The effects of Duchenne muscular dystrophy on the performance of the stomatognathic system: case-control study.

This study aimed to analyze electromyographic activity, masticatory efficiency, muscle thickness, and bite force of individuals with Duchenne muscular dystrophy (DMD).Forty males were selected, divided between the Duchenne group (n=20) and the control group (n=20). They were submitted to electromyography (EMG) analysis (temporalis, masseter and sternocleidomastoid muscles) during the postural control of the jaw, mastication, maximal molar bite force, and ultrasonography analyses.The normalizad EMG signals showed that the Duchenne group presented higher averages for masseter and temporal muscles in rest, protrusion, left and right laterality, and fatigue condition when compared to control group (p≤0.05). For masticatory efficiency of cycles, in analysis of non-habitual chewing of flavorless gum (Parafilm M; Pechinery Plastic Packaging, Batavia, IL, USA), and habitual chewing of peanuts and raisins, the Duchenne group presented lower averages when compared to control group (p≤0.05). For the muscle thickness the results showed that there was a lower muscle thickness in Duchenne group for all muscles during the rest and maximal voluntary contraction, except for masseter and sternocleidomastoid in the maximal voluntary contraction. In the maximum molar bite force, the control group presented the highest values for both sides when compared to Duchenne group (p≤0.05).We conclude that stomatognathic system changes occur in carrier DMD.