Abstract:

Objective This study aimed to investigate the correlation between clinical symptoms and unilateral chewing habits in patients with temporomandibular disorder (TMD) accompanied by tinnitus. Methods A total of 285 patients diagnosed with TMD at the Department of Stomatology of the First Medical Center of Chinese People’s Liberation Army General Hospital between December 2020 and May 2024 were included and divided into two groups: tinnitus group and non-tinnitus group. Analysis was conducted on the proportion of patients with unilateral chewing habits in both groups, the correlation between the side of tinnitus and the side of unilateral chewing, and the correlation of tinnitus with TMD clinical symptoms (joint clicking, joint pain, and limited mouth opening) and unilateral chewing habits. The correlation of the type of disc displacement with unilateral chewing and tinnitus was also examined. Results In the tinnitus group, the proportions of patients with and without unilateral chewing habits were 90.70% (39/43) and 9.30% (4/43), respectively. In the non-tinnitus group, the proportions of patients with and without unilateral chewing habits were 76.03% (184/242) and 23.97% (58/242), respectively. The proportion of patients with unilateral chewing habits in the tinnitus group was significantly higher than in the non-tinnitus group (χ²=4.613, P<0.05). Correlation analysis showed a positive correlation between tinnitus and unilateral chewing habits (P<0.05). In the left-sided tinnitus group, the proportion of left-sided unilateral chewers [54.55% (12/22)] was higher than that of right-sided unilateral chewers [45.45% (10/22)]. In the right-sided tinnitus group, the proportion of right-sided unilateral chewers [81.82% (9/11)] was higher than that of left-sided unilateral chewers [18.18% (2/11)]. The difference was statistically significant (χ²=7.282, P<0.05). A positive correlation was also found between the side of tinnitus and the side of unilateral chewing habits (P<0.05). The proportion of patients with pain was significantly higher in the tinnitus group than in the non-tinnitus group (P<0.05). No significant difference in the proportion of joint clicking or limited mouth opening and disc displacement (no disc displacement, unilateral disc displacement, bilateral disc displacement, reducible disc displacement, or irreducible disc displacement) was found between the tinnitus and non-tinnitus groups (P>0.05). Conclusion TMD with unilateral chewing habits may be a contributing factor to unexplained tinnitus. Unexplained tinnitus is correlated with joint pain in patients with TMD.

Key words: temporomandibular disorder, tinnitus, chewing-side preference, disc displacement of temporomandibular joint, pain in the temporomandibular joint area