1. Department of Oral Biology, Faculty of Dentistry; Naresuan University; Phitsanulok 65000 Thailand
2. Mineralized Tissue Research Unit, Faculty of Dentistry; Chulalongkorn University; Bangkok 10330 Thailand
3. Department of Anatomy, Faculty of Dentistry; Chulalongkorn University; Bangkok Pathumwan 10330 Thailand
4. The Petroleum and Petrochemical College; Chulalongkorn University; Bangkok Pathumwan 10330 Thailand