Skeletal stability after maxillary posterior-superior movement for skeletal Class III deformities: pterygoid process fracture versus removal.

PURPOSE: To evaluate maxillary stability after Le Fort I osteotomy using posterosuperior movement after pterygoid process fracture or removal and mandibular setback surgery for skeletal Class III deformities.

MATERIALS AND

METHODS

A retrospective cohort study was performed of changes in 28 patients with skeletal Class III deformity using 3-dimensional (3D) measurement point coordinates obtained by cone-beam computed tomographic superimposition. The predictor variable was management of the pterygoid process (fracture vs removal). The outcome variables were changes in measurement points based on 3D coordinates obtained preoperatively, immediately postoperatively, and 6 months after surgery. Linear mixed-effects models were applied to evaluate postoperative stability.

RESULTS

The 3D cephalometric outcome variables for 14 patients who had undergone pterygoid process fracture were compared with those for 14 patients who had undergone pterygoid process removal. The postoperative nasopalatine canal points moved superiorly 0.11 mm and inferiorly 0.06 mm in the fracture and removal groups, respectively. However, most of the postoperative relapse was within 1 mm. There were no differences in postoperative skeletal changes shown by the fracture and removal groups (P < .05).

CONCLUSIONS

The results suggest that surgeons can achieve good skeletal stability in posterosuperior movement from Le Fort I osteotomy, regardless of whether the pterygoid process is fractured or removed.