Tehran University of Medical Sciences Journal of Medical Ethics and History of Medicine 2008-0387 19 0 2026 09 30 1703 1703 Merve Erdem DDS, PhD, Department of History of Medicine and Ethics, Maltepe University Faculty of Medicine, Istanbul, Türkiye İbrahim Topçu MD, PhD, Department of History of Medicine and Ethics, Hamidiye Faculty of Medicine, University of Health Sciences Türkiye, Istanbul, Türkiye. Ahmet Beyatlı PhD, Medicinal and Aromatic Plants Program, Hamidiye Vocational School of Health Services, University of Health Sciences Türkiye, Istanbul, Türkiye. Beyzanur KAÇ Research Assistant, Department of History of Medicine and Ethics, Hamidiye Faculty of Medicine, University of Health Sciences Türkiye, Istanbul, Türkiye. İsmail Uzar MD, Resident Doctor, Department of Pediatrics, İstanbul Medipol Üniversitesi, Istanbul, Türkiye. 2026 05 13 2026 07 07 During the medieval Islamic era, and before dentistry emerged as an independent discipline, Rhazes and Avicenna documented their observations on oral and dental health within their broader medical works. This comparative historical analysis examines ulcerative oral lesions within the framework of humoral medicine, using Rhazes's al-Ḥāwī fī al-Ṭibb (Liber Continens) and Avicenna's al-Qānūn fī al-Ṭibb (The Canon of Medicine), and evaluates them for diagnosis, classification, drug repertoire (materia medica), and routes of administration.The findings reveal that Rhazes provides an extensive, multilayered therapeutic repertoire drawing on clinical observations and earlier scholars, while Avicenna adopts a more systematic and classificatory approach. Herbal and mineral drugs constitute the core of both of their therapeutic repertoires. Direct clinical observations are highlighted by the association of childhood oral thrush with milk and an emphasis on the delicacy of the oral mucosa. Their complementary historical approaches offer valuable insights that may warrant further investigation into modern pharmacology. https://jmehm.tums.ac.ir/index.php/jmehm/article/view/1703 https://jmehm.tums.ac.ir/index.php/jmehm/article/download/1703/500