title: The value of long-term follow-up of mandibular advancement surgery in patients with a low to normal mandibular plane angle.
abstract: The objective of this study was to evaluate retrospectively the stability of mandibular advancement via bilateral sagittal split osteotomies. Two fixation methods were compared: intermaxillary fixation (IMF) and rigid internal fixation (RIF). The hypothesis was that, in patients with a low to normal mandibular plane angle (MPA) in retrognathia, the bilateral sagittal split osteotomy (BSSO) to advance the mandible is a predictable and stable procedure and that no significant changes occur after 1 year. Twelve patients with mandibular deficiency with a low to normal MPA (mean 24.7 degrees, range 20.3 degrees-30.7 degrees) underwent BSSO with IMF. The follow-up period was at least 5 years (mean 6.3, range 5-9.1 years). Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T0), within 6 weeks postoperatively (T1), 1 year postoperatively (T2), and at least 5 years postoperatively (T3). The average advancement at B point was 4.7 mm (range: 3-7 mm). The assessment of B point in regard to relapse showed no significant change. One patient showed a relapse due to condylar resorption. Forty-five consecutive patients were treated with RIF. Radiographs were taken preoperatively (T0), 6 weeks postoperatively (T1), and 1 year postoperatively (T2). This group had a mean MPA of 26.2 degrees, range 10 degrees-32 degrees. The average B-point advancement was 4.4 mm (range 1-10 mm). No patient showed a clinically significant relapse at T2.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kennemer Gasthuis, Iocatie EG, Haarlem, The Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Bouwman
authors.forename: D B
authors.initials: DB
authors.lastname: Tuinzing
authors.forename: P J
authors.initials: PJ
authors.lastname: Kostense
authors.forename: R A
authors.initials: RA
authors.lastname: van Teeseling
authors.forename: H
authors.initials: H
authors.lastname: Mokhtari
mesh_terms: D000328:Adult; D016267:External Fixators; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000209:etiology / Q000601:surgery; D008334:Mandible / Q000601:surgery; D009971:Orthodontics, Corrective; D010027:Osteotomy; D063173:Retrognathia / Q000601:surgery*