Blood Vessels of the Rat Molar

M. KINDLOVÁ ¹ and V. MATNA ¹

¹ Physiological Department, Institute of Dental Research, Prague, Czechoslovakia

In histologic and corrosive specimens, the blood supply of the pulp and of the periodontium in permanent rat molars was investigated. It was observed that the arteries which perforated the jaw from outside and branched from the artery which lay in the mandibular canal supplied the molars. The arteries supplying the pulp were not end-arteries. By arch-shaped anastomoses on the bottom of the cavum pulpae they insured a collateral circulation in the coronal part. The veins were connected in a similar way. The peripheral part of the pulp showed a preferential blood supply insured by a continuous capillary network encircling the groups of odontoblasts with meshes. In the rat incisor, where there was a continuous dentin formation, this network was richer than in the molars.

The arteries of the periodontal membrane, with their palisade formation, coursed axially to the neck of the tooth and were partly immersed in the bone. They were mutually connected by a capillary network supplying the tissue of the periodontal space. On the interproximate sides the rows of loops of adjacent teeth intertwined.

The veins passed through the periodontium axially also in the space between the ligaments, and toward the apex they coalesced into a plexus. At the peak of the interradicular septum they formed a rich network.

The arteries and veins of the gingiva lay on the outer side of the alveolus and formed an independent capillary network supplying the gingiva. At the alveolar margin, the gingival capillaries communicated by venous anastomoses with the capillary loops of the periodontal membrane but did not coalesce with them into one rete; on the contrary, they maintained an individual character.

The gingival vessels did not extend below the point of contact of the adjacent teeth. Here the interdental papilla was supplied solely by the vessels of the periodontal membrane.