1. Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea.
2. Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea.
3. Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan.