The electrical activity of the masticatory muscles in children with cleft lip and palate

Background Information regarding masticatory muscle function in children with cleft lip and palate (CLP) is limited. As a consequence, research on masticatory muscle activity in cleft subjects is needed. Aim To assess masticatory muscle activity in children surgically treated for CLP as well as identify the possible factors associated with this activity. Design The sample comprised 82 children with mixed dentition and Class I occlusions (25 children with unilateral CLP and 57 subjects with no cleft abnormalities). A DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) was used to take electromyographical (EMG) recordings of the temporal and masseter muscles both in the mandibular rest position and during maximum voluntary contraction (MVC). Results Patients with clefts showed a significant increase in temporal muscle activity at rest compared with the controls. The presence of clefts and unilateral posterior crossbites are factors strongly associated with increased temporal muscle EMG potentials during rest position. Conclusions Children with clefts have altered temporal muscle function. The presence of posterior crossbites affects the temporal muscle activity in cleft subjects. Early diagnosis and orthodontic treatment of malocclusions are necessary to achieve functional improvement in these patients.