Segmental Maxillary Osteotomies in Conjunction with Bimaxillary Orthognathic Surgery: Indications – Safety – Outcome

Abstract Purpose The purpose of this study was to evaluate the indications, safety, and treating orthodontists’ assessment of outcome after bimaxillary orthognathic surgery that included segmental osteotomies. Material and Methods The authors executed a retrospective cohort study of patients treated by a single surgeon between 2004 and 2013. The index group consisted of a consecutive series of subjects with a bimaxillary dentofacial deformity (DFD) involving the chin and symptomatic chronic obstructive nasal breathing. All subjects underwent: LeFort I osteotomy; bilateral sagittal ramus osteotomies; septoplasty; inferior turbinate reduction; and osseous genioplasty. Predictor variables included: age; sex; pattern of presenting DFD; type of maxillary osteotomy; and maxillary premolar extractions. The outcome variables included: orthodontist assessment of results achieved and occurrence of maxillary complications. The orthodontist assessment was documented through a survey questionnaire completed 1 - 11 years after surgery. Maxillary complications studied include: gingival recession, pulpal injury, oro-nasal fistula, and need for hardware removal. Results During the study period, 262 subjects met the inclusion criteria. Age at operation averaged 25 years (range 13-63) and there were 134 females (51%). The major patterns of presenting DFD included long face (29%) and maxillary deficiency (25%). Twenty-five percent of subjects (66/262) underwent maxillary premolar extractions (MBE) to relieved compensations. Thirty percent of subjects presented for presurgical reassessment with a posterior arch form skeletal anomaly. They underwent a 2-segment LeFort I osteotomy. Thirty-four percent presented with both posterior arch form and curve of Spee skeletal anomalies. The underwent a 3-segment LeFort I osteotomy. Subjects who did not have pre-operative maxillary premolar extractions were more likely to have undergone a 3-segment LeFort 1 osteotomy (p-Value=0.008). There was no direct surgical injury to a dental root in either segmental or non-segmental cases. Analysis of periodontal status of the anterior 6 teeth after maxillary segmental osteotomies confirmed 15/1,008 sites (1.5%) with progressive gingival recession. Similar analysis after non-segmental LeFort I confirmed 11/564 (2%) sites with recession. There was no statistical difference between segmental and non-segmental LeFort I osteotomies, with regard to recession. However, when recession did occur, it was mor