Traumatic dislocation of middle ear ossicles: A new computed tomography classification predicting hearing outcome.

OBJECTIVES: To assess the feasibility of radiologic measurements and find out whether hearing outcome could be predicted based on computer tomography (CT) scan evaluation in patients with temporal bone fractures and suspected ossicular joint dislocation. METHODS: We assessed 4002 temporal bone CT scans and identified 34 patients with reported ossicular joint dislocation due to trauma. We excluded those with no proven traumatic ossicular dislocation in CT scan and patients with bilateral temporal bone fractures. We measured four parameters such as malleus-incus axis distance, malleus-incus angle at midpoints, malleus- incus axis angle and ossicular joint space. The contralateral healthy side served as its own control. Hearing outcome 1-3 months after the index visit was analyzed. We assessed diagnostic accuracy and performed a logistic regression using radiologic measurement parameters for outcome prediction of conductive hearing loss (defined as >20dB air-bone gap). RESULTS: We found excellent inter-rater agreement on the measurement of axis deviation between incus and malleus in CT scans (interclass correlation coefficient 0.81). The larger the deviation of incus and malleus axis, the higher probability of poor hearing outcome (odds ratio (OR) 2.67 per 0.1mm, p = .006). A cut-off value for the axis deviation of 0.25mm showed a sensitivity of 0.778 and a specificity of 0.94 (p < .001) for discrimination between poor and good hearing outcome in terms of conductive hearing loss. CONCLUSION: Adequate assessment of high resolution CT scans of temporal bone in which ossicular chain dislocation had occurred after trauma was feasible. Axis deviations of the incus and the malleus were strongly predictive for poor hearing outcome in terms of air conduction 1-3 months after trauma. We propose a 3-level classification system for hearing outcome prediction based on radiologic measures.

Endoscopic Ossiculoplasty for the Management of Isolated Congenital Ossicular Chain Malformation: Surgical Results in 16 Ears.

OBJECTIVE: The aim of this study is to describe the clinical characteristics and intraoperative findings and further evaluate the efficacy of endoscopic ossiculoplasty for the management of isolated congenital ossicular chain malformation. METHODS: A retrospective study was performed on 16 ears (15 patients) with the isolated congenital ossicular chain malformation who underwent endoscopic ossiculoplasty in our department from May 2017 to January 2019. Endoscopic exploratory tympanotomy was conducted to check the ossicular chain; at the same time, endoscopic ossiculoplasty was performed depending on intraoperative findings. Air-conduction thresholds, bone-conduction thresholds, and air-bone gaps (ABGs) were measured before and after surgery, and the hearing outcome was assessed at 6 months postoperatively. RESULTS: The most common malformations of ossicular chain were the missing of the incus long process and stapes suprastructure. A serial assessment of the hearing status was conducted before and 6 months after surgery. It showed the mean postoperative pure-tone average (PTA) was significantly reduced, and the mean postoperative ABG was obviously closed, respectively (P < .001). The mean PTA gain was 36.3 ± 8.6 dB, and the ABG closure was 35.1 ± 8.3 dB; ABG closure to 20 dB or less and ABG closure to 10 dB or less were achieved in 14 cases (87.5%) and 5 cases (31.3%), respectively. No differences were observed in postoperative hearing outcome between type Ⅲ cases and type Ⅳ cases; however, cases with partial ossicular replacement prosthesis implantation showed a larger hearing gain (P = .049) and a higher proportion of postoperative ABG less than 10 dB (P = .021). No facial palsy and significant sensorineural hearing loss occurred; all patients completed the surgery without the need of canalplasty, and the chorda tympani nerve was preserved in all patients. CONCLUSIONS: This research showed endoscopic surgery was effective in the diagnosis and management of isolated congenital ossicular chain malformation; the endoscopic ossiculoplasty provides an alternative method to manage congenital ossicular chain malformation, with comfortable hearing outcome and the advantage of excellent vision and less invasion.

Wideband absorbance pattern in adults with otosclerosis and ossicular chain discontinuity.

OBJECTIVES: Evidence from previous literature had shown that the use of a single frequency probe tone is not sensitive enough to detect middle ear pathologies, especially related to the ossicles, which hinders accurate diagnosis. The goal of the present study was to compare the outcome of wideband absorbance (WBA) tympanometry and to determine the difference in WBA pattern in adults with otosclerosis and ossicular chain discontinuity. MATERIALS AND METHODS: Estimated adult cases of otosclerosis (10 ears) and ossicular chain discontinuity (06 ears) along with healthy individuals (10 ears) in the age range of 24 to 48 years (mean age: 38.6 years) were considered for the study. WBA was measured at peak and ambient pressure along with resonance frequency and compared with the data obtained from the healthy individuals to determine the WBA pattern. RESULTS: Data analysis revealed a distinct WBA pattern showing high absorbance at 750 Hz for ossicular chain discontinuity compared to healthy individuals, whereas the otosclerosis group showed reduced absorbance (p < 0.05) at low frequencies (250 Hz to 1500 Hz). WBA measured at the peak and ambient pressure did not elicit any significant difference across the frequencies. Also, the average WBA tympanogram measured between 375 Hz and 2000 Hz showed a significant difference in ambient pressure only in the otosclerosis group. In comparison to healthy individuals (901 Hz), ossicular chain discontinuity showed a significant reduction in resonance frequency (674 Hz), whereas in cases with otosclerosis had higher resonance frequency (1445 Hz). CONCLUSIONS AND SIGNIFICANCE: The present study showed different WBA patterns between the groups and the absorbance values were significantly different at the low frequencies. This suggests that WBA has the potential to differentiate ossicles related pathologies from normal and also between the ear with otosclerosis and ossicular chain discontinuity.

A new device for real-time peroperative monitoring of ossicular chain reconstruction during middle ear surgery.

To limit functional surgical failure and reduce the rate of revision surgery in case of surgical ossicular chain reconstruction, a piezoelectric device was developed for assessment of ossicular chain vibrations during the middle ear surgery. The device resembled a pen and consisted of a reusable main body and a disposable sensitive head including piezoelectric polymer sensor. Almost all of components of the device were made of polymer for light weight and for acoustic impedance matching to the middle ear system. Several frequencies can be analyzed simultaneously and several measures can be taken by time. The results showed that the device can record normal and reconstructed ossicular chain vibration in response to an acoustic stimulation, with similar results to those achieved by laser Doppler vibrometer. This light, handheld and low-cost device allows fast, easy and safe assessments of normal ossicular chain mobility and ossicular chain reconstruction efficiency. Primary pre-clinical trial showed very promising performance of the device that could be used to qualitatively control ossiculoplasty during real-time surgical procedure. Clinical assessments will be done to further evaluate the real-life performance of the device.

Ossicular chain defects in adults with chronic otitis media.

BACKGROUND AND OBJECTIVE: Chronic otitis media (COM) is a common condition characterized by the perforation of the tympanic membrane and inflammation of the mucosal lining the hollow space in the middle ear and airy spaces of the temporal bone for at least 2-6 week. This study was carried out to find out the status of the middle ear ossicles in patients with COM and to correlate their status with clinical parameters. METHODS: This retrospective clinical study was conducted on 107 COM patients (52 males and 55 females; age range: 18 to 75 years) submitted to surgery in the Otology Clinic at Imam Khomeini Hospital, Ahvaz Jundishapur University of Medical Sciences, Iran. Initially, a comprehensive case-history was obtained from patients and their hearing thresholds were recorded. Then, ossicles status and their junction condition were evaluated intraoperatively. RESULTS: The malleus was found intact in 70 (65.42%), absent in 10 (9.34), and eroded in 27 (25.24%) patients. Our results revealed that the incus was intact in 33 (30.84%), eroded in 55 (51.41%) and absent in 19 (17.75%) subjects. Stapes was found intact in 54 (50.46%) cases and eroded in 53 (49.54%) cases. The mean Pure Tone Average (PTA) and Air-Bone Gap (ABG) comparisons in "intact" and "discontinuous" ossicular chain groups was not significant (Independent sample t-test, p>0.05). CONCLUSION: Our results demonstrated that incus was the most susceptible middle ear ossicle to erosion in COM, whereas the malleus was the most resistant ossicle. Furthermore, ABG and PTA values cannot be considered as a potential preoperative predictor for ossicular chain status.

Manubrio-incudo-stapedioplasty for reconstruction of Austin-Kartush type B ossicular defects.

OBJECTIVE: Manubrio-incudo-stapedioplasty functional outcomes were compared to those of other methods for reconstructing Austin-Kartush type B ossicular defects. METHODS: Forty-two patients underwent Austin-Kartush type B ossicular defect reconstruction using: manubrio-incudo-stapedioplasty (13 patients), an autologous incus (19 patients) or a titanium ossicular replacement prosthesis (10 patients). For manubrio-incudo-stapedioplasty reconstruction, the malleus head was removed, the manubrium was relocated posteriorly and the incus short process was placed on the mobile footplate. The manubrium was placed on the incus body groove and bone cement was applied to stabilise the manubrium-incus junction. Pre- and post-operative hearing thresholds were assessed. RESULTS: The air-bone gap decreased from 25.9 ± 6.0 dB to 12.3 ± 5.0 dB (p < 0.05) in the manubrio-incudo-stapedioplasty group. The hearing gain was 13.6 ± 5.2 dB for manubrio-incudo-stapedioplasty, 3.4 ± 14.2 dB with the autologous incus, and 3.3 ± 11.07 dB with the titanium ossicular replacement prosthesis. Hearing improvement was greater for manubrio-incudo-stapedioplasty compared to the other reconstruction methods (p < 0.05). CONCLUSION: Manubrio-incudo-stapedioplasty resulted in satisfactory hearing outcomes in patients with Austin-Kartush type B ossicular defects. This technique can be considered a stable, inexpensive and effective method to reconstruct Austin-Kartush type B ossicular defects.

Bone conduction hearing in the Guinea pig and the effect of artificially induced middle ear lesions.

Although human bone conduction (BC) hearing is well investigated, there is a lack of information about BC hearing in most other species. In humans, the amount of conductive loss is estimated as the difference between the air conduction (AC) and BC thresholds. Similar estimations for animals are difficult since in most species, the normal BC hearing thresholds have not been established. In the current study, the normal BC thresholds in the frequency range between 2 kHz and 20 kHz are investigated for the Guinea pig. Also, the effect of a middle ear lesion, here modelled by severing the ossicles (ossicular discontinuity) and gluing the ossicles to the bone (otosclerosis), is investigated for both AC and BC. The hearing thresholds in the Guinea pigs were estimated by a regression of the amplitude of the compound action potential (CAP) with stimulation level and was found robust and gave a high resolution of the threshold level. The reference for the BC thresholds was the cochlear promontory bone velocity. This reference enables comparison of BC hearing in animals, both intra and inter species, which is independent on the vibrator and stimulation position. The vibration was measured in three orthogonal directions where the dominating vibration directions was in line with the stimulation direction, here the ventral direction. The BC thresholds lay between -10 and 3 dB re 1 µm/s. The slopes of CAP growth function were similar for AC and BC at low and high frequencies, but slightly lower for BC than AC at frequencies between 8 and 16 kHz. This was attributed to differences in the stimulus levels used for the slope estimation and not a real difference in CAP slopes between the stimulation modalities. Two kinds of middle ear lesions, ossicular discontinuity and stapes glued to the surrounding bone, gave threshold shifts of between 23 and 53 dB for AC while it was below 16 dB when the stimulation was by BC. Statistically different threshold shifts between the two types of lesions were found where the AC threshold shifts for a glued stapes at 2 and 4 kHz were 9-18 dB greater than for a severed ossicular chain, and the BC threshold shifts for a glued stapes at 4 and 12 kHz were 8-9 dB greater than for a severed ossicular chain.

Model-based hearing diagnostics based on wideband tympanometry measurements utilizing fuzzy arithmetic.

Today's audiometric methods for the diagnosis of middle ear disease are often based on a comparison of measurements with standard curves, that represent the statistical range of normal hearing responses. Because of large inter-individual variances in the middle ear, especially in wideband tympanometry (WBT), specificity and quantitative evaluation are greatly restricted. A new model-based approach could transform today's predominantly qualitative hearing diagnostics into a quantitative and tailored, patient-specific diagnosis, by evaluating WBT measurements with the aid of a middle-ear model. For this particular investigation, a finite element model of a human ear was used. It consisted of an acoustic ear canal and a tympanic cavity model, a middle-ear with detailed nonlinear models of the tympanic membrane and annular ligament, and a simplified inner-ear model. This model has made it possible for us to simulate pathologies like the stiffening of ligaments or joints, because we can simply change the corresponding mechanical parameters of the model. On the other hand, it is also possible to identify pathologies from measurements, by analyzing the parameters obtained by a system identification procedure. This reduces the number of required model parameters through sensitivity studies and parameter clustering. Uncertainties due to the lack of knowledge, subjectivity in numerical implementation and model simplification are taken into account by the application of fuzzy arithmetic. The most confident parameter set can be determined by applying an inverse fuzzy method on the measurement data. The principle and the benefits of this model-based approach are illustrated by the example of a two-mass oscillator, and also by the simulation of the energy absorbance of an ear with malleus fixation, where the parameter changes that are introduced can be determined quantitatively through the system identification.

Development of intra-operative assessment system for ossicular mobility and middle ear transfer function.

Objective measurements of the ossicular mobility have not been commonly performed during the surgery, and the assessment of ossicular mobility is made by palpation in most cases. Palpation is inherently subjective and may not always be reliable, especially in milder degrees of ossicular fixation and in the case of multiple fixation. Although several devices have been developed to quantitatively measure the ossicular mobility during surgery, they have not been widely used. In this study, a new system with a hand-held probe which enables intraoperative quantitative measurements of ossicular mobility has been developed. This system not only measures the ossicular mobility, but also investigates "local" transmission characteristics of the middle ear by directly applying vibration to the ossicles and measuring cochlear microphonic. The basic performance of this system was confirmed by measuring the mobility of artificial ossicles and cochlear microphonics in an animal experiment. Our system may contribute to selection of a better surgical method and reducing the risks of revision surgery.

Differentiating among conductive hearing loss conditions with wideband tympanometry.

OBJECTIVE: This study was aimed to investigate whether wideband tympanometry (WBT) can distinguish among various kinds of conductive hearing loss and provide additional information. METHODS: We recruited normal subjects and patients with conductive hearing loss due to the following reasons: tympanic membrane perforation only, ossicular chain problem only, and one or other of those conditions combined with mastoid problems. Wideband absorbance at ambient pressure, peak pressure, resonance frequency, and averaged tympanogram data were measured by WBT and compared between the normal, tympanic membrane perforation only, ossicular chain problem only, and combined with mastoid problems groups. RESULTS: The normal subjects showed an average peak pressure of -19.51daPa and an average resonance frequency of 965.94Hz. Tympanic membrane perforation only patients showed a very low peak pressure (-124.93daPa) and resonance frequency (73.12Hz). When patients have ossicular chain problems, they showed slightly low peak pressures (43.08daPa) without changes in the resonance frequency (1024.8Hz). Mastoid problem subjects showed slightly decreased resonance frequencies (787.71Hz). Tympanic membrane perforation subjects showed decreased absorbance at low frequencies and ossicular chain problem subjects showed decreases at high frequencies. When comparing the perforation only and ossicular chain subjects by absorbance at 707Hz, the area under the ROC curve was 0.719 (P<0.022). Mastoid problems subjects showed decreased absorbance at all frequencies. CONCLUSION: WBT can help to distinguish tympanic membrane perforation only and ossicular chain problem patients. WBT may provide additional information on "combined with mastoid problems" patients.

High-frequency conductive hearing loss as a diagnostic test for incomplete ossicular discontinuity in non-cholesteatomatous chronic suppurative otitis media.

Chronic suppurative otitis media, with or without cholesteatoma, may lead to erosion of the ossicles and discontinuity of the ossicular chain. In incomplete ossicular discontinuity (IOD), partial erosion of the ossicles occurs, but some sound transmission is noted throughout the ossicular chain. High-frequency conductive hearing loss (HfCHL) has been considered a hallmark of incomplete ossicular discontinuity. This study aims to evaluate the use of HfCHL as a preoperative predictor of IOD in patients with non-cholesteatomatous chronic suppurative otitis media. The HfCHL test was defined as the preoperative air-bone gap (ABG) at 4 kHz minus the average of the ABG at 0.25 and 0.5 kHz. The test was applied in 328 patients before surgery and compared to intraoperative findings as the gold standard. At surgery, 201 (61.3%) patients had an intact ossicular chain, 44 (13.4%) had a complete ossicular discontinuity, and 83 (25.3%) exhibited an IOD. The best cutoff level was calculated as 10 dB. The HfCHL test to diagnose IOD had a sensitivity of 83% and a specificity of 92% with a post-test probability of 78% and a likelihood ratio of 10.2. We concluded that the HfCHL test is highly effective in predicting IOD in patients with non-cholesteatomatous chronic suppurative otitis media and that it should be used routinely as a screening test prior to surgery.

Audiometric Outcomes Following Endoscopic Ossicular Chain Reconstruction.

OBJECTIVE: To evaluate the audiometric outcomes following endoscopic ossicular chain reconstruction (OCR). STUDY DESIGN: Retrospective case series. SETTING: Two tertiary referral centers. PATIENTS: Sixty two ears with ossicular discontinuity. INTERVENTION(S): Endoscopic and microscopic OCR in patients with ossicular discontinuity. MAIN OUTCOME MEASURES: Bone and air pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). RESULTS: Sixty two ears were included for analysis. Patients that underwent ossiculoplasty were subdivided based on prosthesis type (total ossicular replacement prosthesis [TORP] and partial ossicular replacement prosthesis [PORP], primary and staged ossiculoplasties, and surgical approach [microscopic and total endoscopic]). Forty two ears required PORP reconstructions, while 20 ears required TORP reconstructions. The microscope was used to reconstruct the ossicular chain in 31 cases, while an exclusive endoscopic approach was used in the remaining 31 patients. Controlling for the prosthesis, there were no significant postoperative differences in bone PTA, air PTA, and ABG between primary and staged ossiculoplasties, or surgical approach. CONCLUSIONS: Controlling for the type of prosthesis, there were no significant differences in hearing outcomes with respect to staged ossicular chain reconstruction or whether the endoscope or microscope was used for visualization. Thus, in this series, endoscopic OCR yields similar audiometric outcomes when compared with microscopic OCR.

Drill-induced Cochlear Injury During Otologic Surgery: Intracochlear Pressure Evidence of Acoustic Trauma.

HYPOTHESIS: Drilling on the incus produces intracochlear pressure changes comparable to pressures created by high-intensity acoustic stimuli. BACKGROUND: New-onset sensorineural hearing loss (SNHL) following mastoid surgery can occur secondary to inadvertent drilling on the ossicular chain. To investigate this, we test the hypothesis that high sound pressure levels are generated when a high-speed drill contacts the incus. METHODS: Human cadaveric heads underwent mastoidectomy, and fiber-optic sensors were placed in scala tympani and vestibuli to measure intracochlear pressures (PIC). Stapes velocities (Vstap) were measured using single-axis laser Doppler vibrometry. PIC and Vstap were measured while drilling on the incus. Four-millimeter diamond and cutting burrs were used at drill speeds of 20k, 50k, and 80k Hz. RESULTS: No differences in peak equivalent ear canal noise exposures (134-165 dB SPL) were seen between drill speeds or burr types. Root-mean-square PIC amplitude calculated in third-octave bandwidths around 0.5, 1, 2, 4, and 8 kHz revealed equivalent ear canal (EAC) pressures up to 110 to 112 dB SPL. A statistically significant trend toward increasing noise exposure with decreasing drill speed was seen. No significant differences were noted between burr types. Calculations of equivalent EAC pressure from Vstap were significantly higher at 101 to 116 dB SPL. CONCLUSION: Our results suggest that incidental drilling on the ossicular chain can generate PIC comparable to high-intensity acoustic stimulation. Drill speed, but not burr type, significantly affected the magnitude of PIC. Inadvertent drilling on the ossicular chain produces intense cochlear stimulation that could cause SNHL.

[The prevalence of tympanosclerosis and the effectiveness of its surgical treatment]. / Rasprostranennost' timpanoskleroza i éffektivnost' ego khirurgicheskogo lecheniia.

The objective of the present study was to characterize the epidemiological variants of tympanosclerosis and the effectiveness of the surgical treatment of the patients presenting with this condition. We have undertaken the analysis of the results of 1965 surgical interventions on the patients suffering from different forms of chronic otitis media (COM) performed during the period from 2009 till 2014 with a view to determining the frequency of tympanosclerosis (TSC). In 542 cases, it proved possible to evaluate the intraoperative findings, stages and methods of reconstructive surgery, the anatomical and functional outcomes and effectiveness of the intervention. At present, the signs of tympanosclerosis are identified in 27.6% of the patients presenting with chronic otitis media including 88.7% and 11.3% suffering from the perforating and non-perforating forms of this pathology, respectively. In 74% of the cases its manifestations are diagnosed in the patients having the tubotympanic form of COM. In 53.3% of the patients TSC foci are responsible for the fixation of the ossicular chain whereas in 46.7% of the cases the auditory ossicles retain mobility. As many as 88.6% of the patients underwent the one-step surgical intervention, 10.7% were managed using two-step surgery, and 0.7% of the patients were given the three-stage treatment. Type I tympanoplasty was performed in 62% of the patients, type III tympanoplasty in 30.4%, and various types of stapedoplasty in 4.6% of the cases. The favourable anatomical and functional outcomes at the first stage of the surgical intervention with the use of the autogenous tissues for tympano- and ossiculoplastic surgery were achieved in 87.9% of the patients on the average (by means of the closure of the tympanic defect in 92.2% and by re-fixation of the selected elements of the ossicular chain in 17.3%of the cases). The anatomical and functional effectiveness of the second-stage surgical intervention was estimated at 93.1%.

Acoustic effects of the reconstructed lateral epitympanic wall in a temporal bone and clinical study.

OBJECTIVE: Acoustic evaluation of reconstruction of the lateral epitympanic wall with bone or cartilage in a temporal bone study, and evaluation of audiometric data of patients who underwent cholesteatoma surgery with reconstruction of the lateral epitympanic wall with horseshoe-shaped cartilage. STUDY DESIGN: Temporal bone study and retrospective chart review. METHODS: Preparation of temporal bones included reconstruction of the epitympanic wall with fixated and loose cartilage and bone. The volume velocities of the stapes footplate were measured from the inner-ear side of the footplate by laser scanning doppler vibrometry following sound stimulation in the outer ear canal. Additionally, the audiometric data of 13 consecutive patients who underwent epitympanic cholesteatoma surgery, with an intact ossicular chain and reconstruction of the scutum with a horseshoe-shaped cartilage in contact with the malleus' neck, were evaluated retrospectively. RESULTS: The experimental results showed similar volume velocities at the stapes footplate for the fixated and unfixated cartilage as well as for the unfixated bone. However, the fixated bone yielded significantly reduced volume velocities. Clinical data confirmed that the cartilaginous horseshoe- technique allowed for a stable reconstruction of the scutum with satisfying audiometric outcome. CONCLUSION: In case of cholesteatoma surgery and the need for the reconstruction of the scutum, no adverse effects on hearing outcome are to be expected by using the malleus' neck as an anchoring point for cartilaginous scutum reconstruction. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:1427-1434, 2017.

Medidas de imitância acústica de banda larga em indivíduos com otosclerose / Wideband acoustic immittance measurements in subjects with otosclerosis

Na prática clínica, nota-se uma dificuldade em identificar a rigidez do sistema tímpano-ossicular decorrente da Otosclerose por meio dos métodos de avaliação rotineiramente empregados. Assim, as medidas de imitância acústica de banda larga podem fornecer mais informações sobre a condição do sistema tímpano-ossicular por avaliarem uma ampla faixa de frequência. O objetivo do estudo foi caracterizar as medidas de imitância acústica de banda larga com os estímulos tom puro e chirp em indivíduos com diagnóstico de Otosclerose submetidos à estapedectomia ou estapedotomia. Foram avaliados 40 indivíduos na faixa etária de 33 a 80 anos, totalizando 54 orelhas operadas e 22 orelhas não operadas. A avaliação audiológica foi realizada por meio da otoscopia, audiometria tonal liminar, logoaudiometria e imitanciometria. As medidas de imitância acústica de banda larga foram obtidas por meio do sistema de medidas Middle-Ear Power Analyzer MEPA3, versão 5.0 (Mimosa Acoustics), utilizando os estímulos tom puro e chirp. Os dados obtidos foram submetidos à análise estatística descritiva e inferencial, com nível de significância de 0,05. As orelhas com Otosclerose apresentaram maior absorvância em 750 Hz, uma tênue diminuição até 3000 Hz, acentuando-se a partir desta frequência. A magnitude da admitância foi maior na faixa de frequência de 1992 a 4008 Hz, assim como a magnitude da impedância foi maior nas frequências baixas com diminuição até 4008 Hz e aumento em 6000 Hz. Estas orelhas foram dominadas pela rigidez nos sons graves e médios, por resistência entre 3000 e 4008 Hz e a partir desta frequência pela massa. A fase da impedância foi maior em 258 Hz e o delay da reflectância (slope) apresentou uma variação de comportamento entre as frequências, não sendo possível caracterizar um padrão de resposta. Conclui-se que há diferenças nas medidas obtidas nas orelhas com Otosclerose submetidas à cirurgia, quando analisadas as frequências baixas e médias, o que demonstra o impacto positivo da intervenção cirúrgica na funcionalidade do sistema tímpano-ossicular.(AU)

In clinical practice, there is a difficulty in identifying the rigidity of the tympano-ossicular system resulting from Otosclerosis through the routinely employed evaluation methods. Thus, wideband acoustic immitance measurements can provide more information on the condition of the tympanic-ossicle system by evaluating a wide frequency range. This study aimed at characterizing the wideband acoustic immitance measurements with the pure tone and chirp stimuli in individuals diagnosed with Otosclerosis submitted to stapedectomy or stapedotomy. Forty individuals aged 33 to 80 years were evaluated, totaling 54 operated and 22 non-operated ears. Audiology assessment was performed through otoscopy, pure-tone audiometry, logoaudiometry and imitanciometry. Wideband acoustic immitance measurements were obtained using the Middle-Ear Power Analyzer (MEPA3), version 5.0 (Mimosa Acoustics), by means of pure tone and chirp stimuli. Data were submitted to descriptive and inferential statistical analysis, with a significance level of 0.05. The ears with Otosclerosis presented a greater absorbance in 750 Hz, a slight diminution until 3000 Hz, being accentuated from this frequency. The admittance magnitude was higher in the frequency range from 1992 to 4008 Hz, as well as the impedance magnitude was higher in the low frequencies with a decrease up to 4008 Hz and an increase in 6000 Hz. These ears were dominated by rigidity in the low and medium sounds, by resistance between 3000 and 4008 Hz, and from this frequency, by the mass. The impedance phase was higher at 258 Hz and the reflectance delay (slope) showed a behavioral variation between the frequencies, a response not being characterized. It can be concluded that there are differences in the measurements obtained in Otosclerosis ears submitted to surgery, when the low and medium frequencies were analyzed, which demonstrates the positive impact of the surgical intervention on the tympano-ossicle system.(AU)

Preoperative Predictors in Chronic Suppurative Otitis Media for Ossicular Chain Discontinuity: A Cross-Sectional Study.

OBJECTIVE: Ossicular discontinuity may result from chronic suppurative otitis media and is usually detected intraoperatively. Our objective is to determine whether a preoperative audiogram can preoperatively predict the presence or absence of ossicular discontinuity. METHODS: A cross-sectional study was prospectively run on our patients, aged 12-75 years, ultimately operated on for chronic suppurative otitis media. Preoperative audiograms were analyzed to measure frequency-specific air-bone gap (ABG) cutoff values. Intraoperatively, ossicular chain integrity was carefully checked. Logistic regression analysis was done to obtain a predictive model. RESULTS: A total of 270 patients (306 ears) were included. Frequency-specific ABG cutoff values can predict ossicular discontinuity, namely: high ABGs at 1,000 Hz (>27.5 dB) and 2,000 Hz (>17.5 dB) are the most reliable variables associated with ossicular discontinuity. CONCLUSION: Preoperative audiograms can predict the presence of ossicular discontinuity in chronic suppurative otitis media. Large ABGs at both 1,000 and 2,000 Hz can predict ossicular discontinuity with a great degree of certainty.

A 3D-printed functioning anatomical human middle ear model.

The middle ear is a sophisticated and complex structure with a variety of functions, yet a delicate organ prone to injuries due to various reasons. Both, understanding and reconstructing its functions has always been an important topic for researchers from medical and technical background. Currently, human temporal bones are generally used as model for tests, experiments and validation of the numerical results. However, fresh human preparations are not always easily accessible and their mechanical properties vary with time and between individuals. Therefore we have built an anatomically based and functional middle ear model to serve as a reproducible test environment. Our middle ear model was manufactured with the aid of 3D-printing technology. We have segmented the essential functional elements from micro computed tomography data (µCT) of a single temporal bone. The ossicles were 3D-printed by selective laser melting (SLM) and the soft tissues were casted with silicone rubber into 3D-printed molds. The ear canal, the tympanic cavity and the inner ear were artificially designed, but their design ensured the anatomically correct position of the tympanic membrane, ossicular ligaments and the oval window. For the determination of their auditory properties we have conducted two kinds of tests: measurement of the stapes footplate response to sound and tympanometry of the model. Our experiments regarding the sound transmission showed that the model has a similar behavior to a human middle ear. The transfer function has a resonance frequency at around 1 kHz, the stapes' response is almost constant for frequencies below the resonance and a roll-off is observed above the resonance. The tympanometry results show that the compliance of the middle ear model is similar to the compliance of a healthy human middle ear. We also present that we were able to manipulate the transmission behavior, so that healthy or pathological scenarios can be created. For this purpose we have built models with different mechanical properties by varying the hardness of the silicone rubber used for different structures, such as tympanic membrane, oval window and ossicle attachments in the range of Shore 10-40 A. This allowed us to set the transmission amplitudes in the plateau region higher, lower or within the tolerances of normal middle ears (Rosowski et al., 2007). Our results showed that it is possible to build an artificial model of the human middle ear by using 3D-printing technology in combination with silicone rubber molding. We were able to reproduce the anatomical shape of the middle ear's essential elements with high accuracy and also assemble them into a functioning middle ear model. The acoustic behavior of the model can be reproduced and manipulated by the choice of material. If the issues such as resonance of the casing and steep roll-off slope in higher frequencies can be solved, this model creates a reproducible environment for experiments and can be useful for the evaluation of prosthetic devices.

Is endoscopic ear surgery an alternative to the modified Bondy technique for limited epitympanic cholesteatoma?

The objective of this study is to evaluate the outcomes of the modified Bondy's technique performed at our center and for limited epitympanic cholesteatomas and to debate the purported benefits of endoscopic surgery for the same indication. This is a retrospective study. 269 ears of 258 patients with a minimum of 5-year follow-up that were operated for limited epitympanic cholesteatoma using the modified Bondy's technique were included in the study. All patients had primary acquired cholesteatoma with good preoperative hearing in the affected ear and an intact ossicular chain. The outcomes of were analyzed and the results were compared with a literature review of outcomes of endoscopic ear surgery for the same indication. The mean follow-up was 81.63 months. The mean preoperative air-bone gap was 13.6 ± 7 dB. Intraoperatively, the ossicular chain was preserved in all patients. Postoperatively, there was no significant change from preoperative levels in mean air conduction, mean bone conduction and the air-bone gap. There were no recurrent cholesteatomas in our series. A residual pearl-like cholesteatoma was found lateral to the tympanic membrane in 8.1 % of ears, which was removed in the outpatient clinic. Three patients (1.2 %) developed stenosis of the meatoplasty. Eight (3.1 %) ears exhibited retraction pockets involving the attic. Postoperative ear discharge was observed in 1.5 % cases. The modified Bondy technique, which provides excellent postoperative outcomes, is the surgery of choice for limited epitympanic cholesteatomas. The endoscope, despite its better visualization of hidden areas does not provide a distinct overall technical advantage or better results over the microscope.

Bone conduction hearing in congenital aural atresia.

Previous researches focusing on BC hearing mechanisms proved that the two routes, (1) EAC sound radiation and (2) inertial of ossicular chain, partially contribute to normal BC hearing. Therefore, the BC hearing for those patients with congenital aural atresia should partially decrease theoretically due to their abnormal anatomy. However, there are not many studies which mention these patients' BC hearing up till now. The objective of this study is to investigate congenital aural atresia patient's BC hearing by analysis of pre-surgical audiogram and to study their potential BC hearing mechanisms using animal modeling and their ABR measurements. The study methoed involves analyzing 75 patients' pre-operative audiogram. Then we produced an animal model by surgery to measure their BC hearing threshold changes. Clinical data showed that those patients had some BC hearing loss; and there were 25 cases (25/75, 33.3 %) which present with typical Carhart's Notch. The animal experiments proved that inertia of ossicular chain contribute to partial BC hearing, which demonstrated that the inertia produced more affects on high frequencies by comparing with low frequencies. The patients with congenital aural atresia present BC hearing loss, which could be mainly ascribed to the absence of inertia of ossicular chain.