Coffee consumption influence upon the clinico-neurophysiological manifestations of primary sleep bruxism

Background: Caffeine is one of the most widely-used psychoactive substances, having multiple stimulating effects. Caffeine is being considered as eliciting a dose-dependent effect on sleep bruxism. Material and methods: There were investigated 100 patients with primary sleep bruxism. Patients were clinically examined, there were given several questionnaires, and they underwent a series of investigations: sleep bruxism recording; surface electromyography, occlusal reflex determination, jc.SSR (jaw clenching sympathetic skin response) recording and masseter muscle ultrasonography. Results: In patients with primary sleep bruxism, there were observed various coffee intake patterns/24 h: “abstinent” group – 32%; “1-3 cups” group – 38.1%; “4-6 cups” group – 19%; “>6 cups” group – 11%. People who consume >6 cups/24 h, have increased the number of nocturnal clenches. Pathological occlusal reflex indices were observed in the “1-3 cups” group (76.3%), “4-6 cups” group (89.5%), “>6 cups” (100% cases), “abstinent” group (50%). Disorders associated with the temporomandibular joint and the bruxism-associated pain reach pathological values in individuals who consume 4-6 or more cups of coffee. Excessive caffeine consumption leads to the increase of the amplitude of the sympathetic autonomous potential (jc.SSR, A2, mV) without significant changes in the central autonomous regulation time (jc.SSR, T, s). Conclusions: There were observed various coffee intake patterns in patients with primary sleep bruxism. Excessive coffee consumption is associated with the stress level. The masseter muscle thickness and dental wear show no statistically significant elevation trends, under the influence of various caffeine doses