title: The use of an intermaxillary fixation screw for mandibular setback surgery.
abstract: OBJECTIVE
  To assess skeletal stability after mandibular setback surgery with and without an intermaxillary fixation (IMF) screw.
  
  
  METHODS
  The subjects were 40 patients with mandibular prognathism. The subjects underwent sagittal split ramus osteotomy with titanium plate fixation and were divided into 2 groups, 1 with and 1 without an IMF screw. A lateral cephalogram was done preoperatively, immediately after surgery, and 1 month, 3 months, and 6 months postoperatively. The 2 groups were then compared statistically.
  
  
  RESULTS
  In the comparison of the time-course change between the 2 groups with repeated measure analysis of variance, there were significant differences in occlusal plane (between subjects, F = 2.517; df = 4; P = .0437) and convexity (between subjects, F = 4.048; df = 4; P = .0038). However, there was no significant difference in the other measurements.
  
  
  CONCLUSIONS
  This study suggested that in most measurements, there was no significant difference between 2 groups with and without an IMF screw in time-course skeletal change. However, use of IMF screws was helpful for orthognathic surgery as a rigid anchor of IMF.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. kueki@med.kanazawa-u.ac.jp
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueki
authors.forename: Kohei
authors.initials: K
authors.lastname: Marukawa
authors.forename: Mayumi
authors.initials: M
authors.lastname: Shimada
authors.forename: Kiyomasa
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Etsuhide
authors.initials: E
authors.lastname: Yamamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001860:Bone Plates; D001863:Bone Screws; D002508:Cephalometry; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques / Q000295:instrumentation*; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D019647:Oral Surgical Procedures / Q000295:instrumentation / Q000379:methods; D010027:Osteotomy / Q000295:instrumentation* / Q000379:methods; D011378:Prognathism / Q000601:surgery; D016896:Treatment Outcome