title: Three-dimensional assessment of mandibular advancement 1 year after surgery.
abstract: BACKGROUND
  This prospective observational study evaluated changes in the 3-dimensional position and remodeling of the mandibular rami, condyles, and chin at splint removal and 1 year after mandibular advancement surgery.
  
  
  METHODS
  Presurgery, splint removal (4-6 weeks postsurgery), and 1-year postsurgery cone-beam computed tomography scans of 27 subjects were used. Superimposition on the cranial base was used to assess positional or remodeling changes in the anatomic regions of interest. Surface distance displacements were visually displayed and quantified by 3-dimensional color maps. A 1-sample t test was used to assess the average postsurgical changes of each region of interest. The level of significance was set at 0.05.
  
  
  RESULTS
  After antero-inferior chin displacement with surgery (mean, 6.81 +/- 3.2 mm at splint removal), the average 1-year postsurgery displacement was not statistically significant (P = 0.44). Postsurgical adaptations greater than 2 mm were observed in 48% of the patients: 16% with an additional anterior-inferior displacement of the chin of 2 to 4 mm, and 4% with >or= 4 mm; 20% had postero-superior movement of 2 to 4 mm, and 8% had postero-superior movement of >or= 4 mm. The condyles tended to move, on average, <or= 2 mm supero-posteriorly with surgery, and this small positional displacement was maintained 1 year postsurgery (right condyle, P = 0.58; left, P = 0.88). The rami exhibited outward (lateral) movements with surgery, with greater displacement of the inferior part of the rami (2 mm in 65% of the subjects). This torque of the ramus with surgery was stable 1 year postsurgery.
  
  
  CONCLUSIONS
  Three-dimensional assessment of skeletal changes with mandibular advancement surgery shows that nearly half of the patients have >2 mm change in chin position from splint removal to the 1-year follow-up, with approximately equal chances of anterior and posterior movement. Torque of the rami usually occurs with mandibular advancement surgery.
authors.affiliation: Department of Orthodontics, School of Dentistry, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Felipe de Assis Ribeiro
authors.initials: Fde A
authors.lastname: Carvalho
authors.forename: Lucia Helena Soares
authors.initials: LH
authors.lastname: Cevidanes
authors.forename: Alexandre Trindade Simões
authors.initials: AT
authors.lastname: da Motta
authors.forename: Marco Antonio de Oliveira
authors.initials: MA
authors.lastname: Almeida
authors.forename: Ceib
authors.initials: C
authors.lastname: Phillips
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods; D002680:Chin / Q000000981:diagnostic imaging; D003198:Computer Simulation; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008312:Malocclusion, Angle Class II / Q000601:surgery*; D008334:Mandible / Q000000981:diagnostic imaging*; D019186:Mandibular Advancement; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011184:Postoperative Period; D011446:Prospective Studies; D012008:Recurrence; D019291:Skull Base / Q000000981:diagnostic imaging; D012984:Software; D013382:Subtraction Technique; D054159:Torsion, Mechanical; D055815:Young Adult
references.citation: Angle Orthod. 1996;66(2):111-24
references.pmid: 8712489
references.citation: Int J Adult Orthodon Orthognath Surg. 1996;11(3):191-204
references.pmid: 9456622
references.citation: Br J Orthod. 1996 May;23(2):93-102
references.pmid: 8771331
references.citation: Br J Oral Maxillofac Surg. 1998 Jun;36(3):196-201
references.pmid: 9678885
references.citation: Am J Orthod Dentofacial Orthop. 1994 May;105(5):517-21
references.pmid: 8166104
references.citation: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999 Feb;87(2):159-65
references.pmid: 10052369
references.citation: J Oral Maxillofac Surg. 1994 Jun;52(6):536-52; discussion 552-4
references.pmid: 8189289
references.citation: Am J Orthod Dentofacial Orthop. 2007 Jan;131(1):44-50
references.pmid: 17208105
references.citation: Clin Orthod Res. 1998 Nov;1(2):102-6
references.pmid: 10321138
references.citation: Am J Orthod Dentofacial Orthop. 2005 Jul;128(1):16-26
references.pmid: 16027621
references.citation: Anat Rec. 1999 Dec 15;257(6):217-24
references.pmid: 10620751
references.citation: Head Face Med. 2007 Apr 30;3:21
references.pmid: 17470277
references.citation: Int J Adult Orthodon Orthognath Surg. 1994;9(1):55-63
references.pmid: 8006484
references.citation: Am J Orthod Dentofacial Orthop. 2004 Sep;126(3):273-7
references.pmid: 15356484
references.citation: IEEE Trans Inf Technol Biomed. 2007 May;11(3):274-87
references.pmid: 17521077
references.citation: J Oral Maxillofac Surg. 2002 Apr;60(4):395-403
references.pmid: 11928096
references.citation: J Oral Maxillofac Surg. 1999 Jun;57(6):650-4; discussion 654-5
references.pmid: 10368087
references.citation: Am J Orthod Dentofacial Orthop. 2005 Nov;128(5):607-18
references.pmid: 16286208
references.citation: Eur J Orthod. 1983 Feb;5(1):1-46
references.pmid: 6572593
references.citation: Am J Orthod Dentofacial Orthop. 2006 May;129(5):611-8
references.pmid: 16679201
references.citation: J Anat. 2006 Nov;209(5):637-54
references.pmid: 17062021
references.citation: J Oral Maxillofac Surg. 1989 Mar;47(3):223-7
references.pmid: 2921656
references.citation: J Oral Maxillofac Surg. 1984 Sep;42(9):578-88
references.pmid: 6590809
references.citation: Neuroimage. 2006 Jul 1;31(3):1116-28
references.pmid: 16545965
references.citation: Dentomaxillofac Radiol. 2005 Nov;34(6):369-75
references.pmid: 16227481
references.citation: Angle Orthod. 2000 Apr;70(2):112-7
references.pmid: 10832998
references.citation: Int J Adult Orthodon Orthognath Surg. 1994;9(3):233-40
references.pmid: 7814928
references.citation: Int J Oral Maxillofac Surg. 1987 Jun;16(3):257-61
references.pmid: 3112253