Biomaterial Database

[Study on middle ear ventilation using positional tympanometry--post mastoidectomy ear]. 1995

H Ebihara

Department of Otolaryngology, School of Medicine, Tokyo Medical and Dental University.

The middle ear is a cavity surrounded by solid bone, lined with mucosa with a lumen filled with gas. To examine this unique ventilation system under atmospheric pressure, the middle ear pressure of 50 normal ears was previously examined. Positional tympanometry, whereby the middle ear pressure is increased as the subject assumes the lateral position under atmospheric pressure was used. As a result, (1) The middle ear pressure was elevated by the change from the sitting position to the lateral position. Venous pressure was regarded as causative factor of this pressure elevation. (2) The elevation of the middle ear pressure in the lateral position suggested gas production from the mastoid cells of the middle ear. In this study, a proportion of the mastoid cells were removed to resect a tumor of the internal acoustic meatus in conjunction with resection of an acoustic tumor. After resection the area was filled with fascia and fatty tissue. The middle ear pressure of each subject was monitored to determine the effect of a decrease in the mastoid cell volume on middle ear pressure. The results were continuously recorded every 12 seconds for the lower ear when the subjects were in the lateral position. The following results were obtained. (1) The elevation of the middle ear pressure due to positional change among subjects which had had acoustic tumors resected was noticeably greater than the elevation in normal ears. This is thought to have been the result of an elevation in cerebrospinal fluid pressure attributable to positional change, along with an elevation in intravenous pressure. (2) We made comparisons of increases in middle ear pressure 10 minutes after assuming the lateral position in 14 ears after acoustic tumor resection and in 21 normal ears. No noticeable differences were found in the middle ear pressure increases between the two groups despite the fact that the volume of the mastoid cells in the group that had tumors resected had been greatly reduced.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008416	Mastoid	The posterior part of the temporal bone. It is a projection of the petrous bone.	Mastoid Foramen,Mastoid Bone,Mastoid Process,Bone, Mastoid,Foramen, Mastoid,Mastoid Bones,Mastoid Processes,Mastoids,Process, Mastoid
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D008876	Middle Ear Ventilation	Ventilation of the middle ear in the treatment of secretory (serous) OTITIS MEDIA, usually by placement of tubes or grommets which pierce the TYMPANIC MEMBRANE.	Grommet Insertion,Tympanostomy Tube Insertion,Ventilation, Middle Ear,Myringostomy,Tympanostomy,Ear Ventilation, Middle,Ear Ventilations, Middle,Grommet Insertions,Insertion, Grommet,Insertion, Tympanostomy Tube,Insertions, Grommet,Insertions, Tympanostomy Tube,Middle Ear Ventilations,Myringostomies,Tube Insertion, Tympanostomy,Tube Insertions, Tympanostomy,Tympanostomies,Tympanostomy Tube Insertions,Ventilations, Middle Ear
D009464	Neuroma, Acoustic	A benign SCHWANNOMA of the eighth cranial nerve (VESTIBULOCOCHLEAR NERVE), mostly arising from the vestibular branch (VESTIBULAR NERVE) during the fifth or sixth decade of life. Clinical manifestations include HEARING LOSS; HEADACHE; VERTIGO; TINNITUS; and FACIAL PAIN. Bilateral acoustic neuromas are associated with NEUROFIBROMATOSIS 2. (From Adams et al., Principles of Neurology, 6th ed, p673)	Acoustic Neuroma,Melanocytic Vestibular Schwannoma,Schwannoma, Acoustic,Schwannoma, Vestibular,Acoustic Neuroma, Cerebellopontine Angle,Acoustic Tumor,Angle Tumor,Cerebellopontine Angle Acoustic Neuroma,Cerebellopontine Angle Tumor,Neurilemmoma, Acoustic,Neurilemoma, Acoustic,Neurinoma of the Acoustic Nerve,Neurinoma, Acoustic,Neuroma, Acoustic, Unilateral,Vestibular Schwannoma,Acoustic Neurilemmoma,Acoustic Neurilemmomas,Acoustic Neurilemoma,Acoustic Neurilemomas,Acoustic Neurinoma,Acoustic Neurinomas,Acoustic Neuromas,Acoustic Schwannoma,Acoustic Schwannomas,Acoustic Tumors,Angle Tumor, Cerebellopontine,Angle Tumors,Angle Tumors, Cerebellopontine,Cerebellopontine Angle Tumors,Melanocytic Vestibular Schwannomas,Neurilemmomas, Acoustic,Neurilemomas, Acoustic,Neurinomas, Acoustic,Neuromas, Acoustic,Schwannoma, Melanocytic Vestibular,Schwannomas, Acoustic,Schwannomas, Melanocytic Vestibular,Schwannomas, Vestibular,Tumor, Acoustic,Tumor, Angle,Tumor, Cerebellopontine Angle,Tumors, Acoustic,Tumors, Angle,Tumors, Cerebellopontine Angle,Vestibular Schwannoma, Melanocytic,Vestibular Schwannomas,Vestibular Schwannomas, Melanocytic
D011187	Posture	The position or physical attitude of the body.	Postures
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
D004432	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.	Tympanic Cavity,Tympanum,Middle Ear,Cavities, Tympanic,Cavity, Tympanic,Ears, Middle,Middle Ears,Tympanic Cavities,Tympanums
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man