title: Prolonged hypotensive and bradycardic effects of passive mandibular extension: evidence in normal volunteers.
abstract: Various procedures involving stimulations of facial regions are known to induce so-called trigemino-cardiac reflexes that entail a decrease of heart rate and blood pressure. We here report the effects of a specific stimulation that consists in a submaximal passive mandibular extension obtained by means of a dilatator applied for 10 minutes between the upper and lower incisor teeth, associated with partial active masticatory movements. Blood pressure and heart rate were determined in 18 young normal volunteers by Omron M4, before (20 minutes), during (10 minutes) and after mandibular extension (80 minutes) and under control conditions (same overall duration without stimulation). While control values remained stable, mandibular extension was followed by a progressive decline of both blood pressure (up to about 12/11 mmHg) and heart rate (up to about 13 bpm), statistically confirmed by ANOVA both on absolute values and on changes from basal values. The decline of systolic blood pressure and heart rate significantly correlated with basal values. The present findings indicate that submaximal opening of the mouth, associated to partial masticatory movements, induces a prolonged reduction of blood pressure and heart rate in normotensive volunteers.
authors.affiliation: Department of Physiopathology, Experimental and Public Health, University of Siena, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Brunelli
authors.forename: Erika
authors.initials: E
authors.lastname: Coppi
authors.forename: Daniele
authors.initials: D
authors.lastname: Tonlorenzi
authors.forename: Cristina
authors.initials: C
authors.lastname: Del Seppia
authors.forename: Dominga
authors.initials: D
authors.lastname: Lapi
authors.forename: Antonio
authors.initials: A
authors.lastname: Colantuoni
authors.forename: Rossana
authors.initials: R
authors.lastname: Scuri
authors.forename: Sergio
authors.initials: S
authors.lastname: Ghione
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008334:Mandible / Q000502:physiology*; D008409:Mastication / Q000502:physiology*; D012018:Reflex / Q000502:physiology; D013997:Time Factors; D055815:Young Adult