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Results for “MASTOID”

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At least 19 recordsLinked to original sources

PubMed2002

Changes in external ear resonance after mastoidectomy: open cavity mastoid versus obliterated mastoid cavity.

The creation of an open mastoid cavity changes the acoustic characteristics of the external ear. The aim of this study was to ascertain the acoustic change in the external auditory canal caused by an open mastoid cavity and to compare it with mastoid obliteration. The external ear resonance characteristics were measured in 40 normal adult ears, 20 ears with an open mastoid cavity and 40 ears with an obliterated mastoid. The measurement of resonance characteristics was performed using a real ear analyser. An open mastoid cavity changed the mean peak resonant frequency of the external ear from 2.1 kHz to 2.3 kHz (P < 0.02), with a mean attenuation of 8 dB SPL at 4 kHz. An obliterated mastoid produced higher resonance frequencies from 2.5 kHz to 2.8 kHz. The sound pressure gain of the external auditory canal with an open mastoid cavity was higher than with an obliterated mastoid. The author concludes that an open mastoid cavity can affect the resonance frequency, and that this effect is reduced by mastoid obliteration. Therefore, mastoid obliteration results in a more normal ear canal both anatomically and functionally.

Adult↗

PubMed1992

The correlation of middle ear aeration with mastoid pneumatization. The mastoid as a pressure buffer.

Atelectatic ears, which by definition are poorly aerated, are also usually associated with poor mastoid pneumatization. On the other hand, otosclerotic patients, whose middle ears are usually exceptionally well aerated, also have excellent mastoid pneumatization. Three unusual cases are presented, in which partial atelectasis developed in stapedectomized patients. In each case the mastoid was later found to be nonpneumatized, and further analysis revealed that their stapes fixation had in effect most probably been of non-otosclerotic origin. Thus, although these three cases had at first appeared to represent exceptions to the general rule of otosclerotics having a well-aerated middle ear, in fact they support the association between atelectasis and poor pneumatization. The linkage of good middle ear aeration with large mastoid pneumatization and vice versa may suggest that the mastoid plays a role of a pressure buffer in the middle ear, which is a system of a gas pocket with fluctuating pressures. Also, otosclerosis may be considered to be an unlikely cause of conductive deafness in cases of poor pneumatization.

Adult↗

PubMed1991

Treatment of chronic mastoiditis by grafting of mastoid cavities with autologous epithelial layers generated by in vitro culture of buccal epithelium.

Autologous cultured epithelial layers were established from biopsies from the mucosa of the cheek, a non-keratinizing region of the oral cavity. These were grafted to the unepithelialized mastoid cavities of nine patients with chronic mastoiditis and severe otorrhoea varying from two to 30 years' duration. All procedures were performed on an out-patient basis, with no anaesthesia except for topical anaesthesia for the mucosal biopsy. In seven of the patients the grafts took well, with complete resolution of the otorrhoea for a minimum follow-up period of eight months. In one patient there was a partial take of the graft with substantial improvement in the rate of discharge. The mastoid cavities of two patients were biopsied five months after grafting, and demonstrated a stratified squamous epithelium, with keratinization of the epithelium clearly evident.

Adult↗

PubMed1989

Comparison of the mastoid to vertex and mastoid to high forehead electrode arrays in recording auditory evoked potentials.

The ipsilateral mastoid to vertex and ipsilateral mastoid to high forehead electrode arrays were found to have equal efficacy in recording the auditory brain stem and middle latency responses in both open and closed filtered conditions. It is concluded that the ipsilateral mastoid to high forehead electrode array is a valid clinic alternative for use in evoked response testing.

Audiometry, Evoked Response↗

PubMed1994

Solitary plasmacytoma of the mastoid bone presenting as coalescent mastoiditis.

Acute mastoiditis is a complication of acute otitis media that produces air cell opacification and coalescence on computed tomographic (CT) imaging. This appearance, however, is nonspecific and may be seen in patients with infection and tumor. Magnetic resonance imaging (MRI) can aid in differentiating the two on the basis of differences in tissue signal characteristics and by showing the presence or absence of an associated soft-tissue mass. In this report, we demonstrate the utility of MRI as a complementary imaging modality to CT in the diagnosis of a solitary plasmacytoma of the temporal bone that was initially thought to be coalescent mastoiditis.

Biopsy↗

PubMed1978

Mastoiditis and brain hernia (mastoiditis cerebri).

Ten patients with brain hernia occurring as an insidious complication of chronic mastoiditis coincidentally discovered at the time of surgery are described. Four had previous surgery, six did not. A history of trauma was othwise absent. Cerebrospinal fluid otorrhea did not occur. Our method of management is described. Pathology and pathogenesis are discussed. Three patients had pedunculated brain hernias, while seven had diffuse (fungoid) herniation. Granulation tissue appeared as an important part of the disease process. These may represent abortive attempts at brain abscess formation since the widespread use of antibiotics. Pacchionian bodies may also play a role in the pathogenesis.

Adult↗

PubMedDate not supplied

Secretory otitis and pneumatization of the mastoid process: sexual differences in the size of mastoid cell system.

Seventy-nine children (41 girls and 38 boys) were subjected to tympanometry nine times from the age of 2 years to the age of 7 years. In addition, otoscopy was performed, and the children's otologic history was recorded. At the age of 7 years, roentgenograms were taken of the mastoid process, and the area of the air cell system was measured by planimetry. The smallest cell systems were found in ears with a history of secretory otitis or chronic tubal dysfunction--a finding which supports the environmental theory of pneumatization. Boys had significantly smaller cell systems (mean, 7.5 cm2; range, 2.75-16.75) than girls (mean, 9.0 cm2; range, 2.5-15.7). The degree of middle ear pathology was significantly higher in boys, as expressed by the total tympanometric score. The more pronounced middle ear pathology in boys was caused by more frequent and severe episodes of upper respiratory tract infections. The analysis of the sex differences provides substantial support of the environmental theory of pneumatization, since upper respiratory tract infections in childhood often cause tubal dysfunction and secretory otitis, conditions that disturb the normal process of pneumatization and result in hypocellularity.

Acoustic Impedance Tests↗

PubMed2000

When a mastoid swelling is not mastoiditis.

A case is reported of swelling over the mastoid process due to subgaleal abscess possibly secondary to trivial cutaneous trauma. The diagnosis was difficult as subgaleal abscess is an extremely rare condition especially after the advent of the antibiotic era. The route of entry of the infection to the subgaleal space was unclear as there was no skin puncture. The absence of substantial trauma excluded subgaleal haematoma as a precondition. We would like to discuss the possible aetiologies and the management of this rare case in the light of the limited information available in the world literature.

Abscess↗

PubMed1954