Lip movement in patients with a history of unilateral cleft lip.

Objective: The influence of a repaired cleft lip on the stability of coordination between upper and lower lip in nonspeech and speech tasks was investigated.

Design: First, we looked at the effects of a secondary cleft lip repair in three individuals. Second, we compared subjects with a history of repaired unilateral cleft lip and subjects with no history of cleft lip (controls). Lip coordination was measured using continuous estimates of relative phase.

Participants: Subjects were nine children and adolescents with a primary unilateral cleft lip and palate repair and 4 participants without cleft matched for age across different age categories.

Results: In general, the averaged relative phase angle (RPA) angle values were smaller than 180 degrees, indicating an upper lip lead for lip closure. Controls showed a tendency toward a more symmetric type of coordination (close to 180 degrees), compared with subjects with a repaired unilateral cleft lip. The controls also showed less variation in coordination between the lips. For the more complex speech tasks, a general increase in variability of the RPA values for all subjects was observed, most likely suggesting a more flexible type of coordination. Regarding the effect of a secondary cleft lip repair, only one of the three patients showed a clearly less symmetric and less stable type of coordination, compared with preoperation results.

Conclusions: There appear to be differences in lip coordination between speakers without and speakers with a repaired unilateral cleft lip. Furthermore, it seems that the stability of lip coordination tends to increase with age.