Does Surgical Sequencing Influence the Accuracy of Maxillary Positioning in Bimaxillary Cleft Orthognathic Surgery?

BACKGROUND: The purpose of this study was to evaluate whether the sequence of osteotomies influences the accuracy of maxillary positioning in patients with cleft palate with or without cleft lip undergoing bimaxillary orthognathic surgery (OGS). METHODS: This was a prospective study of patients with Veau II through IV clefts who underwent bimaxillary OGS at a tertiary-care children's hospital over a 3-year period. The primary predictor variable was the sequence of osteotomies (maxilla first versus mandible first). The primary outcome of interest was the concordance between the planned and achieved maxillary position, as assessed using linear and angular measurements. Secondary study predictors were demographic and surgical variables. Differences between groups were compared using nonparametric independent samples tests for continuous measures (data reported as median and interquartile range) and chi-square tests for categorical measures. For all analyses, P ≤ 0.05 was considered significant. RESULTS: Participants who underwent maxilla-first ( n = 15) and mandible-first ( n = 16) operations were comparable with regard to age, sex, cleft type, skeletal classification, segmental maxillary osteotomy, and magnitude of maxillary movement ( P ≥ 0.09). The planned sagittal and vertical positions of the maxilla were similarly accurate between the 2 groups ( P ≥ 0.68). Angular accuracy was also comparable ( P ≥ 0.56) between the study groups. CONCLUSION: In patients with cleft palate with or without cleft lip undergoing bimaxillary OGS, use of mandible-first sequencing, when compared with maxilla-first sequencing, does not affect the accuracy of maxillary positioning in the immediate postoperative period in well-selected patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.