Is temporomandibular joint involvement more frequent in patients with epilepsy? A clinical study

Epileptic seizures may affect the stomatognathic system via transmission of an increased load to the dentition and the temporomandibular joint (TMJ), resulting in temporomandibular joint dysfunction (TMD).

The purpose of this clinical study was to assess whether TMD was more prevalent in patients with epilepsy than in those without epilepsy.

A total of 107 participants diagnosed with epilepsy and 100 healthy controls were enrolled in the study. Those with epilepsy were divided according to their dental manageability into 3 subgroups: mild group, moderate group, and severe group. Following general, dental, and TMJ-related history, the range of maximal mouth opening (MMO), laterotrusion, possible deviation and deflection, and presence of crepitation and clicking was recorded, as suggested by the diagnostic criteria for temporomandibular diseases (DC/TMD). Pressure pain threshold (PPT) was also measured by using a pressure algometer on 3 points bilaterally.

Incidence of TMJ complaints was not significantly different between the control (30%) and the group diagnosed with epilepsy (33%); however, the number of complaints experienced was significantly higher in the epilepsy group (C: 3%, E: 16% had 3 or more complaints; P<.001). Joint clicking was significantly more prevalent in the entire epilepsy group (P=.012) and in the mild group (P=.004) than in controls. Crepitation and joint pain were not significantly more common in the epilepsy group. Maximal mouth opening, laterotrusion, and the ratio of restricted mouth opening did not differ significantly in the epilepsy group. Deflection occurred significantly more often in the epilepsy subgroups (mild and moderate groups; P<.001), and the extent of deflection was also significantly higher in all the epilepsy subgroups (P<.001) than in controls. Regarding the pressure pain threshold, significant difference was observed in the severe group at the left masseter muscle points M1 (P=.046) and M2 (P=.028) compared with controls.

All parameters typical of TMD could be found frequently in patients with epilepsy. Because of the seizures and the consequent joint overload, the TMJ involvement was more common or more serious in those diagnosed with epilepsy. Outcomes of this study support the assumption that epilepsy is a risk factor for the development of TMD.