It seems that the presence of TMDH in patients with the temporomandibular disorder is more "severe" form related to greater variations in central pain processing mechanisms comprising pain amplification and reduced pain inhibition. Hence, this may also be a reflection of increased somatic awareness. According to Vivaldi D et al., the improved phenotyping of TMDH will lead to a better understanding of the etiopathophysiology, giving way to more precise treatment methods.

A headache attributed to temporomandibular disorders (TMDH) is defined as a secondary headache by the International Classification of Headache Disorders 3rd edition (ICHD-3). This case-control study investigated the phenotypic features of chronic TMD with and without TMDH. The authors hypothesize that chronic TMD with TMDH is connected with an increased number of bodily pain conditions, higher painful sites in the head and neck region, and a higher TMD pain intensity.

This retrospective cross-sectional review of the medical records of consecutive patients seeking treatment at the University of North Carolina Orofacial Pain Clinic between 2013 - 2014. The inclusion criterion comprised of the diagnosis of myalgia or arthralgia as per the Research Diagnostic Criteria for Temporomandibular Disorders. Also, cases had a diagnosis of TMDH as per the ICHD-3 criteria. The data on the presence and the number of self-reported bodily pain conditions (for example fibromyalgia and LBP), pain intensity, number of painful sites in the head and neck upon palpation, and TMD pain onset were examined.

Total of 295 records was reviewed. There were 34 (29.3%) patients who fulfilled the inclusion criteria for cases (TMD+TMDH) and 82 (70.7%) for controls (TMD-TMDH). Cases had a greater number of bodily pain conditions than the controls, with a mean of 1.97 ± 1.50 and 1.26 ± 1.28 for bodily pain conditions. 55.9% of cases had at least 2 comorbid pain conditions as compared to 37.8% controls. As compared to controls (8.65 ± 5.32), cases (13.05 ± 4.46) showed a greater number of painful sites upon palpation in head and neck area, and a greater TMD pain intensity, with a mean of 6.00 ± 2.17 for the cases and 5.09 ± 2.14 for the controls.

TMDH was significantly concerned with an increased number of self-reported bodily pain conditions, a higher number of painful sites in head and neck areas, and higher TMD pain intensity in chronic TMD patients seeking pain management.