Differences between the activity of the masticatory muscles of adults with cerebral palsy and healthy individuals while at rest and in function

• At rest, masticatoy muscles showed higher activity in the cerebral palsy group than in the control group.
• Higher electromyographic values for mouth opening were also found in the cerebral palsy group.
• During maximal voluntary clench, the cerebral palsy group exhibited lower electromyographic activity than the control group.
• Significant differences were recorded between the electromyographic activity of patients with different degrees of oral motor impairment.

ObjectiveThe aim of the present study was to compare the electromyographic activity of masticatory muscles of adult patients with different degrees of oral motor impairment (cerebral palsy) with the electromyographic activity of healthy individuals in a control group. Electromyographic activity was compared when the masticatory muscles were at rest and in motion.DesignThirty adult patients with cerebral palsy and 30 subjects without neuromotor disorders were enrolled in the present study. Oral motor function impairment was classified for each subject according to the Orofacial Motor Function Assessment Scale. Surface electromyography was bilaterally recorded in the masseter and anterior temporalis muscles at rest, during maximal voluntary clench and mouth opening. Comparisons between the groups were statistically assessed using Mann-Whitney test.ResultsAt rest and mouth opening, electromyographic values were higher among patients with cerebral palsy than control group. During maximal voluntary clench, the opposite occurred. The degree of oral motor impairment affected mouth opening.ConclusionThere are significant differences in masticatory muscle activity between adult patients with CP and healthy individuals, and the degree of oral motor impairment is important.SignificanceTo improve the masticatory function of these patients, muscle therapy should approach rest, mouth opening and clenching differently.