In this paper, data are presented on individual movement characteristics of the upper and lower lip and on interlip coordination in speakers with a repaired unilateral cleft upper lip history and age-matched control participants. The data were acquired using the AG100 EMMA system while the participants produced a selection of nonspeech and speech tasks. The participants with a repaired unilateral cleft upper lip history showed reduced upper-lip movement ranges and peak velocities and a more variable spatiotemporal pattern for individual upper-lip movement cycles, in addition to a more variable interlip coupling. The latter difference also proved to be more pronounced for the younger speakers with a repaired cleft upper lip. Overall, for both groups, the linguistically more complex task showed more variability in the individual upper- and lower-lip movement cycles and their coupling. In the discussion, we address the potential relationships between the kinematic data for upper lip in the repaired-cleft-lip speakers and the findings on movement and coordination stability as they might fit within current notions of coordination dynamics theory.

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.

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.