title: Effects of mandibular symphyseal distraction osteogenesis on mandibular structures.
abstract: BACKGROUND
  The purpose of this study was to evaluate the effects of mandibular symphyseal distraction osteogenesis on dental and mandibular skeletal structures with a tooth- and bone-borne distraction device.
  
  
  METHODS
  The sample comprised 20 patients, ranging in age from 15.8 to 23.3 years (mean, 20.1 +/- 2.3 years) at the start of treatment. The distraction device was activated 1 mm per day. The device was usually maintained in position about 90 days after surgery. Records were obtained at the start of treatment, at the end of distraction (11.4 +/- 2.2 days after surgery), and at follow-up periods (24.1 +/- 4.2 months after surgery). The records included posteroanterior cephalograms and study casts. The data were analyzed statistically by using the repeated measure analysis of variance and paired t test.
  
  
  RESULTS
  Posteroanterior cephalometric analysis demonstrated no significant changes in bigonial widths and ramal angles at the end of distraction period. On the other hand, bimolar widths were significantly increased, whereas bicondylar widths were markedly decreased. The dental cast analysis indicated that the maximum amount of increase was found between the mandibular canines, and the widening effect gradually decreased from the mandibular canines to the second molars. The follow-up data confirmed that the treatment results were stable.
  
  
  CONCLUSIONS
  The long-term findings indicate that mandibular symphyseal distraction osteogenesis is an efficient nonextraction treatment alternative for mandibular dental crowding to increase mandibular skeletal and dental arch widths.
authors.affiliation: Department of Orthodontics, School of Dentistry, University of Selçuk, Konya, Turkey. siddikmalkoc@yahoo.com
authors.forename: Siddik
authors.initials: S
authors.lastname: Malkoç
authors.forename: Haluk
authors.initials: H
authors.lastname: Işeri
authors.forename: Ali Ihya
authors.initials: AI
authors.lastname: Karaman
authors.forename: Necip
authors.initials: N
authors.lastname: Mutlu
authors.forename: Hasan
authors.initials: H
authors.lastname: Küçükkolbaşi
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002508:Cephalometry / Q000706:statistics & numerical data; D002680:Chin / Q000601:surgery; D003724:Dental Arch / Q000033:anatomy & histology / Q000601:surgery; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D008310:Malocclusion / Q000601:surgery*; D008334:Mandible / Q000033:anatomy & histology* / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000295:instrumentation*; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D012189:Retrospective Studies