title: Skeletal and dental effects of tooth-borne versus hybrid devices for mandibular symphyseal distraction osteogenesis.
abstract: OBJECTIVE
  To evaluate and compare, retrospectively, the skeletal and dental effects of mandibular symphyseal distraction osteogenesis (MSDO) achieved through the use of tooth-borne versus hybrid distractors.
  
  
  METHODS
  Pretreatment (T1), predistraction (T2), postdistraction (T3), and posttreatment (T4) orthodontic records were collected and analyzed for 47 patients (20 tooth-borne, 27 hybrid). At each time point, records included intraoral photographs, study models, postero-anterior cephalometric radiographs, and lateral cephalometric radiographs. Submental vertex radiographs were taken at T2, T3, and T4. Changes in a total of 18 measurements were analyzed to compare patients undergoing tooth-borne versus hybrid distraction.
  
  
  RESULTS
  The cumulative effects of orthodontics and MSDO produced similar gains in measured arch widths, with a decreased irregularity index in both groups (P > .05). However, there were differences in the timing during which the expansion was achieved. The hybrid distractor group gained space during the distraction phase of treatment. The tooth-borne group showed greater gains during pre- and postdistraction orthodontics. Comparisons of intercanine and interbone marker widths demonstrated a more parallel separation of bone during distraction with the hybrid distractor (P < .001). Distraction with the tooth-borne distractor was disproportionate, with greater separation of the canines in alveolar bone than of the bone markers in basal bone. During postdistraction orthodontics, the tooth-borne distractor group showed statistically greater increases in measurements.
  
  
  CONCLUSIONS
  Both skeletal and dental expansion was achieved with both appliances. Greater skeletal expansion was achieved with a hybrid distractor. Greater dental expansion was achieved with a tooth-borne distractor.
authors.affiliation: a  Dental Student, School of Dentistry, Virginia Commonwealth University, Richmond, Va.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Niculescu
authors.forename: John W
authors.initials: JW
authors.lastname: King
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Lindauer
mesh_terms: D000293:Adolescent; D000539:Alveolar Process / Q000473:pathology; D001641:Bicuspid / Q000473:pathology; D001861:Bone Regeneration / Q000502:physiology; D002508:Cephalometry / Q000379:methods; D002648:Child; D003481:Cuspid / Q000473:pathology; D003724:Dental Arch / Q000473:pathology / Q000601:surgery*; D004867:Equipment Design; D057918:Fiducial Markers; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008335:Mandibular Condyle / Q000473:pathology; D003765:Models, Dental; D008963:Molar / Q000473:pathology; D009971:Orthodontics, Corrective / Q000295:instrumentation; D019857:Osteogenesis, Distraction / Q000295:instrumentation* / Q000379:methods; D023861:Photography, Dental / Q000379:methods; D012189:Retrospective Studies; D014070:Tooth / Q000473:pathology*