Segmental Maxillary Osteotomies in Conjunction With Bimaxillary Orthognathic Surgery: Indications - Safety - Outcome

Abstract

Purpose: The purpose of the present study was to evaluate the indications, safety, and treating orthodontists' assessment of outcomes after bimaxillary orthognathic surgery that included segmental osteotomies.

Materials and methods: We performed a retrospective cohort study of patients treated by a single surgeon from 2004 to 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 the subjects underwent Le Fort I osteotomy, bilateral sagittal ramus osteotomy, septoplasty, inferior turbinate reduction, and osseous genioplasty. The predictor variables included age, gender, pattern of presenting DFD, type of maxillary osteotomy, and maxillary premolar extractions. The outcome variables included orthodontist assessment of the results achieved and the occurrence of maxillary complications. The orthodontist assessment was documented through a survey questionnaire completed 1 to 11 years after surgery. The maxillary complications studied included gingival recession, pulpal injury, oronasal fistula, and the need for hardware removal.

Results: During the study period, 262 subjects met the inclusion criteria. Their age at surgery averaged 25 years (range 13 to 63), and 134 were female (51%). The major patterns of the presenting DFD included long face (30%) and maxillary deficiency (25%). Of the 262 subjects, 66 (25%) underwent maxillary premolar extractions to relieve dental compensations. Also, 30% of the subjects presented for preoperative reassessment with a posterior arch form of skeletal anomaly. They underwent 2-segment Le Fort I osteotomy, and 34% presented with both posterior arch form and curve of Spee skeletal anomalies. They underwent 3-segment Le Fort I osteotomy. The subjects who had not undergone preoperative maxillary premolar extractions were more likely to have undergone 3-segment Le Fort I osteotomy (P = .008). No direct surgical injury occurred to a dental root in either the segmental or nonsegmental cases. Analysis of the periodontal status of the anterior 6 teeth after maxillary segmental osteotomies confirmed 15 of 1,008 sites (1.5%) with progressive gingival recession. A similar analysis after nonsegmental Le Fort I confirmed 11 of 564 sites (2%) with recession. No statistically significant difference was found between the segmental and nonsegmental Le Fort I osteotomies, with regard to recession. However, when recession did occur, it was more likely to occur at the canine teeth and least likely to occur at the lateral incisors (P = .001 and P = .003, respectively). Of the 1,572 anterior teeth at risk, 3 sustained a pulpal injury. All 3 subjects had undergone 3-segment Le Fort I. Two of the subjects who had undergone segmental osteotomy developed a persistent oronasal fistula and underwent successful closure with palatal flaps. Also, 3 of the 168 segmental subjects required maxillary hardware removal. The treating orthodontists' assessment of the occlusion and facial aesthetics achieved after segmental Le Fort I was favorable for most patients (91 and 97%, respectively).

Conclusions: Most bimaxillary DFDs will have maxillary skeletal arch form anomalies. Those subjects undergoing maxillary premolar extractions were less likely to require maxillary segmentation. Segmentation of the Le Fort I osteotomy is a safe method of addressing these skeletal deformities. Orthodontists reported a high level of satisfaction with the outcomes after orthognathic surgery that has incorporated maxillary segmental osteotomies.