Análisis de la flexión de la base del cráneo en relación al prognatismo maxilar

Abstract

the present study aimed at evaluating cranial base flexure in relation to maxillary prognathism in two Brazíl ian ethnic groups. Methods: the sample comprised 240 dry skulls of white (n = 120) and black (n = 120) Brazilians, of both genders. Cranial base flexure and maxillary prognathism were investigated by estimating the mean valúes of the NHBa and NABa angles, respectively. The N H Ba angle mean valúes were compared between ethnic groups and genders using the Student t-test (a = 0.05). The association between the NHBa and NABa angles was assessed by the linear correlation analysis. Results: NHBa angle mean valúes were higher in black individuáis (females = 183° and males = 181.7°), compared with white individuáis (females = 180.7° and males = 178.4°),p < 0.01. Conversely,the mean valúes relative to the NABa angle were greater in white individuáis (females = 79.4° and males = 78.6°) than in black individuáis (females = 76.7° and males = 76.1°). Most of the correlationsbetween NHBaand NABaangles were not significant. Conclusions: concerning the cranial base flexure, there were ethnic differences and sexual dimorphism between white and black Brazilians. The correlations between the angular variables used to estímate cranial base flexure and maxillary prognathism were not significant, except for black females. This finding suggests a trend to the increased maxillary prognathism as related to the enlargement of the cranial base flexure angle in the above-mentioned group.