Growth-related change in the mandibular plane angle with clinical implications

Abstract

Mandibular plane angle (MPA) is used clinically to diagnose malocclusion and dysmorphology and assess treatment. Numerous cephalometric systems use MPA to categorize individuals into facial types. Accurate models of ontogenetic change in MPA will maximize the efficacy of orthodontic treatment by elucidating normal variation in MPA at different time points. Change in MPA captures several aspects of mandibular and craniofacial development, including mandibular growth rotation and changing anterior and posterior facial heights, resulting in considerable variation between individuals in the rate and magnitude of growth-related change in the MPA. Previous studies demonstrate a tendency for MPA to decrease during childhood and adolescence (1-3), although the timing and rate of these changes vary by study. To evaluate patterns of growth-related change, we examine MPA using cephalometric data compiled from six longitudinal studies of human growth and development.