The cochlear dimensions relevant to hearing capability generally follow a pattern of allometric scaling with body mass in mammals. Nevertheless, humans exhibit cochlear dimensions larger than expected from the body mass, and it has been proposed that this is related to encephalization. In this study, we investigate whether the link between brain mass and cochlear morphology is unique to humans and whether cranial features other than brain mass impinge on the cochlear morphology in catarrhine primates that exhibit considerable variation in brain mass. Cochlear and cranial dimensions (cochlear length, oval window area, endocranial volume, cranial size, and interaural distance) were measured on three-dimensional surface models for 30 hominoid individuals (humans, chimpanzees, gorillas, orangutans, and gibbons) and 20 cercopithecine individuals (Japanese macaques, mandrills, and baboons). Relations between cochlear and cranial variables were evaluated using generalized linear mixed model (GLMM) and phylogenetic generalized least squares (PGLS) analyses. The endocranial volume better predicts cochlear morphology than the other cranial measurements in catarrhines. Specifically, the average cochlear length per turn exhibits a strong correlation, while the oval window area exhibits a weaker correlation with the endocranial volume in both GLMM and PGLS. Humans do not deviate from the common allometric pattern of cochlear length against endocranial volume in the catarrhine primates studied here. It appears that humans do not necessarily represent an exceptional cochlear morphology in catarrhine primates after accounting for the cranial dimensions and phylogeny. Our data thus indicate that the link between endocranial volume and cochlear morphology could be a more general pattern for catarrhine primates than previously recognized.

Otosclerosis is a chronic disorder of the otic capsule. It is characterized by abnormal bone remodeling, which may extend beyond the fenestral region and involve the cochlea and other structures of the bony labyrinth. There are two main types of otosclerosis-retrofenestral (cochlear) and fenestral, the latter of which is much more common. We present multimodal imaging findings of extensive bilateral cochlear otosclerosis in a 59-year-old woman with chronic bilateral sensorineural hearing impairment, classified as grade 3 in the right ear and complete deafness in the left ear. High-resolution computed tomography (CT) demonstrated extensive grade 3 bilateral otospongiotic changes involving multiple cochlear turns and extending toward the vestibule, fissula ante fenestram, oval window, and the lateral semicircular canal. Pre-contrast T1-weighted magnetic resonance imaging (MRI) showed mild pericochlear hyperintensity, suggestive of otospongiotic bone remodeling. Matching post-contrast T1-weighted imaging findings corresponded with bilateral pericochlear and perilabyrinthine enhancement of the otic capsule, which is associated with findings compatible with an active otospongiotic bone remodeling. T2-weighted sequences showed preserved fluid signal within the labyrinth and no corresponding otic capsule abnormality. Although limited for directly depicting otospongiotic changes, the T2-weighted sequence was useful for assessing morphology and excluding alternative pathology. This case illustrates the complementary role of CT and MRI in demonstrating advanced active cochlear otosclerosis and draws attention to MRI findings that might otherwise be overlooked, especially those in post-contrast T1-weighted images.

Gardner syndrome is a precancerous condition featuring familial adenomatous polyposis (FAP), multiple osteomas, and soft tissue tumors. Craniomaxillofacial peripheral osteomas often cause visible facial deformities, enabling early detection of the syndrome-frequently before FAP manifests-thus providing a critical window for intervention to prevent malignant transformation and reduce mortality. A systematic review searched 8 electronic databases from inception to December 2024. This was supplemented by one institutional case of a 21-year-old female with multiple craniomaxillofacial peripheral osteomas, who underwent successful surgical excision at age 26 and remained recurrence-free after 4 years of follow-up. Studies with confirmed craniomaxillofacial peripheral osteomas linked to Gardner syndrome were included. Data on epidemiology, clinical/radiologic features, and treatment were extracted. Pooled analysis of 113 cases (87 published studies plus one new case) showed these osteomas predominantly affect young patients (median age: 20 y). Lesions are typically multiple, located in the skull, paranasal sinuses, and mandible, causing noticeable cosmetic deformities. Imaging (plain radiographs, panoramic views, CT) reveals well-defined, round or oval radiopaque masses. Surgical excision is the main treatment for symptomatic or disfiguring lesions, with rare recurrence. Early recognition of these characteristic osteomas facilitates prompt FAP surveillance, enabling timely preventive measures that significantly improve outcomes and reduce mortality.

Cerebrospinal fluid (CSF) otorrhea represents a breach of the temporal bone separating the subarachnoid space from the middle ear and carries a significant risk of meningitis. While most cases are associated with trauma or prior skull base surgery, congenital fistulas may remain occult until unmasked by otologic procedures. We report the case of a five-year-old male with bilateral profound sensorineural hearing loss and previously unknown labyrinthine anomalies who developed high-flow, pulsatile clear otorrhea during routine left ear myringotomy for recurrent otitis media. Immediate concern for CSF leak prompted fluid collection for beta-2 transferrin analysis and urgent surgical management. Subsequent exploration via lateral temporal bone resection revealed a congenital inner ear fistula with active CSF egress from the vestibule through the oval window. The leak was successfully managed using a multilayer closure technique including vestibular packing with temporalis fascia, cartilage reinforcement, Eustachian tube obliteration, pedicled temporalis muscle flap coverage, and blind sac external auditory canal closure. This case illustrates the recognition and acute intraoperative management of an unanticipated high-flow CSF leak during a routine pediatric otologic procedure, and supports preoperative temporal bone imaging in children with profound sensorineural hearing loss before middle-ear instrumentation. Untreated, such leaks carry a significant risk of life-threatening meningitis.

Effective pharmacotherapy for hearing loss remains a significant challenge because of the blood-labyrinth barrier, which limits systemic drug access and often necessitates local intratympanic (IT) administration. However, the distribution of drugs after IT injection between the vestibular system and cochlea is unclear. Although the round window membrane is the main recognized entry route, in this study, we explored alternative pathways, namely the oval window (OW) and the thin apical otic capsule, using an ex vivo porcine model to assess their permeability to different solvent vehicles. We demonstrated that the route of entry is critically on the solvent composition and additives; in particular, reconstituting dexamethasone-fluorescein in dimethyl sulfoxide enhanced permeability through the OW by 42-fold compared to that with methanol, establishing the OW as a pathway for this solvent type rather than the RWM. Furthermore, we identified the thin apical otic capsule as a third drug-entry route in young pigs. Surgical sealing of this pathway in vivo, which reduces perilymph drug levels, underscores its importance in human translational studies. In summary, we developed a robust ex vivo multi-barrier model integrated with FluidSim to predict the inner ear drug biodistribution.

Background/Objectives: The anatomical relationship between the oval window (OW) and the facial nerve (FN) is of significant importance in the context of stapes and middle ear surgery. However, the influence of mastoid pneumatization on OW morphology and FN proximity remains to be elucidated. Methods: This retrospective study included 220 radiologically normal temporal bones from 110 adults. OW width, OW height, OW niche width, FNt-OW distance, FNm-OW distance, OW-mastoid cell distance, and OW-FNm-FNt corridor area were measured on HRCT images. Mastoid pneumatization was classified using a sigmoid sinus-based grading system. RASCI was developed by integrating OW morphology, OW niche width, and mastoid pneumatization. Results: The mean width of the OW, the height of the OW, and the width of the OW niche were 2.41 ± 0.92 mm, 1.38 ± 0.36 mm, and 1.03 ± 0.38 mm, respectively. The mean FNt-OW and FNm-OW distances were recorded as 0.93 ± 0.33 mm and 2.78 ± 0.94 mm, respectively. It was established that larger OW dimensions and FN-OW distances were associated with higher levels of mastoid pneumatization. The radiological-anatomical constraint was categorised as low in 21.4% of cases, moderate in 69.5%, and high in 9.1% of the temporal bones (RASCI). Conclusions: Mastoid pneumatization appears to be associated with OW morphology and FN-OW spatial relationships. The RASCI could provide an initial HRCT-based framework for grading the constraints of the OW-FN corridor; however, prospective surgical validation is required.

The Eustachian tube is named after the Italian anatomist, Bartolomeo Eustachi, who observed that it was a canal that connected the nasopharynx to the middle ear. The Eustachian tube is also known as the pharyngotympanic tube or the auditory tube.

Third-window anomalies represent a heterogeneous group of inner ear disorders characterized by abnormal openings in the bony otic capsule, resulting in altered cochlear and vestibular fluid mechanics. By creating an alternative pathway for inner ear fluid motion due to a new opening in addition to the oval and round windows, these lesions disrupt normal sound transmission and vestibular function. In pediatric patients, recognition of third-window anomalies is particularly important, as early and accurate diagnosis supports appropriate clinical assessment and management. High-resolution computed tomography of the temporal bone is the primary imaging modality for evaluating third-window anomalies, enabling detailed assessment of the bony labyrinth. However, many of these abnormalities are subtle and may be underestimated or misinterpreted on standard axial images. The use of anatomy-oriented multiplanar reconstructions tailored to the suspected defect significantly improves lesion conspicuity and diagnostic confidence. This educational review summarizes the anatomic and pathophysiologic principles underlying third-window phenomena in children and illustrates the imaging features of major entities, including semicircular canal dehiscence, enlarged vestibular aqueduct, and less common cochlear dehiscence. The aim is to provide a clear and practical imaging-based framework to support radiologists involved in the evaluation of pediatric inner ear abnormalities.

Objective: To investigate the clinical classification and surgical outcomes of congenital middle ear malformations accompanied by facial nerve anomalies. Methods: A retrospective cohort study was conducted to analyze clinical data of patients with congenital middle ear malformations and concomitant facial nerve anomalies who received treatment in the Department of Otolaryngology, Zhujiang Hospital, Southern Medical University, between January 2021 and December 2024. Facial nerve anomalies were categorized into four distinct types: partial obstruction of the oval window, complete obstruction of the oval window, aberrant course over the promontory, and branching anomalies. Ossicular chain malformations were classified in accordance with the Teunissen classification system. Individualized hearing reconstruction strategies were implemented based on the specific anatomical characteristics of the anomalies. All patients were followed up for 3 to 24 months. Postoperative therapeutic efficacy was evaluated by comparing preoperative and postoperative mean air conduction thresholds and air-bone gaps (ABG), while monitoring surgical complications. Results: Thirteen patients (17 ears) aged [M (Q1, Q3)] 15.0 (11.5, 21.0) years were included, with eight males and five females. Facial nerve anomalies were categorized as follows: partial obstruction of the oval window in six ears (three cases of Type Ⅰ, three cases of Type Ⅲ), complete obstruction of the oval window in three ears (one case of Type Ⅰ, two cases of Type Ⅲ), aberrant course over the promontory in six ears (all Type Ⅳ), and branching anomalies in two ears (both Type Ⅳ). Hearing reconstruction modalities employed included: incus-stapedial piston placement following vestibular fenestration in nine ears, malleus-stapedial piston placement following vestibular fenestration in two ears, partial ossicular replacement prosthesis (PORP) implantation in three ears, total ossicular replacement prosthesis (TORP) implantation in one ear, stapes mobilization in one ear, and laser-assisted ossicular chain release in one ear.Statistical analysis revealed that postoperative mean air conduction thresholds [(33.8±15.2) dB HL vs (60.1±13.8) dB HL, P<0.001] and mean ABG [(14.6±6.9) dB vs (37.2±9.2) dB, P<0.001] were significantly reduced compared with preoperative values. Postoperative ABG≤20 dB was achieved in 15 ears (88.2%). Postoperative complications were limited to transient vertigo in five cases and taste disturbance in two cases. No cases of facial paralysis, sensorineural hearing loss, tympanic membrane perforation, or tinnitus were observed. The median follow-up duration was 6.0 (5.5, 20.0) months. Conclusion: Individualized hearing reconstruction strategies based on the classification of facial nerve and ossicular chain anomalies can effectively protect the facial nerve and achieve significant hearing improvement, demonstrating favorable clinical outcomes.

Objective: To explore the clinical efficacy of stapes prosthesis surgery for the treatment of congenital fixation of stapes or oval window atresia in pediatric patients. Methods: The clinical data of children with congenital fixation of stapes or oval window atresia who underwent stapes prosthesis surgery in Xi'an Children's Hospital from January 2017 to July 2025 were retrospectively analyzed. All the children underwent high-resolution computed tomography (HRCT) of the temporal bone and pure-tone audiometry before and after the surgery. According to the type of auditory chain deformity, the children were divided into the stapes fixation group and the oval window atresia group. The surgical methods included incudovestibular fenestration (IVF) and malleovestibulopexy (MVP), with four types of opening methods, namely stapes footplate drilling, stapes resection, vestibular windowing, and vestibular semicircular canal interposition, respectively. The preoperative and postoperative air-conducted pure tone average (PTA), bone-conducted PTA, and air-bone conduction difference (ABG) were observed and compared. Results: A total of 19 children (25 ears) aged (8.9±3.1) years were included, with 13 males and 6 females. There were 13 ears on the right side and 12 ears on the left side. Preoperative HRCT yielded a positive diagnostic rate of 56.0% (14/25), while the incidence of facial nerve malformation was 40.0% (10/25). Surgical intervention was performed in 24 of the 25 affected ears. Among these, 13 ears were diagnosed with stapes fixation, of which four underwent IVF and nine underwent MVP. The remaining 11 ears presented with oval window atresia, with four undergoing IVF and seven undergoing MVP. Six months postoperatively, both the stapes fixation group and oval window atresia group demonstrated statistically significant improvements in air-conduction PTA and ABG compared with preoperative values. In the stapes fixation group, air-conduction PTA decreased from (62.2±8.7) dB HL to (32.8±10.8) dB HL (P=0.002), and ABG improved from (49.3±10.5) dB HL to (22.5±5.8) dB HL (P<0.001). In the oval window atresia group, air-conduction PTA decreased from (66.2±8.4) dB HL to (42.0±11.6) dB HL (P<0.001), and ABG improved from (54.0±5.0) dB HL to (31.1±11.7) dB HL (P<0.001). No statistically significant differences were observed in bone-conduction PTA before and after surgery in either group (both P>0.05). Intergroup comparisons revealed that the stapes fixation group exhibited significantly greater improvements in postoperative air-conduction PTA [(32.8±10.8) dB HL vs (42.0±11.6) dB HL] and ABG [(22.5±5.8) dB HL vs (31.1±11.7) dB HL] compared with the oval window atresia group (both P<0.05). Subgroup analyses based on surgical technique showed that patients who underwent MVP in both the stapes fixation and oval window atresia groups achieved statistically significant reductions in ABG compared with preoperative levels (both P<0.05). In contrast, IVF did not yield statistically significant improvements in ABG in either group (both P>0.05). No statistically significant difference was detected in postoperative ABG between patients who underwent IVF versus MVP, nor among the four different types of window opening techniques (all P>0.05).All patients received outpatient follow-up at six months postoperatively. Nineteen ears were followed up for≥1 year, with a mean duration of (25.1±12.4) months, while five ears were lost to follow-up (loss to follow-up rate: 20.8%). No serious complications, including sensorineural hearing loss or facial paralysis, were reported in any patient. Conclusions: Stapes prosthesis surgery for the management of congenital stapes fixation and oval window atresia in pediatric patients demonstrates a favorable safety profile and sustained therapeutic efficacy. Surgical outcomes for congenital stapes fixation are superior to those for oval window atresia. Neither the choice between IVF and MVP nor variations in window-opening techniques has a statistically significant effect on postoperative hearing outcomes.