Craniofacial differences between skeletal Class II and skeletal Class I malocclusions according to vertical classification

Abstract

The aim of this study was to determine morphological differences among Class II, division 1 (Class II,1) subjects with different rotation models according to mandibular plane inclination and to compare these with normal subjects. The study consisted of 132 subjects (99 Class II,1 and 33 Class I control group). The Class II,1 group included subjects who had ANB (point A-nasion-point B) angles greater than 4° with an overjet equal to or greater than 5 mm. Based on the SN/Go-Gn (cranial base anterior length/gonion-gnathion) angle, subjects were divided into three different rotation models as hypodivergent, normodivergent and hyperdivergent. Variance analysis (ANOVA) was used to assess the presence of differences between groups (p 0.05). Although the ramus (Cd-Go) was significantly shorter in the Class II,1 hyperdivergent group (p < 0.05), the hypodivergent group had similar ramus heights compared with controls. Class II groups showed a similar increase in the ANB angle in spite of a different vertical rotation type. This study concludes that future Class II studies should divide subjects into subgroups according to hypodivergent, neutral and hyperdivergent phenotypes.