The Association between Occlusal Features and Temporomandibular Disorders in Northern Jordan: A Cross-sectional Study

To evaluate the possible correlation between basic occlusal features and the outcomes of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I.

A convenient sample of Northern Jordanians was used in the study. Participants were examined in accordance with DC/TMD protocol. Nine occlusal features represented the independent variables; overjet, overbite, midline deviation, pain-free opening, maximum assisted opening, maximum unassisted opening, lateral excursions and protrusion, in addition to the opening pattern (classified as straight, corrected deviation and uncorrected deviation). DC/TMD diagnostic outcomes and their associated features represented the dependent variables, namely, pain-related TMD, Intra-articular Disorders (IAD), Degenerative Joint Disease (DJD), joint sounds (clicking and crepitus), joint locking and headache attributed to TMD. Binary logistic regression, multinomial logistic regression and Chi-square tests were used for statistical analyses.

A total of 400 participants represented the study population (mean age = 32.3±12.4 years, males=48%, females=52%). 71 subjects (18%) were diagnosed with pain-related TMD, 52 (13%) with IAD, 6 (1.5%) with DJD and 38 (10%) with headache due to TMD. Gender had a significant correlation with pain-related TMD (p= 0.014, OR= 2.16). Maximum pain free opening had a significant inverse relationship with pain related TMD (p= 0.013, OR=0.94), while midline deviation and corrected deviation mouth opening pattern had a significant correlation with IAD (p= 0.04,0.02, OR= 1.30,2.74, respectively). Overbite, midline deviation and pain free opening were significantly associated with unilateral open/close clicking (p= 0.04,0.05,0.03, OR= 0.77, 1.31, 0.94, respectively).

There is a minimal clinical significance of the correlation between dental occlusion and TMD.