METHOD FOR PRODUCING PERIODONTAL INDEX PRODUCTION DEVICE THEREFOR PRODUCTION PROGRAM THEREFOR RECORDING MEDIUM RECORDING SAME METHOD FOR DIAGNOSING PERIODONTITIS DIAGNOSIS DEVICE THEREOF DIAGNOSIS PROGRAM THEREFOR AND RECORDING MEDIUM RECORDING SAME
As subjects teeth having been considered as non preservable and thus extracted are used and several teeth of each tooth type are selected and subjected to measurement. Then the lost periodontal ligament area (S) of each tooth is calculated on the basis of the sample attachment level (M) and total periodontal ligament area (S) thereof. Next the relationship between the bite force coefficient (B) which reflects the bite force of each tooth and varies from tooth type to tooth type and the lost periodontal ligament area (S) at loosing of each tooth is statistically processed for each tooth group. By taking advantage of the linear relationship between these factors existing in this step a linear equation representing the relationship between the bite force coefficient (B) and the lost periodontal ligament area (S) at tooth loosing is formed. Thus [remaining periodontal ligament area modified by bite force (S)]/total periodontal ligament area (S)]×100 (%) is calculated on the basis of the lost periodontal ligament area (S) at tooth loosing as a periodontal index modified by bite force (BPI) that shows the degree of the progress of periodontitis.
