title: Association between mandibular retrognathia and TMJ disorders in adult females.
abstract: OBJECTIVE
  This study assesses the association between temporomandibular joint (TMJ) disorders and mandibular retrognathia.
  
  
  METHODS
  We conducted a case-control study among women, aged 18-70 years, recruited from Kaiser Permanente Northwest Division (KPNW, Portland, OR) and Group Health Cooperative of Puget Sound (GHC, Seattle, WA). Cases (N= 160) were women seeking treatment for TMJ disorders at KPNW and GHC clinics. Controls (N=151) were women without TMJ disorders, selected from among adult female dental hygiene patients at KPNW or GHC enrollees. Case status was determined by questionnaire; mandibular sagittal position (orthognathic, mildly retrognathic, severely retrognathic, or prognathic) was measured using digitized facial photographs. Odds ratios (OR) and associated 95 percent confidence intervals (CI) estimated the magnitude of the association between TMJ disorders and mandibular sagittal position.
  
  
  RESULTS
  Women with TMJ disorders were 4.0 times (95% CI=1.5, 10.8) more likely than controls to have severe retrognathia; no association with mild retrognathia or prognathia was seen. Results were similar when cases were restricted to those with recent onset of TMJ pain (OR=6.3; 95% CI=1.8, 21.8).
  
  
  CONCLUSIONS
  We found a strong association between TMJ disorders and severe mandibular retrognathia in adult females. In some women this likely resulted from TMJ disorders influencing mandibular development over time. However, among a subset of women, our data support the reverse hypothesis--that severe mandibular retrognathia may influence the development of TMJ disorders. Despite this strong association, abnormal mandibular position contributed only a small portion to the overall rate at which women sought treatment for TMJ disorders.
authors.affiliation: University of Washington Medical Pain Center, Seattle, USA. jrmill@u.washington.edu
authors.forename: James R
authors.initials: JR
authors.lastname: Miller
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Burgess
authors.forename: Cathy W
authors.initials: CW
authors.lastname: Critchlow
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D002508:Cephalometry; D016009:Chi-Square Distribution; D004522:Educational Status; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016015:Logistic Models; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D023861:Photography, Dental; D011378:Prognathism / Q000150:complications; D044469:Racial Groups; D063173:Retrognathia / Q000145:classification / Q000150:complications*; D013705:Temporomandibular Joint Disorders / Q000209:etiology*