Audiologic Outcomes After Vestibulotomy in Patients With Congenital Absence of the Oval Window.

OBJECTIVE: To examine the clinical features and surgical outcomes in patients with congenital absence of the oval window (CAOW), and to investigate the potential factors that affect audiologic results. STUDY DESIGN: A retrospective chart review. SETTING: A tertiary academic center. PATIENTS AND INTERVENTION: A total of 17 ears among 16 patients were confirmed to have CAOW. Among them, 13 ears underwent vestibulotomy for hearing reconstruction. Clinical parameters associated with the hearing outcomes were analyzed. MAIN OUTCOME MEASURES: A mean air-bone gap (ABG) after 6-month and long-term follow-up was compared with preoperative measurements. RESULTS: Intraoperative findings showed that anomalies of the malleus or incus were observed in 11 ears (64.7%), stapes anomalies were present in all ears (100%), and facial nerve anomalies were present in 10 ears (58.8%). Because of unfavorable facial nerve anomalies, hearing reconstruction was aborted in four cases (23.5%). In the hearing reconstruction group, the mean ABG at 6 months postoperation was significantly reduced after compared with the preoperative value (44.0 ± 8.4 dB versus 58.8 ± 9.1 dB, p = 0.006). After dividing ears into a success subgroup (ABG ≤ 30 dB, seven ears) and non-success subgroup (ABG > 30 dB, six ears), the use of a drill during vestibulotomy was significantly related to a poor hearing outcome (100% versus 16.7%, p = 0.015). The long-term follow-up result (mean, 60 mo) revealed no deterioration compared with the 6-month postoperative result. Five ears (29.4%) underwent revision surgery, and three of them showed ABG improvements. No serious complications were reported. CONCLUSION: Vestibulotomy is an effective and safe option for hearing restoration in patients with CAOW, particularly when the use of a drill is not required. The long-term audiologic outcome is also reliable.

Bone cement repair of malleus handle fractures: Intraoperative video and case report of two patients.

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.

Linear transmission between malleus and stapes in cases with incus necrosis.

OBJECTIVE: The outcome of cartilage interposition ossiculoplasty was assessed in cases of incus necrosis after posterior malleus repositioning in the plane of the stapes, in terms of hearing gain after ossicular reconstruction. METHODS: A retrospective observational study was conducted of 30 patients admitted to an Ain Shams University hospital from March 2021 to September 2021. All patients with ossicular disruption due to chronic suppurative otitis media and hearing loss of more than 40 dB were included in the study. Pure tone audiometry was conducted for each patient after three months, six months and one year post operation. RESULTS: The audiogram showed a post-operative air-bone gap of 20 dB or less in 83.33 per cent of patients (n = 25) at three months post-operatively and in 80 per cent of patients after six months; after one year, the results remained the same. CONCLUSION: The use of cartilage interposition after malleus posterior mobilisation represents an excellent partial ossicular replacement technique.

Registration of preoperative temporal bone CT-scan to otoendoscopic video for augmented-reality based on convolutional neural networks.

PURPOSE: Patient-to-image registration is a preliminary step required in surgical navigation based on preoperative images. Human intervention and fiducial markers hamper this task as they are time-consuming and introduce potential errors. We aimed to develop a fully automatic 2D registration system for augmented reality in ear surgery. METHODS: CT-scans and corresponding oto-endoscopic videos were collected from 41 patients (58 ears) undergoing ear examination (vestibular schwannoma before surgery, profound hearing loss requiring cochlear implant, suspicion of perilymphatic fistula, contralateral ears in cases of unilateral chronic otitis media). Two to four images were selected from each case. For the training phase, data from patients (75% of the dataset) and 11 cadaveric specimens were used. Tympanic membranes and malleus handles were contoured on both video images and CT-scans by expert surgeons. The algorithm used a U-Net network for detecting the contours of the tympanic membrane and the malleus on both preoperative CT-scans and endoscopic video frames. Then, contours were processed and registered through an iterative closest point algorithm. Validation was performed on 4 cases and testing on 6 cases. Registration error was measured by overlaying both images and measuring the average and Hausdorff distances. RESULTS: The proposed registration method yielded a precision compatible with ear surgery with a 2D mean overlay error of 0.65 ± 0.60 mm for the incus and 0.48 ± 0.32 mm for the round window. The average Hausdorff distance for these 2 targets was 0.98 ± 0.60 mm and 0.78 ± 0.34 mm respectively. An outlier case with higher errors (2.3 mm and 1.5 mm average Hausdorff distance for incus and round window respectively) was observed in relation to a high discrepancy between the projection angle of the reconstructed CT-scan and the video image. The maximum duration for the overall process was 18 s. CONCLUSIONS: A fully automatic 2D registration method based on a convolutional neural network and applied to ear surgery was developed. The method did not rely on any external fiducial markers nor human intervention for landmark recognition. The method was fast and its precision was compatible with ear surgery.

Isolated Fracture of the Malleus: An Overlooked Cause of Conductive Hearing Loss?

OBJECTIVE: To report the largest case series of isolated malleus fractures with systematic review to characterize the disease's presentation and natural history, and provide suggestions for management. DATA SOURCES: PubMed, Embase, Cochrane Library. REVIEW METHODS: Retrospective cohort study was performed on 12 patients with isolated malleus fractures. History, physical exam, pre- and post-treatment audiograms, and imaging were obtained. Systematic review of the literature was performed. RESULTS: Including the cases herein, 58 isolated malleus fractures were identified, the majority of which were published in the 21st century. Mean time to presentation after injury was 34.4 months. Most common etiology was external auditory canal (EAC) manipulation. Physical exam and imaging did not identify any abnormality at presentation in 16% and 21% of cases, respectively. The majority of fractures involved the manubrium. Air-bone gap (ABG) at initial presentation ranged from 16 to 26 dB, and was greater at higher frequencies. Thirty-six cases underwent surgery. ABG improvement was greater at all frequencies for those who underwent surgery. Final ABG was significantly less than initial ABG at nearly every frequency for those who underwent surgery (p < 0.05), while not at any frequency for those who were observed. CONCLUSIONS: Isolated malleus fractures may occur more often than historical data suggests, and are perhaps underdiagnosed. Abrupt removal of a finger from the EAC with pain and hearing loss is nearly pathognomonic. Conductive hearing loss with ABG greater at higher frequencies is most often observed. Observation is unlikely to produce spontaneous improvements in hearing, while surgery demonstrates reliable decreases in ABG. Laryngoscope, 134:1032-1041, 2024.

An Endoscopic Procedure for the Simultaneous Treatment of both Otosclerosis and Malleus Fixation.

To report the case of the simultaneous treatment of otosclerosis and malleus fixation through an entirely endoscopic transcanal approach. A targeted transcanalar epitympanotomy with annular bony ridge conservation was planned preoperatively, with 3D CT localization of the fixed part of the malleus head. The upper part of the malleus head and the superior ossified ligament of the malleus were drilled. A 0.6 mm stapedotomy was performed and a piston inserted. The patient's recovery was uneventful, with closure of the air-bone gap on her postoperative audiogram, associated with an overclosure in 500Hz, 1kHz, 2 kHz and 4 kHz. Laryngoscope, 134:2411-2414, 2024.

Anatomic and morphometric examination of auditory ossicles in sheep.

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

[Analysis of medium and long term efficacy of ossicle chain bypass technique in treatment of tympanosclerosis].

Objective:For tympanosclerosis patients with ossicular chain fixation, we use ossicular chain bypass technique and evaluate its long-term effects. Methods:From June 2017 to June 2019, 147 patients with tympanosclerosis who underwent middle ear surgery with otoscopy in Yinchuan First People's Hospital were reviewed. The subjects were divided into three groups according to the implemented operation plan, 51 cases in the ossicular chain mobilization group（OCM）, 56 cases in the ossicular chain bypass reconstruction group（OCB）, and 40 cases in the malleus-incus complex resection reconstruction group（MICR）. Through a three-year follow-up, the medium and long-term effects of different operation plans were compared and analyzed. Results:There was no significant difference among the three groups in the incidence of tympanic membrane perforation, delayed facial nerve palsy, and the dispatch and displacement of PORP. The incidence of tympanic membrane retraction pocket or cholesteatoma after operation in OCB group（0） was significantly lower than that in OCM group（11.76%） and MICR group（7.5%）（P<0.05）. At 12 months after operation, ΔABG of OCB group and MICR group were better than that in the OCM group（P<0.05）. At 36 months after operation, ΔABG of OCB group was better than that in the OCM group（P<0.05）, and there was no significant difference between OCB group and MICR group. The audiological performance of patients with epitympanic sclerosis（ETS） at 12, 24 and 36 months after operation was better than that of patients with posterior tympanosclerosis（PTS） and total tympanosclerosis（TTS）（P<0.05）. Conclusion:Compared with patients undergoing ossicular chain mobilization and malleus-incus complex resection for ossicular chain reconstruction, patients with tympanosclerosis undergoing bypass technique have better and stable hearing prognosis in medium and long term. This technique can effectively prevent the formation of retracted pocket and cholesteatoma in patients with tympanosclerosis after operation.

Foreign Body Granuloma Originating From the Lateral Process of Malleus: A Case Series of 19 Children.

OBJECTIVE: A special presentation of foreign body granuloma originating from the lateral process of the malleus (FBGLP) was noted in the absence of a history of foreign body entry into the external auditory canal (EAC). This study reported the clinical features, pathology, and prognosis of patients with FBGLP. DESIGN: Retrospective study. SETTING: Shandong Provincial ENT Hospital. PATIENTS: Nineteen pediatric patients (age, 1-10 yr) with FBGLP. INTERVENTIONS: Clinical data were collected from January 2018 to January 2022. MAIN OUTCOME MEASURES: Clinicopathologic characteristics of the patients were analyzed. RESULTS: All patients had an acute course, and were within 3 months of ineffective medical treatment. The most common symptoms were suppurative (57.9%) and hemorrhagic (42.1%) otorrhea. FBGLP imaging examinations demonstrated a soft mass blocking the EAC without bone destruction and occasionally concomitant effusion in the middle ear. The most common pathologic findings were foreign body granuloma (94.7%,18/19), granulation tissue (73.7%, 14/19), keratotic precipitate (73.7%, 14/19), calcium deposition (63.2%, 12/19), hair shafts (47.4%, 9/19), cholesterol crystals (5, 26.3%), and hemosiderin (15.8%, 3/19). Foreign body granuloma and granulation tissue showed higher expression levels of CD68 and cleaved caspase-3 than did the normal tympanic mucosa, whereas Ki-67 levels were similarly low in all tissues. The patients were followed up for 3 months to 4 years without recurrence. CONCLUSION: FBGLP is caused by endogenous foreign particles in the ear. We recommend the trans-external auditory meatus approach for FBGLP surgical excision, as this shows promising outcomes.

Morphological variations in malleus among the male and female.

OBJECTIVE: To determine gender-based morphological variations in malleus. METHODS: The cross-sectional descriptive study was conducted at the Ear-Nose-Throat and Radiology departments of a public-sector hospital in Karachi, from January 20 to July 23, 2021, and comprised subjects of either gender aged 10-51 years who had intact ear ossicles. They were divided into equal male and female groups. After history and a thorough examination of the ear, high-resolution computed tomography scan of petrous temporal bone was done. The images were studied for malleus, to measure the parameters of its head width, length and shape of manubrium, and total length of malleus for possible morphological variations along gender lines. Data was analysed using SPSS 23. RESULTS: Of the 50 subjects, 25(50%) were males with mean width of the head 3.04±0.34mm, mean length of manubrium 4.47±0.48mm, and mean total length of malleus 7.76±0.60mm. The corresponding values in 25(50%) females were 3.00±0.28mm, 4.31±0.45mm and 7.41±0.51mm. The total length of malleus between both genders was significantly different (p= 0.031). The shape of manubrium was straight in 10(40%) males and 8(32%) females, and curved in 15(60%) males and 17(68%) females. CONCLUSIONS: Width of head, length of manubrium and total length of malleus were different in gender terms, but the total length of malleus was significantly different.

A novel technique in treatment of advanced tympanosclerosis: results of malleus replacement and loop prostheses combination; pure endoscopic transcanal approach.

PURPOSE: The objectives of the present clinical trial are to describe our surgical technique for advanced tympanosclerosis (TS) and to present the comparison of pre-and postoperative audiometric results. METHODS: 21 patients suffering from advanced TS (Only type III and IV patients according to Wielinga-Kerr classification) were enrolled in this prospective study. A pure transcanal endoscopic approach was preferred for all patients included in the study. Titanium malleus replacement prosthesis (MRP) and polytetrafluoroethylene (PTFE) loop prosthesis combination were used to bypass fixed ossicles to achieve sound transmission to the inner ear. Pre-and postoperative pure tone audiometry (PTA) measurements and air-bone gap (ABG) results compared, and surgical technique was considered successful if postoperative ABG was less than 20 dB. RESULTS: Six of the 21 patients had been operated on before and the tympanic membrane (TM) was intact. The remaining 15 of the 21 patients were the primary cases, and TM perforation repair and ossiculoplasty using combination of the MRP and PTFE loop prosthesis were performed at single-staged operation. The average preoperative ABG values significantly improved from 37.1 ± 6.2 to 14.5 ± 1.2 dB postoperatively (p < 0.001). The mean preoperative air conduction threshold (ACT) significantly decreased from 51.7 ± 11.4 to 28.5 ± 9.1 dB (p < 0.001). CONCLUSION: TS surgery is still a controversial issue particularly in stapes footplate fixation. However, our surgical and audiological results in this study are quite promising. The combination of titanium MRP and PTFE loop prosthesis for restoring sound transmission in advanced TS cases is reliable, effective and novel treatment option via endoscopic transcanal approach.

Descriptive study of goat external and middle ear through computed tomography and endoscopic evaluation, compared with the human ear.

OBJECTIVE: To describe the external and middle ear of goats, using computed tomography and endoscopic dissection, comparing them with the anatomy of the human ear, aiming to evaluate the viability of this animal model for training in otological endoscopic surgery. METHODS: Images of the external and middle ear of goats were produced by computed tomography in the coronal and axial planes and analyzed. The radiological anatomy of the external and middle goat and human ear are described. Some measures of surgical interest were described, such as the length of the external auditory canal, external and internal cross-sectional area of the external auditory canal, middle ear depth, vertical angle of the external auditory canal, length of malleus and incus. After the tomographic study, we analyzed the importance of evaluations through the endoscopic dissection of the goat ear. RESULTS: The bony canal is extremely tortuous and shows a bony prominence with significant elevation near the lower edge of the tympanic membrane. The middle ear has a large tympanic bulla in the hypotympanum region. The malleus is shaped similarly to that of the human, but its handle is located anterior to its head. The mastoid is not pneumatized. Compared to the human mastoid, there was a statistically significant difference in the external and internal cross-sectional area, at the depth of the middle ear, in the vertical angle of the canal and in the length of the incus. CONCLUSION: Goat morphometric anatomy showed that this model is suitable for surgical simulation in the initial training for endoscopic otological surgery. It is an important contribution to the development of skills to accelerate the subsequent endoscopic otological surgical training in humans, despite some differences found.

Isolated Traumatic Dislocation of the Malleus into the External Auditory Canal.

We report a rare case of isolated malleus dislocation into the external auditory canal with lateralized intact tympanic membrane following a head trauma. The patient was a 63-year-old woman who presented at the outpatient department of our institute with hearing loss of 10 years' duration after a bicycle accident. During physical examination of the patient, total dislocation of the malleus-like bony structure into the external auditory canal on the right side was observed. In the computed tomography scan, an isolated malleus dislocation with intact incus-stapes articulation was identified. The patient was successfully treated with endoscopic exploratory tympanotomy and partial ossicular replacement prosthesis. The isolated malleus dislocation can rarely occur after trauma. A careful diagnostic step through history, physical examination, and temporal bone computed tomography scan are needed to confirm this rare condition.

Petrotympanic Fissure Architecture and Malleus Location in Temporomandibular Joint Disorders.

The aim of this research was to assess possible relationships between petrotympanic fissure (PTF) characteristics, malleus position, and temporomandibular joint disorders (TMD). A retrospective study was performed, including patients with TMD. Magnetic resonance imaging (MRI) and cone-beam computed tomography (CBCT) examination were used to evaluate temporomandibular joint (TMJ) disc position and condylar bone changes. Fifty-eight TMJs from twenty-nine patients (23:6 females: males) were assessed. Erosive changes (DDR-disc displacement with a reduction of 6 (24%), DDwR-disc displacement without a reduction of 8 (61.5%) vs. normal disc position 3 (15%), p = 0.012) and condyle osteophytes production (DDR 6 (24%), DDwR 9 (69.2%) vs. normal condyle 7 (35%), p = 0.012) were more frequent in subjects with disc displacement compared to normal disc position; malleus was closer to PTF in cases with erosive changes (median 2.15 interquartile range: (1.85-2.75) vs. 2.75 (2.25-3.15), p = 0.029) as well as those with condylar osteophytosis (2.25 (1.91-2.75) vs. 2.75 (2.33-3.32), p = 0.015); the PTF length was higher in cases with condylar osteophytosis compared to those without (4.45 (3.50-4.77) vs. 3.67 (3.34-4.28), p = 0.039). The disc position and disc shape were not related to PTF or malleus position. Malleus position and PTF dimensions were not associated with the PTF type. In cases with erosive changes and condylar osteophytosis, malleus was closer to PTF.

Statistical Shape Model of the Temporal Bone Using Segmentation Propagation.

HYPOTHESIS: Automated image registration techniques can successfully determine anatomical variation in human temporal bones with statistical shape modeling. BACKGROUND: There is a lack of knowledge about inter-patient anatomical variation in the temporal bone. Statistical shape models (SSMs) provide a powerful method for quantifying variation of anatomical structures in medical images but are time-intensive to manually develop. This study presents SSMs of temporal bone anatomy using automated image-registration techniques. METHODS: Fifty-three cone-beam temporal bone CTs were included for SSM generation. The malleus, incus, stapes, bony labyrinth, and facial nerve were automatically segmented using 3D Slicer and a template-based segmentation propagation technique. Segmentations were then used to construct SSMs using MATLAB. The first three principal components of each SSM were analyzed to describe shape variation. RESULTS: Principal component analysis of middle and inner ear structures revealed novel modes of anatomical variation. The first three principal components for the malleus represented variability in manubrium length (mean: 4.47 mm; ±2-SDs: 4.03-5.03 mm) and rotation about its long axis (±2-SDs: -1.6° to 1.8° posteriorly). The facial nerve exhibits variability in first and second genu angles. The bony labyrinth varies in the angle between the posterior and superior canals (mean: 88.9°; ±2-SDs: 83.7°-95.7°) and cochlear orientation (±2-SDs: -4.0° to 3.0° anterolaterally). CONCLUSIONS: SSMs of temporal bone anatomy can inform surgeons on clinically relevant inter-patient variability. Anatomical variation elucidated by these models can provide novel insight into function and pathophysiology. These models also allow further investigation of anatomical variation based on age, BMI, sex, and geographical location.

Reparación de fractura aislada del mango del martillo con cemento ionomérico vidrioso autocurado / Repair of a malleus handle fracture using glass ionomer luting cement

Resumen La fractura aislada del mango del martillo es una entidad clínica poco habitual, pero frecuentemente subdiagnosticada. Lo fundamental es la sospecha clínica. El diagnóstico se confirma con la otoscopia neumática o la otomicroscopia con maniobra de Valsalva, en la cual se observa una movilidad anormal del mango del martillo. El rasgo de fractura se puede demostrar con tomografía computada de alta resolución o cone beam. Existen diferentes opciones de tratamiento como interposición de cartílago o uso de prótesis de reemplazo osicular así como cemento óseo. El cemento ionomérico vidrioso autocurado, muy utilizado en odontología, se ha usado en distintas cirugías otológicas con buenos resultados y biocompatibilidad. A nuestro saber no se ha usado en esta patología por lo que presentamos esta serie de tres casos en los cuales se ha usado esta novedosa técnica con buenos resultados clínicos.

Abstract Isolated fracture of the manubrium of the malleus is a rare clinical entity. Clinical suspicion is paramount. The usual clinical presentation is acute otalgia followed by tinnitus and fluctuating hearing loss after a brisk introduction and withdrawal of a finger into the external auditory canal. On physical examination, the eardrum looks normal on otoscopy. Only in pneumatic otoscopy or otomicroscopy with Valsalva an abnormal motility of the manubrium could bee seen. High-resolution computed tomography (CT) or cone beam CT is able to show the fracture line. Several treatment options have been proposed, such as interposition of bone or cartilage between the manubrium and the incus, total or partial ossicular replacement prosthesis; and the use of bone cement. Glass ionomer luting cement, with wide use in dentistry, has been used in several otological procedures with good biocompatibility and results, however, to our best knowledge, it has not been used to repair this type of fractures, so we present this novel material in three cases.

Internal vascular channel architecture in human auditory ossicles.

The vascular supply of the human auditory ossicles has long been of anatomical and clinical interest. While the external blood supply has been well-described, there is only limited information available regarding the internal vascular architecture of the ossicles, and there has been little comparison of this between individuals. Based on high-resolution micro-CT scans, we made reconstructions of the internal vascular channels and cavities in 12 sets of ossicles from elderly donors. Despite considerable individual variation, a common basic pattern was identified. The presence of channels within the stapes footplate was confirmed. The long process of the incus and neck of the stapes showed signs of bony erosion in all specimens examined. More severe erosion was associated with interruption of some or all of the main internal vascular channels which normally pass down the incudal long process; internal excavation of the proximal process could interrupt vascular channels in ossicles which did not appear to be badly damaged from exterior inspection. An awareness of this possibility may be helpful for surgical procedures that compromise the mucosal blood supply. We also calculated ossicular densities, finding that the malleus tends to be denser than the incus. This is mainly due to a lower proportion of vascular channels and cavities within the malleus.

Morphometric study of the human malleus during prenatal development.

OBJECTIVES: Establish normal reference values for the human malleus during the second and third trimesters of pregnancy, and describe its growth dynamics and ossification process. METHODS: Thirty spontaneously aborted human fetuses, 12-36 weeks of age, were examined. Temporal bones were obtained en bloc and processed using the skeletal clearing and staining technique. Each malleus was obtained by microdissection. Measurements of anatomical points of the malleus were performed. Ossification was recorded. Statistics were applied. RESULTS: Sixty mallei were obtained. At the end of development, the following measurements were obtained in millimeters: head length, 2.87 (2.30-3.44); neck length, 1.15 (0.92-1.38); manubrium length, 4.45 (3.75-5.16); total length, 8.51 (8.02-8.99); neck width, 1.33 (0.70-1.97); manubrium width, 0.84 (0.82-0.86); and Meckel cartilage width, 0.43 (0.06-0.95). The angle of the longitudinal axis of the malleus was 160° (156-164°). The ossification process of the malleus followed a stereotyped pattern that began at week 16, at the level of the neck, with a single center that expanded to the head and then to the manubrium. Toward the end of development, only the umbo remained cartilaginous. There were no sex-based differences in human malleus size during prenatal development. From the beginning of the second trimester of pregnancy, the longitudinal axis of the malleus acquires dimensions comparable to adults. CONCLUSION: The study of the malleus development provides clues that would explain some anomalies in its development, and can influence decision-making during the placement and design of prostheses in the malleus.