Middle ear surgery treats problems in the tympanic membrane, the articulated ossicles (hammer, anvil and stirrup) and the mastoid air cells (cavities of the temporal bone). There are two main groups of surgical procedures: tympanoplasty and mastoidectomy. Tympanoplasty encompasses ossiculoplasty (repair of bones) and myringoplasty (closing holes in the eardrum). In this type of surgery, a cut is made through a cut behind the ear or inside the ear canal to enter the middle ear. Procedures may involve the removal of any infection or dead tissue in the eardrum with a graft to repair a perforation in the tympanic membrane or the implantation of prosthesis to replace a damaged bone. Tympanoplasty is advised in cases of large perforations of the eardrum or middle ear infections, including chronic or acute otitis media, which cannot be cured with antibiotics. A mastoidectomy is a surgical procedure to remove diseased mastoid air cells. The operation is to treat complications of ear infections that have spread to the temporal bone (otitis media), mastoiditis, abnormal bone growths, and cholesteatoma (cyst skin cells in the middle ear) or to place cochlear implants.