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

Angle Orthod. 2017 May;87(3):423-431. doi: 10.2319/052516-419.1. Epub 2016 Sep 26.

Abstract

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.

Keywords: Angle Class III; Cleft lip; Cleft palate; Orthodontic anchorage procedure.

MeSH terms

  • Adolescent
  • Anatomic Landmarks
  • Brazil
  • Child
  • Cleft Lip / diagnostic imaging
  • Cleft Lip / therapy*
  • Cleft Palate / diagnostic imaging
  • Cleft Palate / therapy*
  • Cone-Beam Computed Tomography*
  • Female
  • Glenoid Cavity / diagnostic imaging*
  • Glenoid Cavity / growth & development*
  • Humans
  • Male
  • Malocclusion, Angle Class III / diagnostic imaging*
  • Malocclusion, Angle Class III / therapy*
  • Mandible / diagnostic imaging*
  • Mandible / growth & development*
  • Maxillofacial Development
  • Orthodontic Anchorage Procedures*
  • Retrospective Studies
  • Suture Anchors
  • Treatment Outcome