title: Changes in occlusal contact area during oral appliance therapy assessed on study models.
abstract: OBJECTIVE
  To test the hypothesis that long-term use of an oral appliance (OA) does not cause changes in the occlusal contact area (OCA).
  
  
  METHODS
  Baseline and follow-up treatment study models were obtained for 45 patients with obstructive sleep apnea who had been using an OA for 4 or more days/week for more than 5 years. Study models in centric occlusion, with an inserted pressure-sensitive sheet, were loaded in compression. An image scanner was used to evaluate OCA.
  
  
  RESULTS
  A significant change in total OCA was identified in 39 patients (86.7%): a decrease in 26 (66.7%) and an increase in 13 (33.3%) patients. Regional changes >5% were observed in >90% of patients in each of the three regions. In the molar and premolar regions, 24 (53.3%) and 27 (60.0%) of the patients showed an OCA decrease, while only 16 (35.6%) and 15 (33.3%) showed an increase. Conversely, for the anterior region, more increases (24 patients-53.3%) than decreases were identified.
  
  
  CONCLUSIONS
  The hypothesis is rejected. Long-term OA therapy resulted in dramatic changes of occlusion, suggesting that monitoring of occlusal changes is required.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate school of Biomedical Sciences, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ueda
authors.forename: Fernanda R
authors.initials: FR
authors.lastname: Almeida
authors.forename: Alan A
authors.initials: AA
authors.lastname: Lowe
authors.forename: N Dorin
authors.initials: ND
authors.lastname: Ruse
mesh_terms: D001641:Bicuspid / Q000473:pathology; D004396:Coloring Agents; D003481:Cuspid / Q000473:pathology; D003766:Dental Occlusion; D003768:Dental Occlusion, Centric; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor / Q000473:pathology; D007574:Jaw Relation Record / Q000295:instrumentation; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation; D008875:Middle Aged; D003765:Models, Dental; D008963:Molar / Q000473:pathology; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D011093:Polyethylene Terephthalates; D011312:Pressure; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D012913:Snoring / Q000628:therapy; D013499:Surface Properties
chemical_list: D004396:Coloring Agents; D011093:Polyethylene Terephthalates