Relationship Between Vertical Facial Patterns and Palatal Morphology in Class I and Class II Malocclusion

Abstract: (1) The purpose of this study is to relate the bidimensional and tridimensional\r\nmeasures of the palate to the vertical facial pattern defined by the angle “SN-MP” between\r\nthe mandibular plane and the anterior cranial base (Sella–Nasion/mandibular plane angle)\r\nin skeletal Class II untreated patients. Furthermore, the same palatal measures were\r\nused to compare Class II with Class I subjects. (2) A sample of 197 Class II Caucasian\r\nsubjects (112 females and 85 males) with untreated skeletal Class II was collected retrospectively\r\n(from a private dental clinic specialized in orthodontics) and divided into two\r\nmain groups according to the ANB angle: 74 Class I patients (0° ≤ ANB ≤ 4°) and 123 Class\r\nII patients (ANB > 4°). Class II subjects were furthermore divided into three groups depending\r\non the angle SN-MP. Lateral cephalograms and digital 3D maxillary dental scans\r\nwere available. Bidimensional and tridimensional measures were taken on each maxillary\r\ndental scan. The differences among the groups were analyzed for significance using a variance\r\nanalysis. (3) A decrease in the posterior palatal height and an increase in the palatal\r\nsurface area in Class I subjects were reported. The results showed a change in upper arch\r\nform, with a greater intermolar width in patients with a low SN-MP angle and a smaller\r\none in high-angle patients. The more a Class II subject tended towards high-angle divergence,\r\nthe narrower the palate was. (4) A greater posterior palatal height was found in\r\nClass II malocclusion, while greater surface area was noted in Class I malocclusion. In\r\naddition to this result, another statistical significance was detected in Class II malocclusion:\r\nthe intermolar distance was greater in hypodivergent than in hyperdivergent patients.\r\nSimilar volume values were noted across different malocclusions and vertical divergence\r\ngroups. Palatal width seemed to be related to vertical facial pattern, while palatal\r\nheight and area seemed to be related to sagittal malocclusions. These findings underscore\r\nthe importance of considering palatal morphology variations in designing individualized\r\northodontic treatments, thereby improving patient-specific outcomes and broadening\r\nour understanding of skeletal Class II malocclusion.