Pretreatment characteristics of adolescents with Class II malocclusion treated by maxillary second molar extraction / 대한치과교정학회지

ABSTRACT

The purpose of this retrospective study was to estimate the pretreatment characteristics of growing patients with Class II malocclusion, who had been treated with maxillary second molar extractions. The sample comprised of 51 subjects; 18 subjects were classified into the molar extraction group, and 33 subjects were treated without extraction and classified into the nonextraction group. Pretreatment lateral cephalograms were calculated and analyzed by independent t-test and stepwise discriminant analysis. In measurements for skeletal pattern, no anteroposterior measurements and proportions of various vertical dimensions were significantly different, and only some measurements such as AB-MP (degree), Na-Me (mm), AVD (mm) were significantly different between the two treatment groups (p < 0.05). In measurements for dentoalveolar pattern, some measurements, which were related to the position and angulation of the upper and lower permanent first molars, and the angulation of the upper third molars, were significantly different between the two treatment groups. In particular, the maxillary second molar extraction group exhibited more mesial angulation of maxillary first molar to the occlusal plane.