Mandibular and glenoid fossa changes after bone-anchored maxillary protraction therapy in patients with UCLP: A 3-D preliminary assessment

Objective: To assess mandibular and glenoid fossa (GF) changes after bone-anchored maxillary protraction (BAMP) therapy in patients with unilateral complete cleft lip and palate (UCLP). Materials and Methods: The cleft group (CG) comprised 19 patients with (mean initial age of 11.8 years). The noncleft group (NCG) comprised 24 patients without clefts (mean initial age of 11.7 years). Both groups had Class III malocclusion and were treated with BAMP therapy for 18 and 12 months, respectively. Cone-beam computed tomography (CBCT) exams were performed before and after treatment and superimposed on the anterior cranial fossa (ACF). Mandibular rotations and three-dimensional linear displacements of the mandible and GF were quantified. A t-test corrected for multiple testing (Holm-Bonferroni method) and a paired t-test were used to compare, respectively, the CG and NCG and cleft vs noncleft sides (P<.05). Results: Immediately after active treatment, the GF was displaced posteriorly and laterally in both groups relative to the ACF. The overall GF changes in the CG were significantly smaller than in the NCG. Condylar displacement was similar in both groups, following a posterior and lateral direction. The gonial angle was displaced similarly posteriorly, laterally, and inferiorly in both groups. The intercondylar line rotated in opposite directions in the CG and NCG groups. In the CG, most changes of the GF and mandible were symmetrical. Conclusions: Overall GF and mandibular changes after BAMP therapy were similar in patients with and without clefts. The exception was the posterior remodeling of the GF that was slightly smaller in patients with UCLP.