Oral Sensorimotor Integration in Adults Who Stutter

Objective: To investigate the relationship between tendon vibration sensitivity and oral motor control in adults who stutter (AWS). Patients and Methods: Ten controls and 10 AWS first made jaw-opening movements from a closed-mouth position to an 18-mm target. Then, masseter tendon vibration was applied during jaw opening in a separate condition to test whether accuracy and/or variability is related to movement undershoot. Results: AWS made less accurate and more variable jaw movements than controls without visual feedback. Among the normally fluent adult participants, higher accuracy and lower variability were significantly related to masseter vibration undershoot, but significant correlations were not observed for AWS. Conclusion: These results suggest that increased tendon vibration sensitivity may be related to more refined oral motor control. Subtle sensorimotor limitations could be present in stuttering that render speech more susceptible to breakdowns.