Periodontal disease in the rice rat: II. Methods for the evaluation of the extent of periodontal disease

Abstract

Studies of periodontal disease in experimental animals are sufficiently recent that no evaluation system has been accepted as uniquely desirable by the various researchers in the field. Three methods of recording have been used to obtain the data discussed in this article. These are modifications of the three most commonly used methods adapted to the situation encountered in the rice rat. A method based solely on soft tissue lesions was insufficiently exacting to detect stages of alveolar bone resorption that occurred prior to soft tissue destruction. However, this method is of potential value when used parallel to an alveolar bone resorption method to evaluate the possible extent of participation of a systemic influence in the disease process. The method for evaluating alveolar bone resorption developed by Keyes and Gold 7 is particularly precise, although tedious and time consuming. The evaluation of the amount of alveolar bone resorption on the basis of an arbitrary grading system from 0 to 4+ appeared to be particularly desirable with an adequate degree of precision, while at the same time quickly and reproducibly applied. Because of the high degree of bilateral symmetry of the lesions, the evaluation of the extent of periodontal disease involvement in the rice rat may be based satisfactorily on the examination of the buccal and lingual aspects of one maxilla and one mandible.