title: The influence of pre- and intraoperative positioning of the condyle in the centre of the articular fossa on the position of the disc in orthognathic surgery. A magnetic resonance study.
abstract: OBJECTIVE
  We investigated the changes in the temporomandibular joint (TMJ) after bilateral sagittal split osteotomy of the mandible for orthognathic surgery and the influence of positioning of the condylar process in the centre of the articular fossa before and during the operation for preventing changes in the TMJ postoperatively.
  
  
  METHODS
  A total of 28 patients with mandibular retrognathism had bilateral sagittal split osteotomies for mandibular advancement. In one group of 14 patients (28 TMJ), the condyles were placed in the centre of the articular fossa before and during the operation, and in the other group they were not. Differences on magnetic resonance imaging (MRI) were calculated and the results were evaluated.
  
  
  RESULTS
  The main differences were found at maximal mouth opening. 15/28 TMJs (54%) that had not been positioned changed the position of the disc from physiological to anterior disc derangement with and without reduction postoperatively. In the 28 that had been positioned, changes were found in only 3 TMJs (11%) postoperatively.
  
  
  CONCLUSIONS
  Fixing the condylar process in the centre of the articular fossa intraoperatively before bilateral sagittal split osteotomy is a factor in preventing postoperative structural changes in the temporomandibular joint.
authors.affiliation: Department of Maxillofacial and Facial Plastic Surgery, Rostock University, Strempelstrasse 13, 18055 Rostock, Germany. bassam.saka@med.uni-rostock.de
authors.forename: B
authors.initials: B
authors.lastname: Saka
authors.forename: I
authors.initials: I
authors.lastname: Petsch
authors.forename: V
authors.initials: V
authors.lastname: Hingst
authors.forename: J
authors.initials: J
authors.lastname: Härtel
mesh_terms: D006801:Humans; D007430:Intraoperative Care; D019248:Jaw Fixation Techniques; D004204:Joint Dislocations / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008312:Malocclusion, Angle Class II / Q000601:surgery*; D008334:Mandible / Q000601:surgery; D019186:Mandibular Advancement / Q000379:methods*; D008335:Mandibular Condyle / Q000601:surgery*; D017090:Occlusal Splints; D011300:Preoperative Care; D063173:Retrognathia / Q000601:surgery*; D018709:Statistics, Nonparametric; D013704:Temporomandibular Joint / Q000503:physiopathology; D019224:Temporomandibular Joint Disc / Q000473:pathology*