Cholesteatoma either by metaplasia of the middle ear mucosa or by traumatic implantation of ear canal or tympanic membrane skin. In addition, cholesteatoma inadvertently left by a surgeon usually regrows as an epidermal cyst. Some authors have also suggested hereditary factors. More commonly, keratin accumulates in a pouch of tympanic membrane which extends into the middle ear space. This abnormal folding or 'retraction' of the tympanic membrane arises in one of the following ways: Cholesteatoma may also arise as a result of metaplasia of the middle ear mucosa or implantation following trauma. Cholesteatoma is diagnosed by a doctor by physical examination
Membrane operating conditions, cost and performance, it should prevented, and if necessary, removed. Optimizing the operation conditions is important to prevent fouling. However, if fouling has already taken place, it should be removed by using physical or chemical cleaning. Physical cleaning techniques for membrane include membrane relaxation and membrane backwashing. Chemical cleaning. Relaxation and backwashing effectiveness will decrease with operation time as more irreversible fouling accumulates on the membrane surface. Therefore, besides the physical cleaning, chemical cleaning may also be recommended. They include: Optimizing the operation condition. Several mechanisms can be carried out to optimize the operation conditions of the membrane