Craniofacial changes in Class III malocclusion as related to skeletal and dental maturation.

INTRODUCTION

In this large cross-sectional study, we aimed to analyze growth trends in white subjects with Class III malocclusion using both skeletal and dental maturation staging.

METHODS

The sample consisted of 1091 pretreatment lateral cephalometric records of Class III patients (560 female, 531 male). Cephalometric dentoskeletal measurements were compared at subsequent stages in cervical vertebral maturation and Hellman's categorization of dental development by means of ANOVA with Bonferroni post-hoc tests in both sexes separately.

RESULTS

The findings indicated that, in Class III malocclusion, the pubertal peak in mandibular growth occurs between stages 3 and 4 of cervical vertebral maturation, with average increases in total mandibular length of about 8 and 5.5 mm in Class III boys and girls, respectively.

CONCLUSIONS

Significant changes in total mandibular length occur until young adulthood (18 years on average), with increases between late maturation stages (4 through 6) that were twice as large as in subjects with normal occlusion for the Class III females, and 3 times as large as in subjects with normal occlusion for the Class III males. Growth trends toward accentuated Class III profile and increased vertical dimension of the face also become apparent at late developmental stages (corresponding with complete eruption of the second and third molars).