Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Incus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources

Resorption of auditory ossicles and hearing loss in mice lacking osteoprotegerin.

Bones conduct sound in the middle ear. The three ossicles-the malleus, incus, and stapes-form a chain that transmits vibrations from the tympanic membrane to the oval window of the inner ear. Little is known about bone remodeling events in these ossicles and about potential effects of osteoporosis on hearing loss. Osteoclastic bone resorption is enhanced in Opg(-/-) mice lacking osteoprotegerin, which is a soluble decoy receptor for the osteoclastogenic cytokine RANKL. We asked whether auditory ossicles are resorbed in Opg(-/-) mice, and whether these mice suffer from impaired auditory function. All three ossicles in Opg(-/-) mice showed thinning, especially at the malleal manubrium and incus body. Most notably, unlike in the case in wild-type mice, the junction between the stapes and the otic capsule was fixed in Opg(-/-) mice, and the stapedial footplate was thinner and broader. Radiological analyses revealed that malleal cortical thickness was positively correlated with tibial bone mineral density in Opg(-/-) and control littermate mice. Furthermore, progressive hearing loss was detected in Opg(-/-) mice starting at 6 to 15 weeks of age. These data suggest that osteoprotegerin plays a crucial role in hearing by protecting the auditory ossicles and otic capsule from osteoclastic bone resorption.

Acoustic Stimulation↗

Facial nerve anomalies in association with congenital hearing loss.

OBJECTIVE: Facial nerve (FN) anomalies are exceedingly rare. The association between a hearing loss and an anomalous facial nerve has never been touched deeply in the literature. The aim of this study is to report facial nerve anomalies in patients presenting with congenital hearing loss (COHL) and/or facial nerve palsy. METHODS: A retrospective chart review over 10 years from two academic tertiary referral centers. Eight patients were diagnosed with facial nerve anomalies in association with congenital hearing loss. The age ranged from 7 months to 13 years. RESULTS: Five patients had conductive congenital hearing loss (CCHL). Two had congenital sensorineural hearing loss (CSNHL). The eighth patient had a mixed hearing loss (MHL). Surgical findings for patients with conductive congenital hearing loss included facial nerve passing inferior to oval window (OW) (two patients), facial nerve covering head of stapes (three patients), deformed stapes (two patient), deformed incus (two patient), and absent incus (one patient). Radiological findings for patients with congenital sensorineural hearing loss and mixed hearing loss include, single cavity anomaly (one patient), dilated vestibule and superior semicircular canal (one patient), and absent internal auditory canal (IAC) (two patients). For patients with conductive congenital hearing loss, the radiological findings consistency demonstrates a soft tissue opacification in the middle ear. CONCLUSIONS: Congenital hearing loss may be associated with facial nerve anomalies. Pediatric otolaryngologists should be cautious when exploring patients with conductive congenital hearing loss.

Acoustic Impedance Tests↗

[Results of tympanoplasty with antrum exclusion in the treatment of middle ear cholesteatoma].

INTRODUCTION: Exclusion of the antrum was designed to avoid the problem of mastoid ventilation by means of insufficient eustachian tube. MATERIAL AND METHODS: We retrospectively reviewed 72 ears with cholesteatoma who underwent antrum exclusion tympanoplasty (57% in men, mean age 40.9 years). Mean follow-up was 31.2 months (range, 12-64 mo). RESULTS: Exclusively epitympanic-antral cholesteatoma location (28.4%), and the necrosis of the long branch of the incus (54%) were the most common. The most used material to reconstruct the ossicular chain was Torp prosthesis (73.6%), followed by incus autograft (11.1%). We reported the following complications: postoperatory otorrhea (5.5%), perforation of neotympanum (16.7%), prosthesis extrusion (23.6%, time average of 15.6 months), and recurrence of cholesteatoma (4.2%). DISCUSSION/CONCLUSION: The technique with antrum exclusion has reported acceptable results in the control cholesteatoma recidivism. Although the functional results are similar to those of the open techniques, the resulting cavity with the antroexclusion is more anatomic.

Adolescent↗

[Ontogenic peculiarities of the human tympanic ossicular chain].

We have studied the development of the tympanic ossicles in 40 embryo-foetal human series aged between 32 days (6 mm) and newborn. Once performed the measurements to date chronologically embryos and foetuses, we did a meticulous dissection of temporal bones. After fix in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in a sequence of 7 mm, and stained with Martin's trichrome. The tympanic ossicles are developed in the mesenchyme of the two first pharyngeal archs. The head of the malleus, the body and the short limb of the incus arise from the first arch while the handle of the malleus, the long limb of the incus and the mass of the stapes arise from the second arch. The vestibular side of the stapedial footplate develops in the otic capsule. The tympanic ossicles develop from endochondral ossification, while anterior process of the malleus has the membranous ossification. In their ontogenia 6 stages are observed. First stage, the formation of their sketch by mesenchimal condensation, in the second stage, "pre-cartilaginous", the cells of the primordia are differentiated into condroblasts, in the third stage "cartilaginous" the ossicles show a cartilaginous structure, in the forth stage the primary ossification centers are developed, in the fifth stage the ossicles arise in the periostic annulus and inside the endochondral bone, and in the last stage the osseous tissue grows until it acquires a compact osseous structure.

Ear Ossicles↗

Middle-ear dynamics before and after ossicular replacement.

The mechanism of hearing involves conduction of mechanical vibrations along the ossicular chain to the inner ear. An acoustic wave is collected and transformed as it passes down the ear canal and impacts on the tympanic membrane (ear drum). The drum is connected to the inner-ear by three ossicle bones (malleus, incus, and stapes) in a complex arrangement, which serves to further transform the mechanical vibration before it reaches the cochlea of the inner ear. What is the mechanical function of the ossicular chain, and what are the biomechanical consequences of surgical reconstruction with prostheses? To answer these questions, a three-dimensional finite element model of the outer ear canal and middle ear was generated. The dynamical behaviour was predicted for the normal ear, and an ear reconstructed with partial and total ossicular replacement prostheses. For the normal ear, stapes amplitudes of 1x10(-8) m at low frequencies decrease to 4x10(-10)m at approximately 3kHz with several resonance peeks in between, most significantly at approximately 1kHz. Thereafter a further resonance is predicted at 4kHz associated with the ear canal. The behaviour is changed fundamentally by adding a prosthesis; the partial replacement increases the vibratory coupling of the drum and the stapes compared to the normal ear whereas the total replacement does the opposite, and is predicted to have the disadvantage of bringing several new resonances of the ossicular chain into the hearing range. It is hypothesised that the function of the malleus-incus-stapes arrangement is to link the drum to the oval window with the flexibility required for impedance matching but the rigidity to prevent unconstrainable resonances from occurring in the hearing range. If this is true, then the structural stiffness of ossicular chain is the critical design variable for middle-ear replacement prostheses.

Acoustics↗

Ossicular chain reconstruction using a new tissue adhesive.

HYPOTHESIS: A new medical-grade cyanoacrylate tissue adhesive will improve the results of ossicular chain reconstruction in a rat model. BACKGROUND: An ideal tissue adhesive has long been awaited by otologists. Studies examining the older cyanoacrylates have demonstrated variable efficacy and toxicity. Octylcyanoacrylate is a new tissue adhesive that has many ideal properties for otologic surgery. METHODS: Thirteen female C-D rats were anesthetized, and preoperative auditory brainstem response (ABR) testing was performed. A left antrotomy was performed, and the incus was removed. In the adhesive group, the incus was dipped in octylcyanoacrylate and interposed between the tympanic membrane and the stapes; no adhesive was used in the control group. At 8 weeks, postoperative ABR was performed, the integrity of the ossicular chain inspected, and histopathologic analysis of the temporal bones performed. Statistical comparison of ABR results was performed with the Mann-Whitney test. RESULTS: Seven rats were randomized to the adhesive group and six to the control group, of which four survived. There were no histopathologic differences in the temporal bones of the animals other than the presence of mild foreign body reaction around the ossicular chain of the animals in the adhesive group. The ossicular chain was not intact in two of the four controls, whereas the rest were intact at 8 weeks. Postoperative air conduction ABR results (mean dB sound pressure level) (62.5 control versus 34.3 adhesive, p = 0.010) and air-bone gaps (47.5 control versus 18.9 adhesive, p = 0.008) were significantly better in the adhesive group. CONCLUSIONS: This new medical-grade tissue adhesive improves the hearing results of ossicular chain reconstruction, with no apparent histotoxicity in this animal model.

Animals↗

[Otosclerosis imaging: matching clinical and imaging data].

Otosclerosis is a primitive osteodystrophia of the labyrinthine bone. Its diagnosis must be confirmed by a CT scan in order to eliminate the other causes that may lead to conductive hearing loss with an absence of stapedial reflex: fixation of the head of the malleus to the lateral wall of the tympanic cavity, absence of the long process of the incus or stapes, gusher syndrome, primary cholesteatoma, or tympanic facial nerve neuroma blocking the stapes. Particular problems in otosclerosis must be clarified: an extension to the round window (poor postoperative results), and extension to the tympanic cavity blocking the malleus and/or the incus, the labyrinthine lumen, or the internal auditory meatus (very rare). The position of the tympanic facial nerve canal and associated abnormalities must be assessed: stapedial artery, malformations of the ossicles and/or the labyrinth, and chronic otitis media. MRI is indicated in extension to the labyrinthine lumen, the internal auditory meatus, and in postoperative complications with labyrinthitis. MRI can also evaluate the active otosclerotic focus (gadolinium enhancement).

Adult↗

One hundred and seventy-five surgically treated malformations of the external and middle ear: findings and results.

During 10 years 222 patients suffering from malformation of the external and/or middle ear came for treatment to our clinic. One hundred and fifty-seven have been operated on, 139 on one side, 18 bilaterally. This report is based therefore upon 175 cases and deals especially with findings seen during operation, methods of reconstruction and results achieved. Thirty-six patients showed a stenosis of the external meatus, 78 had a partial or complete aplasia. In 61 ears exclusive malformation of middle ear structures was the cause of hearing loss (anomalies of malleus 58.2%, of incus 58.8% and of the stapes nearly always: 172 out of 175 ears). Combinations were frequent. Three structures may affect the development of the ossicular chain, when showing abnormal development themselves: 1) facial nerve, 2) a persistent stapedial artery and 3) the chorda tympani. Anomalies of the course of the facial nerve have been found in 87 ears. In 60 cases these deviations of the course caused obviously a malformation of the ossicular chain, too. A persistent stapedial artery has been seen in six ears. The stapes footplate was always fixed. In four patients a lateral deviation of the chorda tympani's course caused an interruption of the ossicular chain, mainly between the head and the handle of the malleus. The long process of the incus was involved, too, in different degree. The ratio between one-sided and bilateral aplasias was about 2:1. Our method to reconstruct the external meatus is described in detail. The functional results were very satisfying in exclusive anomalies of the ossicular chain.(ABSTRACT TRUNCATED AT 250 WORDS)

Ear, External↗

Diagnostic value of the multifrequency tympanometry in active rheumatoid arthritis.

We carried out a functional evaluation of the malleus-incus and incus-stapes joints in 37 patients with rheumatoid arthritis using multifrequency tympanometry. As a reference point, we calculated the resonance point using two different methods, and the results obtained were classified into two groups according to the phase of the disease: active, with clinical affection of the joint and with no medication; and inactive, asymptomatic. The results were compared with previously published criteria indicating normality, which underlined a significant correlation in the analysis of the resonance point between both groups, and which determined the value of multifrequency tympanometry in that stage and reactivation of the rheumatoid arthritis in active phase.

Acoustic Impedance Tests↗

Stapedectomy in children.

Stapes surgery for correction of conductive hearing loss in adults with otosclerosis is a well-established procedure. Its effectiveness in children, however, has received less scrutiny in the literature. Previous studies from our and other institutions demonstrated similar results in children and adults. Between 1980 and 1994 stapedectomies were done on 95 ears of 81 patients younger than 18 years (83 primary and 12 revisions). Data regarding age of onset, family history, associated anomalies, surgical findings, technique, hearing results, and complications were reviewed. Two groups were identified: congenital stapedial fixation and juvenile otosclerosis. Patients with congenital stapedial fixation had an earlier onset of hearing loss (3 vs 10 years, P < 0.001), a greater incidence of abnormalities of the malleus and incus (25% vs 3%, P < 0.001), and a slightly greater preoperative air-bone gap (35.2 +/- 12.9 vs 27.8 +/- 8.9, P = 0.002). Patients with otosclerosis had a greater frequency of a positive family history of deafness (53% vs 10%, P < 0.001). Overall, 79% of primary cases and 89% of revision cases had an improvement in hearing, with mean postoperative air-bone gaps of 15 dB and 22 dB, respectively. The gap did not widen significantly during the entire length of follow-up (mean 72 months). In primary cases, 59.1% obtained a postoperative air-bone gap of 10 dB or less. Eighty-two percent of children operated on for otosclerosis obtained excellent results (postoperative air-bone gap < or = 10 dB), compared with only 44% of children with congenital stapedial ankylosis (P = 0.02). In revision surgery, 29% of children obtained excellent results. Poorer results in both cases of congenital stapedial fixation and revision stapedectomy appear to be related to the greater incidence of associated anomalies of the malleus and incus. Indications, technique, complications, and considerations pertinent to childhood stapedectomy are discussed.

Audiometry↗

["Fuldaer ventilation surgery"--a surgical concept in severe ventilation disorders of the middle ear].

BACKGROUND: This report presents the long-term results of a special surgical technique in cases of persistent severe dysfunction of the Eustachian tube. PATIENTS AND METHODS: We performed this operation on 16 patients (18 ears) between 1982 and 1997. Almost all patients had undergone previous surgery. This included myringotomies and tube insertions, adenoidectomies, tonsillectomies, myringoplasties and mastoidectomies, sinus surgeries, and an operation on a cleft palate. The concept developed by one coauthor (Draf) combines different methods to improve ventilation of the middle ear and protect the eardrum against partial vacuum. The concept combines mastoidectomy, posterior tympanotomy, and removal of the incus and the head of the malleus with an interposition of the incus. The tympanic membrane is then stabilized with a cartilage-perichondrium graft, and a tube is placed leading from the tympanic cavity to the nose (Wright-tube). A T tube may also be used. The procedure was varied slightly on occasion depending on intraoperative findings. RESULTS: Thirteen patients (15 ears) were available for audiometry at a minimum of 5 months after surgery until 14 years (mean duration of 6.2 years). We compared preoperative and postoperative air-bone gaps. They were measured for the three speech frequencies (500, 1000, and 2000 Hz) at 5 dB intervals. The average preoperative air-bone gap was 25.7 dB versus 18.2 dB postoperatively. This represents an improvement of 7.5 dB. Seven of fifteen ears required revision. Six ears required one revision procedure each (three for cholesteatoma, one for myringitis, one for discharge due to a narrow external auditory meatus, and one for mastoiditis). Another patient required three revision procedures (one for mastoiditis and the other two for cholesteatoma). CONCLUSION: This concept can help prevent cholesteatoma and improve hearing in more than 50 per cent of severe cases of dysfunction of the Eustachian tube.

Adolescent↗

[Reliable fixation of cochlear implant electrode mountings in children and adults--initial experiences with a new titanium clip].

BACKGROUND: There is a reported 1% incidence of delayed migration of extrusions of the electrode arrays out of the cochlea. METHODS: A titanium clip to fix the electrode array of the MED EL Combi 40 Cochlear Implant System is described. The clip is designed and shaped in a double U configuration. The clip material allows easy adaption to the individual anatomical situation. The clip is fixed to a bony bridge at the incus bar and fixes the electrode in a plane parallel to the chorda facial angle. It is closed around the electrode similarly to a stapes piston around the incus. Additional tests which examined the possible risk of damaging the electrode carrier and clinical findings are described. RESULTS: The clip was used in 23 cases with a follow-up period up to 1 year. No signs for dislocation of the electrode were found. In one revision case the clip was covered with a thin mucosal layer. The electrode array showed no signs of damage. Intraoperative findings confirmed the experimental tests on the electrode fixation. CONCLUSION: The titanium clip facilitates safe and quick fixation of the electrode array and prevents dislocation. its flexibility and shape minimizes the risk of damage.

Adult↗

[Stapes revisions: clinical findings and results].

By correlating the intraoperative findings and the postoperative hearing gain it was attempted to determine the recommendable intraoperative management in stapesrevisions in order to obtain the best postoperative hearing. In a retrospective study the findings of 39 stapes revision operations were analyzed. In most of the cases hearing one year postoperatively was compared with preoperative hearing. The prognosis for good hearing was best following replacement of the prosthesis where the prosthesis was too short or dislocated, or in the presence of a loosened wire. Where treatment only entailed retightening the loosened wire at the long process of the incus, postoperative hearing did not improve. Patients with an obliterative otosclerosis or an additional fixed incus had a less favorable prognosis. Overall a postoperative air bone gap of 10 dB or below was obtained in 44% of the patients and a postoperative air bone gap of 20 dB or below in 77% of the patients. Twenty-one percent of the patients remained unchanged, and in one patient postoperative deterioration of the hearing was detected.

Adult↗

Evaluation of hydroxyapatite ossicular chain prostheses.

Hydroxyapatite (HA) middle ear prostheses have gained popularity as an alternative to human autografts and homografts. This study reports on 3 HA prostheses types: total ossicular chain prostheses, used for grafting the stapes footplate to the tympanic membrane; partial ossicular chain prostheses, used for grafting the stapes superstructure to the tympanic membrane; and Kartush incus struts (Smith & Nephew Richards Inc), used for grafting the stapes superstructure to the undersurface of the malleus. This single-surgeon study of 33 consecutive cases revealed a statistically significant difference in mean postoperative air-bone gap and airbone gap closure between incus struts (14/26 dB) or partial (22/11 dB) or total (25/10 dB) ossicular chain prostheses (t test: P<0.05). Prognostic risk factors graded by the Middle Ear Risk Index indicate a tendency for worse postoperative hearing with increasing Middle Ear Risk Index. This study supports the use of HA ossicular prostheses and, in particular, the use of the malleus for ossicular chain construction.

Adult↗

Brain herniation into the middle ear following temporal bone fracture.

Otorrhea of leaked cerebrospinal fluid and meningitis in a 33-year-old male originated from an encephalic herniation into the middle ear following traumatic temporal bone fracture. CT demonstrated a mixed-type fracture consisting of a longitudinal fracture and a posterior oblique fracture of the left temporal bone. The left tegmen tympani was broken into a bellows-like shape and a bone splinter from it had stuck in the epitympanum at the level of the incus body. Surgery via a middle cranial fossa approach confirmed penetration of the brain tissue between the incus and lateral semicircular canal. The diagnosis and management of this condition are discussed in the context of a literature review.

Adult↗

Analysis of the best site on the stapes footplate for ossicular chain reconstruction.

Experiments were performed in 22 fresh human temporal bones to compare the relative acoustic function of three stapes footplate sites for an incus stapes superstructure replacement prosthesis (I-SRP). The three sites evaluated were the anterior, centre and posterior footplates. A new round window (RW) measurement method was used to make the comparisons. A small glass microsphere was placed in the centre of the RW as a target. A Polytec laser Doppler vibrometer was used to measure round window displacement in response to 50 pure tones between 200 and 10,000 Hz presented at 80 dB SPL at the tympanic membrane (TM). After a baseline measurement of RW displacement in the intact temporal bone, the incus was removed and a cement I-SRP (CIRP) formed between the mid-malleus handle and each of the three test footplate sites, in random order. RW displacement was again measured after placement of the CIRP at each of three sites. We found the centre site to be 3.0-7.0 dB better than the anterior site above 2,000 Hz. There were no differences between the anterior and centre sites below 2,000 Hz. The posterior site was the worst at all frequencies.

Aged↗

A new pathogenesis of mesotympanic (congenital) cholesteatoma.

OBJECTIVES: To introduce a new, acquired pathogenetic theory of mesotympanic cholesteatoma behind an intact eardrum in children and to present some doubts on congenital pathogenesis. STUDY DESIGN: Literature review. METHODS: The incidence and origination of mesotympanic cholesteatoma in children were thoroughly analyzed in the world literature and correlated to the histopathological studies on human middle ear epithelia and to epidemiological studies on secretory otitis, tubal occlusion, and acute suppurative otitis media. RESULTS: The new, acquired theory is based on the fact that that the place of origin of the anterosuperior mesotympanic cholesteatoma is the area of the malleus handle and malleus neck, and of the posterosuperior cholesteatoma, the long process of the incus. During the common pathological conditions there is a great risk of retractions and adhesions of the eardrum to these ossicles. After subsequent loosening of the retracted eardrum some cells of the keratinized squamous epithelium may be left behind and become included into the tympanic cavity, eventually causing an inclusion cholesteatoma. Four basic mechanisms of inclusions are proposed and the presence of great dynamics in middle ear disease in children, with high incidence of tubal dysfunction, retractions, secretory otitis, and acute suppurative otitis, is documented, making the acquired pathogenesis probable. The place of origin does not fit with the congenital pathogenesis of epithelial formation localized on the lateral wall of the eustachian tube close to the annulus. The origination around the malleus and incus fits better with the proposed acquired pathogenesis. CONCLUSIONS: There are no definitive proofs for the acquired pathogenesis of the mesotympanic cholesteatoma, nor is there experimental research to prove or disprove it. Mesotympanic cholesteatoma, congenital cholesteatoma, acquired pathogenesis of mesotympanic cholesteatoma, cholesteatoma in children, cholesteatoma behind intact eardrum.

Child↗

Benign paroxysmal positional vertigo after stapedectomy.

OBJECTIVE: To determine the incidence of benign paroxysmal positional vertigo (BPPV) following stapedectomy in a patient group and the efficacy of the Epley maneuver in this group. STUDY DESIGN: Prospective study in a university-based tertiary referral system. METHODS: The patient group comprised 63 patients who had undergone stapedectomy; a control group consisted of normal healthy individuals with no otolaryngological complaints. All individuals underwent the Dix-Hallpike maneuver for the diagnosis of BPPV. Patients who exhibited vertigo, torsional nystagmus (which reverses its direction on return to sitting position) preceded by a latent period, and the fatigability of these findings were considered to have BPPV. If the test result was positive, they underwent the Epley therapeutic maneuver. RESULTS: Four of the patients who had undergone a stapedectomy showed characteristic findings of BPPV. No individual in the control group had BPPV. All patients responded well to the Epley maneuver. CONCLUSIONS: Stapedectomy may be regarded as an etiological factor in BPPV. Because the fenestra is located in the posterior part of the stapes footplate, the pathophysiology appears to be related to utricular rather than saccular trauma. Correct measurement of the distance between the incus and stapes footplate is essential in stapedectomy. An Internet survey of the relevant literature in English shows a scarcity of publications on the incidence of BPPV following stapedectomy. In the present study, 63 patients who had undergone a stapedectomy were investigated for the presence of BPPV; all had Dix-Hallpike maneuvers performed for the diagnosis. Sixty-three individuals with no otolaryngological complaints made up the control group. Four of the patients who had undergone stapedectomy showed characteristic findings of BPPV, and no individual in the control group had BPPV; the difference between the two groups was statistically significant. All four of the patients diagnosed with BPPV responded well to the Epley maneuver. The pathophysiology appears to be related to utricular trauma. Correct measurement of the distance between the incus and stapes footplate is essential in stapedectomy.

Adult↗