title: Three-dimensional evaluation of soft tissue changes in the orofacial region after tooth-borne and bone-borne surgically assisted rapid maxillary expansion.
abstract: OBJECTIVE
  This study seeks to three-dimensionally assess soft tissue changes in the orofacial region following tooth-borne and bone-borne surgically assisted rapid maxillary expansion (SARME).
  
  
  METHODS
  This prospective cohort study included 40 skeletally mature patients with transverse maxillary hypoplasia. A tooth-borne distractor (Hyrax) was used for expansion in 25 patients. In the remaining 15, a bone-borne distractor (transpalatal distractor, TPD) was used. Cone beam computed tomography (CBCT) scans were acquired before treatment (T0) and 22 months later (T1). 3D models were constructed from CBCT data and superimposed using voxel-based matching. Distance maps between the superimposed 3D models were computed to evaluate the degree of skeletal and soft tissue changes in the maxillary region.
  
  
  RESULTS
  Distance maps showed negative distances (mean -1.25 (±1.5) mm) in the middle of the upper lip, indicating posterior repositioning of this area. The cheek region showed positive changes (mean 1.66 (±1.1) mm), reflecting the underlying increase in maxillary width. There was no significant difference between the two groups in all measured distances (p > 0.05). Retro-positioning of the upper lip accompanied skeletal remodeling in the anterior alveolar region at a mean ratio of 88 %, while the cheek region followed 32 % of the alveolar expansion.
  
  
  CONCLUSIONS
  Soft tissue changes following SARME include posterior repositioning of the upper lip and increased projection of the cheek area. These changes were comparable between bone-borne and tooth-borne appliances.
  
  
  CONCLUSIONS
  This study provides clinicians with more information over the expected orofacial soft tissue changes following SARME.
authors: Department of Orthodontics and Craniofacial Biology, Radboud University Nijmegen Medical Centre 309 Dentistry, PO Box 9101, 6500, HB, Nijmegen, The Netherlands.
authors: Rania M
authors: RM
authors: Nada
authors: Bram
authors: B
authors: van Loon
authors: Thomas J J
authors: TJ
authors: Maal
authors: Stefaan J
authors: SJ
authors: Bergé
authors: Yehya A
authors: YA
authors: Mostafa
authors: Anne Marie
authors: AM
authors: Kuijpers-Jagtman
authors: Jan G J H
authors: JG
authors: Schols
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D011446:Prospective Studies
references: Br J Oral Maxillofac Surg. 1999 Aug;37(4):268-72
references: 10475647
references: Int J Oral Maxillofac Surg. 2008 Sep;37(9):810-8
references: 18583098
references: J Craniomaxillofac Surg. 2012 Dec;40(8):757-62
references: 22417772
references: J Craniofac Surg. 2009 Jul;20(4):1132-41
references: 19634218
references: Int J Oral Maxillofac Surg. 2010 Jun;39(6):534-40
references: 20427150
references: Int J Oral Maxillofac Surg. 2006 Jun;35(6):481-7
references: 16567079
references: Am J Orthod Dentofacial Orthop. 2010 Apr;137(4 Suppl):S79-85
references: 20381765
references: Am J Orthod Dentofacial Orthop. 2010 Feb;137(2):274-84
references: 20152686
references: Orthod Craniofac Res. 2011 Nov;14(4):222-33
references: 22008302
references: Am J Orthod Dentofacial Orthop. 2008 Dec;134(6):751-60
references: 19061801
references: Med Oral Patol Oral Cir Bucal. 2012 Mar 01;17(2):e311-9
references: 22143686
references: Angle Orthod. 2006 May;76(3):353-9
references: 16637711
references: Int J Adult Orthodon Orthognath Surg. 2002;17(2):89-97
references: 12099321
references: Am J Orthod Dentofacial Orthop. 1999 Nov;116(5):563-71
references: 10547518
references: J Oral Maxillofac Surg. 2001 Sep;59(9):994-1000; discussion 1001
references: 11526562
references: Am J Orthod Dentofacial Orthop. 2001 Nov;120(5):498-502
references: 11709668
references: Am J Orthod Dentofacial Orthop. 2009 Jul;136(1):94-9
references: 19577154
references: Thorax. 2011 Sep;66(9):797-803
references: 21680567
references: Oral Maxillofac Surg. 2010 Jun;14(2):105-14
references: 20108107
references: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Jan;107(1):36-42
references: 18755615
references: J Oral Maxillofac Surg. 2009 Oct;67(10):2080-92
references: 19761902
references: Plast Reconstr Surg. 2007 Jun;119(7):2192-2199
references: 17519721
references: PLoS One. 2011 Feb 09;6(2):e16520
references: 21347419