Objective The face is an important source of cardiovascular ("trigemino-cardiac") reflexes. Studies in rats (Lapi Arch.Ital.Biol 151:11-23,2013) and humans (Brunelli Arch.Ital.Biol 150:231-237,2012) have shown that submaximal mouth opening (mandibular extension:ME), obtained by a dilatator for 10min, associated to partial masticatory movements in humans (dynamic ME), induces a prolonged reduction of blood pressure (BP), by about 20mmHg in the anesthetized rat and by 10mmHg in the normotensive volunteer (NTV), with a concurrent decline of heart rate (HR). Design and method In this study we assess the effects on BP and HR of ME without masticatory movements (static ME) obtained by a commercial mouth gag (Molt) in 20 NTV (age range 26±2.9yrs; 10M, 10 F) who made in random sequence: 1.) ME (60% of maximal active mouth opening) for 10min (experimental), 2.) keeping for 10min a tongue depressor between the medial incisor teeth (control). BP and HR were measured every 10min by Spacelabs 9027, for 30min before and 120min after the procedure. The subjects remained seated watching nature documentaries ME induced a slight significant reduction of systolic (S)BP (-4mmHg, p=0.025, for at least 90min) and HR (-8bpm, p<0,001, for the entire follow-up). Control procedure induced a slight significant increase of diastolic (D)BP (+3mmHg, p=0.011) and a decrease of HR (-5bpm, p=0.005). A significant inverse correlation was found for ME between basal values and their maximal change for SBP (p=0.005) and HR (p=0.026). Comparison of the effects of ME and control by overall repeated measure ANOVA revealed a statistically significant different effect for HR for both absolute values and changes relative to basal values (p=0.013 and p=0.023). For changes relative to basal values for SBP and DBP the effect fell short of statistical significance (p=0.062 and 0.059). Preliminary results of absolute values in 6 non-treated hypertensives revealed a reduction of SBP (-20mmHg p<0.001), SBP (-9mmHg, NS) and HR (-8bpm p<0.001). Conclusions These results confirm in NTV slight persistent effects of mouth opening on BP and HR and suggest that static procedures may be less effective than a dynamic ones in NTV, but may be effective in hypertensives.
The Hypotensive and bradycardic effects of mouth opening: evidence in the human
C Del Seppia;
2014
Abstract
Objective The face is an important source of cardiovascular ("trigemino-cardiac") reflexes. Studies in rats (Lapi Arch.Ital.Biol 151:11-23,2013) and humans (Brunelli Arch.Ital.Biol 150:231-237,2012) have shown that submaximal mouth opening (mandibular extension:ME), obtained by a dilatator for 10min, associated to partial masticatory movements in humans (dynamic ME), induces a prolonged reduction of blood pressure (BP), by about 20mmHg in the anesthetized rat and by 10mmHg in the normotensive volunteer (NTV), with a concurrent decline of heart rate (HR). Design and method In this study we assess the effects on BP and HR of ME without masticatory movements (static ME) obtained by a commercial mouth gag (Molt) in 20 NTV (age range 26±2.9yrs; 10M, 10 F) who made in random sequence: 1.) ME (60% of maximal active mouth opening) for 10min (experimental), 2.) keeping for 10min a tongue depressor between the medial incisor teeth (control). BP and HR were measured every 10min by Spacelabs 9027, for 30min before and 120min after the procedure. The subjects remained seated watching nature documentaries ME induced a slight significant reduction of systolic (S)BP (-4mmHg, p=0.025, for at least 90min) and HR (-8bpm, p<0,001, for the entire follow-up). Control procedure induced a slight significant increase of diastolic (D)BP (+3mmHg, p=0.011) and a decrease of HR (-5bpm, p=0.005). A significant inverse correlation was found for ME between basal values and their maximal change for SBP (p=0.005) and HR (p=0.026). Comparison of the effects of ME and control by overall repeated measure ANOVA revealed a statistically significant different effect for HR for both absolute values and changes relative to basal values (p=0.013 and p=0.023). For changes relative to basal values for SBP and DBP the effect fell short of statistical significance (p=0.062 and 0.059). Preliminary results of absolute values in 6 non-treated hypertensives revealed a reduction of SBP (-20mmHg p<0.001), SBP (-9mmHg, NS) and HR (-8bpm p<0.001). Conclusions These results confirm in NTV slight persistent effects of mouth opening on BP and HR and suggest that static procedures may be less effective than a dynamic ones in NTV, but may be effective in hypertensives.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
