Comparison of airway dimensions in skeletal Class I malocclusion subjects with different vertical facial patterns

ABSTRACT Objective: The aim of this study was to compare upper airway widths among skeletal Class I malocclusion subjects with different vertical facial patterns. Methods: The sample included a total of 99 lateral cephalograms of post pubertal individuals (18.19 ± 1.76 years old). The vertical facial pattern was determined by the Vert index. The McNamara method was used to quantify upper airway widths. ANOVA test and Student's t test for independent groups were used, when normal distribution was not supported Kruskal-Wallis test and U-Mann-Whitney test were used. A multiple linear regression analysis was also performed. Results: Statistically significant differences in several nasopharyngeal widths were found among the distinct vertical facial patterns. Subjects with brachyfacial pattern presented larger nasopharyngeal widths than subjects with mesofacial (p= 0.030) or dolichofacial (p= 0.034) patterns. The larger the Vert value, the larger the nasopharyngeal widths (R2= 26.2%, p< 0.001). At the level of oropharynx no statistically significant differences were found. Conclusion: It was concluded that nasopharyngeal linear anteroposterior widths in Class I malocclusion brachyfacial are larger than in mesofacial and dolichofacial individuals. The Vert index only explained 25% of the total variability. No correlation was found for the oropharyngeal widths.

RESUMO Objetivo: o objetivo desse estudo foi comparar as dimensões das vias aéreas superiores em indivíduos portadores de má oclusão de Classe I esquelética com diferentes padrões faciais verticais. Métodos: a amostra consistiu de 99 cefalogramas laterais de indivíduos na pós-puberdade (18,19 ± 1,76 anos). O padrão facial vertical foi determinado por meio do índice VERT. O método de McNamara foi utilizado para quantificar as dimensões das vias aéreas superiores. O teste ANOVA e o teste t de Student para grupos independentes foram utilizados e, quando a distribuição normal não era possível, o teste de Kruskal-Wallis e o teste U de Mann-Whitney foram aplicados. Foi também realizada uma análise de regressão linear múltipla. Resultados: diferenças estatisticamente significativas nas dimensões da nasofaringe foram encontradas entre os diferentes padrões faciais verticais. Os indivíduos com padrão braquifacial apresentaram dimensões nasofaríngeas maiores do que os indivíduos com padrão mesofacial (p= 0,030) ou dolicofacial (p= 0,034). Quanto maior o valor do VERT, maior a dimensão nasofaríngea (R2 = 26,2%, p< 0,001). Não foram encontradas, entretanto, diferenças estatisticamente significativas ao nível da orofaringe. Conclusão: pode-se concluir que as dimensões anteroposteriores lineares da nasofaringe nos indivíduos braquifaciais com má oclusão de Classe I são maiores do que nos indivíduos mesofaciais e dolicofaciais. O índice VERT foi capaz de explicar apenas 25% da variabilidade total. Não foi encontrada correlação para as dimensões da orofaringe.

Comparative Analysis of the Reference Lines on McNamara's and Delaires Analyses for the Anterior and Posterior Facial Relationship of Maxillofacial Deformity

Maxillary protraction effects of TTBA (Tandem Traction Bow Appliance) therapy in Korean Class III children / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to investigate the maxillary protraction effects of the Tandem Traction Bow Appliance (TTBA), a new appliance devised several years ago for the treatment of growing skeletal Class III patients. METHODS: Participants were 88 Korean children (42 boys, 46 girls) with skeletal Class III malocclusion treated with TTBA at the orthodontic clinic of Ewha Womans University Mokdong Hospital. Mean age at the start of treatment was 7.5 years +/- 1.5 years. Mean treatment periods were 13 +/- 3 months. Pretreatment and posttreatment lateral cephalograms were traced and superimposed by the same investigator and analyzed by modified McNamara analysis and pitchfork analysis. Changes were evaluated with paired t-tests at a significance level of p < 0.05. RESULTS: The maxilla and maxillary dentition moved forward. The mandible moved backward, although not significantly; and the mandibular dentition moved forward. The net dental changes combined with the apical base change resulted in a favorable total molar relationship correction. Net dental movement was 26% and the apical base change 74% of the total molar relationship correction. CONCLUSION: These results suggest that TTBA has a maxillary protraction effect that can be useful in the treatment of growing skeletal Class III malocclusion with maxillary deficiency.

McNamara cephalometric analysis of the 55 Chongqing adolescents with normal occlusion / 重庆医科大学学报

Objective:The purpose of this study was to obtain the normal value of McNamara analysis for Chongqing adolescents with normal occlusion of permanent dentition.Methods:Chongqing adolescents with normal occlusion were taken 55 lateral cephalograms.McNamara analysis was conducted and the obtained data were compared with that of Chengdu,Shanghai and McNamara,respectively.Results:There was significant difference in the normal values of McNamara analysis between male and female Chongqing adolescents by t test;there was significant difference between Chongqing and Chengdu,Chongqing and Shanghai,Chongqing and McNamara also.Conclusion:There is significant difference in values of normal occlusion of McNamara analysis in different regions and different races.

Correlation between McNamara cephalometric analysis values and craniomaxillary linear parameters in Chongqing adolescents with normal occlusion / 第二军医大学学报

Objective:To establish the normal value of McNamara cephalometric analysis in Chongqing adolescents with normal occlusion and to obtain its regression models. Methods:Fifty five Chongqing adolescents with normal occlusion (male 27 and female 28)were taken lateral cephalograms. McNamara analysis was conducted and the correlation analysis was carried out.Results: There were significant differences in the normal values of McNamara analysis between male and female Chongqing adolescents, namely the effective maxillary length, effective mandibular length, lower anterior facial height and A Np line. There were no significant differences in Pog Np line, upper incisor to point A vertical,lower incisor to A P line.There were correlations between the effective maxillary length and effective mandibular length, effective mandibular length and lower anterior facial height, A Np line and Pog Np line, respectively.When effective mandibular length was fixed,lower anterior facial height and Pog Np line was correlated.The regression models were obtained.Conclusion:There is correlation between the linear measurements of the cephalometrics values.