Abstract

To characterize the activity and the muscle strength of the masseter, the orbicularis oris and mentalis muscles according to the type of swallowing.A probability sampling in a case-control analytic study was used to assess 88 school-age children in each group. A Surface electromyography (SEMG) of the orbicula-ris oris, mentalis and masseter muscles was performed. The compressive strength of the orbicularis oris of the lips (CSO), contractile strength of the right masseter muscle (CSrm), and left masseter muscle (CSlm), and the extensor strength of the lingual muscles (ESlm) and the resistance strength of the orbicularis oris of the lip (RSo) were determined by dynamometry. The Payne Technique was used to diagnose atypical swallowing (AS). They were performed Statistical comparisons with the nonparametric Mann-Whitney test (p <0.05).The contractile strength of masseter muscles showed 0.50 for the control group and 0.40 for the AS group. The extensor strength of lingual M in contrast to 0.44, the compressive strength of the ob-cularisoris 0.38 in contrast to 0.24 for the AS, and lingual extensor 2.73 in contrast to 2,37 for AS. The right masseter activity was 0.94 compared to 0.53 mV in AS with anterior, upper and lower tongue thrusting, and the activity of the left was 84mV compared to 94. The strength of all muscles showed decreased values in atypical swallowing (p <0.05).The activity of the orbicularis oris muscle was increased (p <0.05) in the anterior upper and in the tongue thrusting. The contractile strength of the masseter muscle, the extensor strength of the lingual muscle and the compression strength of the orbicularis oris muscle was diminished in cases of atypical swallowing with tongue thrusting(p <0.05)