title: Improved interaction models of temporomandibular joint anatomic relationships in asymptomatic subjects and patients with disc displacement with or without reduction.
abstract: OBJECTIVE
  To consider temporomandibular joint (TMJ) anatomic interactions in order to refine hard tissue models differentiating (1) joints diagnosed with disc displacement with reduction (DDwR) or without reduction (DDw/oR) from asymptomatic joints (Normals), and (2) DDwR joints from DDw/oR joints.
  
  
  METHODS
  TMJ tomograms of 84 women with unilateral DDwR and 78 with unilateral DDw/oR were compared against each other and against those of 42 female Normal joints through the use of 14 linear and angular measurements, 8 ratios, and 34 interactions. A classification tree model for each comparison was tested for fit with sensitivity, specificity, accuracy, and log likelihood and compared to logistic regression models.
  
  
  RESULTS
  In the classification tree model comparison, the DDwR model versus the Normal model realized 35.9% log likelihood (88.0% sensitivity, 66.7% specificity); the DDw/oR model versus the Normal model realized 38.8% log likelihood (69.6% sensitivity, 85.7% specificity). The DDwR model versus the DDw/oR model realized 33.3% log likelihood (76.0% sensitivity, 73.1% specificity). In the logistic regression model comparison, the DDwR model versus the Normal model realized 40.8% log likelihood (82.1% sensitivity, 78.6% specificity) and the DDw/oR model versus the Normal model realized 61.1% log likelihood (85.9% sensitivity, 90.5% specificity). The DDwR model versus the DDw/oR model realized 21.5% log likelihood (60.3% sensitivity, 79.8% specificity). The addition of interactions to the logistic regression models improved the previously published log likelihood from 99% to 149%.
  
  
  CONCLUSIONS
  The interactions improved logistic regression models and the data suggest that anatomic characteristics influence joint functional status. Because the models incorporated nearly all considered anatomic measurements, no anatomic factor is redundant in the closed TMJ biological system.
authors.affiliation: Division of Oral Biology and Medicine, Section of Orofacial Pain, UCLA School of Dentistry, Los Angeles, CA 90024-1668, USA. DonaldS261@aol.com
authors.forename: Donald A
authors.initials: DA
authors.lastname: Seligman
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Pullinger
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000145:classification / Q000000981:diagnostic imaging / Q000473:pathology*; D016013:Likelihood Functions; D016014:Linear Models; D016015:Logistic Models; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000473:pathology; D008954:Models, Biological; D012680:Sensitivity and Specificity; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000473:pathology; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000145:classification / Q000000981:diagnostic imaging / Q000473:pathology*; D014056:Tomography, X-Ray