Periodontal disease 全国12-74岁6个区段均健康的人数和百分比 年龄(岁) 受检人数健康人数分比(‰) 12 23452 7272 31.01 15 23452 5062 21.58 23452 3475 14.82 3544 23452 668 2.85 65-74 23452 132 0.56 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 3 Periodontal Disease