Does Conservative Temporomandibular Therapy Affect Tinnitus Complaints? A Systematic Review

Aims: To investigate whether temporomandibular disorders treatment can positively influence tinnitus complaints. Methods: Four online databases (PubMed, Web of Science, Scopus, and the Cochrane Library) were searched up to August 2018 for relevant studies. Two independent reviewers extracted the data and performed a risk of bias assessment. Results: A total of 11 studies were included. These studies showed an overall positive effect of the combination of splint therapy and exercise treatment on tinnitus severity and intensity (as measured on a visual analog or numeric rating scale), as well as on global perceived effect. One study specified that the treatment effect was only present in patients with severe to very severe tinnitus, while the others found an effect in the overall study group. The risk of bias in the included studies was high, mainly due to lack of statistical analyses between groups and before vs after treatment, incomplete presentation of the data, and selective reporting. Additionally, most included studies showed a lack of information concerning blinding of the subjects, therapists, and investigators. The heterogeneity of the inclusion criteria, outcome measurements, and treatments made data pooling and meta-analysis impossible. Conclusion: There is low-quality evidence for a positive effect of conservative temporomandibular disorders treatment on tinnitus complaints. The combination of splint therapy and exercise treatment is currently the best investigated treatment approach, showing a decrease in tinnitus severity and intensity. Despite the low level of evidence and the methodologic issues in the included studies, it is noteworthy that all included studies show positive treatment effects. Keywords: occlusal splints, physical therapy modalities, somatic, somatosensory, temporomandibular joint disorders