Thirawass Phumyoo1, Tanvaa Tansatit2, Benrita Jitaree3. 1. Department of Basic Medical Science, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok, Thailand. 2. Department of Anatomy, Faculty of Medicine, and The Chula Soft Cadaver Surgical Training Center, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand. 3. Chakri Naruebodindra Medical Institute, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Samut Prakan, Thailand.