An MRI evaluation of the effects of qat chewing habit on the temporomandibular joint.

OBJECTIVE: The aim of this study was to investigate the effects of the qat chewing habit on the temporomandibular joint by using magnetic resonance imaging. STUDY DESIGN: Sixty patients were included: a study group (40 qat chewers) and a control group (20 nonchewers). On the basis of qat chewing habit duration, the study group was subdivided into 3 further subgroups: subgroup I (5-10 years), subgroup II (11-15 years), and subgroup III (>15 years). Data on qat chewing habit were recorded, and a standardized clinical examination was performed. Bilateral oblique sagittal magnetic resonance imaging sections were obtained to evaluate disk displacement, osteoarthritis, and joint effusion. RESULTS: Clicking and pain were diagnosed in 72.5% and 65% of study group patients, respectively. Significant differences were discovered between the study group and the control group in osteoarthritis and joint effusion (P= .003 and .002, respectively). With regard to qat chewing habit duration, there were differences between study subgroup II and subgroup III versus control group in osteoarthritis (P= .040 and .001, respectively) and the 3 study subgroups versus control group in joint effusion (P= .026, .004, and .001, respectively). Significant correlations were found between osteoarthritis and clicking (P= .006) and muscle pain (P </= .044), and between joint effusion and temporomandibular joint pain (P = .006) and muscle pain (P </= .014). CONCLUSIONS: Qat chewing habit may be a risk factor for temporomandibular joint disorders with high percentages of osteoarthritis and joint effusion.