Classification oI. Chronic Periodontitis (slight: 1-2 mm CAL; moderate: 3-4 mm CAL severe:>5mm CAL) oA. Localized oB. Generalized( 30% of sites are involved Department of Oral Pathology, Shandong University http://course.sdu.edu.cn/oralhistopath.htmlDepartment of Oral Pathology, Shandong University http://course.sdu.edu.cn/oralhistopath.html 17  II. Chronic Periodontitis (slight: 1-2 mm CAL; moderate: 3-4 mm CAL; severe: >5mm CAL) A. Localized B. Generalized (> 30% of sites are involved) Classification