Oral mucosal and periodontal ligament mechanoreceptors (PDLMs) affect antral motility differently

Do oral mucosal mechanoreceptors affect antral motility? PDLMs are activated by tooth movements in chewing. These also occur during simulated mastication, activating antral motility (Can J Physiol Pharmacol 78:29, 2000) and gastric emptying (J Dent Res 81:302, 2002). Because a mouthful of food contacts all oral tissues, the antral motility effects of stimulating 8 oral mucosal sites under pentobarbital were sought. 9 groups of 8 adult female rats fasted 18h. Visual observations avoided disturbing the stomach for cannula or transducer attachment. All studies had 3 five minute periods: baseline, procedure, and post‐procedure. The mucosal procedure was 5 min of gentle movement of a teflon rod against: the mandibular gingiva, anterior & posterior tongue & its undersurface, the oral floor, buccal mucosa, & hard & soft palates. PDLMs were activated by opening & closing the jaw so opposing molars contacted each other extremely gently. This simulated mastication was done 30 times in 12 sec with a 3 sec rest. This sequence was repeated 20 times in 5 min. Statistical analysis: ANOVA & Bonferroni. No mucosal site affected antral motility; their ANOVA P values were 0.173 to 0.969. By contrast, PDLM activation had ANOVA P = 0.010. Its 3 period values (mean + s.d.) were 2.88 + 2.47, 5.50 + 4.11, 8.00 + 2.00. Between the first and last values P = 0.003. PDLMs are the sole basis of periodontogastric reflexes. Personal research support.