Differences in the stability of the lesser and greater maxillary segments after cleft orthognathic surgery: A retrospective study using 3D analysis

Abstract

The aim of this study was to determine whether significant differences in postoperative stability exist between the lesser and the greater maxillary segments after cleft orthognathic surgery in patients with and without residual alveolar cleft. A retrospective study of orthognathic patients with unilateral cleft was conducted. The patients were divided into two groups according to maxillary status before surgery, with group 1 comprising single-piece maxilla and group 2 comprising two-piece maxilla. Four maxillary points were used for intra- and intergroup comparisons of movements and relapses between the two maxillary segments. In total, 24 patients were included. The intragroup comparison showed significant differences in vertical relapses between lesser and greater segments in both group 1 (anterior, p = 0.004 and posterior, p = 0.01) and group 2 (posterior, p = 0.013). With regard to intergroup comparison, the lesser segments in the two groups differed in transverse movements (anterior, p = 0.048) and relapses (posterior; p = 0.04), while the greater segments differed in transverse movements (anterior, p = 0.014 and posterior, p = 0.019), with significant differences in relapses anteriorly (vertical, p = 0.031 and sagittal, p = 0.036) and posteriorly (transverse, p = 0.022). Maxillary changes following cleft orthognathic surgery showed significant differences between the lesser and the greater segments. These findings imply that 3D images should be used to assess each maxillary segment separately with regard to planning and outcome evaluation.