Abstract:
The present study aimed to cephalometrically compare the skeletal, dental and tegumental changes in white and black patients with Class I malocclusion after orthodontic treatment corrective with extractions of four premolars. This was a retrospective study which the sample comprised the initial and final cephalograms and the initial dental casts of a total of 46 subjects, treated in the Undergraduate Orthodontic Course of the Ingá Faculty, units of Bauru, Maringá and Sarandi. The inclusion criteria were the presence of a Class I molar relationship, dental biprotrusion, slight to moderate anterior crowding, treated orthodontically with fixed appliances and extraction of the four first premolars, as well as the presence of all teeth irrupted till the permanent first molars. Group 1 included 28 white patients (9 males; 19 females), at a mean initial age of 14.39 years (s.d.=2.63), treated for a mean period of 2.23 years (s.d.=0.73). Group 2 included 18 black patients (9 males; 9 females), at a mean initial age of 14.81 years (s.d.=3.07), treated for a mean period of 2.14 years (s.d.=0.82). For intergroup comparison, it was used the independent t test. The results demonstrated that the changes occurred due to the extraction of four premolars in the Class I malocclusion were the following: in Blacks there was greater correction of the maxillomandibular discrepancy in relation to the Whites; in Blacks the occlusal plane rotated counterclockwise and in Whites the occlusal plane rotated clockwise; in Blacks there was extrusion of the maxillary incisors in relation to Whites.
