1. Department of Endodontics; Loma Linda University; Loma Linda CA USA
2. Department of Endodontics; Mashad University; Mashad Iran
3. Private Practice; Kennewick WA USA
4. Private Practice; Chico CA USA
5. Department of Endodontics; Kuwait University; Kuwait City Kuwait
6. Department of Anatomy; Loma Linda University; Loma Linda CA USA