Stability between single and segmental maxillary osteotomies in bimaxillary surgery for cleft-associated class III deformity: a CBCT study.

OBJECTIVE: Segmental Le Fort I osteotomy through the cleft is a common strategy to narrow the alveolar cleft in adults. This study compared skeletal stability between single and segmental Le Fort I osteotomies in patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: This retrospective analysis examined 45 adults with complete UCLP-associated class III deformities who underwent bimaxillary surgery with either single (n = 30) or segmental (n = 15) Le Fort I advancement. Cone beam computed tomography (CBCT) scans of the facial skeleton were acquired before surgery, 1-week postsurgery, and at follow-up. Measures of landmarks from the CBCT images for the two treatment groups were compared for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch). RESULTS: Postsurgery, the downward movement of the maxilla was larger in the segmental group than the single group. At follow-up, the maxilla moved backward in both groups, and upward in the segmental group. The mandible moved forward and upward and rotated upward in both groups. The amount of upward movement and rotation was larger in the segmental group than the single group. CONCLUSIONS: Two years after bimaxillary surgery in patients with UCLP-associated class III deformity, greater relapse was found after segmental Le Fort I osteotomies in vertical translation of the maxilla and mandible, and pitch rotation of the mandible compared with single Le Fort I osteotomies. CLINICAL RELEVANCE: The vertical relapse of the maxilla was larger after segmental Le Fort I advancement compared with single Le Fort I advancement in clefts.

Comparison of stability and outcomes of surgery-first bimaxillary surgery for skeletal class III deformity between unilateral and bilateral cleft lip and palate.

OBJECTIVES: Some adults with cleft lip and palate (CLP) require orthognathic surgery due to skeletal deformity. This prospective study aimed to (1) compare skeletal stability following bimaxillary surgery for correction of class III deformity between patients with unilateral CLP (UCLP) and bilateral CLP (BCLP), and (2) identify risk factors of stability. MATERIALS AND METHODS: Adults with CLP and skeletal class III deformities who underwent surgery-first bimaxillary surgery were divided into two groups according to cleft type: UCLP (n = 30) and BCLP (n = 30). Skeletal stability was assessed with measures from cone beam computed tomography images of the maxilla and mandible taken before treatment, 1-week and ≥ 1 year postsurgery for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch); multiple regression analysis examined risk factors. RESULTS: At follow-up, the maxilla moved upwards in both groups, and backwards in the UCLP group. The mandible moved forward and upward, shifted to the cleft (deviated) side, and rotated upward in both groups. The amount of surgical advancement was a risk factor for sagittal stability in the maxilla (ß = -0.14, p < 0.05). The mandible had three risk factors for sagittal stability: age (ß = -0.23, p < 0.05), surgical team (ß = -1.83, p < 0.05), and amount of surgical setback (ß = -0.32, p = 0.001). CONCLUSIONS: Two years after bimaxillary surgery, patients with UCLP had a higher sagittal relapse of the maxilla compared with patients with BCLP, which was due to a greater surgical advancement in the patients with UCLP. CLINICAL RELEVANCE: Surgery-first bimaxillary surgery results in favorable treatment outcomes for correction of cleft-related class III deformity. Severity of jaw discrepancy and surgeons should be considered in the surgical design of overcorrection.