Short-term and long-term effects of chewing training on occlusal perception of thickness

The aim of this study was to investigate the short-term and long-term effects of functional stimuli, induced by intense chewing and by prolonged systematic chewing training, on the response of occlusal perception of thickness. The material comprised 25 young adults divided into an experimental group (17) and a control group (8). The occlusal perception of thickness was tested by successively placing different thicknesses of aluminum foil between five pairs of occluding teeth, i.e. right and left second premolars and canines and one pair of the central incisors. The experimental group was tested 2 wk before the start of the experiment and at the start and the end of the experiment, i.e., after 4 wk systematic chewing training, and before and after 30 min intense chewing. The control group was tested on the same occasions but without performing any special chewing activity. The discrimination threshold increased in most of the subjects after 30 min of chewing, both before and after the 28-day training period. This threshold increase was found in all groups of teeth tested. No changes were found in the discrimination threshold of the teeth tested after 28 days of chewing training. In the controls no differences were found between the recording occasions. Since no statistically significant differences were observed between the groups of teeth tested, the changes in the threshold of occlusal perception after intense chewing may reflect the influence of receptors other than periodontal, for example those in TMJ and muscles, which are involved in the control of other neuromuscular mechanisms such as those that control the postural position of the mandible.