title: The value of maximum jaw motion measurements for distinguishing between common temporomandibular disorder subgroups.
abstract: OBJECTIVE
  The purpose of this study was to determine if mandibular motion measurements could be used to distinguish between common temporomandibular disorder (TMD) subgroups that were established on the basis of only clinical signs and symptoms.
  
  
  METHODS
  Patients were 41 consecutive TMD clinic patients (31 women and 10 men). These patients were divided into 6 typical TMD subgroups. The subgroups were patients with (1) arthromyalgia, (2) arthromyalgia with disk condyle incoordination, (3) disk condyle incoordination only, (4) osteoarthritis, (5) suspected disk displacement without reduction, or (6) other diagnoses.
  
  
  RESULTS
  There were no subjects in the other-diagnosis subgroup and only 1 subject with suspected disk displacement without reduction who was dropped without further consideration. The data for mean age showed that the osteoarthritis subgroup (n = 12) was statistically older (17 years) than the disk-condyle-incoordination-only subgroup (n = 11). The mean age of the other 2 groups, arthromyalgia (n = 11) and arthromyalgia with disk condyle incoordination (n = 6), was between the osteoarthritis and the disk-condyle-incoordination-only subgroups. For the 4 TMD subgroups whose data were analyzed, the mean differences between similar jaw opening measurements ranged from 6 to 8 mm with a standard deviation of approximately 8 to 10 mm. The mean left lateral motions were 0.5 to 1.3 mm larger than observed on the right. The widest mean jaw opening (56 mm) occurred in the disk-condyle-incoordination-only group. These differences were not found to be statistically significant.
  
  
  CONCLUSIONS
  Analysis of opening, lateral and protrusive jaw motion data showed these measurements could not reliably differentiate between patients with osteoarthritis, arthromyalgia, arthromyalgia with disk condyle incoordination and disk condyle incoordination only.
authors.affiliation: Kyushu Dental College, Kitakyushu, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Masumi
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: G T
authors.initials: GT
authors.lastname: Clark
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D018771:Arthralgia / Q000175:diagnosis / Q000503:physiopathology; D003766:Dental Occlusion; D003937:Diagnosis, Differential; D005157:Facial Pain / Q000503:physiopathology; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000503:physiopathology; D004204:Joint Dislocations / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008334:Mandible / Q000503:physiopathology*; D008335:Mandibular Condyle / Q000503:physiopathology; D008406:Masseter Muscle / Q000503:physiopathology; D009068:Movement; D009135:Muscular Diseases / Q000175:diagnosis / Q000503:physiopathology; D009334:Neck Muscles / Q000503:physiopathology; D010003:Osteoarthritis / Q000175:diagnosis / Q000503:physiopathology; D010173:Palpation; D013016:Sound; D013223:Statistics as Topic; D013703:Temporal Muscle / Q000503:physiopathology; D019224:Temporomandibular Joint Disc / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology