Análise funcional dos músculos do complexo cérvico crânio umeral por meio de exame eletromiográfico antes e após cirurgia ortognática: relato de caso

Abstract

The occlusion constitutes the basis of the morphofunctional stability of the posture and its action in the stomatognathic apparatus reflects and interferes in the cervical, thoracic and lumbar regions. Thus, with all the other units that make up the apparatus, they work together. The unbalance of one of them generates unwanted consequences in all the others. Therefore, when there is an occlusal or skeletal imbalance, it is expected that the musculature will also present signs and symptoms resulting from postural disharmony. Thus, a correct occlusion means a balance in the cranio-cervico-humeral lever and, due to this, a better stabilization of the position of the mandible, head, cervical spine and shoulders. Therefore, considering that the muscles are an active component of the stomatognathic apparatus, having their fixations (origin and insertion) in the skeleton, in cases of patients with skeletal dentofacial discrepancies, it is clear that the muscles are affected in their fixations with evident impairment of their function, which can be analyzed by electromyography, which allows the observation of the electrical activity of muscle fibers that are at work. Thus, the aim of this study was to analyze the electrical activity of the masseter muscles, as an active component, and the trapezius and deltoid muscles, as complementary active components of the stomatognathic apparatus, in class III patients, before and after orthognathic surgery. Some of the important results observed was the decrease in values for the left trapezius muscle from 42.12 μV to 14.50 μV and for the left masseter muscle from 82.98 μV to 13.97 μV. We conclude that it is a fact that there is a contributing relationship between the masseter, deltoid and trapezius muscles and that repositioning the mandible interferes with the balance of the craniocervical humeral relationship. Thus, orthognathic surgery is an important intervention to achieve a systemic locomotor balance.