Abstract
Cleft lip and palate (CLP) is the most common cleft malformation occurring in the maxillofacial region, and morphologic changes following treatment have been reported. However, few studies have shown how these changes affect oral function. We investigated changes in the physiologic characteristics of sucking function along with perioral muscle activity in infants with CLP. Ten infants with unilateral CLP underwent a cheiloplasty procedure at the center of the cleft lip and palate at F Health University Hospital. Measurements were obtained preoperatively and postoperatively, and again at 3 months after the cheiloplasty. Electromyogram (EMG) findings from the bilateral temporal (L-R, TM), masseter (L-R, MM), orbicularis oris (OM), and suprahyoid (SM) of the healthy side were recorded. EMG findings obtained from 8 healthy 3-month-old infants were used as a control. The peak amplitude of the OM was significantly increased postoperatively and 3 months later in the CLP group, while the SM was significantly weaker as compared to that in the healthy group. A comparison of the peak time ratio of the SM revealed activation during the first half of the sucking cycle in CLP infants, while that occurred in the latter half of the sucking cycle in the healthy controls. Furthermore, the coordination curve of the SM in CLP infants was obscured as compared with that in the healthy group. Our results indicated that sucking coordination pattern is affected in infants with CLP. In conclusion, as compared to healthy infants, increased OM activity and a weak SM following cheiloplasty, as well as the peak time ratio of SM activation during the first half of the sucking cycle was seen in infants with CLP, resulting in sucking pattern difference as a result of the condition.
