1. Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Ain Shams University
2. Department of Oral and Maxillofacial Surgery El Bank El Ahly Hospital
3. Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, The British University
4. Department of Oral and Maxillofacial Surgery in The Military Hospital
5. Military Medical Academy, Cairo, Egypt