[Quantitative study of the effect of occlusal hypofunction on periodontal ligament with and alveolar osteoclastic resorption in rats].

An occlusal hypofunction has been produced by unilateral extraction of the maxillary molars in the rat and its effect has been studied on the antagonistic lower molars during a period of 15 days to 3 months. The quantitative analysis showed that the alveolar width decreased very significantly as early as the fifteen day. This fact was due to a decrease of the periodontal membrane width from the fifteenth day. This decrease was observed until 1 month on the alveolar surface undergoing apposition. The decrease of the alveolar width was also related to a drop of the periodontal membrane width as soon as fifteen days on the surface in resorption. The radicular width remained constant, confirming that it was the bone apposition and not the cementum apposition which caused the narrowing of the periodontal membrane. The quantitative study of the osteoclastic resorption showed that this later decreased but in a non significant on the alveolar surface undergoing remodeling.