Affiliation: | a Department of Periodontology, School of Dentistry, Kyungpook National University, 188-1, Samduk 2Ga, Jung-Gu, Daegu 700-412, Republic of Korea b Department of Oral & Maxillofacial Radiology, School of Dentistry, Kyungpook National University, Daegu 700-412, Republic of Korea |