Review abstract:

Summary:
The most common cause of chronic oro-facial pain is a group of disorders collectively termed temporomandibular disorders (TMDs). Chronic painful TMD is thought to be a ‘central sensitivity syndrome’ related to hypersensitivity of the nervous system, but the cause is unknown. A similar understanding is proposed for other unexplained
conditions, including chronic fatigue syndrome (CFS). Exploring the comorbidity of the two conditions is a valuable first step in identifying potential common aetiological mechanisms or treatment targets.

Method
Systematic literature review. Studies were included if they recruited community or control samples and identified how many reported having both TMD and CFS, or if they recruited a sample of patients with either TMD or CFS and measured the presence of the other condition.

Results
Six papers met inclusion criteria. In studies of patients with CFS (n=3), 21-32% reported having TMD. In a sample of people with CFS and fibromyalgia, 50% reported having TMD. Studies in people with TMD (n=3) reported 0-43% having CFS. Studies in samples recruited from oro-facial pain clinics (n=2) reported a lower comorbidity with CFS (0-10%) than a study that recruited individuals from a TMD self-help organisation (43%).

Conclusion
The review highlights the limited standard of evidence addressing the comorbidity between oro-facial pain and CFS. There is a valuable signal that the potential overlap in these two conditions could be high; however, studies employing more rigorous methodology including standardised clinical assessments rather than self-report of prior
diagnosis are needed.

A systematic review of the comorbidity between Temporomandibular disorders and Chronic Fatigue Syndrome, by L J Robinson, J. Durham and JL Newton in Journal of Oral Rehabilitation, Nov 9, 2015