Comparative analysis of the anterior and posterior length and deflection angle of the cranial base, in individuals with facial Pattern I, II and III

OBJECTIVE: This study evaluated the variations in the anterior cranial base (S-N), posterior cranial base (S-Ba) and deflection of the cranial base (SNBa) among three different facial patterns (Pattern I, II and III). METHOD: A sample of 60 lateral cephalometric radiographs of Brazilian Caucasian patients, both genders, between 8 and 17 years of age was selected. The sample was divided into 3 groups (Pattern I, II and III) of 20 individuals each. The inclusion criteria for each group were the ANB angle, Wits appraisal and the facial profile angle (G'.Sn.Pg'). To compare the mean values obtained from (SNBa, S-N, S-Ba) each group measures, the ANOVA test and Scheffé's Post-Hoc test were applied. RESULTS AND CONCLUSIONS: There was no statistically significant difference for the deflection angle of the cranial base among the different facial patterns (Patterns I, II and III). There was no significant difference for the measures of the anterior and posterior cranial base between the facial Patterns I and II. The mean values for S-Ba were lower in facial Pattern III with statistically significant difference. The mean values of S-N in the facial Pattern III were also reduced, but without showing statistically significant difference. This trend of lower values in the cranial base measurements would explain the maxillary deficiency and/or mandibular prognathism features that characterize the facial Pattern III. OBJETIVO: o presente estudo avaliou as varia es da base craniana anterior (S-N), base craniana posterior (S-Ba), e angulo de deflex o da base do cranio (SNBa) entre três diferentes padr es faciais (Padr o I, II e III). MéTODOS: selecionou-se uma amostra de 60 telerradiografias em norma lateral de pacientes brasileiros leucodermas, de ambos os sexos, com idades entre 8 anos e 17 anos. A amostra foi dividida em três grupos (Padr o I, II e III), sendo cada grupo constituído de 20 indivíduos. Os critérios de sele o dos indivíduos para cada grupo basearam-se nos valores de ANB, Wits e angulo do contorno facial (Gl.Sn.Pg'). Para observar se houve diferen a nos valores médios de SNBa, S-N e S-Ba entre os diferentes grupos, utilizou-se a Análise de Variancia One Way - ANOVA, seguida de testes post-hoc de Scheffé. RESULTADOS E CONCLUS ES: n o houve diferen a estatisticamente significativa na deflex o da base do cranio entre os diferentes padr es faciais (Padr o I, II e III). Também n o houve diferen a significativa nos valores da base anterior e posterior do cranio entre o Padr o I e o Padr o II. Os valores médios de S-Ba apresentaram-se reduzidos no Padr o III,