The effect of a Clark twin block on mandibular motion: a case report.

Aims: To investigate mandibular motion in six degrees of freedom before, during and after twin block treatment in one individual. Methods: The appliance was worn for eight months, and motion recordings, using a 12-camera opto-electric system, were captured prior to placement of a twin block appliance and 2, 4, 14 and 52 weeks after insertion. Results: The wide variations in mandibular motion that accompany twin block wear disappeared post-treatment, except for an increase in anteroposterior movement of the mandible. Conclusion: Twin block therapy appears to affect mandibular motion temporarily.