The vasculature of the rat molar periodontal ligament

Abstract

The vascular architecture of the rat molar periodontal ligament was investigated using the SEM vascular casting technique. Vascular patterns varied within the different regions of the tooth socket. A different microvascular arrangement was found to be associated with (i) the buccal and lingual walls (ii) the interdental septum and (iii) the interradicular septum. Tracts of four to six vessels coursed occluso‐apically down the buccal and lingual walls. A similar pattern existed at the interdental septum except that the vessels were more closely packed. At the interradicular septum, the postcapillary venules coursed within the ligament for only 100 to 400 μm before re‐entering the bone. Overall, vessels were predominantly postcapillary venules with a lesser number of capillaries. Anastomoses between adjacent vessels coursing in the ligament occurred infrequently, although many communications with the alveolar plexus were noted. Except at the interradicular septum, ligament vasculature arose mainly from the deeper gingival vessels. A few vessels originated from branches of the alveolar plexus, forming a hairpin loop as they entered the plexus. These findings differed markedly from Kindlova & Matěna's (1962) description of morphologically paired arterial and venous systems. On a morphological basis vascular flow was considered to be directed from the coronal down to the apical region of the socket. However, Ligament vessels adjacent to the vertical walls of the interradicular septum received a greater arterial supply than the crestal region, where venous drainage was more prolific. Therefore, the vascular arrangement over the septum suggested a direction of vascular flow opposite to that occurring at the outer walls of the socket, although tidal flow could occur in either direction in the interradicular area.

Developmental changes of the vasculature in the periodontal ligament of rat molars: a scanning electron microscopic study of microcorrosion casts

“…Hairpin-like loops in the PDL vascular network have been reported (14±20). Iwabuchi (15) speculated that these loops, together with the vessels from Volkmans' canals, function as a cushion for occlusal forces, but other reports suggest that the formation of capillary loops is associated with cementum formation (2,14,16,18,20). Ohnishi (18) reported that the loops changed form from hairpin to arcade shapes with the advance of cementum formation.…”

“…Fifteen Wistar white rats (5,10,15,20 and 30 d after birth; 3 rats at each age) were used in this study. Throughout the experiments, the Principles of laboratory animal care (NIH, 1985) were followed.…”

Contribution to the study of the vasculature of submandibular and sublingual glands and lymph nodes of rats by corrosion cast technique combined with scanning electron microscopy

“…The corrosion cast technique provides an understanding of the angioarchitecture of normal or altered anatomical structures (Lametschwandtner et al, 1990). Sometimes, the use of the technique is difficult because of the fragile vascular casts obtained, since the supporting tissue of the vessels is removed in the process (Hodde et al, 1990;Kronka et al, 2001;Lametschwandtner et al, 1990;Selliseth and Selvig, 1995;Sugioka and Ike, 1993;Weekes and Sims, 1986;Ohta et al, 1992). In the present study, taking into account the fragility of the cast and the delicate nature of the salivary glands, the structures were removed en bloc, such that this contained the two submandibular glands, the two sublingual glands, and the regional lymph nodes.…”

“…There are a few studies in rats that make mention of vascularization in these glands (Bezerra et al, 1999). Vascularization plays a fundamental role in neoplasms, as well as in inflammatory and degenerative processes (Lametschwandtner et al, 1990;Konerding, 1991), where the vascular corrosion cast has been widely employed in odontology research (Kronka et al, 2001;Selliseth and Selvig, 1995;Weekes and Sims, 1986). When combined with scanning electron microscopy, it can be applied to the study of the vascular pattern of normal tissues and organs already formed or in development and also of pathological processes (Lametschwandtner et al, 1990).…”

“…When combined with scanning electron microscopy, it can be applied to the study of the vascular pattern of normal tissues and organs already formed or in development and also of pathological processes (Lametschwandtner et al, 1990). The technique allows the filling of the lumen of vessels with low-viscosity resin followed by alkali corrosion of the tissue surrounding the polymerized resin (Hodde et al, 1990;Kronka et al, 2001;Lametschwandtner et al, 1990;Ohta et al, 1992;Selliseth and Selvig, 1995;Sugioka and Ike, 1993;Weekes and Sims, 1986).…”