Mastoid: The posterior part of the temporal bone. It is a projection of the petrous bone.Mastoiditis: Inflammation of the honeycomb-like MASTOID BONE in the skull just behind the ear. It is usually a complication of OTITIS MEDIA.Cholesteatoma, Middle Ear: A mass of KERATIN-producing squamous EPITHELIUM that resembles an inverted (suck-in) bag of skin in the MIDDLE EAR. It arises from the eardrum (TYMPANIC MEMBRANE) and grows into the MIDDLE EAR causing erosion of EAR OSSICLES and MASTOID that contains the INNER EAR.Otologic Surgical Procedures: Surgery performed on the external, middle, or internal ear.Ear, Middle: The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.Ear Canal: The narrow passage way that conducts the sound collected by the EAR AURICLE to the TYMPANIC MEMBRANE.Temporal Bone: Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).Vestibular Neuronitis: Idiopathic inflammation of the VESTIBULAR NERVE, characterized clinically by the acute or subacute onset of VERTIGO; NAUSEA; and imbalance. The COCHLEAR NERVE is typically spared and HEARING LOSS and TINNITUS do not usually occur. Symptoms usually resolve over a period of days to weeks. (Adams et al., Principles of Neurology, 6th ed, p304)Caloric Tests: Elicitation of a rotatory nystagmus by stimulating the semicircular canals with water or air which is above or below body temperature. In warm caloric stimulation a rotatory nystagmus is developed toward the side of the stimulated ear; in cold, away from the stimulated side. Absence of nystagmus indicates the labyrinth is not functioning.Ear Diseases: Pathological processes of the ear, the hearing, and the equilibrium system of the body.Cholesteatoma: A non-neoplastic mass of keratin-producing squamous EPITHELIUM, frequently occurring in the MENINGES; bones of the skull, and most commonly in the MIDDLE EAR and MASTOID region. Cholesteatoma can be congenital or acquired. Cholesteatoma is not a tumor nor is it associated with high CHOLESTEROL.Dysgeusia: A condition characterized by alterations of the sense of taste which may range from mild to severe, including gross distortions of taste quality.Tympanoplasty: Surgical reconstruction of the hearing mechanism of the middle ear, with restoration of the drum membrane to protect the round window from sound pressure, and establishment of ossicular continuity between the tympanic membrane and the oval window. (Dorland, 28th ed.)Autografts: Transplant comprised of an individual's own tissue, transferred from one part of the body to another.Osteoblastoma: A benign, painful, tumor of bone characterized by the formation of osteoid tissue, primitive bone and calcified tissue. It occurs frequently in the spine of young persons. (From Dorland, 27th ed; Stedman, 25th ed)Lateral Sinus Thrombosis: Formation or presence of a blood clot (THROMBUS) in the LATERAL SINUSES. This condition is often associated with ear infections (OTITIS MEDIA or MASTOIDITIS) without antibiotic treatment. In developed nations, lateral sinus thrombosis can result from CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; NEUROSURGICAL PROCEDURES; THROMBOPHILIA; and other conditions. Clinical features include HEADACHE; VERTIGO; and increased intracranial pressure.