Aceil Al-Khatib1, Jaime A Teixeira da Silva2. 1. Faculty of Dentistry, Jordan University of Science and Technology, P. O. Box 3030, Irbid, 22110, Jordan. aceil@hotmail.com. 2. , P. O. Box 7, Miki-cho Post Office, Ikenobe 3011-2, Miki-cho, Kagawa-ken, 761-0799, Japan.