title: Evaluation of marginal alveolar bone in the anterior mandible with pretreatment and posttreatment computed tomography in nonextraction patients.
abstract: BACKGROUND
  Our objectives were to evaluate marginal alveolar bone height in the anterior mandible after orthodontic treatment and to assess any correlations between morphologic and treatment changes.
  
  
  METHODS
  We used 57 pretreatment and posttreatment cone-beam computed tomography images (17 male and 40 female subjects; 22 Class I, 35 Class II; average age, 18.7 ± 10.8 years; average treatment time, 22.7 ± 7.3 months) to measure cortical bone thickness, ridge thickness, distance from the apex to the labial cortical bone, and the distance from the cementoenamel junction to the marginal bone crest. Changes in the cementoenamel junction to the marginal bone crest distance were correlated with pretreatment measurements and treatment changes.
  
  
  RESULTS
  Although there were great variations, the average facial and lingual vertical bone losses were 1.16 ± 2.26 and 1.33 ± 2.50 mm, respectively. The incisor-mandibular plane angle changes were also highly variable, averaging 2.4°.
  
  
  CONCLUSIONS
  Orthodontic treatment causes changes in alveolar bone height and cortical bone thickness around the mandibular incisors. Although pretreatment cortical bone thickness, ridge width thickness, and specific tooth movements all play roles in what happens to the bone during treatment, incisor inclination was not correlated with alveolar bone height changes.
authors.affiliation: Private practice, Denver, Colo.
authors.forename: David T
authors.initials: DT
authors.lastname: Garlock
authors.affiliation: Professor, Department of Orthodontics, Baylor College of Dentistry, Texas A&M University, Dallas, Tex.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Buschang
authors.affiliation: Professor, Department of Orthodontics, Saint Louis University, St Louis, Mo.
authors.forename: Eustaquio A
authors.initials: EA
authors.lastname: Araujo
authors.affiliation: Professor, Department of Orthodontics, Saint Louis University, St Louis, Mo.
authors.forename: Rolf G
authors.initials: RG
authors.lastname: Behrents
authors.affiliation: Associate professor, Department of Orthodontics, Saint Louis University, St Louis, Mo. Electronic address: kkim8@slu.edu.
authors.forename: Ki Beom
authors.initials: KB
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D002508:Cephalometry / Q000379:methods; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D019227:Tooth Apex / Q000000981:diagnostic imaging; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D014081:Tooth Extraction; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult