title: Skeletal stability after mandibular advancement with rigid versus wire fixation.
abstract: OBJECTIVE
  This study examined the stability of skeletal changes after mandibular advancement surgery with rigid or wire fixation up to 2 years postoperatively.
  
  
  METHODS
  Subjects for this multisite, prospective, clinical trial received rigid (n = 78) or wire (n = 49) fixation. The rigid cases were fixed with three 2-mm bicortical position screws and 1 to 2 weeks of skeletal maxillomandibular fixation with elastics, and the wire fixation subjects were fixed with inferior border wires and had 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric radiographs were obtained before orthodontics, immediately before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Linear cephalometric changes were referenced to a cranial base coordinate system.
  
  
  RESULTS
  Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior sagittal advancement of the mandibular symphysis was 4.92 +/3.01 mm in the rigid group and 5.11 +/- 3.09 mm in the wire group, and the inferior vertical displacement was 3.37 +/- 2.44 in the rigid group and 2.85 +/- 1.78 in the wire group. The vertical changes were similar in both groups. Two years postsurgery, the wire group had 30% sagittal relapse of the mandibular symphysis, whereas there was no change in the rigid group (P < .001). Both groups experienced changes in the orientation and configuration of the mandible.
  
  
  CONCLUSIONS
  Rigid fixation is a more stable method than wire fixation for maintaining mandibular advancement after sagittal split ramus osteotomy.
authors.affiliation: Department of Orthodontics, University of Florida, Gainesville, USA. cdolce@dental.ufl.edu
authors.forename: C
authors.initials: C
authors.lastname: Dolce
authors.forename: J E
authors.initials: JE
authors.lastname: Van Sickels
authors.forename: R A
authors.initials: RA
authors.lastname: Bays
authors.forename: J D
authors.initials: JD
authors.lastname: Rugh
mesh_terms: D000328:Adult; D001863:Bone Screws; D002508:Cephalometry; D005260:Female; D006801:Humans; D007103:Immobilization; D019248:Jaw Fixation Techniques / Q000295:instrumentation; D008297:Male; D008312:Malocclusion, Angle Class II / Q000601:surgery*; D019186:Mandibular Advancement / Q000379:methods*; D011446:Prospective Studies; D055502:Secondary Prevention; D018709:Statistics, Nonparametric; D016896:Treatment Outcome