title: Temporomandibular disorders in German and Chinese adolescents.
abstract: OBJECTIVE
  The etiology of temporomandibular disorders (TMD) remains unclear. The aim of this study was, by comparing the prevalence of TMD between adolescents of different ethnic origin, to examine whether certain genetic factors may play a role in causing TMD.
  
  
  METHODS
  We assessed the prevalence of TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) in 1,058 subjects (561 German, 497 Chinese) aged 13 to 18 years from two general population samples.
  
  
  RESULTS
  In total, the prevalence of RDC/TMD diagnoses was 13.9% (N = 147). The difference between German (13.0%, N = 73) and Chinese adolescents (14.9%, N = 74) was not statistically significant. After controlling for the effects of age, gender and orthodontic treatment using multivariable logistic regression analyses, the prevalence of RDC/TMD group II diagnoses (disc displacement) was lower in China than Germany (odds ratio [OR] = 0.5, 95% confidence interval [CI]: 0.3-0.8), whereas the prevalence of RDC/TMD pain diagnoses (group I, III) was higher in China (OR = 3.3, 95%-CI: 1.7-6.5).
  
  
  CONCLUSIONS
  Our study reveals obvious differences in the prevalence of TMD between adolescents of different ethnic origins (Asians and Europeans). These differences cannot be attributed to cultural differences alone, which implies the involvement of genetic factors in the etiology of TMD.
authors.affiliation: Department of Pediatric Dentistry and Primary Prevention, Department of Orthodontics, University of Leipzig, Nürnberger Strasse 57, Leipzig, Germany.
authors.forename: Ning
authors.initials: N
authors.lastname: Wu
authors.forename: Christian
authors.initials: C
authors.lastname: Hirsch
mesh_terms: D000293:Adolescent; D002681:China / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D013705:Temporomandibular Joint Disorders / Q000453:epidemiology* / Q000235:genetics*