Temporomandibular disorder and headache prevalence: A systematic review and meta-analysis

Background: Temporomandibular disorders (TMD) and headaches are prevalent among the global population. Patients often suffer from both conditions, and they are likely to be associated in a bidirectional way. However, the nature of the association remains unclear. Understanding the epidemiological aspects of the relationship between these conditions could have important clinical implications. Objective: To evaluate the prevalence of headaches in TMD patients as well as the prevalence of TMD in patients who suffer from headaches. Method: A systematic literature search was conducted using electronic databases. Studies published in English and those that used an acknowledged diagnostic criteria for TMD and headaches were included. Study quality was assessed using the Newcastle-Ottawa scale and meta-analyses were performed to generate pooled prevalence estimates. Result: Thirty-one studies met the selection criteria for the review; 16 studies evaluated the prevalence of headache in TMD patients and 15 studies evaluated the prevalence of TMD in headache patients. The included studies were of moderate-to-high quality. Meta-analyses revealed moderate-to-large heterogeneities across included studies. Pooled prevalence estimates from meta-analyses indicated similar rates of headaches in TMD patients and of TMD in headache patients (61.58%, 95% CI 45.26–76.66 and 59.42%, 95% CI 51.93–66.60, respectively). Migraines were more commonly observed in TMD patients (40.25%, 95% CI 35.37–45.23) compared to tension-type headaches (18.89%, 95% CI 12.36–26.44). The prevalence of headaches was particularly high in painful-TMD (82.80%, 95% CI 75.41–89.10). Conclusion: Despite large variance in prevalence rates across included studies, this review suggests headache and TMD frequently co-occur, particularly in the case of migraines and muscle related TMD. This association has important clinical, pathophysiological and therapeutic implications.