Geometric Morphometric Evaluation of Facial Type Growth Patterns

Vertical facial divergence patterns are clinically significant due to their strong association with malocclusion and orofacial functional imbalances. Gaining insight into how these divergence types develop throughout growth is essential for tailoring effective orthodontic interventions. This research explores and contrasts craniofacial growth behavior from childhood through adulthood among three vertical facial divergence categories using a longitudinal series of lateral cephalograms derived from the Craniofacial Growth Consortium Study. The study examined 371 participants (183 females, 188 males), who were grouped based on their adult mandibular plane angle (MPA): hyperdivergent (MPA > 39°, n = 40), normodivergent (28° ≤ MPA ≤ 39°, n = 216), and hypodivergent (MPA < 28°, n = 115). Each subject contributed five cephalograms spanning ages 6–20. Thirty-six anatomical landmarks were digitized on each radiograph, aligned using five stable reference points from the anterior cranial base, and normalized by centroid size. Growth patterns for each facial type and sex were modeled through multivariate regression analysis. Analysis revealed distinct developmental trajectories among facial types, with normodivergent and hypodivergent individuals following comparable growth paths, while the hyperdivergent group exhibited a markedly different pattern. Geometric morphometric evaluation uncovered unique features of vertical facial development: hyperdivergent subjects displayed a downward rotation of the maxilla–mandible complex relative to the cranial base and pronounced elongation of the lower anterior facial region. Conversely, normodivergent and hypodivergent participants maintained a stable maxillary orientation accompanied by forward mandibular rotation. Additionally, in hyperdivergent cases, both the maxilla and mandible tended to be shorter and positioned more posteriorly with advancing age. The findings suggest that the distinctive characteristics of hyperdivergent craniofacial growth—particularly the limited forward development of the maxilla—may increase susceptibility to Class II malocclusion. Further studies are needed to refine the understanding of internal growth variations within each vertical facial divergence category.