Aphthous stomatitis countries. Within nations, it is more common in higher socioeconomic groups. Males and females are affected in an equal ratio, and the peak age of onset between 10 and 19 years. About 80% of people with aphthous stomatitis first developed the condition before the age of 30. There have been reports of ethnic variation. For example, in the United States, aphthous stomatitis may be three times more common in white-skinned people than black-skinned people. "Aphthous affectations" and "aphthous ulcerations" of the mouth are mentioned several times in the treatise "Of the Epidemics" (part of the Hippocratic corpus, in the 4th
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