Abstract
In order to estimate the relationships between malocclusion indices and dental caries or periodontal disease indices, an epidemiological study of 140 dental college students by oral examination and model impression of the dental arch was undertaken. A stepwise multiple regression analysis was used to find the various indices of dental malocclusion and oral hygiene that have an influence on dental caries and periodontal diseases. These analyses were used to develop models which are useful in explaining caries indices of DFS and PDFS, periodnntal diseases indices of PMA, PI and BOP, as dependent variables, and the dental malocclusion indices of ALD, NMT, HLD, OFI, CRD and DAI, and oral hygiene indices of DI, CI and PCR, as independent variables. These variables were divided into full mouth, maxilla, mandible, anterior of maxilla, and mandible for calculating by the multiple regression analysis. The results of the analysis were as follows : 1) The relationship of malocclusion indices and oral hygiene indices to dental caries indicated that the independent variables (DFS, PDFS multiple correlation coefficient R=.436, .256 p<0.01) associated with the dependent variables, which were ALD, NMT in the full mouth, showed a high significant partial correlation coefficient. On the other hand, oral hygiene indices were not related to dental caries. 2) The relationship of malocclusion indices and oral hygiene indices to periodontal diseases indicated that the independent variables (PMA, PI, BOP multiple correlation coefficient R=.621, .671, .624 p<0.001) associated with the dependent variables, which were NMT and all oral hygiene indices, especially CI, in full mouth, showed a high significant partial correlation coefficient. In addition, in the case of anterior mandible, CRD has a strong influence on the periodontal diseases and showed a high multiple correlation coefficient and a high significant partial correlation coefficient. 3) The relationship of malocclusion to oral hygiene indicated that malocclusion indices were hardly associated with oral hygiene indices.
