Stomatitis cause deficiencies, which in turn causes stomatitis. Examples include tropical sprue. Aphthous stomatitis (canker sores) is the recurrent appearance of mouth ulcers in otherwise healthy individuals. The cause is not completely understood, but it is thought that the condition represents a T cell mediated immune response which is triggered by a variety of factors. The individual ulcers (aphthae) recur periodically and heal completely, although in the more severe forms new ulcers may appear in other parts of the mouth before the old ones have finished healing. Aphthous stomatitis is one of the most common diseases of the oral mucosa, and
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