Surgically assisted maxillary expansion with or without pterygoid disjunction alters maxillomandibular positioning.

PURPOSE: This study aimed to analyze alterations in mandibular positioning after surgically assisted maxillary expansion (SARME) with and without pterygoid disjunction (PD). METHODS: Cone-beam computed tomography scans of 24 healthy individuals (18-45 years old) with transverse deficiency, superior to 5 mm, underwent SARME with or without PD. The aspects prospectively assessed were (1) alignment and position of the head (ITK-Snap and 3D Slicer software); (2) McNamara's and Steiner-Tweed-Wits' cephalometric analysis (Dolphin Imaging(R)); and (3) colorimetric evaluation based on 3D correspondence analysis (3D Slicer software). RESULTS: A decrease in 1-NA and 1-SN angles as well as an increased occlusal plane in both groups was observed. Superior-inferior and anteroposterior spatial displacements of the chin were statistically significant in the PD group. Altered colorimetric patterns were also observed in the PD group. CONCLUSIONS: This study found more evident tooth inclination in the group without PD; mandibular alterations were more evident in the PD group. Further studies with 3D analysis are strongly recommended for more comprehensive results.