Myogenous Orofacial Pain Disorders: A Retrospective Study

Aim: To assess treatment efficacy in the management of orofacial myogenous conditions by a retrospective study of patients seen at an orofacial pain clinic. Methods: A single researcher conducted a retrospective review of charts of patients assigned to the same provider, to identify those with myogenous disorders. The reviewed charts belonged to patients of the Orofacial Pain and Oral Medicine Center of the University of Southern California, seeing from June 2018 to October 2019. Results: A total of 129 charts included a myogenous disorder; the most common primary myogenous disorder was localized myalgia (58 cases, 45.0%). Arthralgia was the most common TMD concomitant condition (82.9%), followed by internal derangement (41.9%). Forty-six patients were given a home-based conservative physical care protocol; ten additional cases also received trigger point injections (lidocaine or mepivacaine) with pain assessed by verbal numerical rating scale (NRS), pre- and post-treatment follow-up within 24 weeks. There was a significant overall pain improvement in NRS pain from pre- to post-treatment (p<0.001), though no difference was found between conservative treatment and trigger points in NRS pain (p=0.130). However, the rate of NRS unit improvement per week in the conservative treatment group was significantly greater than the trigger point group (p=0.036). These apparently contradictory results might be due to the small sample size of the trigger point injections group (n=10). Conclusion: In this small sample size study, the addition of trigger point injections to conservative treatment provided inconclusive results, further studies are needed.