Blood circulation and its regulation peculiarities in maxillar-facial region.

Blood circulation in dental pulp occurs inside its cavity having the walls. Puls fluctuations of blood volume in closed cavity were to cause tissular pressure increasing and as a result physiological processes in pulp disorders. But it doesn’t occur due to arterial volume pulsal fluctuation transmission to veins. Pulp vascular net possesses effective antistagnational features. Sum crown’s pulp veins space is more than in apical foramen region that’s why circulation linear velocity in root apical foramen region is higher than in pulp. Veins puls fluctuations are the similar to brain veins fluctuations. Pulpal abducting venous vessels anastomosize with periodontal veins and such rich anastomozes net with periodontal veins increases blood circulation system opportunities in pulp.

Blood circulation regulation of this region is performed by nervous, humoral and myogenic mechanism. Nervous mechanism: tonic impulsation comes to these vessels from vascular-motor center through nervous fibres coming from superior cervical sympathetical node. Vasoconstricting reactions into maxillar-facial region and dental pulp are determined by noradrenaline releasing in sympathetical nervous fibre that acts through vascular walls alfa-adrenoreceptors. If it acts to beta-adrenoreceptors – vessels are dilated.

Maxillar-facial region and oral cavity organs vascular space may be also changed under influence of humoral factor: hormones (adrenaline and others), cellular metabolism products and electrolites.

Finally, there is a proper vascular tone regulation myogenic mechanism in this blood circulation region. Muscular type vessels (arterioles and precapillar sphincters) hypertony leads to functionning capillaries amount decreasing that in turn prevents intravascular blood pressure increasing and enforced liquid filtration in tissues, i.e. it serves as tissues physiological protection from oedema development. This myogenic blood circulation regulative mechanism plays important role in dental pulp acvtivity providing. Such mechanism is essential for pulp located in closed space and limited by dental cavity walls for microcirculation regulation under norma and pathology for instance at pulp inflammation (pulpitis). Weakness of this vascular myogenic tone mechanism is one of factors for oedema development in pulp, parodont and other oral cavity tissues. Myogenic vascular tone is significantly decreased at functional loads to tissues that leads to regional blood supply increasing and “working hyperaemia” development. At parodontosis, when parodontal tissues blood supply is disturbed, functional loadings decreasing microvessels myogenic tone (for instance, mastication) may be used for medical and preventive aims to parodont trophycs improvement. It has essential importance because vascular tone functional changes play dominant role in course of parodontosis development.

Humoral action to circulation in oral cavity may give many drugs absorbing there.

Any dentist should remember that oral cavity is a powerful reflexogenic zone afferent impulsation from which can change heart activity and vascular tone and that’s why doctor shoud apply sparing manipulations there. Any dental manipulation is a complicated emotional-painful factor. Practically all people afraid such manipulations. Such noceoceptive factor may influence on heart-vascular system state. And such influence may be sometimes even more significant than medical procedure itself. It is especially actual for patients with heart-vascular diseases for instance suffering from hypertonic disease. These patients have expressed haemodynamic changings at dental influencing, in course of its waiting. Sometimes it is accompanied by crisis, giddiness, faint as the result of brain circulation disorders. Special place have noceoceptive irritations causing significant changings in blood circulation system. Such disorders may vary dependently from painful syndrom intensivity and organism reactiveness. One patients have tachycardia (as a rule, at hypersympathicotony), others – bradycardia (as a rule, at hyperparasympathicotony) as answer reaction to manipulation. Even such process as tooth preparing (in course of orthopedic treatment) is healthy people may cause changes connected to organism individual features. All these must take into account dentist in his daily job.

Rheography is widely used for functional assessment of maxillar-facial region vessels functional state in dentistry. Rheodentography is a method of pulp haemodynamics assessment; rheoparadontography – of parodont haemodynamics.

 

 

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