RESUMEN
The aim of the study was to assess the efficacy of type A Botulinus toxin (BTA) in pain release by TMJ functional pain disorders. The study included 211 patients with TMJ functional pain disorder (20.4% males and 79.6% females; mean age 45.3 years). The patients underwent clinical examination and bioelectric activity assessment of masticatory muscles by electromyography (EMG). EMG specters of 20 healthy volunteers with intact dental arches served as a control. After examination BTA was injected in muscular pain trigger points. All patients had muscular hypertonus, unilateral in 88.6% and bilateral in 11.4%. EMG showed the decrease of masticatory muscle activity on affected side to mean values of 165±20 mkV (30.0%, p<0.05) and on contralateral side to 460±31 mkV (89.6%, p>0.05). BTA injections in tensed muscles released significantly muscle-induced facial pain and improved quality of life. During 6 months follow up myofacial pain disorder relapse was seen in 3 patients. The results allow recommending BTA injection in muscular pain trigger points for treatment of myofacial pain syndrome and prolonged muscle relaxation.
