Profile changes following orthodontic treatment of class I bimaxillary protrusion in adult patients of Dravidian ethnicity: A prospective study.

AIM: To prospectively evaluate soft and hard tissue responses to orthodontic treatment of bimaxillary protrusion (BMP) in Dravidian population using McLaughlin, Bennett, and Trevisi (MBT) mechanics of the preadjusted edgewise appliance. METHODS: Thirty-one adult (18-30 years) Class I BMP patients were treated using the above mechanics after extraction of four first premolars. Forty-five pre- and post-treatment variables on lateral cephalograms were compared using paired t-test and Pearson's correlation coefficient. RESULTS: All linear and angular parameters pertaining to hard and soft tissues showed significant changes, indicating retraction of incisors, upper and lower lips; increase in nasolabial angle; and decrease in circumoral convexity, interlabial gap, and lip thickness. Various correlations established were (1) upper lip to upper incisor retraction 1:2.01, (2) lower lip to upper incisor retraction 1:1.5, (3) lower lip to lower incisor retraction 1:1, and (4) upper incisor retraction to nasolabial angle 1:2.02. CONCLUSIONS: Orthodontic therapy using MBT mechanics is very useful in achieving favorable hard and soft tissue changes, following four first premolar extractions in BMP. The various correlations established between incisor retraction and soft tissue parameters could prove useful to the discerning clinician.

Comparison of arch forms between Turkish and North American.

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.

Comparison of arch forms between Turkish and North American

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.

RESUMO Objetivo: o objetivo deste estudo foi avaliar as diferenças morfológicas entre as arcadas dentárias inferiores de indivíduos turcos e indivíduos norte-americanos leucodermas. Métodos: a amostra incluiu 132 indivíduos turcos (34 Classe I, 58 Classe II e 40 Classe III) e 160 norte-americanos (60 Classe I, 50 Classe II e 50 Classe III). A porção mais vestibular de 13 áreas de contato proximal foi digitalizada a partir de imagens impressas das arcadas dentárias inferiores dos pacientes. Os pontos de colagem dos braquetes foram calculados, para cada dente, com base em dados referentes à espessura dos dentes inferiores. Quatro medidas lineares e duas proporcionais foram obtidas. Os indivíduos foram classificados de acordo com o formato da arcada (triangular, oval e quadrada), permitindo que a frequência de cada formato fosse comparada entre os grupos étnicos, e dentro de cada classificação de Angle. Resultados: o grupo composto por indivíduos turcos apresentou profundidade da arcada na região dos molares significativamente menor, além de uma proporção largura/profundidade da arcada na região dos molares maior em todas as classificações de Angle. Em contrapartida, esse mesmo grupo mostrou maiores distâncias intercaninos nos pacientes Classe III e intermolares nos pacientes Classe II. A arcada oval foi a mais frequente no grupo composto por indivíduos turcos, enquanto a arcada triangular foi a mais frequente no grupo composto por indivíduos norte-americanos leucodermas. Conclusões: os resultados obtidos mostram que, ao tratar pacientes turcos, o profissional deve prever o uso de arcos ortodônticos pré-conformados ovais em um percentual significativo dos pacientes.

Comparison of Japanese and European overbite depth indicator and antero-posterior dysplasia indicator values.

This study evaluated cephalometric differences between 113 Japanese (43 males and 70 females, aged 14.1 ± 5 years) and 106 European subjects (36 males and 70 females, aged 13.5 ± 7.3 years) using two compound angular measurements and their single components: the overbite depth indicator (ODI) for the assessment of vertical skeletal relationships and the antero-posterior dysplasia indicator (APDI) for an evaluation of sagittal dysgnathia. Both populations were assigned to groups representing Angle Classes I, II, and III, and an anterior open bite (AOB) group. Two sample t- and Wilcoxon signed-ranks tests were performed (P < 0.05). The ODI values showed no statistically significant differences between the Japanese and European samples. The Japanese sample showed a significantly smaller APDI but only in the Class II group. In the Japanese Class II and III subjects, the malocclusion patterns were more pronounced than those in the Caucasian sample (overbite, overjet, and APDI).

Anatomical location of various condylar points for jaw movement analysis in Japanese women.

The aim of this study was to determine anatomical locations of the hinge axis point, kinematic axis point and reference point for the palpated lateral condylar pole on lateral cephalograms. Subjects comprised 18 Japanese women selected according to following criteria: normal occlusion; and absence of signs and symptoms of stomatognathic function. Jaw movement and the condylar reference points noted earlier were recorded three-dimensionally with six degrees of freedom, and kinematic axis point and hinge axis point were determined using an optoelectronic jaw-tracking system. Lateral cephalograms were used to determine anatomical locations of the three points in the condyle. Mean location of hinge axis point was 12.9 mm anterior of the porion and 5.3 mm inferior to the Frankfort horizontal plane, the kinematic axis point was situated in 12.8 mm anterior and 0.1 mm inferior, and the reference point for the palpated lateral condylar pole was situated 10.7 mm anterior and 0.8 mm inferior, respectively. The kinematic axis point was located outside the condyle in the majority of subjects. The reference point for the palpated lateral pole offers a useful indicator in the analysis of condylar movements.

Comparação entre a forma e dimensão do arco dentário inferior de brasileiros e norte americanos / Comparison of dental arch form and dimension between brazilian and north american

A largura e a forma do arco dentário são importantes fatores para se determinar os objetivos e a estabilidade do tratamento ortodôntico. Este estudo visa determinar as diferenças morfológicas entre o arco dentário inferior de indivíduos Caucasianos Norte-Americanos (AM) e Caucasianos Brasileiros (BR), de acordo com a Classe de Angle e o gênero. A amostra foi constituída por 331 modelos de gesso pré-tratamento ortodôntico da arcada inferior, tendo sido obtida a partir de dois grupos: 160 Caucasianos Norte-Americanos (60 Classe I, 50 Classe II e 50 Classe III) e 171 Caucasianos Brasileiros (61 Classe I, 60 Classe II e 50 Classe III). As superfícies oclusais dos modelos de gesso foram fotocopiadas; a partir das imagens obtidas, foi identificado o ponto clínico do braquete para cada dente de acordo com a espessura do dente inferior referentes aos dados de Andrews. Baseado nestes pontos, foram realizadas medidas de dimensões do arco dentário com o uso de um paquímetro e verificada a forma do arco com templates ortodônticos. Os dados referentes às dimensões do arco foram avaliados estatisticamente através da análise de Kruskal-Wallis e para se avaliar a diferença na distribuição de freqüência de forma de arco foi utilizado o teste Qui-quadrado. Os resultados mostraram que existem diferenças significativas nas dimensões do arco dentário entre AM e BR. O grupo AM apresentou uma menor largura intercaninos que o grupo BR (p<0,05), exceto para o subgrupo feminino Classe I. A largura intermolares também foi menor no grupo AM (p<0,05), mas não foram encontradas diferenças significativas nos subgrupos de Classe III. Os valores médios de profundidade de arco na região de caninos e de molares foram menores para o grupo BR, porém apenas significativas para o subgrupo feminino Classe I (p<0,05)...

The purpose of this study was to evaluate the morphologic differences between North American Caucasian (AM) and Brazilian Caucasian (BR) mandibular dental arches. The sample consisted of 331 pretreatment mandibular orthodontic plaster models divided in two groups; 160 of North American Caucasians (60 Class I, 50 Class II and 50 Class III) and 171 of Brazilians (61 Class I, 60 Class II and 50 Class III). The occlusal surfaces of the mandibular models were photocopied and the clinical bracket point for each tooth was identified. Templates were overlaid to select the arch form; additionally 4 linear and 2 proportional measurements were taken. The results showed significantly differences in arch dimension between the two ethnic groups. The AM group showed significantly smaller intercanine width (p<0,05), excepting for the Class I aches in the female group. In addition, the AM group also showed a significantly smaller intermolar width (p<0,05); no differences were found in the Class III malocclusion group though. The BR group showed smaller canine and molar depths, but the differences were significantly smaller only in the Class I female group (p<0,05)...

Tooth width predictions in a sample of Black South Africans.

Space analysis during the mixed dentition requires prediction of the mesiodistal widths of the unerupted permanent canines and premolars and prediction tables and equations may be used for this purpose. The Tanaka and Johnston prediction equations, which were derived from a North American White sample, is one example which is widely used. This prediction equation may be inapplicable to other race groups due to racial tooth size variability. Therefore the purpose of this study was to derive prediction equations that would be applicable to Black South African subjects. One hundred and ten pre-treatment study casts of Black South African subjects were analysed from the Department of Orthodontics' records at the University of Limpopo. The sample was equally divided by gender with all subjects having Class I molar relationship and relatively well aligned teeth. The mesiodistal widths of the maxillary and mandibular canines and premolars were measured with a digital vernier calliper and compared with the measurements predicted with the Tanaka and Johnston equations. The relationship between the measured and predicted values were analysed by correlation and regression analyses. The results indicated that the Tanaka and Johnston prediction equations were not fully applicable to the Black South African sample. The equations tended to underpredict the male sample, while slight overprediction was observed in the female sample. Therefore, new equations were formulated and proposed that would be accurate for Black subjects.

Bimaxillary protrusion in the Palestinian population.

OBJECTIVE: To study the prevalence of bimaxillary protrusion among Palestinians. MATERIALS AND METHODS: Cephalometric radiographs for 79 normal occlusion adult Palestinian university students were traced. RESULTS: The interincisal angle was decreased in the Palestinian women compared to the Caucasian means, but this had no impact on lip protrusion. CONCLUSION: Relative to Caucasian cephalometric norms, Palestinians show no extraoral bimaxillary protrusion features, and therefore, these norms can be applied to Palestinian faces.

Cephalometric features of Filipinos with Angle Class I occlusion according to the Munich analysis.

The purpose of this study was (1) to establish cephalometric norms for soft tissue, skeletal and dental relationships among Filipino adults; and (2) to compare these norms with the accepted German standards. Eighty-one Filipino subjects, 44 men and 37 women, were selected from the student population of the Manila Central University on the basis of the following criteria: (1) natural-born ethnic Filipino, traced up to their great-grandparent's generation; (2) good facial aesthetics; (3) Angle Class I occlusion with no crowding; (4) all teeth present (third molars may or may not be present); and (5) no previous history of orthodontic treatment. Clinical examinations and interviews were conducted to ensure that the established criteria were observed properly. The German subjects, 78 men and 123 women, were selected from Hamburg and Munich on the basis of the same criteria. Each lateral headfilm was traced and digitized, and differences between the cephalometric measurements of the two groups were compared using the Student's t-test and cephalometric superimpositions. Significant differences between the two groups were seen predominantly in the lower third of the face. The Filipinos showed more posteriorly inclined apical bases and a less prominent chin. Dentally, they exhibited a bimaxillary dental protrusion resulting in an acute dental pattern and a convexity of the soft tissue profile. These findings suggest that ethnic differences in facial traits exist and awareness of the dentofacial pattern of each ethnic group will ensure better success of treatment in establishing optimal facial harmony.

Occlusal traits in a group of school children in an isolated society in Jerusalem.

The prevalence of occlusal features in 939 children, aged 6-13 years, belonging to an ultra-orthodox community of Jewish Ashkenazi descent living in Jerusalem was studied clinically. Sexual dimorphism was found for overjet, overbite, and habit practising. About one-quarter of the sample exhibited some degree of occlusal mutilation due to caries, thus creating a 'caries-affected' subgroup, the rest forming the 'caries-free' subgroup. In the latter set, normocclusion was scarce (7.4 per cent), Class I being the most frequent malocclusion (49.1 per cent). Caries had a significant effect on the symmetry of bilateral occlusal relationships, lower dental midline deviation, and on crowding/spacing conditions in the mixed dentition stage (except for the maxilla in late mixed dentition). The low prevalence of normocclusion can be attributed to genetic background, environmental influences and the definition attached to normal occlusion.

Prevalência de maloclusöes na América Latina e consideraçöes antropológicas / Prevalence of malocclusion in the Latin America and anthropological considerations

Os autores, após tecerem algumas consideraçöes de natureza antropológica, nas quais mostram as variaçöes morfológicas faciais nas várias raças, apresentam alguns trabalhos epidemiológicos sobre a incidência de maloclusöes na América Latina. Observam que as pesquisas säo escassas, de natureza regional e näo obedecem a uma metodologia uniforme. De maneira geral, os percentuais de maloclusöes obtidos na totalidade destas pesquisas raramente estäo abaixo de 50(por cento)

Craniofacial pattern of Class III deciduous dentition.

The purpose of this study was to investigate the morphological characteristics of the cranio-dento-facial complex of children with deciduous dentition and Class III malocclusion. Forty Chinese children in Taiwan with normal occlusion and 40 with Class III malocclusion in deciduous dentition were selected for cephalometric analysis. Mandibular length was significantly greater and the mandible was situated farther forward in the Class III group. The maxilla was also slightly backward in this group, perhaps in association with the shorter maxillary length. The mandibular incisors were tipped lingually to compensate for the intermaxillary skeletal dysplasia and the maxillary incisors were tipped lingually by the retroinclined mandibular incisors.

[A comparative study of the craniofacial morphology of 2 ethnic groups]. / Eine Vergleichsstudie der kraniofazialen Morphologie zweier ethnischer Gruppen.

The samples consisting of 200 latero-lateral cephalometric X-rays of examinees with nearly normal occlusion from Mainz are compared with homologous one from Zagreb. The purpose of the investigation was to point out the morphological differences in cranio-facial system. 19 variables were analysed by using essential statistic parameters and discriminative analysis. The results show the differences in the anterior face height, the lower border mandible inclination, the interincisal angle as well as the degree of face convexity. The average examinee from Zagreb, in comparison with the same one from Mainz, shows smaller anterior face height, the marked mandibular basal line inclination in the sense of the anterior rotation, the higher interincisal angle as well as smaller facial convexity.

An American Board of Orthodontics case report.

A case report is presented of an Angle Class I dental malocclusion, significant bimaxillary dentoalveolar protrusion, anterior open bite, and spacing of the maxillary and mandibular incisors. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]