Aphthous stomatitis near to the ulcer, described histologically as "perivascular cuffing". Aphthous stomatitis has been classified as a type of non-infectious stomatitis (inflammation of the mouth). One classification distinguishes "common simple aphthae", accounting for 95% of cases, with 3–6 attacks per year, rapid healing, minimal pain and restriction of ulceration to the mouth; and "complex aphthae", accounting for 5% of cases, where ulcers may be present on the genital mucosa in addition to mouth, healing is slower and pain is more severe. A more common method of classifying aphthous stomatitis is into three variants, distinguished by the size, number and location of
The Canon of Medicine He began writing the "Canon" in Gorganj, continued in Rey and completed it in Hamadan in 1025. The result was a "clear and ordered "summa" of all the medical knowledge of Ibn Sīnā's time". It served as a more concise reference in contrast to Galen's twenty volumes of medical corpus. "The Canon of Medicine" is divided into five books: Book 1 is made up of six theses which give a general description of medicine in general, the cosmic elements that make up the cosmos and the human body, the mutual interaction of elements (temperaments), fluids of the body (humours), human