Removable dental appliance alleviates Tourette syndrome

Researchers at Osaka University have developed a custom-made, removable oral splint that can reduce tics in anyone who suffers with Tourette syndrome. The device is applied to the molars to increase the occlusal vertical dimension, altering the alignment of the nose, lips, and chin. More research is needed to understand how the oral splint exerts these effects, but the action of biting down could serve as a sensory trick, a voluntary manoeuvre that usually involves touching parts of the face and head, and can alleviate involuntary movements. Sensory tricks have been well documented to temporarily improve the movement disorder dystonia which is also characterised by uncontrollable tics.

Jumpei Murakami, joint first author of the study, said: “Biting down on the device immediately improved both motor and vocal tics in 10 of the 14 children and 6 of the 8 adults that participated in the study. What’s more, these effects were long lasting. Long-term improvements in motor tics after more than 100 days were especially evident in patients who were younger when their tics first started.”

Co-first author of the study, Yoshihisa Tachibana, said: “Considering previous findings on sensory tricks in patients with cervical dystonia, it seems possible that the oral splint modulates proprioceptive, or ‘touch’ signals. These ‘touch’ signals might be modified by the muscles involved in jaw-closing before being relayed to the brain.”