Abstract
A clinical study to investigate the relationship between The Japan Dental Association classification of periodontitis (JDA 2007), which is widely used in current dental practice in Japan, and the clinical attachment level (CAL) was conducted by 10 Japanese clinicians for 5 years, from 2016 to 2021. The study subjects included 1,375 patients with a total of 125,468 teeth. We thought that clarification of the relationship between the new classification of periodontitis (AAP・EFP 2018) and the results of this investigation would be clinically significant to calculate the periodontitis index. The JDA 2007 periodontitis classification does not include determination of the CAL. Therefore, the relationships between the periodontitis classification (JDA 2007) and the stage and grade of the new periodontitis classification (AAP・EFP 2018) were examined via the CAL value (including the PD value and degree of tooth mobility) based on the results of the above clinical study, in which the CAL value was determined for each tooth. When looking at the number of teeth tested for "CAL at the site of greatest loss" for versus "the Severity" classification in the new classification of periodontitis (AAP・EFP 2018), the correspondence of the JDA 2007 periodontitis classification (P0, P1, P2, P3, P4) to the stages (I, II, III, IV) was determined to be P0 for stage I, P1 for stage II and P2 for stage III and IV in the majority of cases. In terms of the "Maximum probing depth and tooth mobility" for "Complexity", the correspondence was P1 for stage I, P2 for stage II and III, and P3 for stage IV in the majority of cases. However, the relationship between the two classifications was not clear about "tooth loss" for "the Severity" of staging and for "Longitudinal data (CAL)" for "Direct evidence of progression" of grading. This is presumably attributable to the different scope of classification of the test items between the two groups and/or uneven distribution of the number of cases.
