A group of 29 individuals, 17—23 years old, with intact teeth, has been compared with a control group with respect to occurrence of mandibular dysfunction. A statistically significant difference between the groups, with a lower frequency and degree of dysfunction among the intact individuals was established. The results suggest that filling therapy per se may be a possible etiological factor in the mandibular dysfunction. Disorders in the masticatory neuromuscular system may arise from an abnormal tactile response to contacts on fillings, inducing an abnormal pattern of mandibular movement, possibly exceeding the tolerance level of the system.