Comparative study between children with and without cleft tip and cleft palate, part 2: Electromyographic analysis

Objective: This study was conducted to compare electromyographic (EMG) acti vity of superior orbicularis oris muscle between children with repaired cle ft lip and cleft palate and children without clefts. Methods. This study included 28 children with mixed dentition. They were di vided into two groups. The study group included 14 children with repaired u nilateral cleft lip and cleft palate, ranging In age from 6 to 12 years, wh o presented clinically with a short upper lip, abnormal lip seal, and Inhib ition of sagittal development of the midface as assessed radiographically. The control group included 14 children without clefts ranging in age from 8 to 11 years. All had normal lip seal, nasal breathing, and a clinically no rmal body posture. Design: Bipolar surface electrodes were used for EMG recordings of resting level activity and during swallowing of saliva, speech, and chewing and swa llowing of an apple. Results and Conclusions: A significantly higher level of activity at rest a nd during swallowing of saliva was observed in the cleft tip and cleft pala te group. Similar activity during speech and chewing and swallowing of an a pple was observed in both groups. The higher level of activity at rest and during swallowing of saliva In chi ldren with cleft lip and cleft palate seems to suggest that upon higher fun ctional demands their activity increases less than in children without clef ts. From a clinical point of view, if increased EMG activity at rest and during swallowing of saliva reflects increased force on the maxilla, then our fin dings may corroborate Bardach's findings (1990) that surgical treatment of cleft lip has an iatrogenic effect on facial growth, although the lack of s ignificant correlation between the cephalometric data end EMG findings in t he present study.