Search results for "middle ear"
showing 10 items of 43 documents
Disconnecting bones within the jaw-otic network modules underlies mammalian middle ear evolution
2019
The origin of the mammalian middle ear ossicles from the craniomandibular articulation of their synapsid ancestors is a key event in the evolution of vertebrates. The richness of the fossil record and the multitude of developmental studies have provided a stepwise reconstruction of this evolutionary innovation, highlighting the homology between the quadrate, articular, pre-articular and angular bones of early synapsids with the incus, malleus, gonial and ectotympanic bones of derived mammals, respectively. There are several aspects involved in this functional exaptation: (i) an increase of the masticatory musculature; (ii) the separation of the quadrate bone from the cranium; and (iii) the …
Elektrophysiologische Untersuchung zum Einsatz von Streptolysin O und Natrium-Hyaluronat zur Permeabilitätsmodulation der Membran des runden Fensters…
2003
Background: The round window membrane (RWM) acts like a barrier for topically applied substances into the middle ear preventing diffusion into the perilymphatic fluid compartment. Material and Method: In an animal model, modulation of the permeability of the RWM was attempted using Streptolysin-O (SLO) in various concentrations and sodium hyaluronate. Thereafter, the effect of intratympanically applied Lidocain 2% on hearing threshold measured by auditory brainstem response was tested for Lidocain 2 % and Lidocain 2 % in combination with SLO or sodium hyaluronate. Results: The results show that both, SLO and sodium hyaluronate, influence the effect of Lidocain 2 % on hearing thresholds as a…
Localization of Congenital Tegmen Tympani Defects
2007
Objective: This study sets out to demonstrate the normal developmental steps of the tegmen tympani and thus explains the typical localization of congenital tegmental defects. Specimens: For this study, 79 macerated and formalin-fixed human temporal bones from 14th fetal week to adults were observed and prepared. Intervention: Macroscopic and microscopic examination of the prenatal and postnatal changes of the tegmen tympani during its development. Main Outcome Measure: Temporal bones from 14th fetal week to adults underwent descriptive anatomic studies to understand the normal development of the tegmen tympani and to find a possible cause of its congenital defects. Results: The medial part …
Expression of Matrix-Degrading Cysteine Proteinase Cathepsin K in Cholesteatoma
2001
Cholesteatoma is a nonneoplastic lesion of the middle ear space or mastoid that is histologically characterized by a progressive bone erosion of the ossicles and surrounding bone. Several matrix-degrading enzymes have been implicated as mediators of this bone erosion. Because the novel cysteine proteinase cathepsin K has been shown to play a central role in bone resorption, we examined the expression of this enzyme in tissue specimens of cholesteatoma. Tissue specimens of 9 patients with cholesteatoma were obtained during middle-ear surgery. Expression of cathepsin K mRNA was determined by RT-PCR using specific primers. Immunohistochemical analysis of cathepsin K protein expression in tissu…
[Myringoplasties. A retrospective analysis of our surgical outcomes].
2010
Objective: The aim of this study was to present myringoplasty case results in our department. Different factors were studied to confirm their prognostic value. Materials and methods: A total of 126 myringoplasties from 2006 until 2010 were reviewed, collecting patient-related details, descriptions of the anatomical defect and the most interesting surgical aspects. Results: Subtotal perforations (35.7%) were the most frequently observed. In 89.7% of the operations, the transcanal approach was preferred. The medial technique (underlay) to the tympanic membrane was the most performed (97.6%). Cartilage was the principal graft used (82.5%). Complete closure of the perforation was obtained in 71…
Management of chronic otitis by middle ear obliteration with blind sac closure of the external auditory canal.
2008
Objective: Description of a technique of middle ear obliteration (MEO) with blind sac closure of the external auditory canal with discussion of the indications for its use in cases of recalcitrant chronic otitis and in far advanced disease. Patients: All patients underwent otologic examination and audiologic and radiologic assessments in a quaternary center. Results: Fifty-three cases of MEO were analyzed. For 9 patients, primary surgery was performed. One case of residual disease was identified. The minimum follow-up was 2 years. Conclusion: The decision to perform a MEO is one that is made only rarely. However, this is a technique that should be part of every otologist`s armamentarium. Wh…
The Role of Diffusion-Weighted Magnetic Resonance Imaging in Cholesteatoma Diagnosis and Follow-up: Study With the Diffusion PROPELLER Technique
2012
Abstract Introduction and objectives The diagnosis of cholesteatoma is based on clinical evaluation and computed tomography. New non-echo-planar diffusion-weighted magnetic resonance imaging (MRI) techniques, without intravenous contrast, are capable of differentiating cholesteatoma from inflammatory tissue, cholesterol granuloma and granulation tissues. The technique is very helpful in differential diagnosis of cholesteatoma, mainly after canal wall-up tympanoplasty surgery, to avoid routine second-look surgery in these patients. Congenital cholesteatoma and difficult cases can be detected and correctly diagnosed as well. The aim of this study was to evaluate sensitivity, specificity, posi…
Intratympanic Dexamethasone and Hyaluronic Acid in Patients with Low-Frequency and Ménière's-Associated Sudden Sensorineural Hearing Loss
2005
Steroids are widely used for the treatment of cochleovestibular disorders. Direct steroid application in the middle ear cavity, when combined with a round window membrane permeability-modulating substance, increases the level of the steroid reaching the target cells. We measured hearing in patients with idiopathic isolated low-frequency sensorineural hearing loss and in patients with sudden sensorineural hearing loss and a history of Ménière's disease. Contradictory reports about effectiveness of intratympanic steroid therapy on vertigo control and hearing improvement in patients with Ménière's disease exist in the literature.Eighteen patients with isolated low-frequency idiopathic sudden s…
Handheld laser-fiber vibrometry probe for assessing auditory ossicles displacement
2021
Significance: Measurements of auditory ossicles displacement are commonly carried out by means of laser-Doppler vibrometry (LDV), which is considered to be a gold standard. The limitation of the LDV method, especially for in vivo measurements, is the necessity to expose an object in a straight line to a laser beam operating from a distance. An alternative to this approach is the use of a handheld laser-fiber vibrometry probe (HLFVP) with a curved tip. Aim: We evaluate the feasibility of an HLFVP with a curved tip for measuring sound-induced displacement of the auditory ossicles. Approach: A handheld vibrometer probe guiding the laser beam with a fiber-optic cable was used for displacement m…
Bioactive Glass-Ceramics in Middle Ear Surgery An 8-Year Review
1988
An 8-year follow-up of Ceravital middle ear prostheses showed there was extremely good tolerance in the middle ear space. Incompatibility phenomena were not observed, and inflammatory reactions were neither caused nor supported by the implants. The tympanoplasties were always performed without interposition of cartilage between the tympanic membrane or the tympanic membrane graft and the disk-shaped portion of the implant, and extrusions were never observed. Long-lasting inflammatory processes appeared to destroy implants the same way they destroy ossicles. Transient inflammatory periods (such as episodes of purulent otitis media, which occurred soon after the prostheses were implanted) did…