Lip movement in patients with a history of unilateral cleft lip

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

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.

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.

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.

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.