title: Transitional joint effusion in the mandibular prognathic surgery patient: intraoral vertical ramus osteotomy versus sagittal split ramus osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to examine the cause of joint effusion (JE) appearing postoperatively in the temporomandibular joint (TMJ) of patients with mandibular prognathism on T2-weighted magnetic resonance (MR) images.
  
  
  METHODS
  MR imaging was performed before and after surgery in 30 TMJs of 15 subjects with mandibular prognathism who underwent intraoral vertical ramus osteotomy (IVRO) and in 20 TMJs of 10 subjects with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO). The preoperative MR imaging was performed 1 month before surgery, and postoperative MR imaging was performed during maxillomandibular fixation.
  
  
  RESULTS
  Preoperatively, none of SSRO and IVRO groups had JE. Postoperatively, 12 TMJs (40%) of the IVRO group and only 1 TMJ (5%) of the SSRO group had JE. As for the TMJs in the IVRO group, on MR imaging, the degree of downward movement of the condyle after surgery was larger in TMJs with JE (3.8 +/- 2.3 mm) than in TMJs without JE (1.8 +/- 1.6 mm). JE diminished within about 4 months after removal of the maxillomandibular fixation.
  
  
  CONCLUSIONS
  JE appearing postoperatively in the TMJ of patients with mandibular prognathism might be relation to the degree of downward movement of the condyle.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kanazawa Medical University, Kahoku-gun, Japan. masaaki@kanazawa-med.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nishimura
authors.forename: Natsuki
authors.initials: N
authors.lastname: Segami
authors.forename: Jun
authors.initials: J
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Honjou
authors.forename: Kazuma
authors.initials: K
authors.lastname: Fujimura
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques; D008279:Magnetic Resonance Imaging; D008297:Male; D008334:Mandible / Q000601:surgery*; D008335:Mandibular Condyle / Q000473:pathology; D010027:Osteotomy / Q000145:classification / Q000379:methods*; D011183:Postoperative Complications; D011378:Prognathism / Q000601:surgery*; D018709:Statistics, Nonparametric; D013582:Synovial Fluid; D013704:Temporomandibular Joint / Q000473:pathology*; D019224:Temporomandibular Joint Disc / Q000473:pathology