Oral kinesthesia in patients with Duchenne muscular dystrophy

In trials on normal subjects and patients with Duchenne muscular dystrophy (DMD), interdental dimension discrimination (IDD) was tested by assessing the ability of subjects to discriminate between pairs of sticks of different dimensions held between the upper and lower teeth. The IDD ability of the DMD patients was significantly inferior to that of the normal subjects. Further, DMD patients tended to overestimate the dimension of the first stick of each pair even more than did normal subjects. Vibration applied to the mandible seemed to lessen such inaccuracies of oral kinesthesia in the DMD patients. These results are compatible with the idea that muscle receptors, especially muscle spindles in jaw closing muscles, are mainly responsible for IDD.