Aphthous stomatitis with aphthous stomatitis, and it is known that trauma can decrease the mucosal barrier. Trauma could occur during injections of local anesthetic in the mouth, or otherwise during dental treatments, frictional trauma from a sharp surface in the mouth such as broken tooth, or from tooth brushing. Hormonal factors are capable of altering the mucosal barrier. In one study, a small group of females with aphthous stomatitis had fewer occurrences of aphthous ulcers during the luteal phase of the menstrual cycle or with use of the contraceptive pill. This phase is associated with a fall in progestogen levels, mucosal proliferation
Medieval medicine of Western Europe was one of the "leading Italian universities in teaching medicine, identification and treating of diseases and ailments, specializing in autopsies and workings of the body." The most prestigious and famous part of the university is the oldest surviving anatomical theater, in which students studied anatomy by observing their teachers perform public dissections. Surgery was formally taught in Italy even though it was initially looked down upon as a lower form of medicine. The most important figure of the formal learning of surgery was Guy de Chauliac. He insisted that a proper surgeon should have a specific knowledge of the human