アブストラクト(12巻1/2号:The Bulletin of Kanagawa Dental College)

The Bulletin of Kanagawa Dental College

English

Title : Architecture and Ultrastructure of Vasculature in the Articular Disc of the Temporomandibular Joint in Dog
Subtitle : ORIGINAL ARTICLES
Authors : Makoto Mamiya, Yoshiaki Kishi, Tsuneo Takahashi, Seigyo So, Masahiko Kogushi, Kazuto Takahashi
Authors(kana) :
Organization : Department of Oral Anatomy, Kanagawa Dental College
Journal : The Bulletin of Kanagawa Dental College
Volume : 12
Number : 1/2
Page : 5-14
Year/Month : 1984 / 3
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : [Abstract] The time-lapsed changes in the vascular architecture distributed in the articular disc of dogs, from the uneruptive stage of deciduous dentition to the full completion of permanent dentition, were studied in comparison with that of human fetuses. The resin cast method and ultrathinsection method, as well as the conventional India ink perfusion technique were used in the present study. During the uneruptive stage of deciduous dentition, the blood vessels distributed in the disc were directed from mesial, anterior, and posterior margins toward the central area of the disc, branched profusely many times and eventually formed an intricately dense vascular network. The basic vascular structure in articular disc consisted of a main arteriole accompanied by two paralleling venules on both sides. Two paralleling venules were mutually connected by numerous anastomosing branches perpendicular to the venules, similar to the scheme of the ladder. This basic structure was continuous throughout the whole area, irrespective of the repeated divergence of arterioles and venules. The vascular network gradually disappeared with age and finally became an avascular area in the vicinity of central area of the disc. The vessels facing this avascular area appeared as many variant forms of hair-pin loops. The histological section of vessels surrounding the hair-pin loops revealed that the lumen became progressively narrower due to the protuberance of endothelial cell nuclei, leading to erythrocyte congestion and fibrosis. In addition, the opened interendothelial cell junction could be seen, indicating that it had undergone a destructive process. During the time of developmental transition, many new anastomoses between paralleling arterioles and venules formed with subsequent disappearance of peripheral venular branches, whereby capillary hair-pin loops formed. In human fetus, the disappearance of vasculature happened earlier in comparison with that of dog, which occurred rather late. The presence of avascular area could be identified as earlier as two weeks of fetal life. The evidence described previously suggested that the disappearance of the vasculature in the central area of the disc might be triggered by occlusal compression, and that the lumen of main vessels became narrower, ultimately leading to abliteration, while the peripheral vessels formed hair-pin loops by connecting each other with numerous anastomosing branches, whereby the new collateral circulation was formed.
Practice : Dentistry
Keywords : Vasculature, Articular Disc, Temporomandibular Joint, Dog