1. Department of Oral Diagnostic Science, Kyushu Dental College, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan
2. Department of Oral and Maxillofacial Surgery, Kyushu Dental College, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan
3. Department of Bioscience, Kyushu Dental College, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan
4. Department of Otorhinolaryngology, University of Occupational and Environmental Health, Kitakyushu, 807-8555, Japan