[1] Department of Oral Surgery, Sapporo Med. Univ. Sch. of Medicine, Sapporo 060-0061, South 1, West 16, Chuou-ku
[2] Division of Maxillofacial, Graduate School, Tokyo Medical and Dental University, Tokyo
[3] Department of Oral Surgery, National Defense Medical College, Tokorozawa
[4] Instrum. Anal. Res. Ctr. Life Sci., Tokyo Medical and Dental University, Tokyo