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.

Evaluación del triángulo cefalométrico de McNamara en sujetos peruanos con distinto ángulo de convexidad facial / Evaluation of cephalometric Mcnamara triangle in peruvian subjects with different facial convexity angle

Objetivo: Comparar la longitud efectiva de la maxila, de la mandíbula y la altura anteroinferior del Análisis Cefalométrico de McNamara según el tipo de perfil facial en radiografías digitales laterales de cabeza de sujetos que acudieron al Centro de Diagnóstico por Imágenes de Lima durante el 2014. Metodología: El estudio estuvo conformado por 90 radiografías digitales laterales de cabeza divididos en tres grupos. El primer grupo incluye radiografías digitales laterales de sujetos con perfil de clase I; el segundo, sujetos con perfil de clase II y el tercero, de sujetos con perfil de clase III, todos de acuerdo a los criterios de selección. Se realizaron mediciones angulares y lineales de acuerdo al Análisis Cefalométrico de McNamara y al tipo de perfil facial con ayuda del programa MicroDicom. Resultados: No se encontraron diferencias estadísticamente significativas entre los tipos de perfil según clase (p<0.001 prueba de ANOVA y Tukey). Solo se encontraron diferencias estadísticamente significativas en el valor Co-Gn, estando disminuido en el perfil de clase II con un valor de 110.21° y aumentada en el perfil de clase III con valor de 125.55° (p<0.001, prueba ANOVA). Conclusiones: La longitud efectiva de la mandíbula está disminuida en el perfil de clase II y aumentado en el perfil de clase III. La longitud efectiva de la maxila y la altura anteroinferior no presentan diferencias estadísticamente significativas según el tipo de perfil facial. (AU)

Objective:Compare the effective length of the maxilla, the jaw and the anterior height of McNamara cephalometric analysis by type of facial profile in digital lateral radiographs of the head of subjects who attended the Imaging Center of Lima in 2014.Methodology:The study consisted of 90 digital lateral radiographs of head divided into three groups. The first group includes digital lateral radiographs of subjects with class I profile; the second, subjects with class II profile and the third profile of subjects with class III, all according to the selection criteria. Angular and linear measurements according to McNamara cephalometric analysis and the type of facial profile using the program MicroDicom performed.Results:No statistically significant differences between the types of profile class (p< 0.001 ANOVA and Tukey test) were found. Only statistically significant differences in the Co -Gn value being diminished profile class II with a value of 110.21 ° and increased profile of class III with a value of 125.55 ° ( p < 0.001 , ANOVA test ) were found.Conclusions:The effective length of the jaw is decreased in Class II profile and increased profile of class III. The effective length of the maxilla and the anterior height no statistically significant differences by type of facial profile. (AU)

Estudio transversal comparativo de la relación maxilo-mandibular de McNamara aplicadas a sujetos mexicanos / Transversal comparative study of McNamara maxillofacial mandibular ratio applied in Mexican subjects

Las características antropológicas entre diversas razas en las cuales se incluyen etnia, sexo y edad en el mundo varían, es preciso analizar que un estudio establecido para una población no puede ser usado para otra, ya que presenta formas y características diferentes; es por esto que existe la necesidad de realizar estudios en diversas razas comparándolos con las normas establecidas. El objetivo fue comparar la relación maxilo-mandibular de McNamara aplicadas en sujetos mexicanos. Se analizaron 60 radiografías laterales de cráneo con trazados de McNamara. Se identificaron diferencias en los patrones genéticos de crecimiento de los caucásicos y los mexicanos. Nuestros resultados muestran un crecimiento típico de los pacientes clase II esqueletal con maxilar hipotónico posteroanteriormente, una mandíbula disminuida y poca altura vertical, esto como consecuencia de una falta de crecimiento del tercio medio facial por una pobre ventilación aérea.

The anthropological characteristics between different races in which ethnicity, sex and age vary in the world, and it becomes necessary to analyze a set for one population study that cannot be used for another, with different shapes and characteristics. There is a need for studies in different races for comparison with established standards. The objective of the research was to compare the McNamara maxilla-mandibular relationship applied in Mexicans subjects and analyze 60 lateral radiographs of the skulls with McNamara traces. Genetic differences in growth patterns of Caucasians and Mexicans were identified. Our results show typical growth of skeletal class II patients with hypotonic posterior jaw, and jaw with diminished vertical height caused by a lack of midface growth the result of poor air flow.

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

Estudo cefalométrico das alterações dos terços médio e inferior da face em pacientes com diferentes padrões respiratórios e faciais / Cephalometric study of the changes of the medium and lower thirds of the face in patients with different breathing and facial patterns

OBJETIVOS: avaliar a possível relação dos padrões respiratórios e dos tipos faciais com as grandezas da análise de Ricketts - CF-N.CF-A, Po-Or.ENA-ENP, CF-Go, CF-Xi.Po-Or, Xi-Pm, N-P.Go-M, A-NP, Po-Or.Na - e as grandezas da Nasofaringe e da Bucofaringe propostas por McNamara; dos tipos faciais com os padrões respiratórios e dos padrões respiratórios com as variáveis do Vert. MÉTODOS: a amostra consistiu de 88 telerradiografias em norma lateral de brasileiros leucodermas, dos gêneros masculino e feminino, entre 7 e 13 anos (média de idade 10,5 anos), sendo 45 respiradores bucais e 43 nasais. O método cefalométrico computadorizado abrangeu a análise das grandezas para determinação do tipo facial, segundo Ricketts (Índice Vert). Aplicou-se a avaliação do erro do método pela fórmula de Dahlberg (média = 0,52), seguida das avaliações estatísticas teste "t" de Student e Pearson product correlative coefficient test (p < 0,05). RESULTADOS E CONCLUSÕES: observou-se ausência de alterações estatisticamente significativas das variáveis quando relacionadas aos padrões respiratórios, e presença de diferenças estatisticamente significativas das variáveis Convexidade do ponto A, Altura posterior da face, Profundidade da maxila, Cone facial, Comprimento do corpo e Nasofaringe quando relacionadas aos tipos braqui e dolicofaciais. As variáveis Cone facial e Comprimento do corpo também apresentaram diferenças significativas entre os tipos braquifacial e mesofacial. A variável Cone facial apresentou diferenças significativas entre todos os tipos faciais; o tipo braquifacial apresentou correlação significativa (p = 0,011) com o padrão de respiração nasal e a variável Profundidade facial apresentou diferença estatisticamente significativa (p = 0,028) quando relacionada aos padrões respiratórios.

AIM: To assess the possible relation of respiratory patterns and facial types with linear and angular variables of the Ricketts analysis - CF-N.CF-A, Po-Or.ENA-ENP, CF-Go, CF-Xi.Po-Or, Xi-Pm, N-P.Go-M, A-NP, Po-Or.Na - and the Nasopharynx and Oropharynx linear variables proposed by McNamara; and of the facial types with the respiratory patterns, and the respiratory patterns with the Vert variables. METHODS: The sample consisted of 88 lateral teleradiographs of Brazilian leucoderm boys and girls, ranging from 7 to 12 years of age (mean age 10.5 years) of whom 45 were mouth-breathers and 43 nasal breathers. The computerized cephalometric method covered analysis of the variables to determine the facial type, according to Ricketts (Vert Index). After the measurements were taken, assessment of the method error by the Dahlberg formula was applied (mean = 0.52), followed by t Student and chi-square tests (p < 0.05) statistical assessments. RESULTS AND CONCLUSIONS: There were no statistically significant alterations in the variables when related to the respiratory patterns; there were statistically significant differences in the following variables: Convexity of point A, Posterior face height, Maxilla depth, Facial cone, Corpus length and Nasopharynx when related to the brachyfacial and dolicofacial types. The variables Facial cone and Corpus length also presented significant differences between the brachyfacial and mesofacial types, and the variable Facial cone presented significant differences among all the facial types; the brachyfacial type presented significant correlation (p = 0.011) with the nasal respiratory pattern; and Facial depth presented statistically significant difference (p = 0.028) when related to the respiratory patterns.

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.