Evaluation of transverse and sagittal maxillary arch dimensions in growing subjects with Class II Division 1 and Division 2 malocclusion: a retrospective cross-sectional study.

OBJECTIVE: To examine the transverse and sagittal dimensions of the maxillary arch in developing children with Class II Division 1 and Class II Division 2 malocclusions and compare them to those with Class I malocclusion. MATERIALS AND METHODS: This retrospective observational study included 60 growing subjects, comprising 32 females and 28 males, with a mean age of 10.5 ± 1.4 years. The sample was divided into three groups: Class I, n = 20; Class II Division 1, n = 20; and Class II Division 2, n = 20. Plaster models were digitized into STL files and assessed using MeshLab software. Transverse widths were measured at the dental-crown level and at the palatal gingival-margin level as complementary assessments of maxillary arch morphology. Maxillary arch length was also assessed. Method error was evaluated through repeated measurements on 15 randomly selected models after 4 weeks. Intraclass correlation coefficient analysis showed excellent intra-operator consistency for all measurements. RESULTS: The transverse measurements taken at the palatal gingival margin were significantly lower in both Class II groups when compared to Class I subjects. At the cusp level, individuals with Class II Division 1 showed no significant differences compared to those with Class I, while Class II Division 2 individuals remained considerably narrower at both the cusp level and the palatal gingival margin level. In individuals with Class II Division 2, the maxillary arch length was significantly less than in other classifications, while Class II Division 1 and Class I showed no major differences in arch length. CONCLUSIONS: In growing patients, Class II Division 2 and Class II Division 1 malocclusion showed smaller maxillary transverse dimensions. Subjects with Class II Division 2 displayed a reduced maxillary arch length in comparison to the other groups.