Paediatric percutaneous bone anchored hearing aid implant failures: Comparing the experience of a tertiary centre with a systematic review of the literature and meta-analysis.

BACKGROUND: Despite the proven audiological benefits of Percutaneous Bone Anchored Hearing Aids (BAHAs) in paediatric patients with conductive or mixed hearing loss, their adoption has been limited due to concerns over implant failure and associated complications. This paper conducts a systematic review and meta-analysis to assess the prevalence of implant failure in paediatric populations, combined with a case series from our tertiary referral centre. METHODS: A comprehensive literature search identified 562 articles, from which 34 were included in the review, covering 1599 implants in 1285 patients. Our retrospective case series included consecutive patients from our tertiary referral centre who underwent percutaneous BAHA implantation from 2003-2019. RESULTS: Meta-analysis revealed an overall implant failure rate of 11%, predominantly attributed to traumatic extrusion. Our retrospective case series comprised 104 implantations in 76 patients, with a 4.8% failure rate. DISCUSSION: Factors contributing to the lower-than-expected failure rates in the case series likely included consistent use of 4 mm fixtures from a single manufacturer and older age at implantation. The study underscores the need for standardised reporting formats in bone conduction implants research, given the systematic review's limitations in study design heterogeneity, especially with the expected rise in the adoption of novel active devices.

Symmetrical placement of bilateral percutaneous bone-anchored hearing systems via guide-marker.

Objectives: To investigate the use of a novel technique to estimate the symmetrical placement of percutaneous bone-anchored hearing systems (BAHS) with a guide-marker in patients undergoing bilateral surgery with this device. Study Design: Prospective cohort study. Methods: A guide-marker and anatomical landmarks were used to estimate the implant placement and transferred to the contralateral ear in 12 subjects eligible for bilateral BAHS surgery. To investigate the bilateral symmetry, preoperative tri-dimensional (3D) computed tomography (CT) image reconstruction was used to compare the distances between the mandibular condyle and implant placement estimation (mandible-implant distance) in both the right and left ears of the subjects. Results: The guide-marker could be used to estimate the bilateral implant placement in all subjects included in this study, simply and easily, including one subject with craniofacial malformation. The mean mandible-implant distances were 5.37 and 5.38 cm, in the right and left ears of the subjects, respectively, and no differences were observed between them, thereby indicating optimal bilateral symmetry. Conclusion: The use of the guide-marker proved to be an effective tool to provide symmetrical placement of bilateral BAHS. We propose a novel method employing a simple guide-marker and tracing based on symmetrical anatomical landmarks to achieve precise placement and optimal symmetry and which may be easily adopted in the surgical routine of BAHS. Level of Evidence: 3.

Bone-anchored hearing aids: Percutaneous versus transcutaneous attachments - a health economics comparison in paediatric patients.

INTRODUCTION: Bone anchored hearing aids (BAHA) are a useful support when conventional hearing aids are not suitable. The two types of attachment of the aid are onto a percutaneous abutment or a transcutaneous magnet. Anecdotally, the abutment requires more care, revision procedures and causes more infections than magnet-based devices. METHODS: A multicentre, retrospective review was conducted of all patients that underwent a BAHA since our programme began, identified through a prospectively maintained database of patients. Patients' charts were audited for outpatient clinic visits, skin complications and revision surgeries. Developmental delay was also recorded. Patients were censored if the hearing aid was removed, replaced or the patient reached 16 years old. Bilateral or reimplanted patients were recorded as separate implants. Statistical analysis was performed using SAS version 9.4. RESULTS: 150 implants were assessed over 126 patients: 115 transcutaneous and 35 percutaneous. Percutaneous patients had significantly more outpatient clinic attendances (Least square mean 4.19 vs. 1.39 p = 0.00), skin complications (mean 4.82 v 0.11 p = 0.00) and theatre visits (mean 2.8 vs. 1.03 p = 0.00) compared to transcutaneous patients. 77 implants were in patients that had developmental delay; having same made no significant difference to above outcomes. CONCLUSION: There is a significant difference in healthcare burden between percutaneous and transcutaneous systems in a paediatric population. The increased cost of the percutaneous implant to the healthcare system and inconvenience to the patient is cause to consider a transcutaneous system in the first instance.

Implantable Hearing Devices in Ontario: A Population-Based Study of Access to Care and Access to Devices.

INTRODUCTION: The prevalence of hearing loss in Canada is high, with many patients requiring implantable hearing devices (IHDs) as treatment for their disease severity. Despite this need, many eligible patients do not pursue these interventions. The objective of this study was to examine rates of IHD based on geographic location to understand locoregional variation in access to care. STUDY DESIGN: This was a retrospective population-based cohort study. SETTING: All hospitals in the Canadian province of Ontario. METHODS: Of all patients with IHD between April 1, 1992, and March 31, 2021, cochlear implants (CIs) (4,720) and bone-anchored hearing aids (BAHA) (1,125) cohorts were constructed. Place of residence was categorized based on Local Health Integrated Network (LHIN). Summary statistics for place of surgical institution based on LHIN at first surgery, name of institution of first surgery and "as the crow flies" distance (in km) between place of residence and surgical institution were calculated. Rate of implantations was calculated for LHIN regions based on number of surgeries per 1,000,000 persons/years. RESULTS: Toronto Central, Central, Central East, and Champlain regions had >10% of patients undergoing BAHA and CI. 1,019 (90.6%) and 4,232 (89.7%) of patients receiving BAHA and CI, respectively, resided in urban/suburban regions and 94 patients (8.4%) and 436 (9.2%) resided in rural regions. The median distance between residential location and the institution was 46.4 km (interquartile range [IQR], 18.9-103.6) and 44.7 km (IQR, 15.7-96.9) for BAHA and CI, respectively. From 1992 to 2021, the number of CI and BAHA performed across Ontario increased by 17 folds and 6 folds, respectively. CONCLUSION: This large comprehensive population study provides longitudinal insight into the access to care of IHD based on geographic factors. Our findings of the present population-based study indicate an overall increase in access to devices with disproportionate access to care based on geographic locations. Further work is needed to characterize barriers to IHD access to align with demands.

Clinical performance, audiological outcomes, and quality of life of the Cochlear Osia ® system.

OBJECTIVE: The Cochlear Osseointegrated Steady-State Implant Bone Anchored Hearing Device (Osia) is a surgically implanted titanium apparatus that utilizes a piezoelectric actuator under the skin to address conductive and mixed hearing loss as well as single-sided deafness. The purpose of this study is to examine the clinical, audiologic, and quality-of-life outcomes in patients who underwent Osia implantation. METHODS: This is a retrospective study analyzing 30 adult patients (age 27-86) with conductive healing loss (CHL), mixed hearing loss (MHL), or single-sided deafness (SSD) who were implanted with the Osia device from January 2020 to April 2023 at a single institution by the senior author. Preoperative speech score testing (CNC, AzBio in quiet, AzBio in noise) were performed in all subjects while unaided, wearing conventional air conduction hearing aids, and wearing a softband BAHA. These preoperative speech scores were then compared to post-implantation speech scores using paired t-test analysis to assess for degree of speech improvement. In order to analyze quality of life after Osia implantation, each patient filled out the Glasgow Benefit Inventory (GBI) survey. The GBI is a series of 18 questions answered using a five-point Likert scale that addresses the changes in general health status, physical health status, psychosocial health status, and social support after a medical intervention. RESULTS: CHL, MHL, and SSD patients had significant improvement in hearing and speech recognition scores after Osia implantation compared to preoperative unaided hearing: CNC (14 % vs 80 %, p < 0.0001), AzBio in Quiet (26 % vs 94 %, p < 0.0001), and AzBio in Noise (36 % vs 87 %, p = 0.0001). Preoperative speech scores using the softband BAHA were accurate predictors of post-implantation speech scores and can serve to determine surgical candidacy for the Osia. Post-implantation Glasgow Benefit Inventory patient surveys demonstrated significant improvement in quality of life with patients scoring an average increase of +54.1 points in heath satisfaction. CONCLUSION: Adult patients with CHL, MHL, and SSD can receive significant improvement in speech recognition scores after implantation with the Osia device. This translates to improved quality of life, which was confirmed on the post-implantation Glasgow Benefit Inventory patient surveys.

Extraction of a Foreign Body From the Middle Ear Following a Complicated Hearing Aid Fitting: A Case Report.

Ear molding is a safe way to evaluate the ear for hearing aid fitting. A very rare complication of ear molding is the entry of a foreign body into the middle ear. We report the case of a three-year-old boy who had a perforated left tympanic membrane and bilateral sensorineural hearing loss that required the use of hearing aids. During the ear molding procedure, the molding material was unintentionally introduced into his middle ear cavity, necessitating immediate surgery to remove it. Such patients with tympanic membrane perforation must be handled cautiously while an aural impression is taken via ear molding to prevent introducing a foreign body into the middle ear.

Effect of freezing and embalming of human cadaveric whole head specimens on bone conduction.

BACKGROUND AND AIMS: Conserved specimens do not decay and therefore permit long-term experiments thereby overcoming limited access to fresh (frozen) temporal bones for studies on middle ear mechanics. We used a Thiel conservation method which is mainly based on a watery solution of salts. In contrast to pure Formalin, Thiel conservation aims to preserve the mechanical proprieties of human tissue. The aim of this study is to examine the effect of Thiel conservation on bone conduction in the same specimen before and after conservation. METHODS: Nine ears of five defrosted whole heads were stimulated with a direct, electrically driven, bone anchored hearing system (Baha, Baha SuperPower). The motion produced by bone conduction stimulation was measured with a single point laser Doppler vibrometer (LDV) at the promontory, the ossicular chain, and the round window through a posterior tympanotomy. After the initial experiments, the entire whole heads were placed in Thiel solution. In order to enable direct comparison between fresh frozen and Thiel specimens, our Thiel conservation did not include intravascular and intrathecal perfusion. The measurements were repeated 3 and 12 months later. To determine the effect of freezing, defrosting, and embalming on the whole heads, CT scans were performed at different stages of the experimental procedure. Additionally, three extracted temporal bones were stimulated a Baha, motion of the promontory measured by LDV and embalmed in Thiel solution to investigate the direct impact of Thiel solution on the bone. RESULTS: The averaged magnitude of motion on the promontory increased in whole head specimens by a mean of 10.3 dB after 3 months of Thiel embalming and stayed stable after 12 months. A similar effect was observed for motion at the tympanic membrane (+7.2 dB), the stapes (+9.5 dB), and the round window (+4.0 dB). In contrast to the whole head specimens, the motion of the extracted temporal bones did not change after 3 months of Thiel embalming (-0.04 dB in average). CT scans of the whole heads after conservation showed a notable brain volume loss mostly >50% as well as a remarkable change in the consistency and structure of the brain. Partial changes could already be observed before the Thiel embalming but after 1-2 days of defrosting. In an additional experiment, a substitution of brain mass and weight by Thiel fluid did not lead to new deterioration in sound transmission. In contrast, a frozen (non-defrosted) whole head showed a distinctively reduced magnitude of promontory motion before defrosting. DISCUSSION: For our setup, the vibration of the ear due to bone conduction in the same whole head specimens significantly increased after Thiel conservation. Such an increase was not observed in extracted temporal bone specimens. Due to brain changes in the CT scans, we investigated the consequences of the brain volume changes and structure loss on the frozen brain before defrosting. The loss of brain volume alone could not explain the increase of ear vibrations, as we did not observe a difference when the volume was replaced with Thiel fluid. However, freezing and defrosting of the entire brain seems to have a major influence. Beside the destructive effect of freezing on the brain, the modified conservation method without perfusion changed the brain structure. In conclusion, bone conduction in whole heads depends on the physical condition of the brain, rather than on the conservation.

Bridging form and function: A bilateral auricular prosthesis.

Unfortunate loss or absence of an ear has a far-reaching impact on an individual psyche. Auricular defects are seen commonly due to trauma, congenital abnormalities, and malignancies which result in disfigurment of the pinna. Rehabilitation of an auricular defect with a custom-made auricular prosthesis improves social acceptance and self-confidence in an individual. Auricular defects present reconstructive challenges, especially if they are bilateral. Surgical reconstruction provides effective results for defects; however, for some patients, surgical intervention is contraindicated. This case report describes an innovative technique to rehabilitate patients with auricular defects with mixed hearing loss and bilateral microtia using a multidisciplinary approach. The patient was provided with a functional auricular prosthesis. The prime purpose of the treatment rendered was to restore the lost auricular structure to the patient's satisfaction comfortably and cost-effectively. An early rehabilitation promotes physical as well as psychological healing of the patient.

Comparison of passive versus active transcutaneous bone anchored hearing devices in the pediatric population.

OBJECTIVE: Transcutaneous bone anchored hearing devices (BAHDs) were introduced in an effort to avoid potential complications associated with the abutment of percutaneous BAHDs. Transcutaneous BAHDs can be active or passive. While studies have demonstrated good outcomes with both, a direct comparison of audiological and clinical outcomes of these devices in the pediatric population has not yet been studied. STUDY DESIGN: Retrospective, multicenter study. SETTING: Two tertiary academic centers. METHODS: Between 2015 and 2019, all patients who received an active transcutaneous BAHD (Bonebridge, BB) at one center, and patients that received a passive transcutaneous BAHD (Attract, AT) at another center, were included in this study. Exclusion criteria included age > 18 years, and mixed hearing loss or single-sided deafness. Study outcomes included patient demographics, indications, complications and preoperative and one-year postoperative audiometric data. RESULTS: Eighteen BB and eight AT patients met the inclusion criteria. The age range was 5-16 years. There were no significant differences in complication outcomes. Both devices demonstrated similar mean improvements in hearing thresholds at frequencies of 250 Hz (38 dB Active vs. 38 dB Passive), 500 Hz (34 dB vs. 42 dB), 1000 Hz (34 dB vs. 40 dB) and 2000 Hz (31 dB vs. 22 dB). The BB was significantly more effective at frequencies of 4000 Hz (28 dB vs. 7 dB) and 8000 Hz (29 dB vs. 6 dB) (p < 0.05). CONCLUSION: This is the first study comparing audiological outcomes between an active and a passive transcutaneous BAHD in the pediatric population. While both devices improved audiometric outcomes in the low and mid frequencies, the active BAHD demonstrated significantly better outcomes in the higher frequencies.

A Potential Interaction Between Bisphosphonates and Osseointegration of Bone-Anchored Hearing Aid Implants Leading to Late Device Extrusion.

Bisphosphonate therapy is commonly used to treat patients suffering from osteoporosis due to its clinical effectiveness and its generally benign safety profile; however, osteonecrosis of the jaw is a rare side effect that can occur in some patients. A far less elucidated area of concern is the effect of these medications on osseointegrated implants, which require adequate bone formation to ensure long-term viability of the implant. To date, there are no reports in the otolaryngology literature examining the interplay between osteoporosis, bisphosphonate therapy, and osseointegrated bone-anchored hearing aids (BAHA). In this case report, we describe an osteoporotic patient on bisphosphonates experiencing late bilateral failure of her osseointegrated BAHA implants shortly after starting therapy. Certainly, direct causality cannot be determined from this single report, but the temporal relationship described in this case suggests a potential interaction between bisphosphonate use and delayed failure of the osseointegrated hearing devices. Consequently, otolaryngologists who implant osseointegrated hearing devices should consider offering preoperative counseling to patients receiving bisphosphonate therapy.

Análisis de la potencia de salida y del rendimiento auditivo de los dispositivos auditivos osteointegrados / Power output and hearing performance in osseointegrated auditory devices

Antecedentes y objetivos: Los dispositivos auditivos osteointegrados utilizan la transmisión del sonido por vía ósea para producir una mejoría auditiva. Los mecanismos y factores que intervienen en esta transmisión han sido ampliamente estudiados, sin embargo, existen otros aspectos que no conocemos, por ejemplo, la influencia que tiene la potencia de salida del procesador. El objetivo principal de este estudio fue conocer si existe alguna relación entre la potencia que emiten estos dispositivos y la mejoría auditiva que producen. Materiales y métodos: Hemos realizado un estudio en 44 pacientes portadores de un Baha® 5 percutáneo. De cada paciente se obtuvieron los umbrales de vía aérea y ósea en audiometría tonal liminar, en audiometría en campo libre, y en audiometría verbal en silencio y con ruido de fondo, tanto previa como posteriormente a la implantación. También se recogieron los umbrales de conducción ósea directa a través del procesador y los valores de ganancia en la potencia de salida del procesador. (AU)

Background and objective: Osseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve. Materials and methods: Forty-four patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient. The direct bone conduction thresholds and the power output values from the processors were also obtained. (AU)

Clinical and functional results after implantation of the bonebridge, a semi-implantable, active transcutaneous bone conduction device, in children and adults.

PURPOSE: Aim of the study was to evaluate the surgical, clinical and audiological outcome of 32 implantations of the Bonebridge, a semi-implantable transcutaneous active bone conduction implant. METHODS: In a retrospective cohort study, we analyzed data for 32 implantations in 31 patients (one bilateral case; seven age < 16 years) with conductive or mixed hearing loss, malformations, after multiple ear surgery, or with single-sided deafness as contralateral routing of signal (CROS). RESULTS: Four implantations were done as CROS. Five cases were simultaneously planned with ear prosthesis anchors, and 23 implantations (72%) were planned through three-dimensional (3D) "virtual surgery." In all 3D-planned cases, the implant could be placed as expected. For implant-related complications, rates were 12.5% for minor and 3.1% for major complications. Implantation significantly improved mean sound field thresholds from a preoperative 60 dB HL (SD 12) to 33 dB HL (SD 6) at 3 postoperative months and 34 dB HL (SD 6) at > 11 postoperative months (p < 0.0001). Word recognition score in quiet at 65 dB SPL improved from 11% (SD 20) preoperatively to 74% (SD 19) at 3 months and 83% (SD 15) at > 11 months (p < 0.0001). The speech reception threshold in noise improved from - 1.01 dB unaided to - 2.69 dB best-aided (p = 0.0018). CONCLUSION: We found a clinically relevant audiological benefit with Bonebridge. To overcome anatomical challenges, we recommend preoperative 3D planning in small and hypoplastic mastoids, children, ear malformation, and simultaneous implantation of ear prosthesis anchors and after multiple ear surgery.

Effect of transducer placements on thresholds in ears with an abnormal ear canal and severe conductive hearing loss.

OBJECTIVES: Providing hearing compensation to patients with aural atresia is considerably challenging. Hearing aid transducers vibrating the aural cartilage (cartilage conduction; CC) have been devised, and hearing aids utilizing them (CC hearing aids) have quickly become a beneficial option for aural atresia in clinical applications. However, it remains unclear which placement (on the aural cartilage or mastoid) is beneficial to signal transmission. METHODS: This study included 35 patients (53 ears with an abnormal ear canal and severe conductive hearing loss) who were using CC hearing aids. Thresholds were compared between the transducers on the aural cartilage and on the mastoid. RESULTS: In ears with bony aural atresia, thresholds were significantly improved when the transducer was placed on the aural cartilage compared to when it was placed on the mastoid for frequencies ≤ 500 Hz (P < .05). In aural atresia ears with a fibrotic tissue pathway, the aural cartilage stimulation improved the thresholds by approximately 20 dB for frequencies ≤ 1000 Hz (P < .05). In non-atretic ears, the aural cartilage locations significantly worsened the threshold at 4000 Hz (P < .05). CONCLUSION: Our findings demonstrated that placing the transducer at the aural cartilage improved the mid-to-low frequency thresholds compared to mastoid transduction in aural atretic ears. In contrast, no clear improvement to the signal transmission due to the transducer's placement on the aural cartilage was recognized in non-atretic ears. LEVEL OF EVIDENCE: 2.

Clinical evaluation and resonance frequency analysis of laser-ablated titanium bone-anchored hearing implant system in children with Down Syndrome.

OBJECTIVES: To evaluate complication rates and resonance frequency analysis (RFA) of the stability of a new laser-ablated titanium Bone Anchored hearing Implant system in children with Down syndrome. METHODS: A prospective, single-subject, repeat measure, cohort study in which each participant served as their own control. Consecutive paediatric patients 4yrs- 15 years old, with a primary diagnosis of Down syndrome (trisomy 21) were implanted between January 2015-January 2020 with BHX Oticon wide implants. Evaluation of soft tissue reactions, fixture failure rates and post implantation Implant stability Quotient (ISQ) at both fixtures and abutment levels were studied over a 12-month period. Data was analysed for statistical significance through mixed effect modelling with significance set at p = 0.01. RESULTS: 31 consecutive paediatric patients with a diagnosis of Down syndrome were implanted with 43 Ponto BHX Oticon™ implant system. Twelve children had bilateral implants and nineteen were unilateral. Over the 12 month follow up 2 fixtures (4.6%) were lost, and adverse skin reactions (Holgers >2) were recorded in 3.2% of all clinical reviews. Implant level stability quotient showed no statically significant change between first and second stage 71.1-71.7. Abutment level ISQ increased from 46.2 to 56.7 p = 0.0001 at the 12-month review point as compared to that recorded at loading. CONCLUSION: Implant survival and adverse skin reactions were found to be in keeping with those in published literature and much improved compared to previous implant systems placed at this centre. Although abutment level ISQ showed an increase over the review period no correlation between this and implant loss can be concluded.

Cartilage Conduction Hearing and Its Clinical Application.

Cartilage conduction (CC) is a form of conduction that allows a relatively loud sound to be audible when a transducer is placed on the aural cartilage. The CC transmission mechanism has gradually been elucidated, allowing for the development of CC hearing aids (CC-HAs), which are clinically available in Japan. However, CC is still not fully understood. This review summarizes previous CC reports to facilitate its understanding. Concerning the transmission mechanism, the sound pressure level in the ear canal was found to increase when the transducer was attached to the aural cartilage, compared to an unattached condition. Further, inserting an earplug and injecting water into the ear canal shifted the CC threshold, indicating the considerable influence of cartilage-air conduction on the transmission. In CC, the aural cartilage resembles the movable plate of a vibration speaker. This unique transduction mechanism is responsible for the CC characteristics. In terms of clinical applications, CC-HAs are a good option for patients with aural atresia, despite inferior signal transmission compared to bone conduction in bony atretic ears. The advantages of CC, namely comfort, stable fixation, esthetics, and non-invasiveness, facilitate its clinical use.

Power output and hearing performance in osseointegrated auditory devices. / Análisis de la potencia de salida y del rendimiento auditivo de los dispositivos auditivos osteointegrados.

BACKGROUND AND OBJECTIVE: Osseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve. MATERIALS AND METHODS: Forty-four patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient .The direct bone conduction thresholds and the power output values from the processors were also obtained. RESULTS: The pure tone average threshold in free field was 39.29dB (SD 9.15), so that the mean gain was 29.18dB (SD 10.13) with the device. This involved an air-bone gap closure in 63.64% of patients. The pure tone average threshold in direct bone conduction was 27.6dB (SD 10.91), which was 8.4dB better than the pure tone average threshold via bone conduction. The mean gain in speech recognition was 39.15% (SD 23.98) at 40dB and 36.66% (SD 26.76) at 60dB. The mean gain in the signal-to-noise ratio was -5.9dB (SD 4.32). On the other hand, the mean power output values were 27.95dB µN (SD 6.51) in G40 and 26.22dB µN (SD 6.49) in G60. When analysing the relationship between bone conduction thresholds and G40 and G60 values, a correlation from the frequency of 1,000Hz was observed. However, no statistically significant association between power output, functional gain or speech recognition gain was found. CONCLUSIONS: The osseointegrated auditory devices generate hearing improvement in tonal thresholds and speech recognition, even in noise. Most patients closed the air-bone gap with the device. There is a direct relationship between the bone conduction threshold and the power output values from the processor, but only in mid and high frequencies. However, the relationship between power output and gain in speech recognition is weaker. Further investigation of contributing factors is necessary.

Review of Bone Conduction Hearing Devices.

Bone conduction is an efficient pathway of sound transmission which can be harnessed to provide hearing amplification. Bone conduction hearing devices may be indicated when ear canal pathology precludes the use of a conventional hearing aid, as well as in cases of single-sided deafness. Several different technologies exist which transmit sound via bone conduction. Here, we will review the physiology of bone conduction, the indications for bone conduction amplification, and the specifics of currently available devices.

Multimodal Analysis of the Tissue Response to a Bone-Anchored Hearing Implant: Presentation of a Two-Year Case Report of a Patient With Recurrent Pain, Inflammation, and Infection, Including a Systematic Literature Review.

Osseointegration is a well-established concept used in applications including the percutaneous Bone-Anchored Hearing System (BAHS) and auricular rehabilitation. To date, few retrieved implants have been described. A systematic review including cases where percutaneous bone-anchored implants inserted in the temporal bone were retrieved and analyzed was performed. We also present the case of a patient who received a BAHS for mixed hearing loss. After the initial surgery, several episodes of soft tissue inflammation accompanied by pain were observed, leading to elective abutment removal 14 months post-surgery. Two years post-implantation, the implant was removed due to pain and subjected to a multiscale and multimodal analysis: microbial DNA using molecular fingerprinting, gene expression using quantitative real-time polymerase chain reaction (qPCR), X-ray microcomputed tomography (micro-CT), histology, histomorphometry, backscattered scanning electron microscopy (BSE-SEM), Raman spectroscopy, and fluorescence in situ hybridization (FISH). Evidence of osseointegration was provided via micro-CT, histology, BSE-SEM, and Raman spectroscopy. Polymicrobial colonization in the periabutment area and on the implant, including that with Staphylococcus aureus and Staphylococcus epidermidis, was determined using a molecular analysis via a 16S-23S rDNA interspace [IS]-region-based profiling method (IS-Pro). The histology suggested bacterial colonization in the skin and in the peri-implant bone. FISH confirmed the localization of S. aureus and coagulase-negative staphylococci in the skin. Ten articles (54 implants, 47 patients) met the inclusion criteria for the literature search. The analyzed samples were either BAHS (35 implants) or bone-anchored aural epitheses (19 implants) in situ between 2 weeks and 8 years. The main reasons for elective removal were nonuse/changes in treatment, pain, or skin reactions. Most samples were evaluated using histology, demonstrating osseointegration, but with the absence of bone under the implants' proximal flange. Taken together, the literature and this case report show clear evidence of osseointegration, despite prominent complications. Nevertheless, despite implant osseointegration, chronic pain related to the BAHS may be associated with a chronic bacterial infection and raised inflammatory response in the absence of macroscopic signs of infection. It is suggested that a multimodal analysis of peri-implant health provides possibilities for device improvements and to guide diagnostic and therapeutic strategies to alleviate the impact of complications.

Auricular reconstruction using Medpor combined with different hearing rehabilitation approaches for microtia.

BACKGROUND: Congenital microtia-atresia affects patients in two specific ways: severe conductive hearing loss and difficulty in integrating into social environments due to auricle malformation. AIMS/OBJECTIVES: To investigate the safety and efficacy of single-stage auricular reconstruction and hearing rehabilitation in children with microtia and external auditory canal atresia. MATERIAL AND METHODS: From January 2016 to December 2019, we included 32 patients with microtia and external canal atresia who received auricle reconstruction with high-density polyethylene (Medpor) framework and three different hearing rehabilitation approaches at the Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. Twenty patients underwent the traditional external auditory canal and middle ear repair (EACR), eight patients were implanted with Bonebridge (BB) devices, and four patients were implanted with bone-anchored hearing aid (BAHA) in one stage. Postoperative changes in auricle morphology and hearing and speech recognition and occurrence of complications were evaluated. RESULTS: After 6-24 months of follow-up, the auricle shape recovered well in all three groups, and the average score of 14 fine structures in the auricle was 9.43 (EACR), 10.67 (BB), and 9.75 (BAHA) points. The average score of auricle symmetry was 6.83 (EACR), 6.00 (BB), and 6.44 (BAHA) points. No significant differences in auricle shape were observed among the three groups (p > .05). After surgery, the average hearing improvement in the BB group was 43.33 dB, and the average speech recognition threshold declined to 42.28 dB. In the BAHA group, the average hearing improvement was 35 dB, and the average speech recognition threshold declined to 33.5 dB, similar to that of the BB group. However, in the EACR group, the average hearing improvement was only 4.13 dB, and the average speech recognition threshold declined to 11.36 dB. No vertigo, tinnitus, cerebrospinal fluid leakage, facial nerve paralysis, osseointegration failure, and other complications occurred in all the patients. In the EACR group, auricle stent fracture, ear canal restenosis, and canal atresia occurred in one patient each. In the BAHA group, two patients developed local ear infections. CONCLUSIONS AND SIGNIFICANCE: The procedure of single-stage auricular reconstruction and hearing rehabilitation for microtia is feasible and effective. The appropriate method of hearing reconstruction should be determined by evaluating the development of the inner and middle ear of the patients. For those patients with poor development of the mastoid and ossicular chain, hearing aid devices are recommended to achieve a stable and significant hearing effect.