Efeito do ajuste oclusal e placa oclusal na atividade eletromiográfica de pacientes com dor miofascial: um estudo preliminar

Abstract

Myofascial pain syndrome (MPS) is defined as a neuromuscular disorder characterized by presence of sensitive areas in contracted muscle bands that produce referred pain in far or adjacent areas. The etiology is multifactorial and biomechanical, neuromuscular, biopsychosocial and neurobiological factors can contribute to perpetuation of this syndrome. Several studies have evaluated the importance of altered occlusion in the etiology of MPS. However there is no consensus in the literature of the importance of this factor in the development of myofascial pain. Numerous etiologic and therapeutic theories are based on this presupposed association and has been applied to justify certain kind of treatment such as occlusal adjustment and occlusal splint. The study tested the null hypothesis that the occlusal splint and occlusal adjustment has the same effect on electromyographic activity in patients with myofascial pain in the presence of occlusal disturb. Surface electromyography was recorded bilaterally in the superficial masseter and anterior temporal in 10 asymptomatic patients and 10 symptomatic patients classified according to Research Diagnostic Criteria (RDC / TMD) axis I. Patients with myofascial pain were divided into two treatment groups: adjusment occlusal and occlusal splint. Electromyography and measuring the visual analogue scale (VAS) were performed before and after treatment. Muscle activity was recorded in the following conditions: maximum voluntary contraction (MCV), right laterality (RL), left laterality (LE) and protrusion (P). Comparing the muscular activity of the control group with the symptomatic group there was a decrease in EMG activity in the movement of maximal voluntary contraction. In assessing the occlusal adjustment group before and after treatment there was a decrease in EMG activity in the MVC movement and this increase muscle activity in excentric movements. Already in the occlusal splint group every muscle after treatment increased the electromyographic activity in different movements. Moreover, the symptoms decreased for both treatments. Thus it is concluded that the occlusal adjustment 15 and occlusal splint may be indicated to reduce the symptoms in patients with MPS, in case which occlusal disturb is one of the etiology factor.