ELECTROMYOGRAPHIC ANALYSIS OF LIP MUSCLE FUNCTION IN OPERATED CLEFT SUBJECTS

EMG activity of the upper lip was measured with bipolar surface electr odes during speech and nonspeech tasks in order to assess labial funct ion in subjects with repaired clefts. Eighteen patients between 15 and 23 years of age with repaired unilateral cleft lip (isolated or combi ned with repaired cleft palate) were compared to 24 matched noncleft s ubjects. Data analysis demonstrated that the amplitude of action poten tials of the upper lip was significantly greater in the cleft group. W e hypothesize that the enhanced activity of the repaired upper lip dur ing function may contribute to the facial growth abnormalities usually seen in the cleft population.