集団健診における乳歯こう合期歯周疾患評価のための基準歯の選択

Abstract

For evaluating the severity of periodontal disease in deciduous dentition, we used to examine the mesial parts of the gingival margins of all the teeth in the mouth. This method, however, takes too much time for application to mass screening. The purpose of this study was, therefore, to design a simplified method.Materials used were dental health examination data of periodontal disease in the Miyako Islands in Okinawa, obtained from 667 cases of three-year-old children, and 143 cases of one-and-a-half-year-old children. Principal component analysis and multiple regression analysis were applied to these data to select the standard teeth, and to proove the appropriateness of the teeth selected. Comparing the mean scores of periodontal disease of each tooth, high scores were observed at the most posterior teeth in the maxilla. As the result of principal component analysis, the teeth were divided into three groups, i. e. maxillary anterior teeth, mandibular anterior teeth, and maxillary and mandibular posterior teeth in three-year-old children. On the basis of these results each of the most posterior teeth in the maxilla, the maxillary lateral deciduous incisors, and the mandibular deciduous incisors were selected as standard teeth, because no dominant difference was observed between the teeth on the right and left sides. Multiple regression analysis showed that this model predicted means of the periodontal score of all the teeth very well, and adding other variables of teeth did not improve the prediction much. The correlation coefficient between the mean of these teeth and that of Periodontal score was very high (r=0.89-0.90). Almost the same results were obtained in one-and-half-year-old children, in which the unerupted maxillary 2nd deciduous molar was replaced by the most posterior teeth in the maxilla (r=0.87-0.91).