Alveolar and dental arch morphology in Angle Class II division 2 malocclusion: a comparative study.

OBJECTIVE The aim of this study was to analyze the dental and alveolar intercanine, interpremolar and intermolar widths in patients with Class II/2 malocclusion and to compare the data with a patient group with normal occlusion and also with a patient group with Class II/1 malocclusion. MATERIALS AND METHODS The study was conducted on 140 untreated patients with permanent dentition, aged 16 to 25 years, which were divided into three groups, according to Angle's classification of occlusion. The measurements of the dento-alveolar intercanine, interpremolar and intermolar widths were made on virtual study models, scanned using an optical 3D scanner. The unpaired (Student's) t-test was used to determine whether there were any significant differences between the Class II/2 and Class I groups and between Class II/2 and Class II/1 groups, respectively (p<0.05). RESULTS Significant differences were found between Class II/2 and Class II/1 groups in the maxillary and mandibular intercanine widths. Comparing the Class II/2 and Class I groups, significant differences were found in the mandibular intercanine width, in the maxillary and mandibular interpremolar widths and also in the maxillary and mandibular intercanine and interpremolar alveolar widths. CONCLUSIONS The maxillary and mandibular interpremolar widths and the intercanine and interpremolar alveolar widths were larger, while the mandibular intercanine width was shorter in the Class I group than in the Class II division 2 group. The mandibular intercanine width was longer and the maxillary intercanine width was shorter in the Class II division 1 group compared to the Class II division 2 group.