU4B(CCC=0.6307) and DU1-6R(CCC=0.6571). The mean difference is from 0.017 to 0.862, and the average mean difference is 0.104, D%<5%, there were significant differences in some indicators, but it was still clinically acceptable. Conclusions In the digital dental models by laser scanning technique, the accuracy of the width and height of crown was first, followed by the length of dental arch, and then the width of dental arch.

  19. Incisor and molar overjet, arch contraction, and molar relationship in the mixed dentition in repaired complete unilateral cleft lip and palate: A qualitative and quantitative appraisal.

    Science.gov (United States)

    Disthaporn, Suteeta; Suri, Sunjay; Ross, Bruce; Tompson, Bryan; Baena, Diogenes; Fisher, David; Lou, Wendy

    2017-07-01

    To compare the mixed dentition incisor and molar overjet, severity of contraction of the dental arch, and the sagittal molar relationship on the cleft side vs the noncleft side in children with repaired complete unilateral cleft of the lip and palate (UCLP). Orthodontic records taken prior to orthodontic preparation for alveolar bone grafting were screened to select study casts from patients with nonsyndromic repaired complete UCLP who did not have mandibular skeletal or dental asymmetry. The study sample comprised dental casts from 74 children aged 8.9 ± 1 years. Standardized digital photographs were acquired at 1:1 magnification. A coordinate system was developed using digital image-processing software (Photoshop CS4 and Adobe Illustrator). Incisor and molar overjet, Angle's classification, and arch contraction were recorded. Descriptive statistics, paired t-tests, and kappa statistics were used to compare the cleft and noncleft sides. A negative overjet of -1 to -5 mm was often present at the incisors, with greater frequency and magnitude on the cleft side. Class II molar relation was more frequent on the cleft side (61.1%) than on the noncleft side (47.2%). Significantly greater contraction of the cleft side deciduous canine and deciduous first molar was noted, while the difference was very minor at the first permanent molar. Cleft side maxillary arch contraction was most severe in the deciduous canine and first deciduous molar region and progressively less severe in the posterior region of the arch. A greater frequency and severity of negative overjet and Class II molar relationship was seen on the cleft side.

  20. Spin gated GDR widths at moderate temperatures

    Directory of Open Access Journals (Sweden)

    Mukul Ish

    2015-01-01

    Full Text Available We present the evolution of giant dipole resonance (GDR width as a function of angular momentum in the compound nucleus 144Sm in the temperature range of 1.5-2.0 MeV. The high energy γ rays emitted from the decay of excited 144Sm were measured using large NaI detector in coincidence with 4π sum spin spectrometer. GDR widths were found to comply with thermal shape fluctuation model in this temperature range over a wide range of spin. Experimental widths tend to increase rapidly at high angular momentum values.

  1. Nonstationary ARCH and GARCH with t-distributed Innovations

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Søndergaard; Rahbek, Anders

    Consistency and asymptotic normality are established for the maximum likelihood estimators in the nonstationary ARCH and GARCH models with general t-distributed innovations. The results hold for joint estimation of (G)ARCH effects and the degrees of freedom parameter parametrizing the t-distribut......Consistency and asymptotic normality are established for the maximum likelihood estimators in the nonstationary ARCH and GARCH models with general t-distributed innovations. The results hold for joint estimation of (G)ARCH effects and the degrees of freedom parameter parametrizing the t......-distribution. With T denoting sample size, classic square-root T-convergence is shown to hold with closed form expressions for the multivariate covariances....

  2. A case of neonatal arterial thrombosis mimicking interrupted aortic arch.

    Science.gov (United States)

    Gürsu, Hazım Alper; Varan, Birgül; Oktay, Ayla; Özkan, Murat

    2015-06-01

    Neonatal arterial thrombosis is a very rare entity with clinical findings resembling coarctation of aorta or interrupted aortic arch. A two day-old male newborn was admitted to a different hospital with difficulty in sucking and sleepiness. On echocardiographic examination, a diagnosis of interrupted aortic arch was made and he was treated with prostoglandin E2. When the patient presented to our center, physical examination revealed that his feet were bilaterally cold. The pulses were not palpable and there were ecchymotic regions in the lower extremities. Echocardiography ruled out interrupted aortic arch. Computerized tomographic angiography revealed a large thrombosis and total occlusion of the abdominal aorta. Since there was no response to treatment with tissue plasminogen activator, we performed thrombectomy. Homozygous Factor V Leiden and Methylenetetrahydrofolate reductase mutations were found in this patient. Neonatal aortic thrombosis which is observed very rarely and fatal should be considered in the differential diagnosis of coarctation of aorta and interrupted aortic arch.

  3. Clarifying the anatomy of the fifth arch artery

    Directory of Open Access Journals (Sweden)

    Saurabh Kumar Gupta

    2016-01-01

    Full Text Available The artery allegedly forming in the fifth pharyngeal arch has increasingly been implicated as responsible for various vascular malformations in patients with congenitally malformed hearts. Observations from studies on developing embryos, however, have failed to provide support to substantiate several of these inferences such that the very existence of the fifth arch artery remains debatable. To the best of our knowledge, in only a solitary human embryo has a vascular channel been found that truly resembled the artery of the fifth arch. Despite the meager evidence to support its existence, the fifth arch artery has been invoked to explain the morphogenesis of double-barreled aorta, some unusual forms of aortopulmonary communications, and abnormalities of the brachiocephalic arteries. In most of these instances, the interpretations have proved fallible when examined in the light of existing knowledge of cardiac development. In our opinion, there are more plausible alternative explanations for the majority of these descriptions. Double-barreled aorta is more likely to result from retention of the recently identified dorsal collateral channels while abnormalities of brachiocephalic arteries are better explained on the basis of extensive remodeling of aortic arches during fetal development. Some examples of aortopulmonary communications, nonetheless, may well represent persistence of the developing artery of the fifth pharyngeal arch. We here present one such case - a patient with tetralogy of Fallot and pulmonary atresia, in whom the fifth arch artery provided a necessary communication between the ascending aorta and the pulmonary arteries. In this light, we discuss the features we consider to be essential before attaching the tag of "fifth arch artery" to a candidate vascular channel.

  4. Dental caries

    DEFF Research Database (Denmark)

    Pitts, Nigel B; Zero, Domenick T; Marsh, Phil D

    2017-01-01

    , exposed root surfaces. The balance between pathological and protective factors influences the initiation and progression of caries. This interplay between factors underpins the classification of individuals and groups into caries risk categories, allowing an increasingly tailored approach to care. Dental......Dental caries is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues. Caries can occur throughout life, both in primary and permanent dentitions, and can damage the tooth crown and, in later life...... caries is an unevenly distributed, preventable disease with considerable economic and quality-of-life burdens. The daily use of fluoride toothpaste is seen as the main reason for the overall decline of caries worldwide over recent decades. This Primer aims to provide a global overview of caries...

  5. On the Spectrum Width of Wind Waves

    Institute of Scientific and Technical Information of China (English)

    李陆平; 黄培基

    2001-01-01

    Based on the universal expression of wind wave spectra, four commonly used definitions of the spectrum width arere-examined. The results show that the non-dimensional spectrum width can measure the width of non-dimensionalspectra but it does not reflect the developing state of the spectra. The dimensional spectrum width expresses the degree ofconcentration of wave energy of the spectrum in the process of wind wave growth. Tests show that the spectrum widthpresented by Wen et al. can objectively measure the degree of concentration of wave energy of the spectrum, reflect thestate of wind wave growth, and provides a better result for practical application. The rules for definition of the spectrumwidth are discussed.

  6. Bipartite Graphs of Large Clique-Width

    Science.gov (United States)

    Korpelainen, Nicholas; Lozin, Vadim V.

    Recently, several constructions of bipartite graphs of large clique-width have been discovered in the literature. In the present paper, we propose a general framework for developing such constructions and use it to obtain new results on this topic.

  7. Dental Calculus Arrest of Dental Caries

    Science.gov (United States)

    Keyes, Paul H.; Rams, Thomas E.

    2016-01-01

    Background An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms. Materials and methods A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification. Results Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin. Conclusions These observations further document the potential protective effects of dental calculus mineralization against dental caries. PMID:27446993

  8. Unusual Morphology of the Anterior Arch of Atlas

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao Sirasanagndla

    2016-10-01

    Full Text Available Anomalies of anterior arch of atlas vertebra are seldom reported in the literature. Presence of inferior accessory ossicle is one of the reported anomalies of the anterior arch of atlas. In the present case, we report a rare case of unusual morphology of the atlas vertebra. It was observed in one of the bones macerated locally for the teaching purpose. There were two wide accessory bony laminae extending from the middle three fourth of the superior and inferior aspect of the anterior arch proper. Each bony lamina was measured 4 cm x 0.3 mm. Further, there were small foramina along the attached border of the each bony lamina. Anterior tubercle was situated at the lower edge of the anterior arch proper. Accessory bony lamina may interfere with rotatory movements of the atlas and may lead to degenerative changes of the dense. Reporting of unusual morphology of anterior arch of atlas vertebra is clinically important during diagnostic procedures of neck pain. Sometimes this extra growth of the anterior arch may be mistaken for the pathologic mass.

  9. Monitoring system of arch bridge for safety network management

    Science.gov (United States)

    Joo, Bong Chul; Yoo, Young Jun; Lee, Chin Hyung; Park, Ki Tae; Hwang, Yoon Koog

    2010-03-01

    Korea has constructed the safety management network monitoring test systems for the civil infrastructure since 2006 which includes airport structure, irrigation structure, railroad structure, road structure, and underground structure. Bridges among the road structure include the various superstructure types which are Steel box girder bridge, suspension bridge, PSC-box-girder bridge, and arch bridge. This paper shows the process of constructing the real-time monitoring system for the arch bridge and the measured result by the system. The arch type among various superstructure types has not only the structural efficiency but the visual beauty, because the arch type superstructure makes full use of the feature of curve. The main measuring points of arch bridges composited by curved members make a difference to compare with the system of girder bridges composited by straight members. This paper also shows the method to construct the monitoring system that considers the characteristic of the arch bridge. The system now includes strain gauges and thermometers, and it will include various sensor types such as CCTV, accelerometers and so on additionally. For the long term and accuracy monitoring, the latest optical sensors and equipments are applied to the system.

  10. A Comparative Study on the Relationship Between Inter Alar Width, and Inter Commissural Width on Circumferential Arc Width of Maxillary Anterior Teeth in Different Age Groups

    National Research Council Canada - National Science Library

    Kurien, Anjana; Cherian, K P; Mhatre, Shirley; Tharakan, Renji George

    2014-01-01

    This study was done to determine the relationship between interalar width and inter commissural width on circumferential arc width of maxillary anterior teeth in dentulous subjects between the age groups of 20–50 years...

  11. Occlusal Classification in Relation to Original Cleft Width in Patients With Unilateral Cleft Lip and Palate.

    Science.gov (United States)

    Huang, Andrew H; Patel, Kamlesh B; Maschhoff, Clayton W; Huebener, Donald V; Skolnick, Gary B; Naidoo, Sybill D; Woo, Albert S

    2015-09-01

    To determine a correlation between the width of the cleft palate measured at the time of lip adhesion, definitive lip repair, and palatoplasty and the subsequent occlusal classification of patients born with unilateral cleft lip and palate. Retrospective, observational study. Referral, urban, children's hospital Participants : Dental models and records of 270 patients were analyzed. None. Angle occlusion classification. The mean age at which occlusal classification was determined was 11 ± 0.3 years. Of the children studies, 84 were diagnosed with Class I or II occlusion, 67 were diagnosed with Class III occlusion, and 119 were lost to follow up or transferred care. Mean cleft widths were significantly larger in subjects with Class III occlusion for all measures at time of lip adhesion and definitive lip repair (P cleft widths were significantly greater at the alveolus (P = .025) but not at the midportion of the hard palate (P = .35) or posterior hard palate (P = .10). Cleft widths from the lip through to the posterior hard palate are generally greater in children who are diagnosed with Class III occlusion later in life. Notably, the alveolar cleft width is significantly greater at each time point for patients who went on to develop Class III occlusion. There were no significant differences in cleft widths between patients diagnosed later with Class I and Class II occlusions.

  12. 方丝弓矫治器联合前牙转矩辅弓在正畸治疗中的应用%Application of edgewise appliance combined with anterior teeth torquing auxiliary arch in orthodontic treatment

    Institute of Scientific and Technical Information of China (English)

    汪伟材

    2012-01-01

    Objective To investigate the clincial torquing effectts of edgewise appliance combined with anterior teeth torquing auxiliary arch in the treatment of anterior teeth malocclusion. Methods Forty-two patients with Angle Class Ⅱ Category 1 malocclusion receiving tooth extraction in our hospital from June 2006 to December 2008 were randomly divided into the observation group and the control group, with 21 patients in each group respectively. The control group was given the edgewise orthodontic treatment and on this basis the observation group was given the combined treatment of anterior teeth torquing auxiliary arch for fine regulating. The lateral skull positioning X-ray was shooted before and after the gap was closed, and the incisor torques of the two groups were studied comparatively. Results For the observation group, the width of upper dental arch increased significantly, the anterior teeth covering significantly reduced by (3.55+1.68) mm and the anterior teeth overbite decreased by (0.78±0.31) mm. The observation group was significantly different from the control group in the ANB, U1-SN, U1-L1, U1-NA, etc (P < 0.05). Conclusion In the treatment of anterior teeth malocclusion, the edgewise appliance combined with anterior teeth torquing auxiliary arch can effectively control the torque of upper and lower occlusal anterior teeth, reduce the inclination of upper and anterior teeth and lips and anterior teeth covering, and shorten the treatment course. In addition, it is simple and highly safe, thereby worthy of clinical application.%目的 探讨方丝弓联合前牙转矩辅弓在治疗前牙错(牙合)过程中转矩的临床效果.方法 选择我院2006年6月~2008年12月收治的安氏Ⅱ类1分类错(牙合)拔牙患者42例,将其随机分为观察组和对照组,每组各21例,对照组给予方丝弓正畸治疗,观察组在此基础上联合前牙转矩辅弓进行精细调节,关闭间隙前后拍摄X线头颅定位侧位片,对两组上

  13. [Dissertations 25 years after the date 36. Dental development and facial growth during adolescence].

    Science.gov (United States)

    Schols, J G J H

    2013-11-01

    Dental development does not end with the shedding of the deciduous dentition. Partly as a result of the continuing facial growth up to adulthood, adaptations in the position of the teeth and the occlusion occur after the second phase of eruption. The dissertation Gebissentwicklung und Gesichtswachstum in der Adoleszenz, from 1988, was concerned with research into tooth development, facial growth and their interrelationship during the first decade after the second phase of tooth eruption. Changes in the dental arches go together with changes in the occlusion. These physiological changes in the dentition can largely be attributed to the shift of the mandibular dental arch to a more ventral position, with respect to the maxillary dental arch. Facial growth and changes in the morphology of the craniofacial skeleton up to adulthood are especially a result of adaptations which take place under the floor of the nose and as a result of the enlargement of the mandible. Later research in patients up to the age of approximately 40 years, revealed that these dental and skeletal changes continued to occur.

  14. The effect of medial arch support over the plantar pressure and triceps surae muscle strength after prolonged standing

    Directory of Open Access Journals (Sweden)

    Hindun Saadah

    2015-11-01

    Full Text Available Background: The activity with prolonged standing position is one of the causes of abnormalities in the lower leg and foot. The aim of this study is to discover the effect of medial arch support over the distribution of plantar pressure when standing and walking.Methods: This was an experimental study with pre- and post-design the strength of triceps surae muscle after prolonged standing, was also evaluated in an experimental study with pre- and post-design. Variables of plantar pressure measurement are the contact area and pressure peak were measured by using the Mat-scan tool. The measurement of the triceps surae muscle strength was done with a hand-held dynamometer, before and after using the medial arch support. Measurement was performed before and after working with prolonged standing position which took place about seven hours using the medial arch support inserted in the shoes. Data was analyzed using paired T-test.Results: There was a significant difference of peak pressure between standing (p = 0.041 and walking (p = 0.001. Whereas the contact area showed a significant decrease in the width of the contact area when standing (104.12 ± 12.42 vs 99.08 ± 10.21 p = 0.023. Whereas, the triceps surae muscle strength pre- and post-standing prolonged did not indicate a significant difference.Conclusion: There was decrease in peak pressure when standing and walking and decrease in contact area when standing on plantar after used of the medial arch support after prolonged standing.

  15. Dental Training Films.

    Science.gov (United States)

    Veterans Administration Medical Center, Washington, DC.

    This dental training films catalog is organized into two sections. Section I is a category listing of the films by number and title, indexed according to generalized headings; categories are as follow: anatomy, articulator systems, complete dentures, dental assisting, dental laboratory technology, dental materials, dental office emergencies,…

  16. Elastic responses of underground circular arches considering dynamic soil-structure interaction: A theoretical analysis

    Science.gov (United States)

    Chen, Hai-Long; Jin, Feng-Nian; Fan, Hua-Lin

    2013-02-01

    Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equation of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal superposition. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.

  17. [Relationship between aortic arch shape and blood pressure response after coarctation repair].

    Science.gov (United States)

    Ou, P; Mousseaux, E; Auriacombe, L; Pédroni, E; Balleux, F; Sidi, D; Bonnet, D

    2005-01-01

    The mechanisms of secondary hypertension after repair of coarctation of the aorta are not well understood. Abnormalities of the architecture of the aortic arch and their consequences on blood pressure have not been studied. In order to study the relationship between abnormalities or aortic arch architecture and resting blood pressure ninety-four patients without re-coarctation were followed up prospectively from 1997 to 2004 (mean age 16.9 +/- 8.1 years; mean weight 57.5 +/- 18.3 Kg; interval since surgery 16.3 +/- 5.4 years). All underwent MRI angiography of the thoracic aorta which enabled the abnormalities to be classified in 3 groups: gothic arch, crenellated arch and roman arch. Twenty-four patients (25.5%) were hypertensive and 70 (74.4%) normotensive. There were 40 gothic arches (42.5%). 14 crenellated arches (15%) and 40 roman arches (42.5%). Gothic arches were more commonly observed in the hypertensive patients (18/40, [45%, 95% CI 31-62]) than the crenellated arches (4/14, [28.5%, 95% CI 7-48]) or the roman arches (2/40, [5%, 95% CI 2-12]). Only the gothic arch was independently correlated with hypertension on multivariate analysis. The authors conclude that gothic deformation of the aortic arch is an independent predictive factor of hypertension in patients operated for coarctation with an excellent result on the isthmic region. Patients with a gothic appearance of their aortic arch should be followed up closely.

  18. Constraints on widths of mixed pentaquark multiplets

    CERN Document Server

    Mohta, V

    2004-01-01

    We determine constraints on the partial widths of mixed pentaquark multiplets in the framework of heavy baryon chiral perturbation theory (HB$\\chi$PT). The partial widths satisfy a GMO-type relation at leading order in HB$\\chi$PT, for arbitrary mixing. The widths of N(1440), N(1710), and $\\Theta(1540)$ are not consistent with ideal mixing, $\\theta_{N} = 35.3^{\\circ}$, but are consistent with $\\theta_{N} \\lesssim 25^{\\circ}$. Furthermore, there are parameter values in HB$\\chi$PT that produce such a mixing angle while allowing the identification of the mass spectrum above. As an alternative to non-ideal mixing, we also suggest reasons for giving up on N(1440) as a pure pentaquark state.

  19. The Variable Line Width of Achernar

    CERN Document Server

    Rivinius, Th; Baade, D; Carciofi, A C; Leister, N; Štefl, S

    2016-01-01

    Spectroscopic observations of Achernar over the past decades, have shown the photospheric line width, as measured by the rotational parameter $v \\sin i$, to vary in correlation with the emission activity. Here we present new observations, covering the most recent activity phase, and further archival data collected from the archives. The $v \\sin i$ variation is confirmed. On the basis of the available data it cannot be decided with certainty whether the increased line width precedes the emission activity, i.e. is a signature of the ejection mechanism, or postdates is, which would make it a signature of re-accretion of some of the disk-material. However, the observed evidence leans towards the re-accretion hypothesis. Two further stars showing the effect of variable line width in correlation with emission activity, namely 66 Oph and $\\pi$ Aqr, are presented as well.

  20. Graph Operations on Clique-Width Bounded Graphs

    OpenAIRE

    Gurski, Frank

    2007-01-01

    Clique-width is a well-known graph parameter. Many NP-hard graph problems admit polynomial-time solutions when restricted to graphs of bounded clique-width. The same holds for NLC-width. In this paper we study the behavior of clique-width and NLC-width under various graph operations and graph transformations. We give upper and lower bounds for the clique-width and NLC-width of the modified graphs in terms of the clique-width and NLC-width of the involved graphs.

  1. Line width of Josephson flux flow oscillators

    DEFF Research Database (Denmark)

    Koshelets, V.P.; Dmitriev, P.N.; Sobolev, A.S.;

    2002-01-01

    to be proven before one initiates real FFO applications. To achieve this goal a comprehensive set of line width measurements of the FFO operating in different regimes has been performed. FFOs with tapered shape have been successfully implemented in order to avoid the superfine resonant structure with voltage...... spacing of about 20 nV and extremely low differential resistance, recently observed in the IVC of the standard rectangular geometry. The obtained results have been compared with existing theories and FFO models in order to understand and possibly eliminate excess noise in the FFO. The intrinsic line width...

  2. Characterization of the cephalic arch and location of stenosis

    Science.gov (United States)

    Bennett, Shelby; Hammes, Mary S.; Blicharski, Tom; Watson, Sydeaka; Funaki, Brian

    2015-01-01

    Purpose The purpose of this study is to accurately characterize the cephalic arch segments into four domains and to enable more specific evaluation of cephalic arch stenosis (CAS) and determine the frequency of stenosis in each domain. Methods After Institutional Review Board (IRB) approval, a retrospective chart review was done to define a population of patients receiving hemodialysis who developed CAS as apparent on clinically indicated radiologic imaging. A standardized approach was devised to categorize four domains of the cephalic arch. Domain I was defined as the peripheral portion of the arch and Domain IV was the distal portion of the cephalic vein near termination with the axillary vein. The magnitude of stenosis as measured by percentage was determined and compared in the four domains. Results The most frequent location for stenosis was found in domain IV when compared with domains II or I (p<0.01). The magnitude of stenosis differed across all domains (p<0.001) with the least common place for CAS in domain I. Treatment of CAS included angioplasty in all, thrombectomy in eight, and stent placement in five. Conclusions CAS occurs most commonly in the terminal portion of the arch. Four standardized domains have been defined; future work will validate these findings and determine the best intervention for each domain. PMID:25198819

  3. Three-dimensional stiffness of the carpal arch.

    Science.gov (United States)

    Gabra, Joseph N; Li, Zong-Ming

    2016-01-01

    The carpal arch of the wrist is formed by irregularly shaped carpal bones interconnected by numerous ligaments, resulting in complex structural mechanics. The purpose of this study was to determine the three-dimensional stiffness characteristics of the carpal arch using displacement perturbations. It was hypothesized that the carpal arch would exhibit an anisotropic stiffness behavior with principal directions that are oblique to the conventional anatomical axes. Eight (n=8) cadavers were used in this study. For each specimen, the hamate was fixed to a custom stationary apparatus. An instrumented robot arm applied three-dimensional displacement perturbations to the ridge of trapezium and corresponding reaction forces were collected. The displacement-force data were used to determine a three-dimensional stiffness matrix using least squares fitting. Eigendecomposition of the stiffness matrix was used to identify the magnitudes and directions of the principal stiffness components. The carpal arch structure exhibited anisotropic stiffness behaviors with a maximum principal stiffness of 16.4±4.6N/mm that was significantly larger than the other principal components of 3.1±0.9 and 2.6±0.5N/mm (pcarpal tunnel which is accounted for by the stiff transverse ligaments that tightly bind distal carpal arch. The minimal principal stiffness is attributed to the less constraining articulation between the trapezium and scaphoid. This study provides advanced characterization of the wrist׳s three-dimensional structural stiffness for improved insight into wrist biomechanics, stability, and function.

  4. An arch to deal with Chernobyl; Une arche pour liquider Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2009-10-15

    The preliminary works for the construction of a giant arch to cover the old sarcophagus of Chernobyl's ex-reactor No.4 are in progress. This building will have two functions: a safety barrier around the sarcophagus and a protection against bad weather in order to prepare the future dismantling of the inside using robots. The main contractor of the project is Novarka, a Bouygues-Vinci consortium who won the contract on September 18, 2007 in front of the US CH2M Hill. The end of the works is planned to March 31, 2012. 430 million euros have been invested for the improvement of Chernobyl's site safety. (J.S.)

  5. Dental Items of Interest: The Case of Delphic Sibyl by Michelangelo: Solitary Median Maxillary Central Incisor or Mesiodens.

    Science.gov (United States)

    Perciaccante, Antonio; Coralli, Alessia

    2015-01-01

    A case of an anomaly in the maxillary dental arch on "Delphic Sibyl," a fresco by Michelangelo is reported. An accurate analysis of this fresco shows a single incisor tooth is present precisely in the midline. We hypothesize that it may be a case of solitary median maxillary central incisor (SMMCI) and discuss the differential diagnosis with another similar anomaly--the mesiodens.

  6. Diabetes: Dental Tips

    Science.gov (United States)

    ... Diabetes and Oral Health > Diabetes: Dental Tips Diabetes: Dental Tips Main Content Diabetes can cause serious problems ... FOIA Web Policies Privacy Policy National Institute of Dental and Craniofacial Research National Institutes of Health Bethesda, ...

  7. Dental Exam for Children

    Science.gov (United States)

    ... they're most treatable. When to have a dental exam Various factors might determine how frequently your ... wisdom teeth (third molars) at the appropriate age. Dental X-ray A dental X-ray (radiograph) allows ...

  8. Dental Care in Pregnancy

    Science.gov (United States)

    Share with Women Dental Care in Pregnancy Why is dental care in pregnancy important? During pregnancy, you are more likely to have problems ... There are 2 major reasons women can have dental problems during pregnancy: Pregnancy gingivitis— During pregnancy, changes ...

  9. American Dental Education Association

    Science.gov (United States)

    ... Interest Groups ADEA Governance Documents and Publications ADEA Dental Faculty Code of Conduct ADEA Bylaws ADEAGies Foundation ... Benefits for Faculty ADEA Member Benefits for Allied Dental Programs ADEA Member Benefits for Dental Schools ADEA ...

  10. Dental Issues & Down Syndrome

    Science.gov (United States)

    ... Associated Conditions » Dental Issues & Down Syndrome Dental Issues & Down Syndrome Dental care is important for everybody, but people ... is Different About the Teeth of People With Down Syndrome? Delayed Eruption The teeth of people with Down ...

  11. Classification of the height and flexibility of the medial longitudinal arch of the foot

    DEFF Research Database (Denmark)

    Nilsson, Mettte Kjaergaard; Friis, Rikke; Michaelsen, Maria Skjoldahl

    2012-01-01

    BACKGROUND: The risk of developing injuries during standing work may vary between persons with different foot types. High arched and low arched feet, as well as rigid and flexible feet, are considered to have different injury profiles, while those with normal arches may sustain fewer injuries......-off values presented in this study can be used to categorize people performing standing work into groups of different foot arch types. The results of this study are important for investigating a possible link between arch height and arch movement and the development of injuries....

  12. Dental Holography

    Science.gov (United States)

    Dirtoft, Ingegerd

    1983-12-01

    Ten years have passed since the first articles appeared in this new field. The qualities of the laser light together with the need of contactless 3-D measurements for different dental purposes seemed to be extremely promising, but still just a few scientists have used the method and mostly for laboratory studies. For some reason there has been a preponderance for orthodontic measurements. This seems to be a bit peculiar from holographic view compared with measurements for engineering purposes, which usually are made on metals. So naturally holography can become a clinical tool for measurements in the field of fixed bridges, removable partial dentures and implants. One of the problems is that the need for holography in dental research must be fulfilled in collaboration with physicists. Only a two-way communication during an entire experiment can balance both technical and odontological demands and thus give practical and clinical important results. The need for an easy way of handling the evaluation to get all required information is another problem and of course the holographic equipment must be converted to a box easy to handle for everyone. At last the position of dental holography today is going to be carefully examined together with an attempt to look into the hopefully exciting and not to utopic future for this research field.

  13. Dental caries.

    Science.gov (United States)

    Pitts, Nigel B; Zero, Domenick T; Marsh, Phil D; Ekstrand, Kim; Weintraub, Jane A; Ramos-Gomez, Francisco; Tagami, Junji; Twetman, Svante; Tsakos, Georgios; Ismail, Amid

    2017-05-25

    Dental caries is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues. Caries can occur throughout life, both in primary and permanent dentitions, and can damage the tooth crown and, in later life, exposed root surfaces. The balance between pathological and protective factors influences the initiation and progression of caries. This interplay between factors underpins the classification of individuals and groups into caries risk categories, allowing an increasingly tailored approach to care. Dental caries is an unevenly distributed, preventable disease with considerable economic and quality-of-life burdens. The daily use of fluoride toothpaste is seen as the main reason for the overall decline of caries worldwide over recent decades. This Primer aims to provide a global overview of caries, acknowledging the historical era dominated by restoration of tooth decay by surgical means, but focuses on current, progressive and more holistic long-term, patient-centred, tooth-preserving preventive care.

  14. Danish dental education:

    DEFF Research Database (Denmark)

    Moore, Rod

    1985-01-01

    The effects of Danish cultural traditions on dental education in Denmark are described, as well as the system's current structure and developing issues. Some Danish ideas for future exports of dental education programs and dental personnel are also discussed.......The effects of Danish cultural traditions on dental education in Denmark are described, as well as the system's current structure and developing issues. Some Danish ideas for future exports of dental education programs and dental personnel are also discussed....

  15. Danish dental education:

    DEFF Research Database (Denmark)

    Moore, Rod

    1985-01-01

    The effects of Danish cultural traditions on dental education in Denmark are described, as well as the system's current structure and developing issues. Some Danish ideas for future exports of dental education programs and dental personnel are also discussed.......The effects of Danish cultural traditions on dental education in Denmark are described, as well as the system's current structure and developing issues. Some Danish ideas for future exports of dental education programs and dental personnel are also discussed....

  16. Bounding the Higgs boson width through interferometry.

    Science.gov (United States)

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.

  17. Correlation Widths in Quantum--Chaotic Scattering

    OpenAIRE

    Dietz, B.; Richter, A; WeidenmÜller, H.

    2011-01-01

    An important parameter to characterize the scattering matrix S for quantum-chaotic scattering is the width Gamma_{corr} of the S-matrix autocorrelation function. We show that the "Weisskopf estimate" d/(2pi) sum_c T_c (where d is the mean resonance spacing, T_c with 0

  18. Wireline equalization using pulse-width modulation

    NARCIS (Netherlands)

    Schrader, J.H.R.; Klumperink, Eric A.M.; Visschers, J.L.; Nauta, Bram

    2006-01-01

    Abstract-High-speed data links over copper cables can be effectively equalized using pulse-width modulation (PWM) pre-emphasis. This provides an alternative to the usual 2-tap FIR filters. The use of PWM pre-emphasis allows a channel loss at the Nyquist frequency of ~30dB, compared to ~20dB for a

  19. In-Plane MEMS Shallow Arch Beam for Mechanical Memory

    Directory of Open Access Journals (Sweden)

    Md Abdullah Al Hafiz

    2016-10-01

    Full Text Available We demonstrate a memory device based on the nonlinear dynamics of an in-plane microelectromechanical systems (MEMS clamped–clamped beam resonator, which is deliberately fabricated as a shallow arch. The arch beam is made of silicon, and is electrostatically actuated. The concept relies on the inherent quadratic nonlinearity originating from the arch curvature, which results in a softening behavior that creates hysteresis and co-existing states of motion. Since it is independent of the electrostatic force, this nonlinearity gives more flexibility in the operating conditions and allows for lower actuation voltages. Experimental results are generated through electrical characterization setup. Results are shown demonstrating the switching between the two vibrational states with the change of the direct current (DC bias voltage, thereby proving the memory concept.

  20. Game model of safety monitoring for arch dam deformation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Arch dam deformation is comprehensively affected by water pressure,temperature,dam’s structural behavior and material properties as well as other factors.Among them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam’s structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance factors.Therefore,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of dam.On the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

  1. LANGER’S AXILLARY ARCH AND ITS CLINICAL IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Jyothi K C

    2014-09-01

    Full Text Available Introduction: The axillary arch muscle of Langer is the most common anatomical variant of axillary musculature which is of clinical and surgical importance. It may lead to neurovascular compression syndrome in the cervicoaxillary region and can be misinterpreted while examining axilla and also impairs movements of shoulder joint. Observation: During routine dissection of axilla for undergraduate teaching, an unusual muscular slip in the left axilla was observed .The muscular slip was extending from lattisimus dorsi muscle to undersurface of pectoralis major muscle, arching over axillary vessels and cords of brachial plexus. Conclusion: The axillary arch may cause obstruction to axillary vessels and nerves and may be involved in thoracic outlet syndrome and shoulder instability. The knowledge of this muscular variant could help to minimize intraoperative complications related to surgeries in or nearby axilla such as mastectomy, breast reconstruction and axillary lymphadenectomy or lymph node biopsy.

  2. In-Plane MEMS Shallow Arch Beam for Mechanical Memory

    KAUST Repository

    Hafiz, Md Abdullah Al

    2016-10-18

    We demonstrate a memory device based on the nonlinear dynamics of an in-plane microelectromechanical systems (MEMS) clamped–clamped beam resonator, which is deliberately fabricated as a shallow arch. The arch beam is made of silicon, and is electrostatically actuated. The concept relies on the inherent quadratic nonlinearity originating from the arch curvature, which results in a softening behavior that creates hysteresis and co-existing states of motion. Since it is independent of the electrostatic force, this nonlinearity gives more flexibility in the operating conditions and allows for lower actuation voltages. Experimental results are generated through electrical characterization setup. Results are shown demonstrating the switching between the two vibrational states with the change of the direct current (DC) bias voltage, thereby proving the memory concept.

  3. A discrepância de tamanho dentário, de Bolton, na oclusão normal e nos diferentes tipos de más oclusões, bem como sua relação com a forma de arco e o posicionamento dentário Bolton tooth size discrepancy in normal occlusion and in different types of malocclusions and its relationship to arch form and tooth positioning

    Directory of Open Access Journals (Sweden)

    Luiz Sérgio Carreiro

    2005-06-01

    : Group 1 (consisted of 41 pairs of models with Normal Occlusion, 20 males and 21 females; Group 2 (consisted of 44 pairs of models with Class I malocclusion, 22 males and 22 females; Group 3 (consisted of 54 pairs of models with Class II, div. 1, malocclusion, 28 males and 26 females and Group 4 (consisted of 46 pairs of models with Class III malocclusion, 23 males and 23 females. No sexual dimorphism was observed between tooth size discrepancies and different types of dental occlusion; the proportions stated by Bolton were not applied to the Normal Occlusion group; in Normal Occlusion, Class I, Class II and Class III there was an overall ratio excess in the lower arch; in Class I there was an equal anterior excess distribution in upper and lower arches; in Normal Occlusion, Class II and Class III there was a prevalent incidence of anterior ratio excess in lower arch; upper arch excess did not contribute to malocclusion occurrence and overall and anterior discrepancies did not interfere with arch width and length, as well as with anterior tooth positioning.

  4. American Dental Hygienists' Association

    Science.gov (United States)

    ... Resources Student Resources National Exam Student Advisor Resources Dental Hygiene Programs Scholarships and Grants Research Center Transforming Dental Hygiene Education Advocacy Practice Issues Direct Access Scope ...

  5. Management of hypoplastic aortic arch associated with neonatal coarctation.

    Science.gov (United States)

    Caspi, J; Ilbawi, M N; Muster, A; Roberson, D; Arcilla, R

    1994-12-01

    Controversy still exists as to whether hypoplastic aortic arch frequently associated with neonatal coarctation, should be enlarged at the time of coarctation repair. To determine the indications for and the outcome of repair of hypoplastic aortic arch, pre- and postoperative angiograms/echocardigraphy of 77 cases with isolated (n = 25, Group 1) or complex (n = 52, Group 2) neonatal coarctation operated upon between 1/80 and 12/89 were reviewed. Age was 5-14 days (mean 8 +/- 1.6). Aortic arch/ascending aorta diameter ratio (AR/AA) as a measure of the degree of aortic arch hypoplasia was 0.39-0.64 (0.52 +/- 0.04) in isolated and 0.15-0.47 (0.34 +/- 0.06) in complex coarctation (p < 0.05). Left subclavian flap aortoplasty was used in 72 patients; alone in 25, in combination with pulmonary artery banding in 43 patients, and simultaneously with intracardiac repair in 4 patients. Extensive reconstruction of aortic arch and coarctation with synthetic patch was performed in the remaining 5 patients (AR/AO = 0.16 +/- 0.03) using cardiopulmonary by-pass at the time of intracardiac repair. Operative mortality was 2/76 (2.5%). Follow-up is 6.6 +/- 1.4 years. Recoarctation occurred in 3 patients (4%). AR/AA increased to 0.86 +/- 0.1 in isolated (p < 0.05 vs preoperative) and to 0.7 +/- 0.1 in complex coarctation (p < 0.05 vs preoperative). In the majority of cases, hypoplastic aortic arch associated with coarctation grows satisfactorily following simple repair of coarctation with no significant residual narrowing.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Optical silencing of C. elegans cells with arch proton pump.

    Directory of Open Access Journals (Sweden)

    Ayako Okazaki

    Full Text Available BACKGROUND: Optogenetic techniques using light-driven ion channels or ion pumps for controlling excitable cells have greatly facilitated the investigation of nervous systems in vivo. A model organism, C. elegans, with its small transparent body and well-characterized neural circuits, is especially suitable for optogenetic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We describe the application of archaerhodopsin-3 (Arch, a recently reported optical neuronal silencer, to C. elegans. Arch::GFP expressed either in all neurons or body wall muscles of the entire body by means of transgenes were localized, at least partially, to the cell membrane without adverse effects, and caused locomotory paralysis of worms when illuminated by green light (550 nm. Pan-neuronal expression of Arch endowed worms with quick and sustained responsiveness to such light. Worms reliably responded to repeated periods of illumination and non-illumination, and remained paralyzed under continuous illumination for 30 seconds. Worms expressing Arch in different subsets of motor neurons exhibited distinct defects in the locomotory behavior under green light: selective silencing of A-type motor neurons affected backward movement while silencing of B-type motor neurons affected forward movement more severely. Our experiments using a heat-shock-mediated induction system also indicate that Arch becomes fully functional only 12 hours after induction and remains functional for more than 24 hour. CONCLUSIONS/SGNIFICANCE: Arch can be used for silencing neurons and muscles, and may be a useful alternative to currently widely used halorhodopsin (NpHR in optogenetic studies of C. elegans.

  7. Dental Fear among Medical and Dental Undergraduates

    Directory of Open Access Journals (Sweden)

    H. Hakim

    2014-01-01

    Full Text Available Objective. To assess the prevalence and level of dental fear among health related undergraduates and to identify factors causing such fear using Kleinknecht’s Dental Fear Survey (DFS questionnaire. Methods. Kleinknecht’s DFS questionnaire was used to assess dental fear and anxiety among the entire enrollment of the medical and dental undergraduates’ of the University of Malaya. Results. Overall response rate was 82.2%. Dental students reported higher prevalence of dental fear (96.0% versus 90.4%. However, most of the fear encountered among dental students was in the low fear category as compared to their medical counterpart (69.2 versus 51.2%. Significantly more medical students cancelled dental appointment due to fear compared to dental students (P=0.004. “Heart beats faster” and “muscle being tensed” were the top two physiological responses experienced by the respondents. “Drill” and “anesthetic needle” were the most fear provoking objects among respondents of both faculties. Conclusion. Dental fear and anxiety are a common problem encountered among medical and dental undergraduates who represent future health care professionals. Also, high level of dental fear and anxiety leads to the avoidance of the dental services.

  8. Dental students--dental advocates.

    Science.gov (United States)

    Bensch, Brittany

    2010-01-01

    Student advocacy and involvement in the political process is built into the structure of the American Student Dental Association (ASDA), especially in its Legislative Grassroots Network and an internal communication network among students to ensure political awareness. Students are concerned with such issues as a universally accepted, non-patient-based licensure process, mid-level providers, loan availability and tax deductibility, financial support for schools, and service early in one's professional career (giving forward rather than giving back). Through collaboration with the American Dental Education Association and with many state associations, students participate in lobbying, awareness campaigns, and behind the scenes as legislative aids. Although students share the same love for the profession that animates established practitioners, they are perceived by legislators as being different. Students are involved in the legislative process because it represents their future.

  9. Planning and Analysis of an Arched Indoor Stadium

    Directory of Open Access Journals (Sweden)

    Alice T V

    2014-04-01

    Full Text Available This paper deals with planning and designing of a multilevel indoor stadium with hanging table tennis court and Olympic standard swimming pool. In order to support the large span the stadium is designed as an arched structure. The materials for the construction are chosen so as to have a minimum carbon di-oxide foot print. Static and earthquake analysis were done by using STAAD.Pro V8i. The paper also does a comparison between arched structure and plane frame structure.

  10. Aneurysm of the superficial palmar arch: a case report.

    Science.gov (United States)

    Estrella, Emmanuel P; Lee, Ellen Y

    2008-01-01

    Aneurysms of the hand are uncommon lesions. The most common location is the ulnar artery. We present a case of a young female who consulted us for a hand mass with a history of trauma to the hand. Pre-operative arteriogram showed a superficial palmar arch aneurysm. The mass was excised and the arch was reconstructed using a reversed Y-shaped vein graft. Fourteen months after surgery, there was no recurrence of the aneurysm and the patient only reported occasional cold intolerance.

  11. AORTIC ARCH-STUDY OF DIFFERENT BRANCHING PATTERNS

    Directory of Open Access Journals (Sweden)

    Nijagunappa

    2016-01-01

    Full Text Available INTRODUCTION The arch of aorta is the continuation of ascending aorta which arises from the left ventricle inside the fibrous pericardium. The arch is convex upwards, behind and somewhat towards the left sided if it has to be described in 3 dimensionally. The study was conducted in the Department of Anatomy at KMCT, Kozhikode from 2014-2015. Fifty formalin fixed heart specimens of both sexes with age ranging between 50 to 70 years were used. Mainly three types were noted.

  12. Full-arch milled titanium implant bridge: technical report.

    Science.gov (United States)

    Peché, Wendy-Ann; Van Vuuren, Ludwig Jansen; Park, Chae

    2011-09-01

    The manufacturing of full-arch fixed implant-supported bridges with the use of the traditional lost wax technique remains a technical challenge. Distortion of the alloy during casting and subsequent heating cycles during porcelain build-up causes numerous problems. Fracturing of porcelain on large restorations is difficult and costly to restore. The fitting problems can be eliminated by utilising CAD/CAM technology in the manufacturing of long-span or full-arch titanium bridges. Repair of damaged porcelain can be simplified with the use of discrete, individually-removable crowns on the bridge.

  13. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

    Full Text Available A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force generator.

  14. Numerical study of free-fall arches in hopper flows

    Science.gov (United States)

    Lin, P.; Zhang, S.; Qi, J.; Xing, Y. M.; Yang, L.

    2015-01-01

    Beverloo's law describes the flow rate of grains discharging from hoppers, where the assumption of a free-fall arch (FFA) is very useful in understanding the physical picture of this process. The FFA has been observed in previous experiments but a clear systematic study of the FFA is still necessary. In this paper, dense granular flow in hoppers was studied by numerical simulations, in attempts to explore the free-fall region and its boundary. Generally, the numerical simulation results support the free-fall arch assumption, although the statistical description of the FFA is not exactly equivalent to its strict definition.

  15. Can they really be opposite? A new look at four critical aspects of anterior dental morphology.

    Science.gov (United States)

    Greenberg, Joseph R

    2008-09-01

    Human dental anatomy has not changed significantly in hundreds of years. Dental students and students of dental laboratory technology learn human dental anatomy as fundamental to their didactic work. Yet, so often we see dental restorations that do not follow the accepted basic design criteria of natural teeth. A possible conclusion is that the information was correctly presented as a basic science, but not completely carried over into clinical practice. When visually essential aspects of dental anatomy and composition are not accurately incorporated into esthetic restorations, patients are not completely served, and practitioners may be frustrated as well. This article reviews four essential aspects of anterior dental morphology--anterior tooth width/length proportions, bilateral symmetry, incisal edges, and incisal embrasures--that often are not accurately incorporated into dental restorations, and positions them in an easy to remember format: opposites.

  16. Self-tapping Intermaxillary Fixation Screw: An Alternative to Arch Bar.

    Science.gov (United States)

    Barodiya, Animesh; Thukral, Rishi; Agrawal, S M; Chouhan, Anil S; Singh, Sidharth; Loksh, Yogesh

    2017-02-01

    The use of intermaxillary fixation (IMF) in the treatment of faciomaxillary fractures is the key factor for reduction and immobilization. Various techniques of IMF have been described in the past and recently IMF screws have been introduced. This technique has various advantages, including ease of use, less time consumption, less trauma to the surrounding soft tissues, and relatively reduced risk of needle stick injury. This study evaluates the efficacy of IMF screws over arch bar IMF before definitive fixation of facial fractures. This study is a randomized clinical study. Study population consists of 20 patients with mandibu-lar fractures requiring IMF with open reduction and reported to Department of Oral Surgery, Modern Dental College and Research Centre, Indore, Madhya Pradesh, India between September 2012 and April 2015. Two groups were formed with 10 patients in each group. In the first group, IMF was achieved using the Erich's arch bar and wires. In the second group, IMF was achieved using self-tapping IMF screw. The patients were assessed for various parameters, such as the time required in minutes for the IMF stability of fixation, postoperative occlusion, postoperative pain, periodontal health, oral hygiene, and incidence of needle stick injury. All the cases had stable IMF in both groups. At the end of 14th day, overall oral hygiene was poor in group I and good in group II, significant statistically (p = 0.031). Iatrogenic injury to tooth was absent in group I and present in 1 case in group II, not significant statistically (p = 0.305). Average time taken for the IMF in group I was 74.9 minutes, with the range of 58 to 88 minutes, and in group II was 16.1 minutes, with the range of 11 to 22 minutes, which is highly significant statistically (p = 0.001). Needle stick injuries were taken as positive if glove perforation was present and these were reported in four cases in group I, whereas in group II, no case had incidence of needle stick injuries, which

  17. Influence of space of double row piles on soil arching effect

    Directory of Open Access Journals (Sweden)

    Zhao bo

    2015-02-01

    Full Text Available FLAC3d software, based on continuous theory, is used to analysis influence of space of double row piles on soil arching effect. The result shows that different from single row pile, double row piles will produce soil arching effect at front pile and rear pile severally, this phenomenon is called multiple soil arching effect; the residual load of front of front row pile will increase,the soil arch zone and the soil arching effect will decrease with the continuous increase of double row pile spacing.At the same time the soil arching effect of rear pile decreases, while the soil arching effect of front pile increases and finally the soil arching effect between front pile and rear pile will be equal.

  18. The surgical importance of an axillary arch in sentinel node biopsy.

    LENUS (Irish Health Repository)

    Ridgway, P F

    2011-03-01

    When Carl Langer described the aberrant axillary arch in 1846 its relevance in sentinel node biopsy (SNB) surgery could not have been contemplated. The authors define an incidence and elucidate relevance of the arch in SNB of the axilla.

  19. Thoracoscopic Resection of a Rare Case of Hemangioma of the Azygos Venous Arch

    Directory of Open Access Journals (Sweden)

    Ma Husai

    2017-01-01

    Full Text Available Hemangioma of the azygos venous arch is an exceedingly rare incident. This is a case of a thoracoscopic complete resection of a hemangioma of the azygos venous arch in a 37-year-old woman.

  20. Posterior partially edentulous jaws, planning a rehabilitation with dental implants.

    Science.gov (United States)

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-16

    To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.

  1. Immediate loading of 2 (all-on-2) versus 4 (all-on-4) implants placed with a flapless technique supporting mandibular cross-arch fixed prostheses: preliminary results from a pilot randomised controlled trial.

    Science.gov (United States)

    Cannizzaro, Gioacchino; Felice, Pietro; Soardi, Elisa; Ferri, Vittorio; Leone, Michele; Esposito, Marco

    2011-01-01

    To evaluate the clinical outcome of 2 implants versus 4 implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses. Sixty patients from two different centres were randomised: 30 to the allon- 2 group and 30 to the all-on-4 group. To be immediately loaded, implants had to be inserted with a minimum torque of 40 Ncm. Outcome measures were prosthesis and implant failures, and biological and biomechanical complications. Flaps were raised in 18 patients. Two implants in 2 patients did not reach the planned insertion torque and were immediately replaced by larger diameter ones. Four months after loading, no drop-out or implant failure occurred. One biomechanical complication occurred in the all-on-2 group versus 4 in the all-on-4 group. There were no statistically significant differences between groups for complications. There were no differences between centres. These very preliminary results, just 4 months after loading, suggest that immediately loaded mandibular cross-arch fixed dental prostheses can be supported by only 2 dental implants. Longer follow-ups (around 10 years) are needed to understand whether cross-arch mandibular prostheses can be successfully supported by only 2 dental implants.

  2. Dental erozyon

    NARCIS (Netherlands)

    Özen, B.; Yönel, N.; Çetiner, S.

    2015-01-01

    Dental erozyon, plak içermeyen diş yüzeyleri üzerinde içsel ve dışsal asitlerin veya şelatların etkileriyle oluşan kimyasal bir aşınmadır. İçsel ve/veya dışsal kaynaklar nedensel faktörler olarak tanımlanırken tükürük ve pelikıl gibi biyolojik faktörler, yeme ve içme alışkanlıkları ve ağız hijyeni

  3. K- nuclear states: Binding energies and widths

    Science.gov (United States)

    Hrtánková, J.; Mareš, J.

    2017-07-01

    K- optical potentials relevant to calculations of K- nuclear quasibound states were developed within several chiral meson-baryon coupled-channels interaction models. The applied models yield quite different K- binding energies and widths. Then the K- multinucleon interactions were incorporated by a phenomenological optical potential fitted recently to kaonic atom data. Though the applied K- interaction models differ significantly in the K-N subthreshold region, our self-consistent calculations of kaonic nuclei across the periodic table lead to conclusions valid quite generally. Due to K- multinucleon absorption in the nuclear medium, the calculated widths of K- nuclear states are sizable, ΓK-≥90 MeV, and exceed substantially their binding energies in all considered nuclei.

  4. Radiative widths of neutral kaon excitations

    Indian Academy of Sciences (India)

    Sunil V Somalwar; KTeV Collaboration

    2004-03-01

    We observe 147 events of the axial vector pair $K_{1} (1270) - K_{1} (1400)$ produced in the Coulomb field of a Pb target and measure the radiative widths $ (K_{1} (1400) → K^{0} + ) = 280.8 ± 23.2$ (stat.) $± (40.4)$ (syst.) keV and $ (K_{1} (1270) → K^{0} + ) = 73.2 ± 6.1$ (stat.) $± 28.3$ (syst.) keV. These first measurements are lower than the quark-model predictions. We also place upper limits on the radiative widths for $K^{*} (1410)$ and $K_{2}^{*} (1430)$ and find that the letter is very small in accord with $SU(3)$ invariance in the naive quark model.

  5. Exotic Meson Decay Widths using Lattice QCD

    CERN Document Server

    Cook, M S

    2006-01-01

    A decay width calculation for a hybrid exotic meson h, with JPC=1-+, is presented for the channel h->pi+a1. This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and pi+a1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative pi+a1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes.

  6. Reliability and Correlation of Static and Dynamic Foot Arch Measurement in a Healthy Pediatric Population.

    Science.gov (United States)

    Scholz, Timo; Zech, Astrid; Wegscheider, Karl; Lezius, Susanne; Braumann, Klaus-Michael; Sehner, Susanne; Hollander, Karsten

    2017-07-14

    Measurement of the medial longitudinal foot arch in children is a controversial topic, as there are many different methods without a definite standard procedure. The purpose of this study was to 1) investigate intraday and interrater reliability regarding dynamic arch index and static arch height, 2) explore the correlation between both arch indices, and 3) examine the variation of the medial longitudinal arch at two different times of the day. Eighty-six children (mean ± SD age, 8.9 ± 1.9 years) participated in the study. Dynamic footprint data were captured with a pedobarographic platform. For static arch measurements, a specially constructed caliper was used to assess heel-to-toe length and dorsum height. A mixed model was established to determine reliability and variation. Reliability was found to be excellent for the static arch height index in sitting (intraday, 0.90; interrater, 0.80) and standing positions (0.88 and 0.85) and for the dynamic arch index (both 1.00). There was poor correlation between static and dynamic assessment of the medial longitudinal arch (standing dynamic arch index, r = -0.138; sitting dynamic arch index, r = -0.070). Static measurements were found to be significantly influenced by the time of day (P static arch height index is influenced by gender (P = .004), whereas dynamic arch index is influenced by side (P = .011) and body mass index (P static foot measurements are reliable for medial longitudinal foot arch assessment in children. The variation of static arch measurements during the day has to be kept in mind. For clinical purposes, static and dynamic arch data should be interpreted separately.

  7. W mass and width at the LHC.

    CERN Document Server

    Malberti, Martina

    2006-01-01

    The precision measurement of the W boson properties, such as its mass and width, constitutes an important consistency check of the Standard Model. This paper, in particular, describes methods to measure the W mass with improved precision at the Large Hadron Collider, exploiting the large number of Z bosons produced. The precision on the W boson mass achievable with an integrated luminosisty of 10~fb^-1 is discussed.

  8. Dental Care for Medicaid and CHIP Enrollees

    Science.gov (United States)

    ... Close Home > Medicaid > Benefits > Dental Care Dental Care Dental Care Dental Care for Medicaid and CHIP Enrollees Dental health ... services and opportunities and challenges to obtaining care. Dental Benefits for Children in Medicaid Medicaid covers dental ...

  9. Are there any good digraph width measures?

    CERN Document Server

    Ganian, Robert; Kneis, Joachim; Meister, Daniel; Obdržálek, Jan; Rossmanith, Peter; Sikdar, Somnath

    2010-01-01

    Several different measures for digraph width have appeared in the last few years. However, none of them shares all the "nice" properties of treewidth: First, being \\emph{algorithmically useful} i.e. admitting polynomial-time algorithms for all $\\MS1$-definable problems on digraphs of bounded width. And, second, having nice \\emph{structural properties} i.e. being monotone under taking subdigraphs and some form of arc contractions. As for the former, (undirected) $\\MS1$ seems to be the least common denominator of all reasonably expressive logical languages on digraphs that can speak about the edge/arc relation on the vertex set.The latter property is a necessary condition for a width measure to be characterizable by some version of the cops-and-robber game characterizing the ordinary treewidth. Our main result is that \\emph{any reasonable} algorithmically useful and structurally nice digraph measure cannot be substantially different from the treewidth of the underlying undirected graph. Moreover, we introduce \\...

  10. How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

    Science.gov (United States)

    Habertheuer, Andreas; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther; Vallabhajosyula, Prashanth

    2015-01-01

    Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA) or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data. PMID:26713319

  11. How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

    Directory of Open Access Journals (Sweden)

    Andreas Habertheuer

    2015-01-01

    Full Text Available Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP and retrograde cerebral perfusion (RCP. Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data.

  12. Visualization of soil arching in flexible piled embankments

    Indian Academy of Sciences (India)

    Tuğba Eskışar

    2015-10-01

    Piled embankments rely on soil arching, but, when geogrid reinforcements are used, membrane action within the reinforcement contributes to load distribution. The arching of soil in unreinforced and reinforced piled embankments is evaluated in this study. A small-scale test apparatus is used to model the settlement up to 5 mm in an embankment with four pile elements. Visual inspection of the soil settlement and soil-reinforcement interaction is important to explain the mechanism of arching. In this study, X-ray Computed Tomography (CT) method was used as a non-destructive technique. The arching of soil between the piles was observed in the case of rigid piles and in the case of flexible piles with grid type of reinforcement. The load carrying capacity increased up to 33% in the case of geogrid reinforcement, and the differential settlement decreased around 35%, proving the efficiency of piled embankments with geogrid reinforcements. It is also shown that, using X-ray CT method and visualization techniques provides a better understanding of soil behavior in a reinforced embankment with the flexible pile foundation system.

  13. Do We Often Find ARCH Because Of Neglected Outliers?

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); D.J.C. van Dijk (Dick)

    1997-01-01

    textabstractIn this paper we test for (Generalized) AutoRegressive Conditional Heteroskedasticity [(G)ARCH] in daily and weekly data on 22 exchange rates and 13 stock market indices using the standard Lagrange Multiplier [LM] test for GARCH and a new LM test that is resistant to additive outliers. T

  14. UNILATERAL INCOMPLETE SUPERFICIAL PALMAR ARCH: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Subhankar Chakraborty

    2015-12-01

    Full Text Available The functional importance of hand is revealed by its rich vascularity contributed by superficial and deep palmar arches (SPA and DPA.Superficial palmar arch is located superficial to flexor tendons, and deep palmar arch deep to lumbrical muscles. Variations are found more often in SPA than DPA, later being more or less constant. During routine undergraduate dissection, we observed, unilateral incomplete SPA being formed by superficial palmar branches of ulnar and radial artery in the right hand of a male cadaver. These two arteries remained independent without anastomosis forming incomplete arch (SPA.The superficial branch of ulnar artery entered hand superficial to flexor retinaculum and supplied middle, ring and little finger by three branches. The superficial branch of radial artery via its two branches supplied index finger and thumb. Classical SPA formation was seen on left side. The presence of an incomplete SPA as in this case is a potential danger in RA harvesting for CABG.Variations in SPA play a pivotal role in microvascular surgical procedures of hand, RAinterventions and arterial graft applications.

  15. Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, Andreas H., E-mail: mahnken@med.uni-marburg.de [University Hospital Giessen and Marburg, Philipps University of Marburg, Department of Diagnostic Radiology (Germany); Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M., E-mail: anneke.damberg@rwth-aachen.de [University Hospital RWTH Aachen, Department of Thoracic, Cardiac and Vascular Surgery (Germany)

    2013-08-01

    BackgroundAortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described.MethodsWe report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case.ResultsBoth procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence.ConclusionTreating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

  16. ArchDB 2014: structural classification of loops in proteins

    Science.gov (United States)

    Bonet, Jaume; Planas-Iglesias, Joan; Garcia-Garcia, Javier; Marín-López, Manuel A.; Fernandez-Fuentes, Narcis; Oliva, Baldo

    2014-01-01

    The function of a protein is determined by its three-dimensional structure, which is formed by regular (i.e. β-strands and α-helices) and non-periodic structural units such as loops. Compared to regular structural elements, non-periodic, non-repetitive conformational units enclose a much higher degree of variability—raising difficulties in the identification of regularities, and yet represent an important part of the structure of a protein. Indeed, loops often play a pivotal role in the function of a protein and different aspects of protein folding and dynamics. Therefore, the structural classification of protein loops is an important subject with clear applications in homology modelling, protein structure prediction, protein design (e.g. enzyme design and catalytic loops) and function prediction. ArchDB, the database presented here (freely available at http://sbi.imim.es/archdb), represents such a resource and has been an important asset for the scientific community throughout the years. In this article, we present a completely reworked and updated version of ArchDB. The new version of ArchDB features a novel, fast and user-friendly web-based interface, and a novel graph-based, computationally efficient, clustering algorithm. The current version of ArchDB classifies 149,134 loops in 5739 classes and 9608 subclasses. PMID:24265221

  17. Right-sided aortic arch with Kommerell′s aneurysm

    Directory of Open Access Journals (Sweden)

    Sanjay Orathi Patangi

    2014-01-01

    Full Text Available We present a case report of a 55-year-old lady who presented with progressive dysphagia and was diagnosed with a Kommerell′s aneurysm and a right-sided aortic arch. This case report outlines our management strategy and the challenges encountered during the perioperative period in a patient with this rare anomaly.

  18. 3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography

    Science.gov (United States)

    Pang, Yu; Shu, Yi; Shavezipur, Mohammad; Wang, Xuefeng; Mohammad, Mohammad Ali; Yang, Yi; Zhao, Haiming; Deng, Ningqin; Maboudian, Roya; Ren, Tian-Ling

    2016-01-01

    Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems. PMID:27345766

  19. Arch Venture Partners' investment considerations for CBRNE products and opportunities

    Science.gov (United States)

    Crandell, K.; Lazarus, S.; Gardner, P. J.

    2008-04-01

    ARCH is interested in building leading, highly-valued companies from leading research. Toward that end we value innovations created by the leading researchers in the world, many of which are funded to solve critical scientific challenges including those in the instrumentation and CBRNE area. The most important CBRNE innovations we have seen at ARCH are breakthroughs involving significant unaddressed technology risk and have the potential for broad proprietary intellectual property as a result. The model ARCH has evolved in instrumentation is to look for a breakthrough innovation, with strong intellectual property and continue to strengthen the patent estate through the life of the company. ARCH looks to build companies around leading interdisciplinary scientific and engineering teams, and we favor platform technology that can be applied to multiple market applications both commercial and government. As part of a strategy to build a great company, addressing important CBRNE challenges can help a company strengthen its technical team and its IP estate. This supports a focus on early low volume markets on the way toward addressing a fuller portfolio of applications. Experienced Venture Capitalists can help this process by identifying important executive talent, partners and applications, offering financial syndication strength, and helping shape the company's strategy to maximize the ultimate value realized.

  20. File list: ALL.Emb.50.AllAg.Maxillary_arch_junction [Chip-atlas[Archive

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  1. File list: His.Emb.50.AllAg.Maxillary_arch_junction [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  2. File list: ALL.Emb.05.AllAg.Maxillary_arch [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  4. File list: ALL.Emb.20.AllAg.Maxillary_arch_junction [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: ALL.Emb.50.AllAg.Maxillary_arch [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. Child Indicators: Dental Health.

    Science.gov (United States)

    Lewit, Eugene M.; Kerrebrock, Nancy

    1998-01-01

    Reviews measures of dental health in children and the evidence on child dental health. Although children's dental health has improved over the past two decades, many poor children do not receive necessary dental health services, and reasons for this failure are summarized. (SLD)

  7. Weaker dental enamel explains dental decay.

    Science.gov (United States)

    Vieira, Alexandre R; Gibson, Carolyn W; Deeley, Kathleen; Xue, Hui; Li, Yong

    2015-01-01

    Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is "weaker" while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution.

  8. Reconstruction and measurement of a digital dental model using grating projection and reverse engineering%光栅投影技术及逆向工程在重建和测量牙颌数字化模型中的应用

    Institute of Scientific and Technical Information of China (English)

    王珍珍; 逯宜; 宋君; 陈军; 周秦

    2015-01-01

    目的:利用光栅投影技术采集数字化牙颌模型并用逆向工程分析测量模型特征,为建立正常牙列数字化模型数据库奠定基础。方法在计算机控制下将光栅投影在正常牙颌模型上,通过多角度拍摄模型获得三维数据外形轮廓,利用逆向工程重建数字化模型和测量分析牙列形态特征,并与石膏模型测量结果进行对比分析。结果重建的三维数字化模型结构清晰。数字化模型的两次测量结果无统计学差异(P>0.05);数字化模型与石膏模型的测量指标中,牙冠长度和牙弓宽度均无统计学差异(P>0.05),而牙冠宽度和牙弓长度均有统计学差异(P0.05). When digital and plaster models were measured, we found that the crown length and arch width were not statistically different (P>0.05), whereas the difference between the crown width and arch length was statistically significant (P<0.05). Conclusion The reconstruction of a digital model by using the grating projection technique and reverse engineering can be used for dental model measurement in clinic al and scientific research and can provide a scientific method for establishing a digital model database with normal occlusion.

  9. CREATIVITY METHODS IN TEACHING THE ARCH-DESIGN STUDIO

    Directory of Open Access Journals (Sweden)

    EIGBEONAN Andrew B.

    2013-07-01

    Full Text Available The aim of this paper is to search and find methods of fostering creativity or ideas relating to creativity in teaching the arch-design studio. Teaching creativity through its methods will be making the students grounded in designing with creativity ideas and therefore we can have professionals that design and build with satisfaction, safety and complementary. It means we can have real buildings and places that satisfy our clients, the society and in harmony with the environment. Although there are similarities in the curricula of training architects all over the world, but educators go about it in their own convenient and suitable ways and styles. The ideas of creativity have been part of architecture from the onset, but are not deligently applied and also not formally incorporated in the curricula of training. The topic is also very relevant and timely as arch-educators and other stakeholders are of the opinion that something has to be done to improve the ways and methods of training architects, especially the teaching of the arch-design studio with regards to creativity. Through exploration of literature and interviews (physical and telephone call this paper finds methods of stimulating creativity ideas in the teaching of arch-design studio. Some of the methods of motivating creativity found in teaching the arch-design studio are: analogy, metaphors, biomimicry, brainstorming, attribute listing, mental map, TRIZ, restrictions, charrette, browsing, excursions, focus groups, other peoples viewpoints, using crazy ideas, using experts, visualizing a goal, working with dreams and images and giving students design tools such as drawings CAD and model making.

  10. Implant-retained dentures for full-arch rehabilitation: a case report comparing fixed and removable restorations.

    Science.gov (United States)

    Zafiropoulos, Gregory-George; Hoffman, Oliver

    2011-01-01

    Dental implants as abutments for full-arch restorations are a well-documented treatment modality. This report presents a case in which the patient was treated initially with fixed restorations supported by either implants or natural teeth and subsequently treated with a removable implant/telescopic crown-supported overdenture. Advantages and disadvantages of each approach are described and discussed. While the fixed restoration resulted in a functionally satisfactory treatment outcome, the patient was displeased with the esthetic appearance. The main concern was the unnaturally long tooth shape necessary to compensate for the insufficient alveolar ridge height. Replacement of the existing restoration with an implant-supported removable overdenture led to a functionally and esthetically acceptable result. When deciding whether to use a fixed or removable implant-supported full-arch restoration, a multitude of factors must be considered. Due to the possible need for additional surgical steps to enhance the esthetic appearance surrounding fixed restorations, removable implant-supported partial dentures often are the better choice.

  11. Posttreatment quantification of patient experiences with full-arch implant treatment using a modification of the OHIP-14 questionnaire.

    Science.gov (United States)

    Babbush, Charles A

    2012-06-01

    Patient well-being is always the goal of rehabilitation of edentulism; however, evaluations of treatment success often overlook the patient's subjective feelings about comfort, function, speech, social image, social inhibitions, psychological discomfort, and/or disabilities. The purpose of this study was to assess these patient responses using an oral health questionnaire. To assess such feelings, a self-administered 20-question multiple-choice patient-reported Edentulous Patient Impact Questionnaire was developed, based upon the previously validated Oral Health Impact Profile patient-assessment tool. Responses were solicited from randomly selected patients treated with an implant-supported, fixed, immediately loaded full arch prosthesis. The questionnaires were completed by 250 patients. Of the respondents, 95% described themselves as being either extremely satisfied (74%) or satisfied (21%) with their new teeth, and 98% said they would definitely recommend similar treatment (88%) or consider recommending it (10%) to a friend or colleague. Based upon an oral health impact survey completed by 250 patients treated with full-arch implant-supported, immediately loaded fixed dental prostheses, it appears that patient satisfaction is high and that treated patients would generally be willing to recommend this treatment to others.

  12. Lucy's flat feet: the relationship between the ankle and rearfoot arching in early hominins.

    Directory of Open Access Journals (Sweden)

    Jeremy M DeSilva

    Full Text Available BACKGROUND: In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present evidence from radiographs of modern humans (n = 261 that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8% have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and "Lucy" (A.L. 288-1, a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles. CONCLUSIONS/SIGNIFICANCE: This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis "Lucy" has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch

  13. Assessment of age based on the pulp cavity width of the maxillary central incisors

    Directory of Open Access Journals (Sweden)

    Uday Ginjupally

    2014-01-01

    Full Text Available Aims and Objectives: The aim of this study was to estimate the age of the patients belonging to the age group of 15 - 55 years, attending the Department of Oral Medicine and Radiology, St. Joseph Dental College and Hospital, Eluru, based on the radiographic evaluation of the pulp cavity width of the maxillary central incisors. Materials and Methods: The study group comprised of 120 subjects. Intraoral periapical radiographs of the maxillary central incisors were taken for all subjects, using the conventional paralleling angle technique and the pulp cavity width was measured at the cervical and middle third using a digital vernier caliper. The data obtained was subjected to correlation and regression analysis. Results: A negative linear relationship was obtained between the age and pulp cavity width (cervical third, r = -0.459 and middle third, r = -0.704. Cubic regression analysis was done and the regression formulae were obtained. A mean difference of 0.1 years was obtained between the estimated age and real age, indicating the reliability of the derived formula. Conclusion: It can be concluded that the width of the pulp cavity of maxillary central incisors are reliable for estimation of age.

  14. Biological Width around One- and Two-Piece Implants Retrieved from Human Jaws

    Directory of Open Access Journals (Sweden)

    Ricardo Judgar

    2014-01-01

    Full Text Available Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece and two-piece (external hexagon with a healing abutment implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (P0.05. Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

  15. Correlation between arch form and facial form: A cross sectional study

    Directory of Open Access Journals (Sweden)

    Sanjna Nayar

    2015-01-01

    Full Text Available Arch form is a key determinant in teeth position. Teeth selection and placement must be based on the functional and esthetic needs of the patient. Keeping in mind, the biomechanics involved with the prosthesis. The aim of the study was to evaluate the correlation between arch form and facial form. About 40 individuals in the age group of 20-25 years were involved in the study. The arch form and facial form were analyzed statistically to check for any correlation. It was found that, 63.63% of leptoprosophic individuals had squarish arch form while, 54.6% of mesoprosophic faces had ovoid arch form.

  16. The effect of clinical use and sterilization on selected orthodontic arch wires.

    Science.gov (United States)

    Smith, G A; von Fraunhofer, J A; Casey, G R

    1992-08-01

    The effect of clinical use and various sterilization/disinfection protocols on three types of nickel-titanium, and one type each of beta-titanium and stainless steel arch wire was evaluated. The sterilization/disinfection procedures included disinfection alone or in concert with steam autoclave, dry heat, or cold solution sterilization. No clinically significant differences were found between new and used arch wires. The direction of load application to the arch wire and the particular segment of arch wire tested was found to cause substantial differences in generated loads for certain arch wire types.

  17. Artifacts for Calibration of Submicron Width Measurements

    Science.gov (United States)

    Grunthaner, Frank; Grunthaner, Paula; Bryson, Charles, III

    2003-01-01

    Artifacts that are fabricated with the help of molecular-beam epitaxy (MBE) are undergoing development for use as dimensional calibration standards with submicron widths. Such standards are needed for calibrating instruments (principally, scanning electron microscopes and scanning probe microscopes) for measuring the widths of features in advanced integrated circuits. Dimensional calibration standards fabricated by an older process that involves lithography and etching of trenches in (110) surfaces of single-crystal silicon are generally reproducible to within dimensional tolerances of about 15 nm. It is anticipated that when the artifacts of the present type are fully developed, their critical dimensions will be reproducible to within 1 nm. These artifacts are expected to find increasing use in the semiconductor-device and integrated- circuit industries as the width tolerances on semiconductor devices shrink to a few nanometers during the next few years. Unlike in the older process, one does not rely on lithography and etching to define the critical dimensions. Instead, one relies on the inherent smoothness and flatness of MBE layers deposited under controlled conditions and defines the critical dimensions as the thicknesses of such layers. An artifact of the present type is fabricated in two stages (see figure): In the first stage, a multilayer epitaxial wafer is grown on a very flat substrate. In the second stage, the wafer is cleaved to expose the layers, then the exposed layers are differentially etched (taking advantage of large differences between the etch rates of the different epitaxial layer materials). The resulting structure includes narrow and well-defined trenches and a shelf with thicknesses determined by the thicknesses of the epitaxial layers from which they were etched. Eventually, it should be possible to add a third fabrication stage in which durable, electronically inert artifacts could be replicated in diamondlike carbon from a master made by

  18. Clique Cover Width and Clique Sum

    OpenAIRE

    Shahrokhi, Farhad

    2015-01-01

    For a clique cover $C$ in the undirected graph $G$, the clique cover graph of $C$ is the graph obtained by contracting the vertices of each clique in $C$ into a single vertex. The clique cover width of G, denoted by $CCW(G)$, is the minimum value of the bandwidth of all clique cover graphs of $G$. When $G$ is the clique sum of $G_1$ and $G_2$, we prove that $CCW(G) \\le 3/2(CCW(G_1) + CCW(G_2))$.

  19. Dental erozyon

    NARCIS (Netherlands)

    Özen, B.; Yönel, N.; Çetiner, S.

    2015-01-01

    Dental erozyon, plak içermeyen diş yüzeyleri üzerinde içsel ve dışsal asitlerin veya şelatların etkileriyle oluşan kimyasal bir aşınmadır. İçsel ve/veya dışsal kaynaklar nedensel faktörler olarak tanımlanırken tükürük ve pelikıl gibi biyolojik faktörler, yeme ve içme alışkanlıkları ve ağız hijyeni g

  20. A Dental Education Perspective on Dental Health Policy.

    Science.gov (United States)

    Morris, Alvin L.

    1985-01-01

    Two issues related to dental health policy are examined: the contribution of dental education to the process by which dental health policy is established, and the nature of dental education's response to established policies. (MLW)

  1. An Analytical Solution for Lateral Buckling Critical Load Calculation of Leaning-Type Arch Bridge

    Directory of Open Access Journals (Sweden)

    Ai-rong Liu

    2014-01-01

    Full Text Available An analytical solution for lateral buckling critical load of leaning-type arch bridge was presented in this paper. New tangential and radial buckling models of the transverse brace between the main and stable arch ribs are established. Based on the Ritz method, the analytical solution for lateral buckling critical load of the leaning-type arch bridge with different central angles of main arch ribs and leaning arch ribs under different boundary conditions is derived for the first time. Comparison between the analytical results and the FEM calculated results shows that the analytical solution presented in this paper is sufficiently accurate. The parametric analysis results show that the lateral buckling critical load of the arch bridge with fixed boundary conditions is about 1.14 to 1.16 times as large as that of the arch bridge with hinged boundary condition. The lateral buckling critical load increases by approximately 31.5% to 41.2% when stable arch ribs are added, and the critical load increases as the inclined angle of stable arch rib increases. The differences in the center angles of the main arch rib and the stable arch rib have little effect on the lateral buckling critical load.

  2. Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

    Science.gov (United States)

    Cortes, Arthur Rodriguez Gonzalez; Cortes, Djalma Nogueira; No-Cortes, Juliana; Arita, Emiko Saito

    2014-06-01

    The present retrospective case series is aimed at evaluating a staged approach using a removable partial denture (RPD) as an interim prosthesis in treatment to correct a failing dentition until such time as a full-arch fixed implant-supported prosthesis may be inserted. Eight patients, who had undergone maxillary full-arch rehabilitation with dental implants due to poor prognosis of their dentitions, were analyzed. All treatment included initial periodontal therapy and a strategic order of extraction of hopeless teeth. An RPD supported by selected teeth rehabilitated the compromised arch during implant osseointegration. These remaining teeth were extracted prior to definitive prosthesis delivery. Advantages and drawbacks of this technique were also recorded for the cases presented. Among the advantages provided by the staged approach are simplicity of fabrication, low cost, and ease of insertion. Additionally, RPD tooth support prevented contact between the interim prosthesis and healing abutments, promoting implant osseointegration. The main drawbacks were interference with speech and limited esthetic results. Implant survival rate was 100% within a follow-up of at least 1 year. The use of RPDs as interim prostheses allowed for the accomplishment of the analyzed rehabilitation treatments. It is a simple treatment alternative for patients with a low smile line.

  3. Transition from hopeless dentition to full-arch fixed-implant-supported rehabilitation by a staged extraction approach: rationale and technique.

    Science.gov (United States)

    Mijiritsky, Eitan; Mazor, Ziv; Lorean, Adi; Mortellaro, Carmen; Mardinger, Ofer; Levin, Liran

    2014-05-01

    Transition from a hopeless dentition to a fixed-implant-supported full-arch reconstruction can be difficult for patients if wearing a transitional removable denture is involved. In addition, an increased risk for trauma to bone augmentation areas and to the implant-bone interface exists when using a removable transitional complete denture during the implant healing period; such risk can compromise implant success or increase crestal bone loss around implants before the final restoration. This article describes a treatment approach that allows replacement of the hopeless dentition with an osseointegrated fixed prosthesis, without rendering the patient totally edentulous before the delivery of the final implant-supported prosthesis. A staged approach using a few hopeless teeth to support a provisional fixed restoration during the healing process can help avoid discomfort and improve implants' outcome. A treatment plan for a maxillary arch reconstruction is used to illustrate the staged approach protocol. This protocol addresses patients' psychologic need to remain dentate during partial or full-mouth rehabilitation, while providing good esthetics and function during restoration of a dental arch.

  4. COMMUNITY DENTAL HEALTH SURVEY TRAINING TO DENTAL HEALTH PERSONNEL

    OpenAIRE

    Sandra Fikawati; Ita Yulita

    2015-01-01

    Dentist and dental nurse as dental health personnel in community health center are spearheads in community dental health service. The effectiveness and efficacy of community dental health service needs updated adequate dental health knowledge and skill. One effort to assure the fulfillment of those needs is by providing community dental health survey training. This training aims at improving the skill and capability of dental health personnel to conduct dental health survey. The training cons...

  5. Resonance trapping and saturation of decay widths

    CERN Document Server

    Persson, E; Rotter, I

    1998-01-01

    Resonance trapping appears in open many-particle quantum systems at high level density when the coupling to the continuum of decay channels reaches a critical strength. Here a reorganization of the system takes place and a separation of different time scales appears. We investigate it under the influence of additional weakly coupled channels as well as by taking into account the real part of the coupling term between system and continuum. We observe a saturation of the mean width of the trapped states. Also the decay rates saturate as a function of the coupling strength. The mechanism of the saturation is studied in detail. In any case, the critical region of reorganization is enlarged. When the transmission coefficients for the different channels are different, the width distribution is broadened as compared to a chi_K^2 distribution where K is the number of channels. Resonance trapping takes place before the broad state overlaps regions beyond the extension of the spectrum of the closed system.

  6. Optical antennas with sinusoidal modulation in width.

    Science.gov (United States)

    Dikken, Dirk Jan; Segerink, Frans B; Korterik, Jeroen P; Pfaff, Stefan S; Prangsma, Jord C; Herek, Jennifer L

    2016-08-08

    Small metal structures sustaining plasmon resonances in the optical regime are of great interest due to their large scattering cross sections and ability to concentrate light to subwavelength volumes. In this paper, we study the dipolar plasmon resonances of optical antennas with a constant volume and a sinusoidal modulation in width. We experimentally show that by changing the phase of the width-modulation, with a small 10 nm modulation amplitude, the resonance shifts over 160 nm. Using simulations we show how this simple design can create resonance shifts greater than 600 nm. The versatility of this design is further shown by creating asymmetric structures with two different modulation amplitudes, which we experimentally and numerically show to give rise to two resonances. Our results on both the symmetric and asymmetric antennas show the capability to control the localization of the fields outside the antenna, while still maintaining the freedom to change the antenna resonance wavelength. The antenna design we tested combines a large spectral tunability with a small footprint: all the antenna dimensions are factor 7 to 13 smaller than the wavelength, and hold potential as a design element in meta-surfaces for beam shaping.

  7. Investigating Starburst Galaxy Emission Line Equivalent Widths

    Science.gov (United States)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  8. Effects of hypnotic focused analgesia on dental pain threshold.

    Science.gov (United States)

    Facco, Enrico; Casiglia, Edoardo; Masiero, Serena; Tikhonoff, Valery; Giacomello, Margherita; Zanette, Gastone

    2011-01-01

    The rate, intensity, and selectivity of hypnotic focused analgesia (HFA) were tested with dental pulp stimulation. Thirty-one healthy subjects were hypnotized, and hypnotic suggestions were given for anesthesia of the right mandibular arch. A posthypnotic suggestion of persisting analgesia was also given. The pain threshold of the first premolar was bilaterally measured before, during, and after hypnosis using a pulp tester. During hypnosis, the pain threshold increased significantly (p < .0001) for both sides. The posthypnotic right pain threshold was also significantly (p < .0015) higher than in the basal condition.

  9. Complete removable dental prosthesis with the swing lock system: a clinical report.

    Science.gov (United States)

    Aggarwal, Harshit; Cho, Seok-Hwan

    2014-11-01

    This clinical report describes the fabrication of a maxillary complete removable dental prosthesis with the swing lock system. The patient presented with large undercuts on the buccal and labial areas of the edentulous maxillary arch and a history of various failed alveoloplasty procedures that had attempted to remove the exostoses preventing denture insertion. The prosthodontic planning and treatment approach are discussed. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  10. Oral findings and dental treatment in a child with West syndrome.

    Science.gov (United States)

    Regis, Rômulo Rocha; Rocha, Cristiane Tomaz; Torres, Carolina Paes; Queiroz, Ivna Fernandes; de Queiroz, Alexandra Mussolino

    2009-01-01

    West syndrome (WS) is a rare, severe form of epilepsy that typically manifests early in infancy. It is considered a malignant condition that combines episodes of spasms that occur in clusters (infantile spasm), hypsarrhythmia on the electroencephalogram, and neuropsychomotor delay. Although WS has been widely investigated from a medical standpoint, few reports have focused on the oral findings in patients with this syndrome. This article reports the case history of a 7-year-old child diagnosed with WS. The major clinical features were generalized tooth wear and gingival enlargement, altered chronology and sequence of dental eruption, primary canine cusp-to-cusp relationship, ectopic dental eruption, and mildly arched palate. Multiple white spot lesions were also observed, possibly associated with poor oral hygiene, due to a fermentable carbohydrate-rich diet, and continuous use of sugar-containing medications. Dental care management of patients with special needs is discussed and the dental treatment for this child with WS is described.

  11. Super-light pearl-chain arch vaults

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Halding, Philip Skov

    2014-01-01

    in the vault. This means that the structure can sustain 4 hours standard fire. That it has a very high level of sound insulation, efficient sound damping properties, optimized production, a low production of CO2 that has already given rise to several awards, and easy transport of plane elements instead of what......Arch vaults are known as optimal and impressive structures, but due to their curved shapes they are extremely costly to produce in countries, where the cost of labor is high. By means of super-light pearl-chain technology arch vaults can be constructed from equal plane prefabricated elements, which...... are assembled on the erection site by means of post-tensioning and lifted in place in buildings and bridges. The super-light SL-deck element is developed by the company Abeo Ltd and The Technical University of Denmark for plane floor structures in buildings. However, this deck element is designed in such a way...

  12. Antenatal evaluation of fetal interrupted aortic arch type B

    Directory of Open Access Journals (Sweden)

    Ali Babacan

    2015-06-01

    Full Text Available Interruption of the aortic arch (IAA is a rare, severe form of congenital heart defect characterized by complete anatomical discontinuity between two adjacent segments of the aortic arch. The data on the features and outcomes of fetal IAA are limited. Three anatomical types have been described according to the site of interruption. The current recommendations for screening on the obstetric fetal anomaly scan include identification of a 4-chamber view, all 4 valves, and the outflow tracts, all of which can appear to be normal to the ultrasonographer in fetuses with conotruncal anomalies. Although the identification of IAA on a prenatal echocardiogram can be challenging, a number of anatomic features can facilitate the diagnosis. We aim to present the features and outcome of a case of IAA type B referred to our centre in the light of literatures.

  13. Device-width dependence of plateau width in quantum Hall states

    Science.gov (United States)

    Kawaji, S.; Hirakawa, K.; Nagata, M.

    1993-02-01

    Hall bar type devices having a total length of 2900 μm, a source and drain electrode width of 400 μm and different widths w ranging from 10 to 120 μm in its central 600 μm long part are fabricated from a GaAs/AlGaAs wafer with electron mobility of 21 m 2V -1s -1. The current at which the quantum Hall plateau for i=2 at B=9.7T at T=1.2K disappears is proportional to w. The average critical current density is Jcr=(1.6±0.2) A m -1

  14. Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch.

    Science.gov (United States)

    Krishnan, Sumant G; Bennion, Phillip W; Reineck, John R; Burkhead, Wayne Z

    2008-10-01

    Proximal humerus fractures are the most common fractures of the shoulder girdle, and initial management of these injuries often determines final outcome. When arthroplasty is used to manage proximal humeral fractures, surgery remains technically demanding, and outcomes have been unpredictable. Recent advances in both technique and prosthetic implants have led to more successful and reproducible results. Key technical points include restoration of the Gothic arch, anatomic tuberosity reconstruction, and minimal soft tissue dissection.

  15. Double arch mirror study. Part 3: Fabrication and test report

    Science.gov (United States)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    A method of mounting a cryogenically cooled, lightweight, double arch, glass mirror was developed for infrared, astronomical telescopes such as the Space Infrared Telescope Facility (SIRTF). A 50 cm, fused silica mirror which was previously fabricated was modified for use with a new mount configuration. This mount concept was developed. The modification of the mirror, the fabrication of the mirror mount, and the room temperature testing of the mounted mirror are reported. A design for a SIRTF class primary mirror is suggested.

  16. Right cervical aortic arch with aberrant left subclavian artery.

    Science.gov (United States)

    Tjang, Yanto S; Aramendi, José I; Crespo, Alejandro; Hamzeh, Gadah; Voces, Roberto; Rodríguez, Miguel A

    2008-08-01

    The combination of right cervical aortic arch, aberrant retroesophageal left subclavian artery originating from a Kommerell's diverticulum, and a ligamentum arteriosum, constitutes a rare form of vascular ring. Two patients aged 21 days and 54 years, who were diagnosed by multislice 3-dimensional computed tomography and magnetic resonance imaging, underwent surgical division of a vascular ring. The adult required resection of a Kommerell's aneurysm and subclavian artery reimplantation.

  17. Congenital absence of the atlas posterior arch. A case report.

    Science.gov (United States)

    Huggare, J

    1995-02-01

    A report of a healthy young adult woman with non-pathological congenital absence of the lateral and posterior parts of the atlas is presented. This occurred in association with a steep mandibular plane angle and an extremely obtuse gonial angle. Similar facial features are common in females with hypoplastic dorsal arches, and this case illustrates the intimate developmental association between the upper part of the cervical spine and the craniofacial complex.

  18. Eine Archäologie spiritueller Gotteserfahrung im christlichen Mittelalter

    Directory of Open Access Journals (Sweden)

    Wolfram Bergande

    2008-03-01

    Full Text Available Die Autorin vergleicht die christliche Praktik des so genannten „Genießens Gottes“ bei Bernhard von Clairvaux und Hildegard von Bingen mit dem Ziel einer Archäologie des Genießens in der Mystik des 12. bis 14. Jahrhunderts. Ihr lesenswerter Vergleich zwischen den beiden Klerikern ist kulturgeschichtlich fundiert, medienwissenschaftlich kenntnisreich und anschlussfähig für Philosophen, Historiker, Religionssoziologen und Theologen.

  19. Modelling autogenous expansion for magnesia concrete in arch dams

    Institute of Scientific and Technical Information of China (English)

    Feng JIN; Guoxin ZHANG; Xiaoqing LUO; Chuhan ZHANG

    2008-01-01

    Magnesia Concrete is a kind of expansive con-crete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expan-sion on the stresses of arch dams, a simple model of auto-genous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expan-sion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogen-ous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite ele-ment arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.

  20. C-arm guided closed reduction of zygomatic arch fracture

    Energy Technology Data Exchange (ETDEWEB)

    Eo, Yoon Ki; Lee, Dong Kun [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of); Kim, Jeong Sam; Jang, Young Il [Kwangyang College, Kwangyang (Korea, Republic of)

    1999-04-01

    The zygomatic arch is structurally protruded and is easily fractured. The classic management of zygomatic arch fracture has been mentioned the Keen, Lothrop, Dingman and Alling and threaded K-wire. All of the above methods have advantages and disadvantages. To minimize the disadvantages, we performed threaded K-wire for the first time using C-arm image intensifier. The subjects were 16 patients with Knight North group II (Zygomatic arch fracture). Among them the C-arm was used in 12 patients and the operator used sensitivity general method in 4 patients and confirmed the operation by mobile X-ray equipment. In conclusion, both groups were satisfied surgically and cosmetically. Using the C-arm, actual image at the time operation was clear and satisfied, the surrounding tissue damage was minimized and at was more accurately completed. The operation time was shortened by 30 to 60 minutes proving it to be an efficient method. We suggest though that further studies be needed to evaluate the radiation effect on these patients.

  1. First and second branchial arch syndromes: multimodality approach

    Energy Technology Data Exchange (ETDEWEB)

    Senggen, Elodie; Laswed, Tarek; Meuwly, Jean-Yves; Maestre, Leonor Alamo; Meuli, Reto; Gudinchet, Francois [University Hospital of Lausanne, Radiology Department, Lausanne (Switzerland); Jaques, Bertrand [University Hospital of Lausanne, Department of Otorhinolaryngology, Lausanne (Switzerland)

    2011-05-15

    First and second branchial arch syndromes (BAS) manifest as combined tissue deficiencies and hypoplasias of the face, external ear, middle ear and maxillary and mandibular arches. They represent the second most common craniofacial malformation after cleft lip and palate. Extended knowledge of the embryology and anatomy of each branchial arch derivative is mandatory for the diagnosis and grading of different BAS lesions and in the follow-up of postoperative patients. In recent years, many new complex surgical approaches and procedures have been designed by maxillofacial surgeons to treat extensive maxillary, mandibular and external and internal ear deformations. The purpose of this review is to evaluate the role of different imaging modalities (orthopantomogram (OPG), lateral and posteroanterior cephalometric radiographs, CT and MRI) in the diagnosis of a wide spectrum of first and second BAS, including hemifacial microsomia, mandibulofacial dysostosis, branchio-oto-renal syndrome, Pierre Robin sequence and Nager acrofacial dysostosis. Additionally, we aim to emphasize the importance of the systematic use of a multimodality imaging approach to facilitate the precise grading of these syndromes, as well as the preoperative planning of different reconstructive surgical procedures and their follow-up during treatment. (orig.)

  2. Direct measurement of the W boson width

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Alberta U. /Simon Fraser U. /McGill U.; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP; Alton, A.; /Michigan U. /Northeastern U.

    2009-09-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.

  3. Direct measurement of the W boson width.

    Science.gov (United States)

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Andeen, T; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; DeVaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Galea, C F; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Golovanov, G; Gómez, B; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jamin, D; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, W M; Leflat, A; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Mättig, P; Magaña-Villalba, R; Mal, P K; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Mendoza, L; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Tiller, B; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Wenger, A; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zutshi, V; Zverev, E G

    2009-12-04

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.

  4. Monolithic Lithium Disilicate Full-Contour Crowns Bonded on CAD/CAM Zirconia Complete-Arch Implant Bridges With 3 to 5 Years of Follow-Up.

    Science.gov (United States)

    Pozzi, Alessandro; Tallarico, Marco; Barlattani, Alberto

    2015-08-01

    This study was carried on to assess the clinical performance of a novel restorative concept consisting in single monolithic lithium disilicate full-contour crowns bonded on computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia complete-arch implant bridges, to overcome the drawbacks related to the chipping of porcelain fused to zirconia restorations. Sixteen patients received 18 implant-supported hybrid screw-cement-retained complete-arch restorations, consisting of single monolithic lithium disilicate full-contour crowns bonded on CAD/CAM zirconia frameworks. The restorations were supported by 4-8 implants. All patients were followed up for at least 3 years on function (range 36 to 60 months, mean 49.3 months). Clinical controls were scheduled every 4 months. The outcomes were implant and prosthetic survival and success rates, any complications, patient satisfaction, and soft tissue parameters. No dropouts occurred. The overall implant and prosthesis survival rates were 100%. One of 18 restorations (1 of 236 dental units) showed a chip-off fracture of the veneering ceramic that was polished intraorally without any additional treatment, scoring a cumulative prosthetic success rate of 100%, according to the California Dental Association index. All patients were functionally and esthetically highly satisfied with their restorations. Successful soft tissue parameters were found around all implants. Single monolithic lithium disilicate full-contour crowns, bonded on CAD/CAM screw-retained complete-arch zirconia frameworks, showed favorable preliminary outcomes with medium-term follow-up. However, randomized controlled studies of this technique are required for further conclusive recommendations.

  5. The Correlation between Different Facial Measurements and the Width of Maxillary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Hassan Ahangari A.

    2011-08-01

    Full Text Available Statement of Problem: One of the most important procedures in the rehabilitation of an edentulous space in the anterior segment is the selection of an appropriate size of the anterior teeth in order to achieve the perfect esthetic results.Purpose: The purpose of this study was to examine the correlation between horizontal measurements of the face and width of the maxillary anterior teeth.Material and methods: In this descriptive-analytical and cross-sectional study, the face and teeth of the 77 subjects (39 women and 38 men aged between 20-30 with no facial and dental deformities were examined. Some horizontal dimensions of the face including IC (intercanthal, IP (interpupillary, BZW (bizygomatic width, IA (interalar, and ICm (Intercomussural width and perceived width of the teeth were calculated with AutoCAD software with 0.1 mm accuracy on the photos. The actual width of the teeth was calculated with a digital caliper by 0.1 mm accuracy on the maxillary casts. The data were analyzed in SPSS software using the Pearson correlation coefficient and t-test.Results: Except for the IC and the sum of the actual width of the six maxillary anterior teeth on the cast, the rest of the measurements were significantly different by gender ( p < 0.05. All the correlations between facial measurements and width of the teeth were bigger than when they were separated by gender. In women, the correlation between IC and the six anterior teeth in the front view (SANTF was the highest one ( r = 0.436, p = 0.005. However, the highest correlation was related to the ICm and SANTF in men. (r = 0.0501, p =0.001Conclusion: Within the limitation of this study, the results suggest that except for the BZW, the rest of the facial measurements including IC, IP, IA and ICm can be used as a preliminary criterion for determining the width of the maxillary anterior teeth of the edentulous patients.

  6. Comparison of the Load-Deflection Characteristics of Aesthetic and Conventional Super Elastic Ni-Ti Orthodontic Arch Wires in Conventional and Metal-Insert Ceramic Brackets

    Science.gov (United States)

    Aghili, Hosseinagha; Yassaei, Soghra; Joshan, Neda

    2016-01-01

    Introduction Coated arch wires and ceramic brackets have been introduced to improve aesthetics during orthodontic treatment. Aim The aim of this study was to determine the effects of coating on the physical properties of aesthetic orthodontic wires. Material and Methods Five round wires (0.016 inch) were obtained from each of three brands: conventional uncoated super elastic Nickel Titanium (Ni-Ti) (Rematitian Lite; Dentaurum, Ispringen, Germany), HUBIT (Teflon Coated, Korea), G&H (Epoxy Coated, Greenwood, Indiana, USA) which belonged to maxillary arch. Two types of standard ceramic brackets (conventional and metal-insert type, Ortho Technology, Tampa, Florida, USA) with the slot size of 0.022×0.028 inches were used. A simulation device was fabricated to resemble a model of human dental arch and each of the specimen was tested in three-point bending test. The test was conducted in the buccolingual plane with crosshead speed of 1mm/minute pressure from metal pole. Each sample was loaded until a deflection of 3.0 mm was produced. The mean values of maximum loading force, unloading force and clinical plateau length were recorded. One-way ANOVA and Tukey tests were used at p<0.05. Results Uncoated Ni-Ti arch wire showed higher mean values of maximum loading and unloading force than that of coated aesthetic wires similar to ceramic brackets while G&H wire and metal-insert ceramic brackets presented the lowest values. The longest clinical plateau length was observed in G&H wires and metal-insert ceramic bracket. Conclusion The coating processes for HUBIT (Teflon Coated, Korea), G&H (Epoxy Coated, Greenwood, Indiana, USA) wires might influence bending behaviour which can cause decrease in loading and unloading force. PMID:28208994

  7. Pulse-Width Jitter Measurement for Laser Diode Pulses

    Institute of Scientific and Technical Information of China (English)

    TANG Jun-Hua; WANG Yun-Cai

    2006-01-01

    @@ Theoretical analysis and experimental measurement of pulse-width jitter of diode laser pulses are presented. The expression of pulse power spectra with all amplitude jitter, timing jitter and pulse-width jitter is deduced.

  8. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  9. Mechanics Evolution Characteristics Analysis of Pressure-arch in Fully-mechanized Mining Field

    Directory of Open Access Journals (Sweden)

    S.R. Wang

    2014-09-01

    Full Text Available Based on a practical engineering, the three-dimension computational model was built using FLAC3D under the fullymechanized mining condition. Considering four variation factors, such as the distance of mining advancing, the strength of the surrounding rock, the speed of mining advancing and the dip angle of the coal seam, the mechanics evolution characteristics of the pressure-arch were analyzed. The result showed that for the horizontal seam, the geometric shape of the pressure-arch varied from flat arch to round arch gradually and the height and thickness of the pressure-arch also increased; the maximum principal stress in the skewback also increased with the working face advancing. With the strength of the surrounding rock from soft to hard, the arch thickness reduced, and the arch loading decreased. To improve the mining speed can do some contributions to the stability of the pressure-arch in the mining field. With the increase of dip angle of the seam, the pressure-arch displayed an asymmetric shape, the vault was tilted and moved to the upward direction. At the same time, the thickness of the pressure-arch increased, and the stress concentration in the skewback tended to be further intensified.

  10. Effect of aging on the configurational change of the aortic arch

    Directory of Open Access Journals (Sweden)

    Atsuhiro Kojima

    2016-04-01

    Full Text Available We explored the relationship between aging and the configuration of the aortic arch using computed tomography angiography (CTA. We retrospectively reviewed CTA obtained in 140 cases. The configuration of the aortic arch was categorized into three types based on the criteria mentioned by Madhwal et al., and the relationships between each configuration and patient characteristics were analyzed. Anomalies of the aortic arch were also explored. Twenty patients had a type-1 aortic arch (mean age, 56.1 years, 30 patients had a type-2 aortic arch (mean age, 66.3 years, and 89 patients had a type-3 aortic arch (mean age, 71.7 years. The mean age of patients with a type-3 aortic arch was significantly higher than that of patients with a type-1 aortic arch. No significant correlations between the type of aortic arch and other factors, such as smoking habit, were seen. The configuration of the aortic arch in our study appears to be significantly affected by the age of the patients.

  11. The Foot’s Arch and the Energetics of Human Locomotion

    Science.gov (United States)

    Stearne, Sarah M.; McDonald, Kirsty A.; Alderson, Jacqueline A.; North, Ian; Oxnard, Charles E.; Rubenson, Jonas

    2016-01-01

    The energy-sparing spring theory of the foot’s arch has become central to interpretations of the foot’s mechanical function and evolution. Using a novel insole technique that restricted compression of the foot’s longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms−1) level running increased metabolic cost by + 6.0% (p < 0.001, d = 0.67; unaffected by foot strike technique). A simple model shows that the metabolic energy saved by the arch is largely explained by the passive-elastic work it supplies that would otherwise be done by active muscle. Both experimental and model data confirm that it is the end-range of arch compression that dictates the energy-saving role of the arch. Restricting arch compression had no effect on the cost of walking or incline running (3°), commensurate with the smaller role of passive-elastic mechanics in these gaits. These findings substantiate the elastic energy-saving role of the longitudinal arch during running, and suggest that arch supports used in some footwear and orthotics may increase the cost of running. PMID:26783259

  12. A STUDY ON SUPERFICIAL PALMAR ARCH AND IT’S VARIATIONS

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao

    2015-03-01

    Full Text Available INTRODUCTION: Knowledge of the frequency of anatomical variations of arterial pattern of hand is crucial for safe and successful hand surgical approach, diagnostic and therapeutic procedures. The superficial pal mar arch is a major blood supply to the hand. Various ano malous patterns in the superficial arch of hand are reported. The superficial pal mar arch is formed predominantly by ulnar artery with a contribution from superficial branch of radial artery. OBSERVATIONS: Superficial palmar arch is dissected within the p alm and observed from its origin to termination. Variations in its origin, branches were observed. A classic superficial palmar arch was found in 10% [5/50]. O ut of dissected specimens complete arch found in 67% and incomplete arch was 33%. Incomplete arch is formed by ulnar artery alone. It supply four and half fingers and give five branches. Majority of arches is supplied by three and half fingers and gives four branches. DISCUSSION: Many attempts have been made to classify these variations. A complex cla ssification of superficial pal mar arch by Coleman & Anson [1961]. S ince then, many other classification have been suggested by different authors [Karlsson & N iechajev, 1982; al - Turk & Metcalf, 1984; Doscher et al. 1985; Ruengsakulrachh et al. 2001;] provi des simplest understanding of distribution of the arches. Although the classical pattern of the arch occurs in frequently, anatomical presence of a complete superficial palmar arch varies from 84% to 66% [Coleman & Anson]. This incidence was lower in the c urrent study and might be a reflection of sample size [52 hands]. The median artery was found in 10% of the hands, similar frequency to that reported by McCormack et al. [1953].

  13. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  14. Dental education in Malaysia.

    Science.gov (United States)

    Komabayashi, Takashi; Razak, Abdul Aziz Abdul; Bird, William F

    2007-12-01

    There was only one dental school in Malaysia until 1997 but five new schools have been established since 1998. This review provides information about dental education in Malaysia including; the history of dental education, the current dental school system and curriculum, and dental licensure. There are four public and two private dental schools in Malaysia. High school graduates are required to take the nationwide matriculation entrance examination or the Higher School Certificate (HSC) to apply for a dental degree programme. A five-year dental programme leads to the BDS or the DDS degree. National or state examinations are not required to practise dentistry. Currently, there are approximately 2,500 dentists, with a ratio of 1 dentist for every 10,000 people.

  15. Dental Care in Scleroderma

    Science.gov (United States)

    Dental Care in Scleroderma People living with scleroderma face unique challenges while trying to maintain their oral ... They are more likely to be affected by dental conditions such as small mouth, dry mouth, jaw ...

  16. Dental care - child

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002213.htm Dental care - child To use the sharing features on ... and rinsing daily. It also includes having routine dental exams, and getting necessary treatments such as fluoride, ...

  17. AUTHORITARIANISM AND DENTAL CARIES.

    Science.gov (United States)

    in particular. If so, dental decay among nonauthoritarians might well progress further than among authoritarians. To determine whether or not there...is any relationship between dental decay and authoritarianism is the purpose of the present study. (Author)

  18. Dental Effluent Guidelines

    Science.gov (United States)

    Overview and documents for Dental Office Category regulation (40 CFR Part 441); comprising pretreatment standards for discharges of dental amalgam pollutants, including mercury, into publicly owned treatment works (POTWs).

  19. Dental Sealants Prevent Cavities

    Science.gov (United States)

    ... MMWR RSS VitalSigns RSS Error processing SSI file Dental Sealants Prevent Cavities Effective protection for children Language: ... more use of sealants and reimbursement of services. Dental care providers can Apply sealants to children at ...

  20. Smile dental journal

    National Research Council Canada - National Science Library

    "Smile dental journal is quarterly issued, peer-reviewed open access journal. Subject coverage is dentistry, dealing with all specialties of dentistry, its management, besides dental health related subjects...

  1. The Layout and Simulation of Logarithmic Spiral Double Curved Arch Dam Transverse Joints%The Layout and Simulation of Logarithmic Spiral Double Curved Arch Dam Transverse Joints

    Institute of Scientific and Technical Information of China (English)

    DU Ting-na; DU Qi-lu; HUI Yuan

    2011-01-01

    Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C++ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.

  2. ARCHES: Advancing Research & Capacity in Hydrologic Education and Science

    Science.gov (United States)

    Milewski, A.; Fryar, A. E.; Durham, M. C.; Schroeder, P.; Agouridis, C.; Hanley, C.; Rotz, R. R.

    2013-12-01

    Educating young scientists and building capacity on a global scale is pivotal towards better understanding and managing our water resources. Based on this premise the ARCHES (Advancing Research & Capacity in Hydrologic Education and Science) program has been established. This abstract provides an overview of the program, links to access information, and describes the activities and outcomes of student participants from the Middle East and North Africa. The ARCHES program (http://arches.wrrs.uga.edu) is an integrated hydrologic education approach using online courses, field programs, and various hands-on workshops. The program aims to enable young scientists to effectively perform the high level research that will ultimately improve quality of life, enhance science-based decision making, and facilitate collaboration. Three broad, interlinked sets of activities are incorporated into the ARCHES program: (A1) the development of technical expertise, (A2) the development of professional contacts and skills, and (A3) outreach and long-term sustainability. The development of technical expertise (A1) is implemented through three progressive instructional sections. Section 1: Students were guided through a series of online lectures and exercises (Moodle: http://wrrs.uga.edu/moodle) covering three main topics (Remote Sensing, GIS, and Hydrologic Modeling). Section 2: Students participated in a hands-on workshop hosted at the University of Georgia's Water Resources and Remote Sensing Laboratory (WRRSL). Using ENVI, ArcGIS, and ArcSWAT, students completed a series of lectures and real-world applications (e.g., Development of Hydrologic Models). Section 3: Students participated in field studies (e.g., measurements of infiltration, recharge, streamflow, and water-quality parameters) conducted by U.S. partners and international collaborators in the participating countries. The development of professional contacts and skills (A2) was achieved through the promotion of networking

  3. 75 FR 33169 - Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation...

    Science.gov (United States)

    2010-06-11

    ...-AG21 Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam, Mercury, and Amalgam Alloy; Technical Amendment AGENCY: Food... classified dental amalgam as a class II device, reclassified dental mercury from class I to class II, and...

  4. Role of Probiotics in Dental Caries and Periodontal Disease

    Directory of Open Access Journals (Sweden)

    Amit Bhardwaj

    2012-02-01

    Full Text Available Probiotics have been found to be beneficial to host health. In medicine, probiotics are used mainly in support therapy for gastro-intestinal diseases. In recent years, probiotics have been used as a treatment to promote oral health. There has also been a change in understanding of the oral disease process because of better understanding of the ecology and microbiology of the oral cavity. Very encouraging studies exploring probiotics in the fields of caries, periodontal diseases and few other areas have come up in the recent past and the results tend to suggest beneficial effects of probiotics on oral health and on the whole body in general. Extensive research to create a probiotic product intended to maintain dental and periodontal health is needed. This article reviews the role of probiotics in dental caries and periodontal disease. [Arch Clin Exp Surg 2012; 1(1.000: 45-49

  5. Dental Practice Management

    OpenAIRE

    Gheorghe Raftu

    2016-01-01

    the population. Private dental practices in Romania require personnel specialized in dental management. Success in dentistry depends, on the one hand, on the management of clinical aspects, and equallyon the efficient management of the dental practice. Patient satisfaction is influenced by factors related to the communication between the physicianand the patient, technical competence and by the environment provided by dental practice. The realization of the paper followed a review...

  6. Nance弓和横腭杆在拉尖牙远移中支抗效果的研究%A clinical trail of the anchorage by Nance arch and transpalatal arch in the labioversion canine distal move

    Institute of Scientific and Technical Information of China (English)

    边翔; 杨永进; 法永红; 沈焕; 李志韧

    2012-01-01

    Objective: To evaluate the anchorage effects of Nance arch and transpalatal arch(TPA) in the labioversion canines dish move. Methods; Forty patients were recruited and randomly allocated into TPA group and Nance arch group. Enrollment criteria ir eluded Class I or Class II devision 1 maloclussion, moderate crowding and extraction of upper and lower first premolars. The caninj distal- movement therapy was completed in all the patients. Lateral cephalograms and study casts were collected before treatment and ; the clinical end point. Statistical analysis was performed using software package SPSS 17.0. Results: There was no significant diflei ence between the TPA and Nance arch groups in terms of prevention of mesial drift,stable width, vertical displacement and distal tip ping (P>0.05). However, the molar rotation was 8.50??.59?in TPA group and 3.70??1.20?in Nance arch group(P<0.05) Conclusion: Nance arch is more effective in prevention of mesio-palatal rotation in the canine-distal-movement therapy.%目的:研究Nance弓和横腭杆在拉尖牙远移过程中,二者在三维方向上磨牙支抗效果的比较.方法:选择Angle Ⅰ类中度拥挤,或Angle Ⅱ类Ⅰ分类软组织侧貌前突不明显者40人,随机分组,上、下颌减数双侧第一前磨牙,设计方案为中度支抗,两步法关闭拔牙间隙.排齐整平后和治疗阶段结束时取模型,拍摄口内像和头颅侧位片.测量各标志点的线距和磨牙角度变化.应用SPSS 17.0统计软件对测量结果行统计学分析.结果:2组在阻止上颌第一恒磨牙近中前移、水平宽度或垂直方向、近中倾斜差异无显著性,但在磨牙旋转的控制上,Nance弓组磨牙向近中舌向旋转3.70°±1.20°,横腭杆组向近中舌向旋转8.50°±3.59°(p<0.05).结论:在磨牙旋转支抗控制上,Nance弓明显优于横腭杆.

  7. Changing step width alters lower extremity biomechanics during running.

    Science.gov (United States)

    Brindle, Richard A; Milner, Clare E; Zhang, Songning; Fitzhugh, Eugene C

    2014-01-01

    Step width is a spatiotemporal parameter that may influence lower extremity biomechanics at the hip and knee joint. The purpose of this study was to determine the biomechanical response of the lower extremity joints to step width changes during running. Lower extremity data from 30 healthy runners, half of them male, were collected during running in three step width conditions: preferred, wide, and narrow. Dependent variables and step width were analyzed using a mixed model ANOVA and pairwise t-tests for post hoc comparisons. Step width was successfully altered in the wide and narrow conditions. Generally, frontal plane peak values decreased as step width increased from narrow to preferred to wide. Peak hip adduction and rearfoot eversion angles decreased as step width increased from narrow to wide. Peak knee abduction moment and knee abduction impulse also decreased as step width increased from narrow to wide. Although men and women ran differently, gender only influenced the effect of step width on peak rearfoot inversion moment. In conclusion, step width influences lower extremity biomechanics in healthy runners. When step width increased from narrow to wide, peak values of frontal plane variables decreased. In addition to previously reported changes at the rearfoot, the hip and knee joint biomechanics were also influenced by changes in step width.

  8. Stress Among Dental Students

    NARCIS (Netherlands)

    A.M. Alzahem (Abdullah)

    2015-01-01

    markdownabstractAbstract Dental students are facing many stressors in dental education, causing many negative outcomes. The most common are the exams and the clinical requirements. We suggest exposing the dental students to patient care as early as possible in their curriculum. This can help to bal

  9. [Dental records and responsibility

    NARCIS (Netherlands)

    Brands, W.G.

    2006-01-01

    Dental records are more than a small part of the bookkeeping. In most dental practises, keeping records is the task of a dental assistant. In civil court, the dentist is in most countries liable for the mistakes of his employees. In disciplinary court however there may be doubt whether the dentist i

  10. Stress Among Dental Students

    NARCIS (Netherlands)

    A.M. Alzahem (Abdullah)

    2015-01-01

    markdownabstractAbstract Dental students are facing many stressors in dental education, causing many negative outcomes. The most common are the exams and the clinical requirements. We suggest exposing the dental students to patient care as early as possible in their curriculum. This can help to bal

  11. Dental Assistant, Advanced. Revision

    Science.gov (United States)

    1989-02-01

    a jaw fracture, leukemia, dental caries, and periodontal disease. Dental diabetes mellitus , rheumatic fever, allergies, car- disease can be prevented...Dentistry ........................ 4-1 5. Oral Surgery, Endodontics, and Periodontics ................ 5-1 6. Prosthodontics...Diagnosis Periodontics Medical clinics may have branch clinics subor- Operative Dentistry Preventive Dentistry dinate to them. Although dental

  12. The Average Widths and Non-linear Widths of the Classes of Multivariate Functions with Bounded Moduli of Smoothness

    Institute of Scientific and Technical Information of China (English)

    Yong-ping Liu; Gui-qiao Xu

    2002-01-01

    The classes of the multivariate functions with bounded moduli on Rd and Td are given and their average a-widths and non-linear n-widths are discussed. The weak asymptotic behaviors are established for the corresponding quantities.

  13. Global synchronization of parallel processors using clock pulse width modulation

    Science.gov (United States)

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  14. SOL Width Scaling in the MAST Tokamak

    Science.gov (United States)

    Ahn, Joon-Wook; Counsell, Glenn; Connor, Jack; Kirk, Andrew

    2002-11-01

    Target heat loads are determined in large part by the upstream SOL heat flux width, Δ_h. Considerable effort has been made in the past to develop analytical and empirical scalings for Δh to allow reliable estimates to be made for the next-step device. The development of scalings for a large spherical tokamak (ST) such as MAST is particularly important both for development of the ST concept and for improving the robustness of scalings derived for conventional tokamaks. A first such scaling has been developed in MAST DND plasmas. The scaling was developed by flux-mapping data from the target Langmuir probe arrays to the mid-plane and fitting to key upstream parameters such as P_SOL, bar ne and q_95. In order to minimise the effects of co-linearity, dedicated campaigns were undertaken to explore the widest possible range of each parameter while keeping the remainder as fixed as possible. Initial results indicate a weak inverse dependence on P_SOL and approximately linear dependence on bar n_e. Scalings derived from consideration of theoretical edge transport models and integration with data from conventional devices is under way. The established scaling laws could be used for the extrapolations to the future machine such as Spherical Tokamak Power Plant (STPP). This work is jointly funded by Euratom and UK Department of Trade and Industry. J-W. Ahn would like to recognise the support of a grant from the British Foreign & Commonwealth Office.

  15. Aperture width of the osteomeatal complex as a predictor of successful treatment of odontogenic maxillary sinusitis.

    Science.gov (United States)

    Tomomatsu, N; Uzawa, N; Aragaki, T; Harada, K

    2014-11-01

    Odontogenic maxillary sinusitis (OMS) is an inflammatory disease caused by the spread of dental inflammation into the sinus. The long-term administration of antibiotic medicine and/or treatment of the causative tooth are the usual initial treatments. These initial treatments are not always effective, and the reason is not well understood. The purpose of this study was to identify factors of significance that may contribute to the results of the initial treatment of OMS. Thirty-nine patients were studied, divided into two groups according to the results of initial treatment: effective or non-effective. The effective group comprised 20 patients who were cured by initial treatment. The non-effective group comprised 19 patients who required an additional operation. The duration of symptoms, spread into the other sinuses, aperture width of the osteomeatal complex (OMC) on the side of the maxillary sinus, and anatomical variations in the sinuses were compared between the groups. The only significant difference found was in the aperture width of the OMC, which was significantly narrower in the non-effective group than in the effective group. The aperture width of the OMC may be a significant predictor of the effectiveness of initial treatment of OMS.

  16. Initial arch wires for alignment of crooked teeth with fixed orthodontic braces.

    LENUS (Irish Health Repository)

    Wang, Yan

    2010-01-01

    The initial arch wire is the first arch wire to be inserted into the fixed appliance at the beginning of orthodontic treatment and is used mainly for correcting crowding and rotations of teeth. With a number of orthodontic arch wires available for initial tooth alignment, it is important to understand which wire is most efficient, as well as which wires cause the least amount of root resorption and pain during the initial aligning stage of treatment.

  17. Stiffness of the human foot and evolution of the transverse arch

    OpenAIRE

    Venkadesan, Madhusudhan; Dias, Marcelo A.; Singh, Dhiraj K.; Bandi, Mahesh M.; Mandre, Shreyas

    2017-01-01

    Foot stiffness underlies its mechanical function, and is central to the evolution of human bipedal locomotion. The stiff and propulsive human foot has two distinct arches, the longitudinal and transverse. By contrast, the feet of non-human primates are flat and softer. Current understanding of foot stiffness is based on studies that focus solely on the longitudinal arch, and little is known about the mechanical function of the transverse arch. However, common experience suggests that transver...

  18. Classification of the height and flexibility of the medial longitudinal arch of the foot

    OpenAIRE

    2012-01-01

    Abstract Background The risk of developing injuries during standing work may vary between persons with different foot types. High arched and low arched feet, as well as rigid and flexible feet, are considered to have different injury profiles, while those with normal arches may sustain fewer injuries. However, the cut-off values for maximum values (subtalar position during weight-bearing) and range of motion (ROM) values (difference between subtalar neutral and subtalar resting position in a ...

  19. GAP WIDTH STUDY IN LASER BUTT-WELDING

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    In this paper the maximum allowable gap width in laser butt-welding is intensively studied. The gap width study (GWS) is performed on the material of SST of W1.4401 (AISI 316) under various welding conditions, which are the gap width : 0.00-0.50 mm, the welding speed : 0.5-2.0 m/min, the laser...... to the welding speed, (2) the larger laser power leads to the bigger maximum allowable gap width and (3) the focal point position has very little influence on the maximum gap width....... power : 2 and 2.6 kW and the focal point position : 0 and -1.2 mm. Quality of all the butt welds are destructively tested according to ISO 13919-1.Influences of the variable process parameters to the maximum allowable gap width are observed as (1) the maximum gap width is inversely related...

  20. A rare cause of cervical spinal stenosis: posterior arch hypoplasia in a bipartite atlas

    Energy Technology Data Exchange (ETDEWEB)

    Atasoy, C. [Emek, Kirim Caddesi, Ankara (Turkey); Department of Radiology, Ankara University School of Medicine (Turkey); Fitoz, S.; Karan, B.; Erden, I.; Akyar, S. [Department of Radiology, Ankara University School of Medicine (Turkey)

    2002-03-01

    We describe CT and MRI of a previously unreported combination of atlantoaxial anomalies consisting of posterior arch hypoplasia in a bipartite atlas with an os odontoideum, in a 30-year-old woman presenting with neck and left arm pain. MRI showed the os odontoideum, marked stenosis of the spinal canal at the level of the atlas, with cord compression and evidence of myelopathy. CT revealed a bipartite atlas with midline clefts in anterior and posterior arches, thickening in the anterior arch and hypoplasia of the posterior arch with incurving of both hemiarches. Flexion and extension radiographs demonstrated atlantoaxial instability. (orig.)

  1. [Diagnosis and follow-up of reduction of fractures of the zygomatic arch].

    Science.gov (United States)

    Friedrich, R E; Volkenstein, R J

    1994-08-01

    Ultrasound and standard x-ray investigations before and after the reduction of the fractures were performed in 17 patients with zygomatic arch fractures. The ultrasound investigation of the bone surface is recommended as an additional diagnostic tool in the diagnosis and control of the reduction of zygomatic arch fractures. Intraoperative ultrasound imaging under sterile conditions is easy to apply and enables the surgeon to optimise therapeutic results. In 5 cases based on an intraoperative sonogram further reductions of zygomatic arch fractures were carried out. In another referred patient the diagnosis of a zygomatic arch fracture was excluded by ultrasound and confirmed by standard x-ray examinations.

  2. Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yumin; Zhu, Ming; Sun, Aimin; Li, Yuhua [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China); Jaffe, Richard B. [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States); Gao, Wei [Shanghai Jiao Tong University School of Medicine, Department of Cardiology, Shanghai Children' s Medical Center, Shanghai (China)

    2007-03-15

    Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information. (orig.)

  3. The Foot’s Arch and the Energetics of Human Locomotion

    OpenAIRE

    Stearne, Sarah M.; McDonald, Kirsty A.; Jacqueline A Alderson; Ian North; Oxnard, Charles E; Jonas Rubenson

    2016-01-01

    The energy-sparing spring theory of the foot’s arch has become central to interpretations of the foot’s mechanical function and evolution. Using a novel insole technique that restricted compression of the foot’s longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms−1) level running increased metabolic cost by + 6.0% (p ...

  4. Out-of-plane free vibration analysis of a cable-arch structure

    Science.gov (United States)

    Kang, H. J.; Zhao, Y. Y.; Zhu, H. P.

    2013-02-01

    Cable-arch structure has been widely used in many long-span structures such as cable roofs and cable-stayed arch bridges, but its dynamics is still not well understood. In this paper, the out-of-plane dynamic behavior of a cable-arch structure is investigated. The equations governing the out-of-plane free vibration of the structure are derived using d'Alembert's principle. A transfer matrix method is used to solve the governing equations and determine the frequencies of the out-of-plane vibration. The theories are then used to study two specific cases: free vibration of a model cable-arch and simulation of an arch erection process. The effects of some key parameters of cable and arch, such as tension of cable and radius, open-angle and shape of arch, are examined. The results indicate that in-plane and spatial cables can largely improve the out-of-plane dynamic behavior of arch structures, which are further verified by analyzing the out-of-plane buckling of cable-arch structures. The present work should be valuable and significant not only for the fundamental research but also engineering design of roofs and bridges.

  5. Congenital aortic arch anomalies: diagnosis using contrast enhanced magnetic resonance angiography

    Institute of Scientific and Technical Information of China (English)

    ZHU Ming; ZHONG Yu-min; LI Yu-hua; SUN Ai-min; JIN Biao

    2005-01-01

    @@ Congenital aortic arch anomalies occur most commonly in children. The disease can be classified into three types: ① obstructive congenital abnormalities, including coarctation of aorta (CoA) and interruption of aortic arch (IAA); ② non-obstructive congenital abnormalities, including double aortic arch and others; ③ congenital shunt abnormalities, including different types of patent ductus arteriosus (PDA). Management of patients with congenital aortic arch anomalies relies on imaging. Routine imaging modalities, such as conventional X-ray plain film and transthoracic echocardiography (TTE), have been recently complemented by magnetic resonance imaging (MRI).

  6. Elastic responses of underground circular arches considering dynamic soil-structure interaction: A theoretical analysis

    Institute of Scientific and Technical Information of China (English)

    Hai-Long Chen; Feng-Nian Jin; Hua-Lin Fan

    2013-01-01

    Due to the wide applications of arches in underground protective structures,dynamic analysis of circular arches including soil-structure interactions is important.In this paper,an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained.The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equation of motion.By neglecting the influences of shear,rotary inertia and tangential forces and assuming the arch incompressible,the equations of motion of the buried arches were set up.Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal superposition.Arches with different opening angles,acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch.The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.

  7. Earthquake safety assessment of concrete arch and gravity dams

    Institute of Scientific and Technical Information of China (English)

    Lin Gao; Hu Zhiqiang

    2005-01-01

    Based on research studies currently being carried out at Dalian University of Technology, some important aspects for the earthquake safety assessment of concrete dams are reviewed and discussed. First, the rate-dependent behavior of concrete subjected to earthquake loading is examined, emphasizing the properties of concrete under cyclic and biaxial loading conditions. Second, a modified four-parameter Hsieh-Ting-Chen viscoplastic consistency model is developed to simulate the rate-dependent behavior of concrete. The earthquake response of a 278m high arch dam is analyzed, and the results show that the strain-rate effects become noticeable in the inelastic range. Third, a more accurate non-smooth Newton algorithm for the solution of three-dimensional frictional contact problems is developed to study the joint opening effects of arch dams during strong earthquakes. Such effects on two nearly 300m high arch dams have been studied. It was found that the canyon shape has great influence on the magnitude and distribution of the joint opening along the dam axis. Fourth, the scaled boundary finite element method presented by Song and Wolf is employed to study the dam-reservoir-foundation interaction effects of concrete dams. Particular emphases were placed on the variation of foundation stiffness and the anisotropic behavior of the foundation material on the dynamic response of concrete dams. Finally, nonlinear modeling of concrete to study the damage evolution of concrete dams during strong earthquakes is discussed. An elastic-damage mechanics approach for damage prediction of concrete gravity dams is described as an example. These findings are helpful in understanding the dynamic behavior of concrete dams and promoting the improvement of seismic safety assessment methods.

  8. Oro-dental features of Pallister-Killian syndrome: Evaluation of 21 European probands.

    Science.gov (United States)

    Bagattoni, Simone; D'Alessandro, Giovanni; Sadotti, Agnese; Alkhamis, Nadia; Rocca, Alessandro; Cocchi, Guido; Krantz, Ian David; Piana, Gabriela

    2016-09-01

    Pallister-Killian syndrome (PKS) is a rare sporadic multi-systemic developmental disorder caused by a mosaic tetrasomy of the short arm of chromosome 12. A wide range of clinical characteristics including intellectual disability, seizures, and congenital malformations has previously been described. Individuals with PKS show a characteristic facial phenotype with frontal bossing, alopecia, sparse eyebrows, depressed nasal bridge, long philtrum, telecanthus, and posteriorly rotated ears. Oro-dental features, such as "Pallister lip," macroglossia, delayed eruption of primary teeth, high arched-palate, prognathism, and cleft palate have been occasionally reported in the medical literature. The aim of the study was to assess the oro-dental phenotype of PKS and to describe the oral health status in a cohort participating in the First European Workshop on PKS. A clinical dental examination was performed in 21 Caucasian probands and data regarding medical and dental history collected. Twelve probands (57%) showed an atypical dental pattern, with multiple missing teeth (primarily the first permanent molars) and 2 (10%) a double teeth. The severity of gingivitis and dental caries increased with age and gingival overgrowth was a common finding. A characteristic occlusive phenotype was found: a high-arched palate with mandibular prognathism associated with an anterior openbite and crossbite and with posterior crossbite (unilateral or bilateral). The prevalence of oral habits (non-nutritive sucking, mouth breathing, bruxism) was high, even in older probands. This study suggests that individuals affected by PKS should be observed closely for oro-dental diseases and a multidisciplinary approach is needed to implement the right preventive measures. © 2016 Wiley Periodicals, Inc.

  9. Effects of different medial arch support heights on rearfoot kinematics

    Science.gov (United States)

    Mayer, Frank; Baur, Heiner

    2017-01-01

    Background Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait. Methods Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05). Results Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high. Conclusion Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait. PMID:28257426

  10. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  11. Abnormal foramina on the posterior arch of atlas vertebra

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    Nayak SB

    2008-10-01

    Full Text Available Atlas is the first cervical vertebra. It articulates with the occipital bone above and the axis vertebra below. It plays an important role in movement of the skull and the neck. We found a rare variation of the atlas vertebra. The posterior arch of the atlas had one accessory foramen just behind each lateral mass. Foramen on the right side was larger than that of the left. The knowledge of this variation may be of importance to orthopedic surgeons, neurosurgeons, radiologists and anthropologists.

  12. Full-Arch Rehabilitation of a Patient With Cyclic Neutropenia.

    Science.gov (United States)

    Block, Michael S; Brindis, Marco; Block, Celeste A; Berron, Joaquin M

    2015-09-01

    The purpose of this report is to discuss the treatment of a patient with cyclic neutropenia. This patient presented with flared teeth, thin alveolar bone, and mobile teeth. A staged approach was used to remove her teeth, augment the bone, use immediate fixed provisional to determine the type of final prostheses, and ultimately to use cone-shaped overdenture attachments to retain her final prostheses. The result was rehabilitation of the patient with esthetic full-arch fixed-removable dentures with no adverse sequelae in this patient with this systemic disease.

  13. A comparative study of inter-abutment distance of dies made from full arch dual-arch impression trays with those made from full arch stock trays: An in vitro study

    OpenAIRE

    Reddy Jagan; Prashanti E; Kumar G; Suresh Sajjan M; Mathew Xavier

    2009-01-01

    Objectives: The dual-arch impression technique is convenient in that it makes the required maxillary and mandibular impressions, as well as the inter-occlusal record in one procedure. The accuracy of inter-abutment distance in dies fabricated from dual-arch impression technique remains in question because there is little information available in the literature. Materials and Methods: This study was conducted to evaluate the accuracy of inter-abutment distance in dies obtained from full ar...

  14. Avaliação do espaço adicional requerido no perímetro do arco inferior para o nivelamento da curva de Spee Assessment of the additional lower arch perimeter needed for leveling the curve of Spee

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    Marcio José da Silva Campos

    2009-08-01

    Full Text Available OBJETIVO: determinar o perímetro de arco adicional necessário para o nivelamento da curva de Spee através de uma técnica laboratorial em modelos de estudo. MÉTODOS: foram utilizados 70 modelos inferiores nos quais se mediu a profundidade da curva de Spee e o perímetro do arco (de segundo molar a segundo molar. Nos mesmos modelos, após a simulação do nivelamento da curva de Spee, o perímetro de arco foi novamente avaliado, mantendo sua forma e comprimento. RESULTADOS: foi confirmada a correlação entre a profundidade da curva de Spee e o perímetro de arco adicional, sendo deduzida a fórmula [Paa = 0,21 CSmax - 0,04]. CONCLUSÃO: a técnica proposta permitiu, através da avaliação do perímetro de arco com curva de Spee nivelada, a determinação do espaço disponível para o alinhamento dentário.AIM: To determine the additional arch perimeter needed for leveling the curve of Spee by means of a laboratory technique using dental casts. METHODS: Seventy lower dental models were used for measuring the depth of the curve of Spee and assessing the arch perimeter from second molar to second molar. In these dental casts, after simulation of leveling the curve of Spee, arch perimeter was reevaluated, after maintaining its form and length. RESULTS: The correlation between the depth of the curve of Spee and the additional arch perimeter was ratified, as can be shown by the formula [Paa = 0,21 CSmax - 0,04]. CONCLUSION: The proposed technique allowed, through the assessment of the arch perimeter with the leveled curve of Spee, the determination of the space available for tooth alignment.

  15. Aortic knob width reflects left ventricular diastolic function assessed by gated myocardial perfusion single photon emission computed tomography in patients with normal myocardial perfusion.

    Science.gov (United States)

    Kurisu, Satoshi; Higaki, Tadanao; Sumimoto, Yoji; Ikenaga, Hiroki; Watanabe, Noriaki; Ishibashi, Ken; Dohi, Yoshihiro; Fukuda, Yukihiro; Kihara, Yasuki

    2017-04-01

    Aortic knob width on chest radiography represents the extent of aortic dialation and tortuosity of the aortic arch. We tested the hypothesis that aortic knob width reflected left ventricular (LV) diastolic function assessed by gated myocardial perfusion single photon emission computed tomography (SPECT) in patients with normal myocardial perfusion. One hundred and thirty patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled in this study. Aortic knob width was measured along the horizontal line from the point of the lateral edge of the trachea to the left lateral wall of the aortic knob. The peak filling rate (PFR) and the one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters. There were 114 male and 16 female patients. Age ranged from 43 to 88 years (69.9 ± 8.9 years). Aortic knob width ranged from 24.2 to 53.4 mm (37.6 ± 5.7 mm). There was a significant correlation between age and aortic knob width (r = 0.34, p perfusion.

  16. Reliability of CBCT in the diagnosis of dental asymmetry

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    Antônio Carlos de Oliveira Ruellas

    2014-04-01

    Full Text Available Objective: The aim of this study was to validate a method used to assess dental asymmetry, in relation to the skeletal midline, by means of CBCT. Methods: Ten patients who had CBCT scans taken were randomly selected for this study. Five different observers repeated 10 landmarks (x, y and z variables for each and 12 linear measurements within 10 days. Measurements were taken in both arches to evaluate symmetry of first molars, canines and dental midline in relation to the skeletal midline. Intraclass correlation coefficient (ICC was carried out to assess intra- and interobserver reliability for landmarks and distances. Average mean difference was also assessed to check measurement errors between observers. Results: ICC landmarks was ≥ 0.9 for 27 (90% and 25 (83% variables for intra- and interobserver, respectively. ICC for distances was ≥ 0.9 for 7 (58% and 5 (42%, respectively. All ICC landmarks for distances were >0.75 for both intra- and interobserver. The mean difference between observers was ≤ 0.6 mm for all the distances. Conclusion: The method used to assess dental asymmetry by means of CBCT is valid. Measurements of molars, canines and dental midline symmetry with the skeletal midline are reproducible and reliable when taken by means of CBCT and by different operators.

  17. Dental treatment of a child with congenital central hypoventilation syndrome.

    Science.gov (United States)

    Boka, V; Lefkelidou, A; Athanasiadou, E

    2016-06-01

    Congenital Central Hypoventilation Syndrome (CCHS) is a rare condition combining respiratory hypoventilation with symptoms of autonomic dysregulation. Management of patients requires both medical and dental expertise to achieve a successful outcome. The aim of this paper is to present the dental management of a child diagnosed with CCHS, without pharmacological measures and in cooperation with medical expertise. A 7-year-old girl was referred to a private dental practice with the chief complaints being pain and poor aesthetics. The child had been diagnosed with CCHS since infancy and had undergone several courses of medication. Although the patient was uncooperative, the paediatric pulmonologist advised against general anaesthesia. As a result, she was treated in the operating theater (OT) without sedatives, being monitored throughout the entire procedure. A total of eight primary teeth needed dental treatment (3 were restored, 4 were extracted and 1 was restored with a preformed metal crown). A mandibular lingual holding arch was placed, two weeks later. The patient was seen after 6 months and 1 year. Her oral hygiene had improved significantly and her mother reported that the child ate better, brushed her teeth on a daily basis and was careful with dietary habits. The collaboration between medical experts and a paediatric dentist was of crucial importance. The use of basic behaviour management techniques in conjunction with monitoring the patient's vital signs led to a successful outcome and an improvement in the behaviour of the patient.

  18. Dental implants for severely atrophied jaws due to ectodermal dysplasia

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    Preetha Balaji

    2015-01-01

    Full Text Available The aim was to present the successful esthetical and functional rehabilitation of partial anodontia in a case of severe ectodermal dysplasia with complete atrophy of the jaws. A 17-year-old male with Class III malocclusion with partial anodontia sought dental implant treatment. His expectation was that of Class I occlusion. The challenge in the case was to match the expectation, reality, and the clinical possibilities. Ridge augmentation was performed with a combination of rib graft and recombinant human bone morphogenetic protein-2. Simultaneously, 6 implants (Nobel Biocare™ - Tapered Groovy were placed in maxillary arch and 10 in the mandible. Simultaneous placement ensured faster and better osseointegration though a mild compromise of the primary stability was observed initially. After adequate healing, Customized Zirconia Procera™ system was used to build the framework. Zirconia crown was cemented to the framework. Radiological and clinical evidence of osseointegration was observed in all 16 dental implants. Successful conversion of Class III to Class I occlusion was achieved with the combination of preprosthetic alveolar ridge augmentation, Procera™ Implant Bridge system. Abnormal angulations and or placement of dental implants would result in failure of the implant. Hence conversion of Class III to Class I occlusion needs complete and complex treatment planning so that the entire masticatory apparatus is sufficiently remodeled. Planning should consider the resultant vectors that would otherwise result in failure of framework or compromise the secondary stability of the dental implant during function. A successful case of rehabilitation of complex partial anodontia is presented.

  19. An epidemiological study of malocclusion and occlusal traits related to different stages of dental development

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    Lejla Redžepagić Vražalica

    2017-04-01

    Full Text Available Abstract Introduction: Various types of malocclusions present one of the most common dental problems of today’s population. Planning the implementation of orthodontic therapy, especially preventive and interceptive measures is one of many activities of public sector health, and it requires information regarding the prevalence of malocclusion in different parts of our country. Aim: The aim of this study was to determine the prevalence of malocclusion of preschool and school children in the city of Sarajevo. Materials and methods: This study was comprised of 373 children out of which 200 preschool and school children were included in the final sample according to the inclusion and exclusion criteria for participation. 100 children were five-year-olds with complete deciduous dentition, and 100 children were 14-year-olds with permanent dentition. The examined variables in the study were: dental status and existence of caries, overjet, depth of overbite, a presence of premature contacts, a presence of diastemas, crowding of teeth in the dental arch (for 14-year-olds and rotation of teeth in the dental arch (for 14-year-olds. Results: The prevalence of malocclusion was 58% in the group of preschool children and 83% in the group of school children. Conclusion: Results of this study demonstrate a need for the implementation of preventive and interceptive orthodontic methods in primary health care, which would reduce the need for expensive and long term orthodontic therapy.

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

    Science.gov (United States)

    Rahpeyma, Amin; Khajehahmadi, Saeedeh; Hosseini, Vahid Reza

    2013-09-01

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