Research of masticatory function using hemiplegia simulator equipment

<jats:p><jats:italic>doi: 10.1111/j.1741‐2358.2011.00559.x</jats:italic> 
 <jats:bold>Research of masticatory function using hemiplegia simulator equipment</jats:bold></jats:p><jats:p><jats:bold>Background and objective: </jats:bold> Hemiplegic patients often exhibit a characteristic condition called Wernicke‐Mann contracture. Therefore, the occlusal pattern in hemiplegic patients is considered to be adapted to stress because of this characteristic limb position. We created a sham Wernicke‐Mann contracture in healthy individuals using hemiplegia simulator equipment and compared the functional occlusion in this position with that in the normal state to evaluate dynamic adaptive responses.</jats:p><jats:p><jats:bold>Methods: </jats:bold> Wernicke‐Mann contracture was simulated using a device to create sham hemiplegia (Manabi‐tai, Hemiplegia Experiencing Set; Tokushu‐iryo, Inc.). In addition to the measurement of the occlusal force using Dental Prescale<jats:sup>®</jats:sup> and Occluzer<jats:sup>®</jats:sup>, the occlusion was evaluated using an electromyogram and stabilometer.</jats:p><jats:p><jats:bold>Results: </jats:bold> There was a significant difference in the occlusal force between the normal state and during simulated hemiplegia. The surface electromyo‐potential of the masseter muscle showed significantly higher values during simulated hemiplegia. It is significantly higher during simulated hemiplegia than in the normal state on the paralysed side, but not for the normal state on the non‐paralysed side. The position and velocity vectors changed in the antero‐posterior direction in the normal state but in the lateral direction during simulated hemiplegia.</jats:p><jats:p><jats:bold>Conclusions: </jats:bold> The hemiplegia simulator equipment is useful for research on hemiplegia, and that the occlusal balance is disturbed in the posture characteristic of hemiplegia.</jats:p>