Cephalometric Study in Adolescents with Class-II-Malocclusion Treated with Mandibular Propulsion

Objectives: The purpose of this study was a prospective assessment during the pubertal growth spurt of subjects with normal occlusion and patients with Class II division 1 malocclusion treated for 18 months with an orthopedic appliance for mandibular advancement, the Fränkel Regulator II. Our objectives were to verify dento-skeletal alterations and facial type changes between the beginning and the end of the observation period. Methods: The sample size consisted of 166 lateral cephalograms acquired from 83 white subjects: control (n=28), treated (n=28) and with normal occlusion (n=27). The data from these 3 groups were tested using analysis of variance, Tukey test (5%) e Wilcoxon test (1,7%). Results: These statistical tests of the cephalometric data revealed in the experimental group a significant restriction of anterior maxillary displacement (P=0,0001), increase in the effective length of the mandible (P=0,0001),as well as a more forward mandibular position relative to the cranial base. With regard to the dento-alveolar component the upper incisors were up righted and retruded (P=0,0016) and the vertical and horizontal trespass were corrected when we compared the treated to the control and normal occlusion groups. We did not observe any significant alteration of the Ricketts vert for the 3 studied groups between the beginning and end of the observation period. Conclusions: This investigation has sown that Fränkel therapy corrected the occlusal Classe II relationship in the treated patients and significant mandibular growth. These alterations aided the achievement of balanced apical bases relationship, without altering the patients facial type.