Growth patterns and overbite depth indicators of long and short faces in Korean adolescents: Revisited through mixed-effects analysis.

OBJECTIVE: The purpose was to evaluate skeletal factors related to the growth of subjects with skeletal open and deep bites based on lateral cephalographs from 9 years of pure longitudinal data using mixed effect analysis.

SETTING AND SAMPLE POPULATION: Fifty-one children with extreme lower anterior facial height to total anterior facial height (LAFH/TAFH) ratio values at the age of 14 were assigned to either skeletal open bite or skeletal deep bite groups from a total of 223 subjects.

MATERIAL & METHODS: The palatal plane angle (PPA), mandibular plane angle (MPA), gonial angle (GA), palatomandibular plane angle (PMA), upper gonial angle (UGA), lower gonial angle (LGA), occlusal plane angle (OPA) and overbite depth indicator (ODI) were measured and analysed. Mixed-effects regression model analysis was used for the interpretation of data with random effects.

RESULTS: Morphological differences were evident from the beginning and became more pronounced with age in MPA, GA, PMA, ODI and LGA. The initial values of all variables were statistically significant. Annual increases with age were statistically significant in GA, OPA, ODI and UGA. The morphological differences in the annual increases in MPA, GA, PMA and UGA were also statistically significant.

CONCLUSIONS: Morphologically different growth patterns were mainly contributed by lower anterior facial height dimensions. The extent of individual variations mandates judicious decision-making in clinical situations.