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Scientific Reports Jun 2024Sound transmission to the human inner ear by bone conduction pathway with an implant attached to the otic capsule is a specific case where the cochlear response depends...
Sound transmission to the human inner ear by bone conduction pathway with an implant attached to the otic capsule is a specific case where the cochlear response depends on the direction of the stimulating force. A finite element model of the temporal bone with the inner ear, no middle and outer ear structures, and an immobilized stapes footplate was used to assess the directional sensitivity of the cochlea. A concentrated mass represented the bone conduction implant. The harmonic analysis included seventeen frequencies within the hearing range and a full range of excitation directions. Two assessment criteria included: (1) bone vibrations of the round window edge in the direction perpendicular to its surface and (2) the fluid volume displacement of the round window membrane. The direction of maximum bone vibration at the round window edge was perpendicular to the round window. The maximum fluid volume displacement direction was nearly perpendicular to the modiolus axis, almost tangent to the stapes footplate, and inclined slightly to the round window. The direction perpendicular to the stapes footplate resulted in small cochlear responses for both criteria. A key factor responsible for directional sensitivity was the small distance of the excitation point from the cochlea.
Topics: Humans; Temporal Bone; Bone Conduction; Finite Element Analysis; Cochlea; Vibration; Round Window, Ear; Stapes; Models, Biological; Acoustic Stimulation
PubMed: 38877090
DOI: 10.1038/s41598-024-64377-x -
Forensic Sciences Research Jun 2024The auricular cartilage, which is typically soft and flexible, can calcify or ossify because of diseases such as diabetes mellitus, trauma, radiation therapy for cancer,...
The auricular cartilage, which is typically soft and flexible, can calcify or ossify because of diseases such as diabetes mellitus, trauma, radiation therapy for cancer, and more commonly from frostbite. Calcified, ossified, or hardened auricular cartilage is a rare finding in the clinical literature and appears to be absent in the physical and forensic anthropological literature. This study examines the ossified auricular cartilage and tests whether the hypothesis can be identified in postmortem skeletonized tissue and be part of the external auditory meatus. A total of 290 crania were examined for accessory ossicles. A descriptive and interpretative analysis was performed grossly, histologically, and morphometrically to document the morphology and location of the ossicles, investigate their structure, and perform hypothesis testing. Results revealed that seven females and one male crania from a total of 290 crania (2.76%) exhibit semi-ossified auricular cartilage attached to the tympanic plate of the temporal bone. The morphology and location of the ossicles at the junction of the auricle and external auditory meatus indicate they are hardened auricular cartilage that was verified with histological observations. Regression analysis indicates that addition of the ossicle to the depth of the auditory tube significantly changes coefficient of determination () with respect to cranial breadth. In conclusion, results indicate that small cartilaginous structures of the external ear may ossify forming accessory tympanic plate ossicles that potentially could be identified in skeletal remains as a new osteological entity. This report highlights the types of information that can be gained using an approach that integrates forensic anthropology, gross anatomy, and histology.
PubMed: 38774863
DOI: 10.1093/fsr/owae003 -
Cureus Apr 2024When pharmacological treatments are inadequate, facial nerve paralysis from various etiologies, including Bell's palsy, Hunt syndrome, and trauma, often requires...
When pharmacological treatments are inadequate, facial nerve paralysis from various etiologies, including Bell's palsy, Hunt syndrome, and trauma, often requires surgical intervention. Facial nerve decompression surgery aims to relieve nerve compression and restore function, with preserving hearing function, especially in pediatric cases, being crucial. Conventional methods, like the transmastoid approach, risk affecting auditory function due to ossicle manipulation. Herein, we describe the case of a 12-year-old boy with left facial palsy diagnosed with zoster sine herpete (ZSH) syndrome. Despite medical treatment, the patient's condition did not improve, prompting facial nerve decompression surgery. Employing the intact transmastoid ossicle (ITO) swaying technique, we minimized ossicular manipulation, preserving auditory function while effectively achieving facial nerve decompression. The patient demonstrated improvement postoperatively in auditory and facial nerve functions. Furthermore, audiometric assessments demonstrated no substantial deterioration in hearing thresholds, and the facial nerve function improved from Grade V to Grade II on the House-Brackmann scale. The ITO technique provides a less invasive alternative compared to conventional approaches, lowering the chance of the ossicular chain and the risk of postoperative hearing loss. This case highlights the significance of customized surgical approaches in pediatric facial nerve decompression surgery, resulting in improved patient outcomes. Further research is required to validate the efficacy and safety of this method across various clinical contexts.
PubMed: 38752103
DOI: 10.7759/cureus.58269 -
BMC Surgery May 2024Transcanal endoscopic ear surgery (TEES) reportedly requires a long learning curve and may be associated with more complications and longer operative times than...
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.
Topics: Humans; Ear Ossicles; Male; Female; Retrospective Studies; Adult; Adolescent; Endoscopy; Child; Middle Aged; Young Adult; Treatment Outcome; Operative Time; Otologic Surgical Procedures
PubMed: 38745291
DOI: 10.1186/s12893-024-02445-9 -
BMC Medical Imaging May 2024Precision and intelligence in evaluating the complexities of middle ear structures are required to diagnose auriculotemporal and ossicle-related diseases within...
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.
Topics: Humans; Tomography, Spiral Computed; Ear Ossicles; Deep Learning; Ear Diseases; Temporal Bone; Adult; Neural Networks, Computer
PubMed: 38724896
DOI: 10.1186/s12880-024-01277-6 -
BMC Medical Education Apr 2024In otosurgical training, cadaveric temporal bones are primarily used to provide a realistic tactile experience. However, using cadaveric temporal bones is challenging...
BACKGROUND
In otosurgical training, cadaveric temporal bones are primarily used to provide a realistic tactile experience. However, using cadaveric temporal bones is challenging due to their limited availability, high cost, and potential for infection. Utilizing current three-dimensional (3D) technologies could overcome the limitations associated with cadaveric bones. This study focused on how a 3D-printed middle ear model can be used in otosurgical training.
METHODS
A cadaveric temporal bone was imaged using microcomputed tomography (micro-CT) to generate a 3D model of the middle ear. The final model was printed from transparent photopolymers using a laser-based 3D printer (vat photopolymerization), yielding a 3D-printed phantom of the external ear canal and middle ear. The feasibility of this phantom for otosurgical training was evaluated through an ossiculoplasty simulation involving ten otosurgeons and ten otolaryngology-head and neck surgery (ORL-HNS) residents. The participants were tasked with drilling, scooping, and placing a 3D-printed partial ossicular replacement prosthesis (PORP). Following the simulation, a questionnaire was used to collect the participants' opinions and feedback.
RESULTS
A transparent photopolymer was deemed suitable for both the middle ear phantom and PORP. The printing procedure was precise, and the anatomical landmarks were recognizable. Based on the evaluations, the phantom had realistic maneuverability, although the haptic feedback during drilling and scooping received some criticism from ORL-HNS residents. Both otosurgeons and ORL-HNS residents were optimistic about the application of these 3D-printed models as training tools.
CONCLUSIONS
The 3D-printed middle ear phantom and PORP used in this study can be used for low-threshold training in the future. The integration of 3D-printed models in conventional otosurgical training holds significant promise.
Topics: Printing, Three-Dimensional; Humans; Models, Anatomic; Cadaver; Ear, Middle; Temporal Bone; Ossicular Prosthesis; Otolaryngology; X-Ray Microtomography; Simulation Training; Otologic Surgical Procedures; Internship and Residency
PubMed: 38658934
DOI: 10.1186/s12909-024-05436-9 -
PloS One 2024Elephants have a unique auditory system that is larger than any other terrestrial mammal. To quantify the impact of larger middle ear (ME) structures, we measured 3D...
Elephants have a unique auditory system that is larger than any other terrestrial mammal. To quantify the impact of larger middle ear (ME) structures, we measured 3D ossicular motion and ME sound transmission in cadaveric temporal bones from both African and Asian elephants in response to air-conducted (AC) tonal pressure stimuli presented in the ear canal (PEC). Results were compared to similar measurements in humans. Velocities of the umbo (VU) and stapes (VST) were measured using a 3D laser Doppler vibrometer in the 7-13,000 Hz frequency range, stapes velocity serving as a measure of energy entering the cochlea-a proxy for hearing sensitivity. Below the elephant ME resonance frequency of about 300 Hz, the magnitude of VU/PEC was an order of magnitude greater than in human, and the magnitude of VST/PEC was 5x greater. Phase of VST/PEC above ME resonance indicated that the group delay in elephant was approximately double that of human, which may be related to the unexpectedly high magnitudes at high frequencies. A boost in sound transmission across the incus long process and stapes near 9 kHz was also observed. We discuss factors that contribute to differences in sound transmission between these two large mammals.
Topics: Animals; Humans; Elephants; Ear, Middle; Sound; Stapes; Hearing; Vibration
PubMed: 38598472
DOI: 10.1371/journal.pone.0298535 -
Cureus Feb 2024A clinical condition known as chronic otitis media (COM) is characterized by tympanic membrane perforation, varying degrees of hearing loss, and otorrhea that lasts...
BACKGROUND
A clinical condition known as chronic otitis media (COM) is characterized by tympanic membrane perforation, varying degrees of hearing loss, and otorrhea that lasts for two to six weeks. COM alone or with cholesteatoma may result in ossicular chain discontinuity and ossicular erosion. The hearing restoration procedure includes repairing the eardrum and building the ossicular chain in ears with damaged ossicles. Multiple studies suggest the predictive value of preoperative air-bone gap (ABG) to detect the ossicular chain status can help with proper preoperative planning for surgery.
OBJECTIVE
To determine the degree of hearing improvement and reduction in ABG after tympanoplasty and to investigate the correlation between preoperative ABG and the status of the ossicular chain during surgery. Study design, setting, and date: This retrospective hospital file-based study was conducted at Aseer Central Hospital, Southern Region, Saudi Arabia, between November 2022 and April 2023. Hospital records of patients who underwent tympanoplasty during 2018-2023 were reviewed. Eighty-five patients were diagnosed with chronic suppurative otitis media (CSOM) between 2018 and 2023. A data collection sheet was employed to record extracted data, including the patient's age, sex, hearing assessment, type of surgical intervention, and outcome. We calculated the average of ABG decibels (dB) by summing the ABG values at 500 Hz, 1000 Hz, and 2000 Hz frequencies and dividing by three.
RESULTS
In the present study, data from 85 patients who underwent tympanoplasty were analyzed. Approximately one-third of the patients were in the age group of 31 to 40 years (25, 29.4%), and 50 (58.8%) of them were females. Chronic medical conditions were observed in 30 (35.3%) patients, with diabetes being reported in 19 (63.3%) of those cases. CSOM was found to be present in the left ear of 47 (56.0%) patients. Among the patients, 25 (29.4%) had subtotal perforations, 12 (14.1%) had marginal perforations, and two (2.4%) had total tympanic membrane perforations. The majority of patients (67, 78.8%) exhibited conductive hearing loss, while the remaining 18 (21.2%) had mixed hearing loss. Of the patients, 13 (15.3%) and 20 (23.5%) had fixed and disrupted ossicular chains, respectively. In terms of ossicular disruption, incudostapedial joint (ISJ) fixing (21.2%), fixed stapes (18.2%), and ISJ dislocation (18.2%) were the most prevalent kinds. Prior to operations, the mean ± SD of ABG was 22.6 ± 7.5. ABG values were 19.0 ± 9.3 on average after surgery. The statistical difference between pre- and postoperative ABG was statistically significant (paired t-test, p = 0.007), with a mean difference of -3.7. There were no significant differences between the different statuses of ossicular chains and the type of tympanic membrane perforation.
CONCLUSION
This study suggests that the degree of preoperative ABG (dB) is a valuable predictor of intraoperative ossicular chain status and can aid in preoperative planning for ossicular chain reconstruction. Furthermore, the study found that the type of tympanic membrane perforation preoperatively is not a reliable indicator of the ossicular chain status. Finally, tympanoplasty is considered a beneficial surgical procedure with a significant improvement in hearing status postoperatively.
PubMed: 38558666
DOI: 10.7759/cureus.55159 -
Fish and Fisheries (Oxford, England) Jul 2023Ernst Weber stated in 1819, based on dissections, that the swimbladder in the European wels (, Siluridae) and related cyprinids serves as an eardrum and that the...
Ernst Weber stated in 1819, based on dissections, that the swimbladder in the European wels (, Siluridae) and related cyprinids serves as an eardrum and that the ossicles connecting it to the inner ear function as hearing ossicles similar to mammals. In the early 20th century, K. von Frisch showed experimentally that catfishes and cyprinids (otophysines) indeed hear excellently compared to fish taxa lacking auxiliary hearing structures (ossicles, eardrums). Knowledge on hearing in catfishes progressed in particular in the 21st century. Currently, hearing abilities (audiograms) are known in 28 species out of 13 families. Recent ontogenetic and comparative studies revealed that the ability to detect sounds of low-level and high frequencies (4-6 kHz) depends on the development of Weberian ossicles. Species with a higher number of ossicles and larger bladders hear better at higher frequencies (>1 kHz). Hearing sensitivities are furthermore affected by ecological factors. Rising temperatures increase, whereas various noise regimes decrease hearing. Exposure to high-noise levels (>150 dB) for hours result in temporary thresholds shifts (TTS) and recovery of hearing after several days. Low-noise levels reduce hearing abilities due to masking without a TTS. Furthermore, auditory evoked potential (AEP) experiments reveal that the temporal patterns of fish-produced pulsed stridulation and drumming sounds are represented in their auditory pathways, indicating that catfishes are able to extract important information for acoustic communication. Further research should concentrate on inner ears to determine whether the diversity in swimbladders and ossicles is paralleled in the inner ear fine structure.
PubMed: 38505404
DOI: 10.1111/faf.12751 -
American Journal of Otolaryngology 2024Isolated malleus fractures are a rare occurrence with few reported cases in the literature. Symptoms include sudden otalgia, hearing loss, tinnitus and aural fullness....
Isolated malleus fractures are a rare occurrence with few reported cases in the literature. Symptoms include sudden otalgia, hearing loss, tinnitus and aural fullness. Work-up and diagnosis are based on a combination of thorough anamnesis and careful otoscopic evaluation or high-resolution computer tomography. We present two cases of isolated malleus handle fractures who were diagnosed based on a combination of pneumatic otoscopy and tympanometry. Both fractures were surgically repaired using hydroxyapatite bone cement as showcased in the supplemental video material. Post-operative audiometry showed improvement in the pure-tone-average of both patients as well as normalisation of tympanometry. Isolated malleus fracture should be suspected in cases of sudden hearing loss and tinnitus following digital manipulation of the outer ear canal together with a conductive hearing loss with a mostly high-frequent air-bone-gap and hypercompliant tympanometry with hypermobility of the tympanic membrane on pneumatic insufflation. Surgical repair of the fracture using bone cement has good hearing outcomes and leads to improvement in auditory symptoms.
Topics: Humans; Bone Cements; Malleus; Male; Fractures, Bone; Female; Adult; Hearing Loss, Conductive; Otoscopy; Acoustic Impedance Tests; Tomography, X-Ray Computed; Middle Aged; Audiometry, Pure-Tone; Hydroxyapatites
PubMed: 38492552
DOI: 10.1016/j.amjoto.2024.104256