title: Temporomandibular joints in asymptomatic and symptomatic nonpatient volunteers: a prospective 15-year follow-up clinical and MR imaging study.
abstract: OBJECTIVE
  To determine the incidence, prevalence, and progression of temporomandibular joint (TMJ) magnetic resonance (MR) imaging findings and symptoms during 15 years in adult asymptomatic and symptomatic volunteers (nonpatients).
  
  
  METHODS
  A regional committee for medical research ethics approved the study, and informed volunteer consent was obtained. Fifty-three volunteers were examined at study inception. For clinical assessment, a self-administered questionnaire was given, followed by an interview with each volunteer at study inception, at 1 year later, and at 15 years later. Bilateral TMJ MR imaging and clinical examination were performed at inception and at 15-year follow-up. The MR images were assessed for disk position, bone status, and joint fluid. All 53 volunteers participated at 1-year follow-up, and 50 of 53 volunteers participated at 15-year follow-up; of these 50 volunteers, 47 underwent MR imaging. The Fisher exact test was used to determine differences between groups, and the Wilcoxon signed-rank test was used to determine differences in prevalence of TMJ symptoms among the three examination times.
  
  
  RESULTS
  At study inception, TMJ disk displacement was observed in 31% of asymptomatic volunteers (nine of 29) compared with 89% of symptomatic volunteers (16 of 18, P < .001). Inceptive TMJ status was maintained after 15 years in 91% (43 of 47). Unilateral progression was observed in four volunteers (9%); one was symptomatic and three were asymptomatic. Progression involved development of new disk displacement (n = 1), development of new bone changes (n = 2), and aggravation from reducing to nonreducing disk displacement (n = 1). Prevalence of TMJ symptoms did not change significantly between examination times (P = .77). TMJ clicking was the most common clinical symptom.
  
  
  CONCLUSIONS
  Volunteers with mild symptoms had a prevalence of disk displacement of the same magnitude as that reported in patients, although most volunteers, symptomatic as well as asymptomatic, maintained their TMJ status during 15 years.
authors.affiliation: Oral and Maxillofacial Radiology Division, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden. hanna.sale@mah.se
authors.forename: Hanna
authors.initials: H
authors.lastname: Salé
authors.forename: Fredrik
authors.initials: F
authors.lastname: Bryndahl
authors.forename: Annika
authors.initials: A
authors.lastname: Isberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis* / Q000453:epidemiology