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Hearing Research Oct 2016The tympano-mallear connection (TMC) is the soft-tissue connection between the tympanic membrane (TM) and the manubrium of the malleus. Some studies suggest that its...
BACKGROUND
The tympano-mallear connection (TMC) is the soft-tissue connection between the tympanic membrane (TM) and the manubrium of the malleus. Some studies suggest that its mechanical properties may have a substantial influence on the mechanics and transfer function of the middle ear. However, relatively little is known about the dimensions of the TMC and its variability among individuals.
METHOD
Thirteen samples were collected from human temporal bones, consisting of only the malleus and the TM. They were imaged using μCT without contrast enhancing agent. From the μCT images, the TMC dimensions were measured in both anterior-posterior direction (TMC width) and medial-lateral direction (TMC thickness). Three selected samples were examined using histological microscopy.
RESULTS
Both TMC width and thickness featured a large variability among individuals. The minimal TMC width along the manubrium for different individuals covered a range between 83 and 840 μm. The minimal thickness ranged from 48 to 249 μm and the maximal thickness from 236 to 691 μm. Histological sections showed that the TMC consists of a narrow core of dense regular connective tissue, surrounded by loose connective tissue. In some samples, either of these two components was absent in the TMC at some manubrium locations. The configuration of these components varied among the samples as well.
CONCLUSION
Our data confirm that a large inter-individual variability exists in the properties of the TM-malleus connection in humans in terms of its dimensions, tissue composition and configuration. Average data and their variability margins will be useful input for testing the importance of the TMC in finite element models.
Topics: Algorithms; Ear, Middle; Humans; Malleus; Pressure; Reproducibility of Results; Temporal Bone; Tympanic Membrane; X-Ray Microtomography
PubMed: 26701786
DOI: 10.1016/j.heares.2015.12.002 -
The Laryngoscope Oct 2002To assess the functional performance of remodeled malleus allografts in a malleus-footplate assembly in terms of hearing results and mid long-term stability.
OBJECTIVE
To assess the functional performance of remodeled malleus allografts in a malleus-footplate assembly in terms of hearing results and mid long-term stability.
STUDY DESIGN
A retrospective study of 60 consecutive patients who underwent a malleus allograft ossiculoplasty from 1993 until 2000. In all cases the incus and the stapedial arch were missing as the result of cholesteatoma (49), chronic otitis (5), incus necrosis resulting from stapes prosthesis (5), and congenital ossicular malformations (1). In all cases malleus allografts were remodeled to form a malleus-stapes assembly.
RESULTS
The audiometric results, using such an ossiculoplasty, revealed an overall median gain of 18.3 dB at 2 months, 22.3 dB at 6 months, and 25 dB 1 year postoperatively on Fletcher frequencies. An air-bone gap closure within 20 dB was achieved in 81% of all cases 1 year postoperatively. No cases of extrusion have been seen in our series.
CONCLUSION
Our findings suggest that malleus allografts are capable of generating good and stable functional results as malleus-stapes assembly.
Topics: Adolescent; Adult; Aged; Audiometry; Child; Child, Preschool; Cholesteatoma, Middle Ear; Ear Ossicles; Female; Humans; Male; Malleus; Middle Aged; Ossicular Replacement; Postoperative Complications; Retrospective Studies; Transplantation, Homologous
PubMed: 12368615
DOI: 10.1097/00005537-200210000-00014 -
AJNR. American Journal of Neuroradiology 2014"Boomerang" malleus-incus fusion deformity is identified on axial high-resolution CT in a subset of patients with congenital aural atresia, and it is associated with an...
"Boomerang" malleus-incus fusion deformity is identified on axial high-resolution CT in a subset of patients with congenital aural atresia, and it is associated with an absent incudostapedial joint and stapes capitulum and attachment of the incus to the tympanic segment of the facial nerve canal. Twelve patients with this deformity were identified on a retrospective review of imaging from a cohort of 673 patients with congenital aural atresia, with surgical confirmation in 9 of these patients. Eight of 9 patients underwent partial ossicular replacement prosthesis reconstruction with improvement in hearing outcome. We hypothesize that the boomerang anomaly represents a more severe ossicular anomaly than is normally seen in congenital aural atresia, arising from an arrest earlier in the embryonic development of the first and second branchial arch. This has potentially important implications for surgical planning because hearing outcomes with placement of prosthesis may not be as good as with conventional atresia surgery, in which reconstruction is performed with the patient's native ossicular chain.
Topics: Congenital Abnormalities; Ear; Female; Humans; Incus; Male; Malleus; Prosthesis Implantation; Plastic Surgery Procedures; Retrospective Studies
PubMed: 24994825
DOI: 10.3174/ajnr.A4022 -
Journal of the Association For Research... Aug 2014In previous studies, 3D motion of the middle-ear ossicles in cat and human was explored, but models for hearing research have shifted in the last few decades to smaller...
In previous studies, 3D motion of the middle-ear ossicles in cat and human was explored, but models for hearing research have shifted in the last few decades to smaller mammals, and gerbil, in particular, has become a popular hearing model. In the present study, we have measured with an optical interferometer the 3D motion of the malleus and incus in anesthetized gerbil for sound of moderate intensity (90-dB sound pressure level) over a broad frequency range. To access the ossicles, the pars flaccida was removed exposing the neck and head of the malleus and the incus from the malleus-incus joint to the plate of the lenticular process. Vibration measurements were done at six to eight points per ossicle while the angle of observation was varied over approximately 30 ° to enable calculation of the 3D rigid-body velocity components. These components were expressed in an intrinsic reference frame, with one axis along the anatomical suspension axis of the malleus-incus block and a second axis along the stapes piston direction. Another way of describing the motion that does not assume an a priori rotation axis is to calculate the instantaneous rotation axis (screw axis) of the malleus/incus motion. Only at frequencies below a few kilohertz did the screw axis have a maximum rotation in a direction close to that of the ligament axis. A slight slippage in the malleus-incus joint developed with increasing frequency. Our findings are useful in determining the sound transfer characteristics through the middle ear and serve as a reference for validation of mathematical middle-ear models. Last but not least, comparing our present results in gerbil with those of previously measured species (human and cat) exposes similarities and dissimilarities among them.
Topics: Animals; Cats; Finite Element Analysis; Gerbillinae; Hearing; Humans; Imaging, Three-Dimensional; Incus; Malleus; Models, Animal; Models, Theoretical; Rotation; Vibration
PubMed: 24691793
DOI: 10.1007/s10162-014-0452-1 -
Otology & Neurotology : Official... Feb 2009To describe and compare 2 different surgical techniques used in treatment of malleus fixation syndrome.
OBJECTIVE
To describe and compare 2 different surgical techniques used in treatment of malleus fixation syndrome.
STUDY DESIGN
A retrospective study including 24 patients (25 ears). In 11 of them, the attical fixation was removed via a transmastoid approach without disruption of the ossicular chain. In 14 patients, an ossiculoplasty was performed via a transcanal approach; the malleus head was removed with the incus, and the ossicular chain was reconstructed either by incus interposition (9 cases) or by using a partial ossicular replacement prosthesis (5 cases). The hearing results were analyzed according to the Committee on Hearing and Equilibrium Guidelines of the American Academy of Otolaryngology.
RESULTS
In the group of attical fixation removed via a transmastoid approach, the preoperative air-bone gap (ABG) attained 25.2 dB, and the postoperative ABG at 1 year followup was 9.1 dB. In the group of ossiculoplasty, the average preoperative ABG reached 26.5 dB, and the postoperative ABG at 1-year follow-up was 8.2 dB.
CONCLUSION
There was no statistically significant difference (p = 0.79) between the 2 surgical techniques used to improve hearing in malleus head fixation.
Topics: Adolescent; Adult; Aged; Autoradiography; Bone Conduction; Child; Ear Ossicles; Female; Follow-Up Studies; Hearing Loss, Conductive; Humans; Image Processing, Computer-Assisted; Male; Malleus; Mastoid; Middle Aged; Otologic Surgical Procedures; Otosclerosis; Stapes; Tomography, X-Ray Computed; Treatment Outcome; Tympanic Membrane
PubMed: 19180677
DOI: 10.1097/mao.0b013e318191a66d -
Otology & Neurotology : Official... Sep 2002To evaluate the role of ossiculoplasty techniques using neomalleus struts combined with assembly prostheses, in middle ear reconstruction.
OBJECTIVE
To evaluate the role of ossiculoplasty techniques using neomalleus struts combined with assembly prostheses, in middle ear reconstruction.
STUDY DESIGN
A retrospective case review of 272 consecutive ossiculoplasty cases in which the malleus was replaced with an autograft strut.
BACKGROUND
Current ossiculoplasty methods have experienced tangible difficulties, including extrusion and displacement (columellae), plus inefficiency and instability (assemblies).
SETTING
Private single-surgeon tertiary referral otologic practice.
PATIENTS
Ossiculoplasty candidates in whom the malleus was unsuitable for assembly reconstructions because of disease or malpositioning.
INTERVENTIONS
Ossicular reconstructions using an autograft strut to replace an absent or malpositioned malleus, combined with Spanner assembly prostheses.
MAIN OUTCOMES MEASURES
Pure tone audiology, subdivided into Austin groups, and also progressive pathologic severity groups, using Surgical, Prosthetic, Infection, Tissues, Eustachian (SPITE) indicators.
RESULTS
Two months postoperatively, neomalleus cases returned favorable results in comparison with those of previous techniques, in equivalent situations. The technique appeared to be durable in the longer term.
CONCLUSIONS
Neomalleus techniques offer enhanced success rates when the malleus handle is displaced, diseased, or absent.
Topics: Audiometry, Pure-Tone; Ear Diseases; Humans; Malleus; Ossicular Prosthesis; Retrospective Studies
PubMed: 12218611
DOI: 10.1097/00129492-200209000-00005 -
European Archives of... Dec 2015The aim of the present study was to describe our surgical approach for isolated malleus fixation in patients with tympanosclerosis and to analyze the postoperative...
The aim of the present study was to describe our surgical approach for isolated malleus fixation in patients with tympanosclerosis and to analyze the postoperative results. A total of 30 patients presented with isolated malleus fixation were operated. The fixation was reached via canalplasty. Fixated areas were cleaned without damaging the ossicle. Pre- and postoperative audiometric results were evaluated for each patient. Improvement of the pure-tone average (PTA) by at least 10 dB and an air-bone gap (ABG) of less than 20 dB after 12 months of follow-up was accepted to indicate success. The recovery of the postoperative PTA and ABG measurements was significant. Pre- and postoperative PTA was 48.00 ± 11.86 and 24.90 ± 12.45 dB, respectively (p < 0.001). According to PTA measurements, 40-50 dB recovery was achieved in four (13.3 %) patients, 31-40 dB in six (20 %) patients, 21-30 dB in ten (33.3 %) patients, and 11-20 dB in five (16.6 %) patients, with a total success rate of 25/30 (83.2 %). Pre- and postoperative ABG levels were 38.95 ± 9.92 and 16.10 ± 7.79 dB (p < 0.001), respectively. The ABG level was between 0 and 10 dB for 8 (26.6 %) patients, and 11-20 dB for 16 (53.3 %), with a total success rate of 24/30 (80 %). In cases of isolated malleus fixation with tympanosclerosis, performing a canalplasty to clean the sclerotic plaques without damaging the normal anatomy of the ossicle system using a diamond burr is a safe surgical option that provides significant recovery in hearing levels.
Topics: Adult; Audiometry, Pure-Tone; Female; Follow-Up Studies; Histological Techniques; Humans; Male; Malleus; Middle Aged; Myringosclerosis; Otologic Surgical Procedures; Postoperative Period; Retrospective Studies; Treatment Outcome
PubMed: 25503358
DOI: 10.1007/s00405-014-3445-0 -
The Laryngoscope Jan 2005Preoperative clinical diagnosis of malleus fixation can be difficult. "Fixation" of the malleus can be caused by various disorders or diseases: fibrous tissue, bony...
OBJECTIVES/HYPOTHESIS
Preoperative clinical diagnosis of malleus fixation can be difficult. "Fixation" of the malleus can be caused by various disorders or diseases: fibrous tissue, bony spurs, and neo-osteogenesis around the malleus head or stiffening of the anterior malleal ligament. The conductive hearing loss produced by these disorders or diseases has not been well characterized. The study goals were 1) to determine the effects of various types of malleus fixation using a cadaveric temporal bone preparation and 2) to assess the clinical utility of umbo velocity measurements in preoperative differential diagnosis of malleus fixation and stapes fixation.
METHODS
Umbo and stapes velocity were measured in 18 fresh cadaveric human temporal bones with laser vibrometry before and after controlled application of adhesives to the malleus, stapes, or both ossicles.
RESULTS
Each simulated pathological condition produced a specific degree of loss in stapes velocity: stiffening of anterior malleal ligament, 0 to 8 dB; fibrous tissue around malleus head, less than 10 dB; bony bar to malleus head, 10 to 30 dB; and extensive neo-osteogenesis around malleus head, greater than 35 dB. Simulated malleus fixations generally produced similar reductions in both umbo and stapes velocity. Stapes fixation reduced stapes velocity with little change in umbo velocity. Because the change in stapes velocity would be similar to conductive hearing loss, experimental results were directly compared with clinical measurements of umbo velocity in surgically confirmed cases of malleus or stapes fixation. The effects of malleus and stapes fixations between the clinical and experimental data were similar.
CONCLUSION
The study showed that measurements of umbo velocity and air-bone gap can enable one to diagnose malleus fixation and specifies how to differentiate malleus from stapes fixation.
Topics: Aged; Aged, 80 and over; Bone Conduction; Fibrosis; Hearing Loss, Conductive; Humans; In Vitro Techniques; Ligaments; Malleus; Middle Aged; Movement; Ossification, Heterotopic; Stapes
PubMed: 15630384
DOI: 10.1097/01.mlg.0000150692.23506.b7 -
Acta Oto-laryngologica Mar 2006Isolated fracture of the malleus seems to be an extremely rare ossicular injury. All previously reported cases involved the handle of the malleus. This is the first...
Isolated fracture of the malleus seems to be an extremely rare ossicular injury. All previously reported cases involved the handle of the malleus. This is the first reported case of fracture of the neck of the malleus. The diagnosis can easily be missed because the tympanic membrane remains intact. Furthermore, the history may not be suggestive. Surgical repair is particularly difficult.
Topics: Audiometry; Female; Follow-Up Studies; Fracture Fixation; Fracture Healing; Fractures, Bone; Hearing Loss, Conductive; Humans; Malleus; Middle Aged; Otoscopy; Rare Diseases; Recovery of Function; Risk Assessment; Treatment Outcome
PubMed: 16618663
DOI: 10.1080/00016480410022895 -
Journal of Morphology Jan 2018The anterior anchoring of the malleus of 30 extant species of Lagomorpha (rabbits, hares, pikas) has been studied on the basis of histological serial sections and...
The anterior anchoring of the malleus of 30 extant species of Lagomorpha (rabbits, hares, pikas) has been studied on the basis of histological serial sections and µCT-scans. It is shown that former studies of Oryctolagus, Lepus, and Ochotona are incomplete, because the rostral part of the processus anterior of the malleus is always lacking due to damage of this extremely delicate structure. Our study shows that in perinatal stages of Leporidae the praearticulare develops a prominent processus internus that fits into a groove at the ventral side of the tegmen tympani; this "tongue and groove"-arrangement may act as a hinge. In adult stages, the rostral end of the praearticulare fuses synostotically with the medial process of the ectotympanic. Torsional strain produced by rotation around the axis of the middle ear ossicles at sound transmission must, therefore, be experienced by the extremely thin but highly elastic bony pedicle of the processus internus praearticularis. The free ending processus anterior of a late fetal Ochotona shows a short processus internus praearticularis, which does not articulate with the tegmen tympani. During postnatal development the middle ear of Ochotona becomes considerably remodelled: not only does excessive pneumatization of the tegmen tympani and tympanic cavity wall occur, but the short processus anterior is fused synostotically to a bone trabecula of the tegmen tympani meshwork. The thin and elastic bone bridges are not equivalent in Leporidae and Ochotonidae, that is, they must have evolved convergently. Fleischer's classification with Oryctolagus possessing a "freely mobile type" of middle ear ossicles cannot be supported by our observations. The same holds true for Ochotona, which does not represent a "freely mobile type" either. Thus, we suggest for the lagomorph middle ear ossicles a new category: the "bone elasticity type."
Topics: Animals; Bone and Bones; Ear, Middle; Extinction, Biological; Fetus; Imaging, Three-Dimensional; Lagomorpha; Malleus; Rabbits; Skull; X-Ray Microtomography
PubMed: 29068074
DOI: 10.1002/jmor.20759