Superior Orbicularis Oris Muscle Activity in Children Surgically Treated for Bilateral Complete Cleft Lip and Palate

The aim of this cross-sectional study was to evaluate the electromyographic activity of the superior orbicularis oris muscle both in children surgically treated for bilateral complete cleft lip and palate (BCCLP) as well as in subjects without BCCLP. The study comprised 77 children aged 6.6 to 12.5 years. All the patients with clefts had previously undergone lip and palate surgery. The upper lip electromyographic (EMG) assessments were made with a DAB-Bluetooth device (Zebris Medical GmbH, Germany) at rest, while swallowing saliva, protruding lips and compressing lips. EMG measurements were also made when the subjects produced phonemes /p/, /b/, and /m/ with the vowel /a/. The Mann-Whitney U test was applied to statistically analyze the EMG values. Significantly higher median upper lip EMG activity under working conditions such as swallowing saliva, lip compression, and production of the phoneme /p/ with the vowel /a/ was observed in patients with BCCLP compared to those without a cleft. The results of the study showed that the upper lip muscle activity increases in children with BCCLP when swallowing saliva, compressing lips and during some speech movement tasks. This may be important in the aspect of the effect of surgical lip repair on the craniofacial growth.