1Department of Prosthodontics, Faculty of Dentistry, Thamar University, Thamar, Yemen
Department of Oral Rehabilitation, Faculty of Dentistry, Khartoum University, Khartoum, Sudan
*Corresponding Author: Dr. Mohammed Nasser Alhajj, Department of Oral Rehabilitation, Faculty of Dentistry, Khartoum University, Khartoum, Sudan. Tel: +249928978938, Email: dr_alhaj@hotmail.com
Online published on 21 September, 2016.