Avaliação cefalométrica das alterações do perfil facial naturais e induzidas pelos aparelhos de Herbst e Bionator no tratamento da má oclusão de classe II, divisão 1ª

The aim of this study was to evaluate the facial profile changes due to natural growth and induced by Herbst appliance and Bionator in the treatment of Class II, division 1 malocclusion. In order to do that, we used a sample of 90 lateral radiographs of 45 individuals in pre-pubertal stage, divided up in two experimental groups and one control. The first group, composed of 15 brazilian individuals, with initial mean age of 9.4 years, was treated with the Herbst appliance for a period of seven months. The second experimental group consisting of 15 brazilian individuals, initial mean age of 9.9 years has gone through bionator therapy for an average period of 21 months. The control group of 15 individuals, who were not treated orthodontically, comes up from the Burlington Growth Centre, University of Toronto, Canada. The intragroup comparison was performed using the Student t test and intergroup comparisons by ANOVA complemented by the Bonferroni test. The results have shown that only the group treated with the Herbst appliance presented significant changes in facial profile with improvement of its convexity and lower lip protrusion.