Microvascular bed and adrenergic nerve endings of the pulp during permanent teeth eruption

Abstract

   The aim of the study was to reveal associations between the number of functioning microvessels and formation of adrenergic control (nerve endings containing catecholamine) of the dental pulp in children and adolescents of Udmurtia during the period of permanent teeth eruption.   Material and methods. The study included neurovascular bundle of the pulp of teeth extracted for medical reasons at the age of 5 to 14 years. At the light-optical level, the number of functioning capillaries was counted; an electron microscopic technique was used to qualitative assess the microvascular bed. Identification of catecholamines and counting the number of adrenergic nerve endings were performed histochemically using glyoxylic acid.   Results. The process of permanent teeth eruption is accompanied by an intensively increased number of functioning capillaries and an increased density of adrenergic nerve endings. The number of functioning microvessels increases significantly (by 3.36 times) during childhood (from 5 to 9 years); the number of capillaries stabilizes in adolescence. The increased number of nerve endings by the end of the childhood period (9 years) is 45.2 ± 12.4 % compared with the age of 5 years. Notably, adrenergic nerve endings modify qualitatively: a pronounced variety of mediatorcontaining forms is replaced by their isomorphic phenotype. With age, predominant distribution of nerve endings along the vessels of the microvasculature tends to increase.   Conclusion. Active formation of the microvascular bed during the eruption of permanent teeth is accompanied by an age-dependent increase in the density of localization and qualitative restructuring of adrenergic nerve endings, which provides full catecholaminergic control from the sympathetic nervous system.