A publicly available newborn ear shape dataset for medical diagnosis of auricular deformities.

Early and accurate diagnosis of ear deformities in newborns is crucial for an effective non-surgical correction treatment, since this commonly seen ear anomalies would affect aesthetics and cause mental problems if untreated. It is not easy even for experienced physicians to diagnose the auricular deformities of newborns and the classification of the sub-types, because of the rich bio-metric features embedded in the ear shape. Machine learning has already been introduced to analyze the auricular shape. However, there is little publicly available datasets of ear images from newborns. We released a dataset that contains quality-controlled photos of 3,852 ears from 1,926 newborns. The dataset also contains medical diagnosis of the ear shape, and the health data of each newborn and its mother. Our aim is to provide a freely accessible dataset, which would facilitate researches related with ear anatomies, such as the AI-aided detection and classification of auricular deformities and medical risk analysis.

Quantitative Framework Fabrication with Autogenous Costal Cartilage in Microtia Reconstruction.

Hearing improvement is another basic requirement for microtia patients in addition to aesthetic needs. This quantitative framework fabrication method can reduce the learning curve, obtain satisfactory aesthetic results with few complications, and reserve a certain space for future canalplasty. Laryngoscope, 134:148-153, 2024.

The Effects of BCDs in Unilateral Conductive Hearing Loss: A Systematic Review.

Bone conduction devices (BCDs) are widely used in the treatment of conductive hearing loss (CHL), but their applications on unilateral CHL (UCHL) patients remain controversial. To evaluate the effects of BCDs in UCHL, a systematic search was undertaken until May 2023 following the PRISMA guidelines. Among the 391 references, 21 studies met the inclusion criteria and were ultimately selected for review. Data on hearing thresholds, speech recognition, sound localization, and subjective questionnaire outcomes were collected and summarized. Moderate hearing threshold improvements were found in UCHL patients aided with BCDs. Their speech recognition abilities improved significantly. However, sound localization results showed wide individual variations. According to subjective questionnaires, BCDs had an overall positive influence on the daily life of UCHL patients, although several unfavorable experiences were reported by some of them. We concluded that the positive audiological benefits and subjective questionnaire results have made BCDs a credible intervention for UCHL patients. Before final implantations, UCHL patients should first go through a period of time when they were fitted with non-implantable BCDs as a trial.

The role of medial olivocochlear activity in contralateral suppression of auditory steady-state responses.

OBJECTIVE: The auditory steady-state response (ASSR) amplitudes fall in the presence of contralateral noise. However, whether and to what extent medial olivocochlear (MOC) activity involves in contralateral suppression of ASSR remain unclear. Therefore, we assess the role of MOC activity in contralateral suppression of ASSR. METHODS: Mice were treated with strychnine to completely eliminate MOC activity and then measured ASSR amplitudes in the presence of contralateral noise. RESULTS: The contralateral noise reduces ASSR amplitudes at some stimulus intensity. After treating with the strychnine to eliminate MOC activity, ASSR amplitudes recovered again. CONCLUSIONS: MOC activity participated in contralateral suppression of ASSR.

The Effect of Fixation Materials on the Long-Term Stability of Cartilage Framework for Microtia Reconstruction.

Objective: To observe the effect of fixation materials on the long-term stability of the cartilage framework in auricular reconstruction. Methods: Consecutive patients who underwent the first stage of auricular reconstruction by the same surgical team from September 2018 to March 2021 were included. Those with braided absorbable suture, polypropylene suture, and titanium wire were defined as Groups A, B, and C, respectively. Six months later, when the patients underwent the second stage of surgery, absorption and deformation of the framework were assessed. Results: A total of 604 patients (622 ears) were included. The most common occurrence was spot absorption in the antihelix and was observed in 34.7%, 17.4%, and 22.8% ears in the A, B, and C groups, respectively (p < 0.05). There were also significant differences regarding severe absorption and severe deformation. The histological examination suggested that those in Group A had more T cells and macrophages around the suture than those in Groups B and C. Conclusion: Absorbable suture seems to correlate with higher risk of cartilage absorption and helix displacement. Titanium wire had the lowest rate of helix pop-out or fracture, which means the best stability.

The Effect of Endolymphatic Hydrops and Mannitol Dehydration Treatment on Guinea Pigs.

Background: Endolymphatic hydrops (EH) is considered as the pathological correlate of Menière's disease (MD) and cause of hearing loss. The mechanism of EH, remaining unrevealed, poses challenges for formalized clinical trials. Objective: This study aims to investigate the development of hearing loss, as well as the effect of dehydration treatment on EH animal models. Methods: In this study, different severity EH animal models were created. The laser Doppler vibrometer (LDV) and auditory brainstem responses (ABR) were used to study the effects of EH and the dehydration effects of mannitol. The LDV was used to measure the vibration of the round window membrane (RWM) reflecting the changes in inner ear impedance. ABR was used to evaluate the hearing changes. Furthermore, tissue section and scanning electron microscopy (SEM) observations were used to analyze the anatomical change to the cochlea and outer hair cells. Results: The RWM vibrations decreased with the severity of EH, indicating an increase in the cochlear impedance. The dehydration therapy lowered the impedance to restore acoustic transduction in EH 10- and 20-day animal models. Simultaneously, the ABR thresholds increased in EH models and were restored after dehydration. Moreover, a difference in the hearing was found between ABR and LDV results in severe EH animal models, and the dehydration therapy was less effective, indicating a sensorineural hearing loss (SNHL). Conclusion: Endolymphatic hydrops causes hearing loss by increasing the cochlear impedance in all tested groups, and mannitol dehydration is an effective therapy to restore hearing. However, SNHL occurs for the EH 30-day animal models, limiting the effectiveness of dehydration. Our results suggest the use of dehydrating agents in the early stage of EH.

Anatomic Measurements of Distances from Lateral Surface of Cranium to Cochlea in Congenital Aural Atresia and Stenosis Patients.

INTRODUCTION: Studies have shown that higher response levels can be obtained when the bone conduction stimulation position is closer to the cochlea. However, the morphological characteristics of round window niche and posterior tympanum in congenital aural atresia (CAA) and stenosis (CAS) patients were different from the normal. These affected the position of the cochlea at the cranial base. It was still unknown whether the distances from the cranium of CAA and CAS patients to the cochlea were the same as those of normal patients or not. OBJECTIVE: To measure distances from various points on the lateral surface of the cranium to the cochlea and the cranium thickness on these points among a CAA group, CAS group and normal control group, which may provide valuable information for the better position of bone conduction stimulation. METHODS: CT images of CAA, CAS patients and these patients' healthy sides were analyzed. Firstly, the Frankfurt horizontal plane (Pfrkt) was established. Secondly, a model of part of the cranium was three-dimensionally reconstructed. Then, the Pfrkt plane was rotated down 20, 30 and 40° according to the superior margin of the external auditory canal. At every angle, points 25, 30, 35 and 40 mm away from the superior margin of the external auditory canal were marked out on the surface of the model and recorded as P20A, P30A, P40A, P20B, etc. The spatial distances between the cranium and ipsilateral cochlea were defined as lengths of points on the surface of the model to the cochlea apex (CA), cochlear base (CB) and modiolus midpoint (MM), respectively, recorded as P20A/CA, P20A/CB, P20A/MM, P30A/CA, etc. Results and Conclusions: In all groups, the length of P20D/CA was the shortest compared to P30D/CA and P40D/CA (p < 0.05). The P20A/CB and P20A/MM were also the shortest (p < 0.05). When the Pfrkt plane was rotated down 30 and 40°, the results were the same as at 20° (p < 0.05). However, P20D, P30D and P40D were almost on the mastoid air cells. We suggest that the bone conduction stimulation position is placed closer to the ear, while avoiding the mastoid air cells in the CAA and CAS patients.

Long-term moderate noise exposure enhances the medial olivocochlear reflex.

OBJECTIVE: To investigate the effects of long-term moderate noise on hearing functions, MOCR, and MEMR. METHODS: Mice were exposed to the moderate noise (11.2 - 22.4 kHz, 80 dB SPL, 6 h/day, 4 weeks). Subsequently, the hearing functions, including threshold and input-output roles of ABR (auditory brainstem response) and cubic (2f1-f2) DPOAEs (distortion product otoacoustic emissions) were evaluated. Also, MEMR and MOCR were assessed shortly after or at four weeks following the termination of exposure to the noise. RESULTS: The mice's acoustic suppression reflex was strengthened, hearing functions and MEMR were unaffected four weeks after the moderate noise. For primary tones of 16, 20 and 24 kHz, the strengths of contralateral and ipsilateral suppression in the noise group were about double those recorded in the control group. In order to further determine whether the functional changes of the afferent or efferent nerves increased the strengths of acoustic suppression, the mouse's left ear was inserted the earplug, and then exposed the moderate noise for four weeks. The strengths of contralateral suppression at 16, 20 and 24 kHz were increased for the noise + earplug than for the control group and were indistinguishable between the noise + earplug and the noise group. While no significant changes were found in the strengths of ipsilateral suppression at all frequencies for the noise + earplug group compared with the control group. Under ketamine/xylazine anesthesia, the broadband suppressor noise did not stimulate the MEMR by 20 min post-induction at all frequencies in three groups. CONCLUSION: Our data demonstrated that the long-term moderate noise-exposure strengthened mice's MOCR by changing its afferent nerves, and unaffected cochlear hair cells and type I spiral ganglion neurons.

Feasibility of direct promontory stimulation by bone conduction: A preliminary study of frequency-response characteristics in cats.

BACKGROUND: As an alternative pathway to air conduction, bone conduction is a multipathway process that transmits sound energy to the inner ear through the skull in general. Based on this mechanism, bone conduction devices (BCDs) have been used widely in the rehabilitation of hearing loss. Although great efforts have been devoted to improving BCDs, drawbacks still exist in most categories of BCDs due to the complicated process of bone conduction. We hypothesized that if a bone conduction transducer was placed on the cochlea to stimulate it directly, the attenuation would be minimized, and the frequency dependency would be different from that of the vibratory response induced by traditional BCDs. This study aimed to explore the feasibility of direct promontory stimulation and to investigate its frequency-response characteristics. METHODS: Measurements were conducted in twelve cat ears. To stimulate the promontory directly, the floating mass transducer (FMT) of the Vibrant Soundbridge© (VSB) implant was glued to the promontory coupled with an oval window (OW) coupler. Auditory brainstem response (ABR) and laser Doppler vibrometry (LDV) measurements were used to evaluate the auditory response induced by the FMT. In both measurements, the FMT was driven by direct voltage stimuli. RESULTS: ABR waves could be induced under direct promontory stimulation by the FMT. In the frequency range of 1-12 kHz, the variation in the voltage threshold level were limited to 16 dB SPL with a maximum of 0.2 V at 1 kHz and a minimum of 0.04 V at 10 kHz. In the LDV measurements and the relative motion of the round window membrane (RWM) and the promontory were used to evaluate the cochlear response. The LDV results indicated a weak frequency dependency from 1 to 12 kHz. CONCLUSION: Different from traditional stimulation via transcranial bone conduction, direct promontory stimulation is a new method in which a small bone conduction transducer stimulates the cochlear shell directly. The current experimental data demonstrate that it is feasible to generate sensations through bone conduction by stimulating the cochlea directly. Furthermore, the cochlear response induced by this type of stimulus in cats was weakly frequency dependent at frequencies ranging from 1 to 12 kHz. This study may provide a basis for the design of new transducers that can perform well over a wide range of frequencies.

Assessment of Cochlea Endolymphatic Hydrops Using 3-D FLAIR and 3-D Real IR Sequence in Guinea Pigs via 3T MRI After Intratympanic Gadolinium: A Histopathological Comparison.

OBJECTIVE: We assessed whether the three-dimensional fluid-attenuated inversion-recovery (3-D FLAIR) and three-dimensional inversion-recovery with real reconstruction (3-D real IR) sequences can be used to detect cochlea endolymphatic hydrops (EHs) in guinea pigs using 3 Tesla magnetic resonance imaging (3T MRI). The results of 3-D real IR imaging were compared with histopathological outcomes. MATERIALS AND METHODS: Fourteen healthy men and women albino guinea pigs were used in this study. Their right ears received procedures that promoted EHs, and their left ears were used as untreated controls. High-resolution 3T MRI, combined with the intratympanic injection of gadolinium (Gd) in both ears, was performed 8 to 12 weeks after surgery. Both sides of the cochlea midmodiolar sections were observed under a light microscope and saved as the histopathological images. The signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) between the T2-weighted 3-D FLAIR and T2-weighted 3-D real IR sequences were compared. The appearance of EHs in the basal, second, third, and apical turns of the cochlea was further evaluated using 3-D FLAIR, 3-D real IR, and the histopathological images. Moreover, the maximum scala media area ratios (SMRs) on the histopathological sections were compared with the grading of the EHs on the 3-D real IR sequence with regard to each turn of the cochlea. RESULTS: Significant differences were found between the 3-D FLAIR and 3-D-real IR sequences with regard to the SNRs and CNRs (p < 0.05): the 3-D FLAIR sequence exhibited higher SNRs (SNRROI: 347.95 ±â€Š105.01; SNRB: 103.28 ±â€Š17.61) compared with the 3-D real IR sequence (SNRROI: 86.71 ±â€Š30.11; SNRB: 11.11 ±â€Š3.45), whereas the 3-D real IR sequence showed higher CNRs (2.78 ±â€Š0.58) compared with the 3-D FLAIR sequence (2.18 ±â€Š0.55). Various degrees of EHs were observed in each turn of the cochlea in the experimental ears on the basis of the histopathological images. Thirteen, 10, 4, and 0 EHs were observed in the basal, second, third, and apical turns of the cochlear using 3-D FLAIR images, respectively, whereas 14, 14, 14, and 13 EHs were found using 3-D real IR images, respectively. Significant differences were found between the two sequences when evaluating the second, third, and apical turns of the cochlear but not with regard to the basal turn (p < 0.05). The SMRs were proportional to the extent of the EHs on 3-D real IR imaging in each turn of the cochlea. CONCLUSIONS: 3-D real IR images are clearer than 3-D FLAIR images, and they can display cochlea EHs more precisely using 3T MRI in guinea pigs. The extent of the EHs on 3-D real IR imaging was more consistent with the histopathological observations in each turn of the cochlea.

Morphometric Study of the Vestibular Aqueduct in Patients With Enlarged Vestibular Aqueduct.

OBJECTIVE: To test whether there are significant differences in the morphologic features of the enlarged vestibular aqueduct (EVA) and its anatomic relationships with adjacent structures between EVA patients with and without other inner ear malformations. METHODS: The morphology of vestibular aqueduct, volume of vestibule, and anatomic location of facial nerve (FN) were compared among 3 groups. Group A, 18 control subjects; group B, 32 EVA patients without other inner ear malformations; group C, 14 EVA patients with other inner ear malformations. RESULTS: The isthmus of the aqueduct and vestibular volume in group C were larger than those in group B (P < 0.05). Positive correlations were identified between the length of the aqueduct and the vestibular volume in groups B and C. The vertical FN segment in group C located more anteriorly than that in groups A and B (P < 0.05). CONCLUSIONS: Compared with EVA patients without other inner ear malformations, the aqueduct, and vestibule in EVA patients with other inner ear malformations are larger, the vertical FN segment locates more anteriorly.

The positional relationship between facial nerve and round window niche in patients with congenital aural atresia and stenosis.

To investigate whether differences existing in the distance between facial nerve (FN) and round window niche opening among congenital aural atresia (CAA), congenital aural stenosis (CAS) and a normal control group and to assess its effect on the round window implantation of vibrant soundbridge, CT images of 10 normal subjects (20 ears), 27 CAS patients (30 ears) and 25 CAA patients (30 ears) were analyzed. The distances from the central point of round window niche opening to the terminal point of the horizontal segment, the salient point of pyramidal segment, the beginning point of the vertical segment, and the vertical segment of the facial nerve (abbreviate as OA, OB, OC, OE, respectively) were calculated based on three-dimensional reconstruction using mimics software. The results suggested that the pyramidal segment of the FN was positioned more closely to round window niche opening in patients with both CAA and CAS groups than that in control group, whereas there was no significant difference between CAA and CAS group (P < 0.05). The vertical portion of the FN was positioned more closely to round window niche opening in the CAA group than those in both the CAS and control groups with statistical significance (P < 0.05). Furthermore, the vertical portion of the FN was positioned more closely to round window niche opening in the CAS group than that in control group (P < 0.05). In conclusion, the dislocation between facial nerve and round window niche in patients with congenital auditory canal malformations could have significant effects on the round window implantation of vibrant soundbridge. Moreover, three-dimensional measurements and assessments before surgery might be helpful for a safer surgical approach and implantation of vibrant soundbridge.

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.

Morphological Characteristics of Round Window Niche in Congenital Aural Atresia and Stenosis Patients.

OBJECTIVE: The aim of this study was to measure the round window niche (RWN) among congenital aural atresia (CAA), congenital aural stenosis (CAS) and control groups and to analyze whether differences exist between them. METHODS: Computed tomography images of 10 normal subjects (20 ears), 27 CAS patients (30 ears) and 25 CAA patients (30 ears) were analyzed. We measured RWN on the basis of 3-dimensional reconstruction. RESULTS: The anterior wall length and the depth of RWN were smaller in control group than those in the CAS group; furthermore, the anterior wall length and the depth of RWN in CAS group were smaller than those in CAA group (P < 0.05). The posterior wall length of RWN was found smaller in the control group than that in both hCAS and CAA groups (P < 0.05). The superior and inferior wall lengths of RWN were found smaller in control group than those in the CAA group (P < 0.05). There were no statistically significant differences in the sizes of the round window membrane and niche opening or the angle between the plane of the RWN opening and the round window membrane plane among all groups. CONCLUSIONS: The RWN walls lengths and its depth tended to be longer with the aggravation of the aural malformations. Our calculation results may provide some information for a better design and a safer implantation of the floating mass transducer in the area of RWN.

[Three-dimensional morphological measurements of the utricle, saccule and stapes footplate].

OBJECTIVE: To determine the optimal drill area on the footplate with the 3D measurements of the stapes and the vestibular end organs. METHODS: Four temporal bones were extracted from the fresh cadavers and undecalcified polymer-embedded. After serially sectioning, image processing and the 3D precisely reconstruction, a local Cartesian coordinates was established in which the tympanic surface of the footplate was supposed to be XY plane and the Z coordinate axis passed through the central point of the footplate and was vertical to the XY plane. The configurations of the utricle and saccule were delineated quantitatively, and then any distance between one point on the surface of the footplate and another point on the surface of the utricle or saccule and its orientation can be measured. RESULTS: There was a "V" shaped cleft between the utricle and the saccule. The angle of the" V" shaped cleft was 50.31 +/- 19.90 (17.00 - 68.00) degrees. The apex of the cleft directed anterosuperiorly and approached the footplate center, while beneath the posteroinferior part of the footplate was an open and deep area. The vertical distance from the center point of the footplate to the vestibular end organs was (2.20 +/- 0.548) mm, the maximum of 3.0 mm and the minimum of 1.6 mm. CONCLUSIONS: The posterior and inferior quadrant of the footplate may be the optimal drill area for the fenestra.