Aphthous stomatitis the lesions, the healing time of individual ulcers and whether a scar is left after healing (see below). This is the most common type of aphthous stomatitis, accounting for about 80–85% of all cases. This subtype is termed minor aphthous ulceration (MiAU), or minor recurrent aphthous stomatitis (MiRAS). The lesions themselves may be referred to as minor aphthae or minor aphthous ulcers. These lesions are generally less than 10 mm in diameter (usually about 2–3 mm), and affect non-keratinized mucosal surfaces (i.e. the labial and buccal mucosa, lateral borders of the tongue and the floor of the mouth). Usually several
The Canon of Medicine anatomy, and physiology. The book explains the causes of health and disease. Avicenna believed that the human body cannot be restored to health unless the causes of both health and disease are determined. He defined medicine ("tibb") as follows: Avicenna begins part one by dividing theoretical medicine and medical practice. He describes what he says are the "four causes" of illness, based on Aristotelian philosophy: The material cause, the efficient cause, the formal cause, and the final cause: Avicenna's thesis on the elements of the cosmos is described by Gruner as "the foundation of the whole "Canon"". Avicenna insists here