The contribution of mechanoreceptive neurones in the gingival tissues to the masticatory-parotid salivary reflex in man

The masticatory-parotid salivary reflex has been studied in fully dentate s ubjects. Salivary flow was recorded by siting a modified Lashley cup over t he orifice of the parotid duct on one side of the mouth. Subjects chewed on small pieces of silicone rubber for 1-min periods which resulted in a refl ex secretion of parotid saliva. The secretion was greatest when the subject chewed on the same side of the mouth (ipsilateral) as the salivary flow wa s recorded. Less salivary flow resulted when the subjects chewed on the opp osite side of the mouth (contralateral). Selected areas of the buccal or li ngual gingival tissues were then anaesthetized on the side ipsilateral to t he Lashley cup. Anaesthesia of the lingual and buccal gingival tissues toge ther resulted in a reduction of salivary flow in response to similar chewin g cycles. Anaesthesia of the lingual gingival tissues alone also resulted i n a reduction of salivary now, but anaesthesia of the buccal gingival tissu es alone did not. During mastication it is likely that mechanoreceptors in the gingival tissues will be stimulated which may result in salivary flow. This requires further study as other mechanoreceptive neurones are also kno wn to be involved in the masticatory-parotid salivary reflex.