Effect of Khat Chewing on Gingival Health of Patients with Fixed Orthodontic Appliances: A Controlled-Clinical Trial. - Al-Haj, Ahmed Taher; Ishaq, Rami; Shamala, Anas; Al-Wesabi, Mohammed; Aldhorae, Khalid; Alakhali, Mohammed Sultan; Al-Labani, Mohammed (Pertanika Journal of Science & Technology, 2022)