Surface electromyography of masticatory and neck muscles in patient with temporomandibular disorders and headache

Background

Headeaches and temporomandibular disorders (TMD) are highly prevalent conditions that frequently co-exist in the same patient. They are often associated whit myofascial pain of masticatory, pericranial and neck muscles as well as dental occlusion alterations. In order to determine the correct management and treatment, clinical examination should be coupled whit functional assessment. Surface electromyography(sEMG) can make an objective recording - before and after treatment - of the masticatory and neck muscles (dys)function induced by dental occlusion, as a possible cause or aggravation factor of TMD associated with headeache.

Case report

53-year-old woman affected by:

• Chronic tension-type headeache (according to ICHD3- beta criteria)
• Pericranial tenderness
• TMD with myofascial long-lastin pain
• Dental occlusion alteration
• Dual bite
• Bruxism

To verify the neuromuscolar equilibrium induced by dental contact , the standardized sEMG activities of right and left anterior temporal, masseter and sternocleidomastoidal (SCM) muscles were recorded during maximum voluntary clench.

Before treatment, sEMG data show an increased and more asymmetric standardized activity of temporalis anterior muscles, an anterior position of occlusal barycentre, the presence of right mandibular torque (precontact dental), asymmetric activities of SCM with cervical load, and decreased muscle work values compatible with pain and muscolar fatigue - probably as a consequence of nociceptive inputs.

After a month of treatment combining drugs, stabilization appliance and counseling, complete remission of muscle symptoms and normalization of all sEMG's indexes was registered, which confirms a successful outcome of the therapy.

Conclusions

sEMG , joined with a set of clinical and morfological tests, allows to objectively assess the relationship between clinical symptoms (pain related to muscles and palpation) and dental occlusion on masticatory and neck muscle activity in TDM associated with headeache.