Treatment of periodontal disease, Chengdu, Sichuan, China, ca. 19461940-1950Also included in the International Mission Photography Archive.Dr. Lin Ts'en-hen Staff member, School of Dentistry, treating periodontal (gingival & bone) disease. Male patient sitting in dentist's chair with white cloth over his chest while Dr. Lin (in white smock) works with tools in his mouth; several other people are partly visible in the background.still image