Superior Orbicularis Oris Muscle Activity in Children with and without Cleft Lip and Palate

An analysis of integrated electromyographic (IEMG) activity of the superior orbicularis oris muscle was undertaken in 15 children with cleft lip and palate who have undergone surgery compared to 10 children without clefts (control group). Bipolar surface electrodes were used for IEMG recordings of resting level activity and during the swallowing of saliva. Similar resting level activity was observed in both groups. During the swallowing of saliva, activity in children with cleft lip and palate was higher than in children without clefts (noncleft children). Moreover, in the cleft lip and palate group, children with abnormal lip seal showed the highest values for IEMG activity during the swallowing of saliva. This fact suggests that with each swallow of saliva, a greater counteracting effect of the superior orbicularis oris muscle could be produced on the growing maxilla. This may result in a significant long-term effect on the growth of the stomatognathic system, since the process of swallowing is a 24-hour function repeated between 600 and 2400 times each day.