Classification of ossicular fixation based on a computational simulation of ossicular mobility.

Ossicular fixation disturbs the mobility of the ossicular chain and causes conductive hearing loss. To diagnose the lesion area, otologists typically assess ossicular mobility through intraoperative palpation. Quantification of ossicular mobility and evidence-based diagnostic criteria are necessary for accurate assessment of each pathology, because diagnosis via palpation can rely on the surgeons' experiences and skills. In this study, ossicular mobilities were simulated in 92 pathological cases of ossicular fixation as compliances using a finite-element (FE) model of the human middle ear. The validity of the ossicular mobilities obtained from the FE model was verified by comparison with measurements of ossicular mobilities in cadavers using our newly developed intraoperative ossicular mobility measurement system. The fixation-induced changes in hearing were validated by comparison with changes in the stapedial velocities obtained from the FE model with measurements reported in patients and in temporal bones. The 92 cases were classified into four groups by conducting a cluster analysis based on the simulated ossicular compliances. Most importantly, the cases of combined fixation of the malleus and/or the incus with otosclerosis were classified into two different surgical procedure groups by degree of fixation, i.e., malleo-stapedotomy and stapedotomy. These results suggest that pathological characteristics can be detected using quantitatively measured ossicular compliances followed by cluster analysis, and therefore, an effective diagnosis of ossicular fixation is achievable.

[Analysis of the efficacy of fiber laser stapes fenestration in the treatment of 58 cases of otosclerosis and ossicular malformation].

Objective: To explore the surgical efficacy of conductive deafness caused by otosclerosis and ossicular malformation with 980 nm fiber laser stapedial floor fenestration. Methods: Data of 58 patients (ears) who were diagnosed with conductive deafness caused by otosclerosis (49 ears) and ossicular malformation (9 ears) treated by 980 nm Diode laser small-fenestra stapedotomy were retrospectively analyzed. Air conduction (AC) thresholds, bone conduction (BC) thresholds, and air-bone gap (ABG) at 0.5, 1, 2, 4 kHz pure tone frequencies were compared before and 3 months after surgery, and the advantages and precautions of 980 nm fiber laser were summarized. Paired t-test (SPSS 26.0 software) was use to analyze the listening data. Results: Fiber optic laser stapes fenestration and artificial stapes implantation were successfully completed in all 57 cases (ears), the hearing of another one patient (ear) with floating malformation of detachment of stapedial floor was lower than that before surgery. Preoperative at 0.5, 1, 2, 4 kHz frequencies of AC thresholds, BC thresholds, and ABG were (65.4±9.7) dB, (27.2±8.9) dB, and (38.2±9.8) dB respectively. Postoperative 3 months at the same frequency of AC thresholds, BC thresholds, and ABG were (42.1±11.3) dB, (26.9±6.6) dB, and (15.2±9.1) dB. Preoperative and postoperative of AC threshold and ABG were statistically significant at 0.5, 1, 2, 4 kHz (t value was 13.270 and13.948, both P<0.01), and yet the BC threshold was not statistically significant before and after surgery at the same frequency (t=0.418, P>0.05). Conclusions: 980 nm fiber laser stapes floor fenestration is an effective treatment for conductive deafness caused by otosclerosis and ossicular malformation.

Distinct audiometric patterns in congenital round window atresia: A comparative study with common congenital middle ear anomalies.

OBJECTIVE: Little is known about the hearing characteristics in patients with congenital round window atresia (CRWA). This study aimed to investigate hearing characteristics in patients with CRWA by comparing them with two relatively common congenital middle ear anomalies: congenital stapedial fixation (CSF) and congenital ossicular discontinuity (COD). METHODS: Literature searches yielded five patients with surgically confirmed CRWA (seven ears), who were included in the CRWA group, along with one of our patients. Air and bone conduction thresholds; air-bone gap (ABG); and presence and depth of the Carhart notch were analyzed. These audiometric variables in the CRWA group were compared with those in the CSF (n = 15) and COD (n = 22) groups, comprising patients identified from our institution's medical database. RESULTS: Average bone and air conduction thresholds in the CRWA group were 16.4 (standard deviation [SD]: 2.9; 95 % confidence interval [CI]: 14.6-18.3) and 44.6 (SD: 3.5; 95 % CI: 42.6-47.3) dB hearing level (HL). Bone conduction thresholds at high frequencies (≥2 kHz) were higher than those at low frequencies (<2 kHz), while air conduction thresholds at high frequencies were lower than those at low frequencies: ABGs at high frequencies were significantly smaller than those at low frequencies (2 kHz vs. 0.5 kHz, p = 0.027; 2 kHz vs. 1 kHz, p = 0.041; 4 kHz vs. 0.5 kHz, p = 0.042; 4 kHz vs. 1 kHz, p = 0.027). There were no between-group differences in incidence and depth of the Carhart notch. CONCLUSION: CRWA could manifest as a distinct audiometric pattern with poorer bone conduction and better air conduction at ≥2 kHz, resulting in significantly smaller ABGs at higher frequencies than that at lower frequencies. Our findings indicated that this pattern differed from that of CSF and COD. The unique beer bottle-shaped audiogram associated with CRWA might facilitate its early diagnosis in patients with congenital conductive hearing loss.

Characterizing bone density pattern and porosity in the human ossicular chain using synchrotron microtomography.

The auditory ossicles amplify and transmit sound from the environment to the inner ear. The distribution of bone mineral density is crucial for the proper functioning of sound transmission as the ossicles are suspended in an air-filled chamber. However, little is known about the distribution of bone mineral density along the human ossicular chain and within individual ossicles. To investigate this, we analyzed fresh-frozen human specimens using synchrotron-based phase-contrast microtomography. In addition, we analyzed the volume and porosity of the ossicles. The porosity for the auditory ossicles lies, on average, between 1.92% and 9.85%. The average volume for the mallei is 13.85 ± 2.15 mm3, for the incudes 17.62 ± 4.05 mm3 and 1.24 ± 0.29 mm3 for the stapedes. The bone density distribution showed a similar pattern through all samples. In particular, we found high bone mineralization spots on the anterior crus of the stapes, its footplate, and along areas that are crucial for the transmission of sound. We could also see a correlation between low bone mineral density and holey areas where the bone is only very thin or missing. Our study identified a similar pattern of bone density distribution within all samples: regions exposed to lower forces generally show higher bone density. Further, we observed that the stapes shows high bone mineral density along the anterior crus and its footplate, which may indicate its importance in transmitting sound waves to the inner ear.

Clinical application of high-resolution spiral CT scanning in the diagnosis of auriculotemporal and ossicle.

Precision and intelligence in evaluating the complexities of middle ear structures are required to diagnose auriculotemporal and ossicle-related diseases within otolaryngology. Due to the complexity of the anatomical details and the varied etiologies of illnesses such as trauma, chronic otitis media, and congenital anomalies, traditional diagnostic procedures may not yield accurate diagnoses. This research intends to enhance the diagnosis of diseases of the auriculotemporal region and ossicles by combining High-Resolution Spiral Computed Tomography (HRSCT) scanning with Deep Learning Techniques (DLT). This study employs a deep learning method, Convolutional Neural Network-UNet (CNN-UNet), to extract sub-pixel information from medical photos. This method equips doctors and researchers with cutting-edge resources, leading to groundbreaking discoveries and better patient healthcare. The research effort is the interaction between the CNN-UNet model and high-resolution Computed Tomography (CT) scans, automating activities including ossicle segmentation, fracture detection, and disruption cause classification, accelerating the diagnostic process and increasing clinical decision-making. The suggested HRSCT-DLT model represents the integration of high-resolution spiral CT scans with the CNN-UNet model, which has been fine-tuned to address the nuances of auriculotemporal and ossicular diseases. This novel combination improves diagnostic efficiency and our overall understanding of these intricate diseases. The results of this study highlight the promise of combining high-resolution CT scanning with the CNN-UNet model in otolaryngology, paving the way for more accurate diagnosis and more individualized treatment plans for patients experiencing auriculotemporal and ossicle-related disruptions.

Validity of endoscopic ossiculoplasty immediately after its introduction for ossicular chain disruption.

BACKGROUND: Transcanal endoscopic ear surgery (TEES) reportedly requires a long learning curve and may be associated with more complications and longer operative times than microscopic ear surgery (MES). In this study, we aimed to examine the usefulness and validity of TEES for ossicular chain disruption in the early stages of its introduction in our institution. METHODS: TEES was performed on 11 ears (10 with congenital ossicular chain discontinuity and 1 with traumatic ossicular chain dislocation), and MES was performed with a retroauricular incision on 18 ears (6 with congenital ossicular chain discontinuity and 12 with traumatic ossicular chain dislocation) in a tertiary referral center. Postoperative hearing results, operative times, and postoperative hospital length of stay were retrospectively reviewed. The Mann-Whitney U test and Fisher's exact test was performed to compare variables between the TEES and MES groups. Pre- and postoperative air- and bone-conduction thresholds and the air-bone gap of each group were compared using the Wilcoxon signed-rank test. The Mann-Whitney U test and Wilcoxon signed-rank was performed to compare the pre- and postoperative air-bone gaps between the diagnoses. RESULTS: No significant differences in the postoperative air-conduction thresholds, bone-conduction thresholds, air-bone gaps, or incidence of air-bone gap ≤ 20 dB were observed between the TEES and MES groups. The air-conduction thresholds and air-bone gaps of the TEES group significantly improved postoperatively. The air-conduction thresholds and air-bone gaps of the MES group also significantly improved postoperatively. No significant difference was observed in the operative times between the groups (TEES group: median, 80 min; MES group: median, 85.5 min). The TEES group had a significantly shorter postoperative hospital stay (median, 2 days) than the MES group (median, 7.5 days). CONCLUSIONS: TEES was considered appropriate for the treatment of ossicular chain disruption, even immediately after its introduction at our institution. For expert microscopic ear surgeons, ossicular chain disruption may be considered a suitable indication for the introduction of TEES.

Analysis of the effect of reconstructing the ossicular chain under otoendoscopy with and without a stapes superstructure.

BACKGROUND: Numerous studies have been conducted on the effect of the stapes superstructure after ossicular chain reconstruction, but the findings are not uniform. OBJECTIVE: To compare the hearing outcomes of ossicular chain reconstruction with partial ossicular replacement prosthesis (PORP) or total ossicular replacement prosthesis (TORP) under otoendoscopy. MATERIALS AND METHODS: The records of 111 patients diagnosed with chronic suppurative otitis media were retrospectively analyzed. These patients were divided into PORP group (n = 57) and TORP group (n = 54). They were further subdivided into subgroups PORP-a (with a malleus handle) and PORP-b (without a malleus handle), subgroups TORP-a and TORP-b. Pre- and postoperative audiometric results were analyzed. RESULTS: The mean postoperative air conduction hearing thresholds improvement, mean air-bone gap improvement, and the success rate of reconstruction were significantly higher in the PORP group than in the TORP group (p < .05). The mean postoperative air conduction hearing thresholds improvement and the success rate of reconstruction were significantly higher in the PORP-a group than in the TORP-a group (p < .05); and similar results were concluded in comparison of the PORP-b group and the TORP-b group. CONCLUSIONS AND SIGNIFICANCE: The stapes superstructure has an important positive effect on the postoperative outcome of endoscopic ossicular chain reconstruction.

The human middle ear in motion: 3D visualization and quantification using dynamic synchrotron-based X-ray imaging.

The characterization of the vibrations of the middle ear ossicles during sound transmission is a focal point in clinical research. However, the small size of the structures, their micrometer-scale movement, and the deep-seated position of the middle ear within the temporal bone make these types of measurements extremely challenging. In this work, dynamic synchrotron-based X-ray phase-contrast microtomography is used on acoustically stimulated intact human ears, allowing for the three-dimensional visualization of entire human eardrums and ossicular chains in motion. A post-gating algorithm is used to temporally resolve the fast micromotions at 128 Hz, coupled with a high-throughput pipeline to process the large tomographic datasets. Seven ex-vivo fresh-frozen human temporal bones in healthy conditions are studied, and the rigid body motions of the ossicles are quantitatively delineated. Clinically relevant regions of the ossicular chain are tracked in 3D, and the amplitudes of their displacement are computed for two acoustic stimuli.

Piezoelectric Multi-Channel Bilayer Transducer for Sensing and Filtering Ossicular Vibration.

This paper presents an acoustic transducer for fully implantable cochlear implants (FICIs), which can be implanted on the hearing chain to detect and filter the ambient sound in eight frequency bands between 250 and 6000 Hz. The transducer dimensions are conventional surgery compatible. The structure is formed with 3  × 3 × 0.36 mm active space for each layer and 5.2 mg total active mass excluding packaging. Characterization of the transducer is carried on an artificial membrane whose vibration characteristic is similar to the umbo vibration. On the artificial membrane, piezoelectric transducer generates up to 320.3 mVpp under 100 dB sound pressure level (SPL) excitation and covers the audible acoustic frequency. The measured signal-to-noise-ratio (SNR) of the channels is up to 84.2 dB. Sound quality of the transducer for fully implantable cochlear implant application is graded with an objective qualification method (PESQ) for the first time in the literature to the best of the knowledge, and scored 3.42/4.5.

[Advances in research on treatment of tympanosclerosis].

Tympanosclerosis is the hyaline degeneration and calcium deposition of the lamina propria of tympanic membrane and the submucosa of middle ear under long-term chronic inflammatory stimulation. At present, treatment primarily involves the surgical removal of sclerotic foci and reconstruction of auditory ossicular chain. However, excision of sclerotic lesions near critical structures like the facial nerve canal and vestibular window may result in complications like facial paralysis, vertigo, and sensorineural hearing loss. Developing safer and more effective treatments for tympanosclerosis has become an international research focus. Recent years have seen novel explorations in the treatment of tympanosclerosis. Therefore, this article reviews the latest advancements in research on the treatment of tympanosclerosis.

Middle Ear Ossicular Joint Changes in Type 2 Diabetes Mellitus: A Histopathological Study.

OBJECTIVES: Although previous research has indicated inner ear changes in diabetes mellitus (DM) patients, no prior study has explored the middle ear, particularly the ossicles and their joints, in DM patients. This study aimed to investigate whether type 2 DM is associated with middle ear changes, specifically affecting the ossicular chain and joints. METHODS: This study included 47 ears from 25 patients with DM (male = 13, female = 12, age: 51.0 ± 20.5) and age- and sex-matched controls (male = 10, female = 10, age: 54.8 ± 15.9) (sex; p = 1.000, Age; p = 0.991). Otopathological evaluations of the auditory ossicles and incudomalleolar joint (IMJ) were performed using light microscopy. RESULTS: In the IMJ of DM cases, malleus hyalinized cartilage (Malleus hC) and incus hyalinized cartilage (Incus hC) were significantly increased compared with control cases (Malleus hC; DM, 34.17 ± 9.71 µm vs. control 21.96 ± 4.16 µm, p < 0.001) (Incus hC; DM 35.11 ± 10.12 µm vs. control 22.42 ± 4.368 µm, p < 0.001). In addition, bone-line distance was significantly longer than in DM cases than control cases (DM 266.72 ± 59.11 µm vs. control 239.81 ± 35.56 µm p = 0.040). On the other hand, joint discus distance was longer in the control group than in DM cases (DM 96.84 ± 36.80 µm vs. Control 113.63 ± 23.81 µm, p = 0.001). CONCLUSIONS: This study reveals a notable increase in the hyalinized cartilage layer and bone-line distance accompanied by reducing joint discus distance within the IMJ in DM cases. These findings suggest that DM may influence microjoints, such as the IMJ, and potentially impact auditory function. EVIDENCE LEVEL: N/A Laryngoscope, 134:2871-2878, 2024.

Partial Ossicular Reconstruction With a Novel Ball Joint Prosthesis: The mCLIP ARC Partial Prosthesis.

OBJECTIVE: Middle ear surgery involves reconstruction of the ossicular chain, predominately using rigid implants. New middle ear prostheses strive to mimic the physiologic micromovements of the ossicular chain and prevent dislocation, protrusion, and preloading of the annular ligament due to pressure fluctuations. METHODS: Thirty-five patients were included in a monocentric, prospective observational study. Patients received tympanoplasty with ossicular reconstruction using the mCLIP ARC partial prosthesis. This titanium prosthesis is equipped with a clip mechanism for coupling at the stapes and a ball joint connecting headplate and shaft. At short-term (ST) and mid-term (MT) follow-up, pure-tone audiometry was performed and the pure tone average of 0.5, 1, 2, and 3 kHz (PTA4) was calculated. The audiological outcome was compared with retrospective data of the Dresden titanium clip prosthesis. RESULTS: The new prosthesis shows favorable clinical results. Pure-tone audiometry showed satisfactory results in ST and MT follow-up, with the PTA4 air-bone gap (ABG) decreasing from 24.5 (±11) dB to 17.4 (±7.9) dB at the ST follow-up at 27 days to 15.6 (±10.3) dB at MT follow-up at 196 days (n = 32). A PTA4-ABG value of less than 20 dB was achieved by 63% of patients at ST follow-up and by 77% at MT follow-up. There was no significant difference in PTA4 ABG compared to the Dresden titanium clip prosthesis during ST follow-up (p = 0.18). CONCLUSION: The mCLIP ARC partial prosthesis, a new middle ear prosthesis with a balanced ball joint, shows promising audiological results and is a safe and effective choice for patients with chronic ear disease. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3323-3328, 2024.

Surgical results of 29 ears with congenital middle ear anomalies; Microscopic vs. endoscopic ear surgery.

OBJECTIVE: Although congenital middle ear anomalies include various types of ossicular anomalies, all of these can be treated by ossiculoplasty or stapes surgery. Transcanal endoscopic ear surgery (TEES) is a minimally invasive surgical method for middle ear disease with an excellent surgical view that has been widely adopted worldwide. To determine the efficacy of TEES for middle ear anomalies, we describe the surgical results and compare the hearing outcomes between patients treated by TEES and microscopic ear surgery (MES). METHODS: A total of 39 ears with congenital middle ear anomalies were treated surgically at the University Hospital of Kochi Medical School between January 2011 and December 2021. In total, 29 ears of 23 patients were included in the study. Demographics, type of anomaly, surgical methods, pre- and postoperative hearing thresholds, and surgical complications were investigated by retrospective chart review. RESULTS: Of the 29 ears, 11 were treated by MES and 18 were treated by TEES. There were no differences in sex, age, preoperative hearing thresholds, or rate of stapes surgery between the two groups. The mean air-bone gap improvement was 20.6 dB in the MES group and 28.8 dB in the TEES group; these values were not significantly different. The median operation time was not significantly different between the MES and TEES groups (125 and 130 min, respectively). The improvements of air conduction in class 1 and 2 (stapes surgery) and class 3 (ossiculoplasty) cases were also not different between the groups. CONCLUSIONS: TEES achieved comparable hearing outcomes to MES without postauricular or endaural incisions. Further, class 1 and 2 anomalies demonstrated hearing improvement similar to class 3 without major complications. Since the surgical field limited around the ossicular chain, coupled with the fact that the middle ear anomaly itself does not exhibit inflammation leading to unfavorable bleeding, TEES is a feasible surgical procedure for all types of congenital ossicular anomalies.

Evaluation of the ear ossicles with photon-counting detector CT.

Recently, computed tomography with photon-counting detector (PCD-CT) has been developed to enable high-resolution imaging at a lower radiation dose. PCD-CT employs a photon-counting detector that can measure the number of incident X-ray photons and their energy. The newly released PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Forchheim, Germany) has been in clinical use at our institution since December 2022. The PCD-CT offers several advantages over current state-of-the-art energy-integrating detector CT (EID-CT). The PCD-CT does not require septa to create a detector channel, while EID-CT does. Therefore, downsizing the anode to achieve higher resolution does not affect the dose efficiency of the PCD-CT. CT is an indispensable modality for evaluating ear ossicles. The ear ossicles and joints are clearly depicted by PCD-CT. In particular, the anterior and posterior legs of the stapes, which are sometimes unclear on conventional CT scans, can be clearly visualized. We present cases of congenital anomalies of the ossicular chain, ossicular chain dislocation, tympanosclerosis, and cholesteatoma in which PCD-CT was useful. This short article reports the usefulness of PCD-CT in the 3D visualization of the ear ossicles.

Minimally invasive ossiculoplasty via an endoscopic transtympanic approach.

INTRODUCTION: The aim of this study was to evaluate the feasibility of ossiculoplasty via a minimally invasive endoscopic transtympanic approach (ETTA). CASE SERIES: We investigated the exposure of target structures (incus and stapes) on 4 human temporal bones by placing an endoscope into the middle ear cleft through the 4 tympanic quadrants. Then, on 3 additional specimens, we performed an incudostapedial disjunction and repaired it with a drop of hydroxyapatite cement via ETTA. We measured the size of tympanic perforation, and the acoustic transfer function of the middle ear (125-8000Hz) before and after repair by placing an insert in the external auditory canal and recording the acoustic signal in the utricle by a microphone. The acoustic signal gain was estimated in dB µV. Exposure was similar in all four quadrants but ergonomics was better with a posteroinferior myringotomy. Ossicular chain repair was conducted successfully in all cases and the acoustic transfer function of the middle ear was significantly improved. Residual tympanic perforation (n=3) was 2±0.3mm in diameter. CONCLUSION: ETTA to reconstruct incudostapedial joint with bone cement was feasible and effective. It opens perspectives for robot-based procedures guided by augmented reality.

Endoscopic ossiculoplasty in traumatic conductive hearing loss with intact tympanic membrane: a five-year experience.

BACKGROUND: Exploratory tympanotomy in cases of traumatic ossicular disruption with intact tympanic membrane is crucial for both diagnostic and therapeutic purposes. Performing this procedure using the endoscope is gaining popularity. Hence, this study aimed to demonstrate varieties of ossicular pathology and their management in our institution. METHODS: A retrospective evaluation was conducted of 136 ears in patients with traumatic ossicular disruption with an intact tympanic membrane, who underwent endoscopic exploratory tympanotomy. A proposed algorithm was followed, to incorporate different traumatic ossicular possibilities. Assessment of hearing outcomes and surgical complications was performed six months post-operatively. RESULTS: Incudostapedial dislocation was the most commonly encountered type of traumatic ossicular disruption (35.3 per cent). Air conduction threshold improved significantly following endoscopic ossiculoplasty, from 50.9 ± 6.35 dB pre-operatively to 22.35 ± 3.27 dB post-operatively, with successful air-bone gap closure. CONCLUSION: Endoscopic ear surgery is effective in the diagnosis and management of challenging cases of post-traumatic ossicular disruption with an intact tympanic membrane.

A New Floating Piezoelectric Microphone for Fully Implantable Cochlear Implants in Middle Ear.

OBJECTIVE: Our team designed a long-lasting, well-sealed microphone, which uses laser welding and vacuum packaging technology. This study examined the sensitivity and effectiveness of this new floating piezoelectric microphone (NFPM) designed for totally implantable cochlear implants (TICIs) in animal experiments and intraoperative testing. METHODS: Different NFPM frequency responses from 0.25 to 10 kHz at 90 dB SPL were analyzed using in vivo testing of cats and human patients. The NFPM was tested in different positions that were clamped to the ossicular chains or placed in the tympanic cavity of cats and human patients. Two volunteers' long incus foot and four cats' malleus neck of the ossicular chain were clamped with the NSFM. The output electrical signals from different locations were recorded, analyzed, and compared. The NFPM was removed after the test without causing any damage to the middle-ear structure of the cats. Intraoperative tests of the NFPM were performed during the cochlear implant surgery and the cochlear implant surgery was completed after all tests. RESULTS: Compared with the results in the tympanic cavity, the NFPM could detect the vibration from the ossicular chain more sensitively in cat experiments and intraoperative testing. We also found that the signal output level of the NFPM decreased as the acoustic stimulation strength decreased in the intraoperative testing. CONCLUSION: The NFPM is effective in the intraoperative testing, making it feasible as an implantable middle-ear microphone for TICIs. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:937-944, 2024.

Anatomic and morphometric examination of auditory ossicles in sheep.

It is important to know the morphometry of the auditory ossicles for middle ear surgical applications. The present study aims to investigate the morphometric measurements of sheep auditory ossicles and the relationship between these ossicles. In this study, 100 malleus, incus and stapes of 50 Akkaraman sheep were examined using at trinocular stereo microscope and a total of 19 morphometric measurements were taken. The mean values of the morphometric measurements were obtained, and correlation analysis was performed between each part of each auditory ossicle. Similarities were found between the measurements of the lengths of the malleus, manubrium mallei and incus, and the width of the base of the stapes with morphometric measurements in human auditory ossicles. A significant positive correlation was found between the length of the malleus with the length of the manubrium mallei, between the length of the incus with the lengths of the long crus and corpus incudis, between the length of the stapes with the lengths of the rostral crus, caudal crus, caput stapedis, and the length and width of the intercrural foramen. Due to the anatomic similarities between sheep and human auditory ossicles, it was concluded that the auditory ossicles of sheep are suitable for use in the training of human ear surgery applications.

Advances in research on treatment of tympanosclerosis / 临床耳鼻咽喉头颈外科杂志

Tympanosclerosis is the hyaline degeneration and calcium deposition of the lamina propria of tympanic membrane and the submucosa of middle ear under long-term chronic inflammatory stimulation. At present, treatment primarily involves the surgical removal of sclerotic foci and reconstruction of auditory ossicular chain. However, excision of sclerotic lesions near critical structures like the facial nerve canal and vestibular window may result in complications like facial paralysis, vertigo, and sensorineural hearing loss. Developing safer and more effective treatments for tympanosclerosis has become an international research focus. Recent years have seen novel explorations in the treatment of tympanosclerosis. Therefore, this article reviews the latest advancements in research on the treatment of tympanosclerosis.

Wideband frequency impedance for diagnosis of ossicular chain abnormality.

BACKGROUND: The accurate estimation of the ossicular chain abnormalities using existing functional examinations has been difficult. AIMS/OBJECTIVES: This study aimed to verify the accuracy of preoperative diagnosis of ossicular chain abnormalities using a wideband frequency impedance (WFI) meter, which can measure the dynamic characteristics of the middle ear. MATERIAL AND METHODS: Retrospective cohort study. Fourteen ears of patients with ossicular chain abnormalities that were definitively diagnosed surgically were included in this study. The following data were collected for each participant: sound pressure level (SPL) curve measured using the WFI meter and a sweep frequency impedance (SFI) meter, WFI measurements plotted on the resonance frequency (RF)-ΔSPL plane, distribution map of the dynamic characteristics of the middle ear, preoperative audiometry results, and the definitive surgical diagnosis. RESULTS: The SPL curve obtained using the WFI meter had lesser noise than that obtained using the SFI meter. The distribution map revealed that the ossicular chain separation range and ossicular chain fixation range were completely separated. The hearing data tended to be poor in cases with small ΔSPL. CONCLUSIONS AND SIGNIFICANCE: WFI can potentially enhance the accuracy of SFI. In addition, it can also be used for the classification of ossicular chain separation and fixation as well as the quantification of fixation in cases of ossicular chain anomalies that cannot be diagnosed using conventional tests.