Denture-related stomatitis upper teeth, worn by someone with no natural teeth in their upper jaw). Denture-related stomatitis is more likely to develop when the denture is left constantly in the mouth, rather than removing it during sleep, and when the denture is not cleaned regularly. The Newton classification divides denture-related stomatitis into three types based on severity. Type one may represent an early stage of the condition, whilst type two is the most common and type three is uncommon. Despite the alternative name for this condition, "denture sore mouth", it is usually painless and asymptomatic. The appearance of the involved mucosa is
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