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In forensic anthropology, sex estimation is a fundamental step in assessing individual biological profiles when analyzing human skeletons. Yet, current methods are not reliable enough to allow an accurate sex identification of highly fragmented, burnt, or subadult remains. This paper aims to investigate sexual dimorphism of the bony labyrinth on both identified subadult and adult individuals. The bony labyrinth is of particular interest for sex estimation since it is alleged to complete size and maturation pre‐pubertally and is located inside the petrous part of the temporal bone which protects it from taphonomic processes. The study was performed on 93 CT scans of identified individuals from two Belgian osteological collections (19–20th century) and from current pediatric images (Erasme hospital, Brussels). Linear and angular measurements were taken on 2D slices of right bony labyrinths. Intra‐ and interobservers error measurements were calculated. Statistical tests were used to unravel any morphological variations between subadult and adult bony labyrinths and to highlight differences between females and males, separately in subadults and adults. Linear discriminant functions were established by cross‐validation and tested on an independent sample from Belgium. Some measurements were significantly different between subadults and adults, and between females and males within both subadult and adult samples. Univariate functions achieved 72.7% in subadults and 68.4% in adults whereas multivariate equations increased accuracy respectively up to 84.9% and 78.4%. This study entails promising results to design a sex estimation method suitable for fragmented and/or subadult remains. Further metric approaches are needed to explore bony labyrinth sexual dimorphism. [ABSTRACT FROM AUTHOR]

Background: Otosclerosis causes conductive, sensorineural and mixed hearing loss (CHL, SNHL, MHL) and tinnitus in young adults. It is best diagnosed on high-resolution CT (HRCT). Occasionally, patients presenting with SNHL and/or tinnitus may undergo temporal bone MRI as the first investigation. In this study, we have described the role of MRI as the first-line modality in the detection of previously undiagnosed otosclerosis. Using search words 'MRI otosclerosis' we found 15 cases in the PACS of our institute, (University Hospitals, KU Leuven, Belgium) from 2003 to 2018. Of these, 2 were known cases of otosclerosis, hence excluded from the study. The remaining 13 patients underwent MRI as first-line investigation for unilateral SNHL (8/13), bilateral SNHL (3/13), unilateral MHL (1/13) and bilateral pulsatile tinnitus (1/13). All MRI studies were reported by the same senior radiologist. Results: Of these 13 cases, 12 were reported as showing MRI features suspicious for otosclerosis. The typical positive findings in these cases were intermediate T1 signal and post-contrast enhancement in the perilabyrinthine/pericochlear regions. Out of 13 patients, 9 underwent subsequent HRCT, confirming otosclerosis in all. The single MRI which was reported as normal initially showed otosclerosis on HRCT. Retrospective evaluation of this MRI study showed subtle positive findings of otosclerosis. Conclusion: The end point of this study was to validate the subtle findings of otosclerosis on MRI, by comparison to the gold-standard modality HRCT. Our hypothesis is that in the appropriate clinical setting, familiarity with MRI features of otosclerosis would increase the diagnostic 'catch' in the first 'net' itself i.e. first-line MRI. [ABSTRACT FROM AUTHOR]

The round window niche area is dramatically important in terms of cochlear implantation as its individual variations influences approach to the scala tympani of the cochlea. Methods. The syntopy of round window niche area and adjacent regions was examined on 20 cadaveric temporal bones. Results and discussion. Three types of free edge of the round window niche tegmen were distinguished. In 11 specimens out of 20 well-formed free edge of the tegmen was revealed and round window membrane was fully visualized. In 6 cases a well-formed free edge of the tegmen was detected but due to the angle of this anatomic structure the membrane was only partly observed. In 3 specimens free edge of the tegmen was hypertrophic and protruded medially obscuring the membrane and the chamber of the round window niche. In 16 cases in hypotympanum area we observed a tunnel between the finiculus and fustis. This tunnel connected tympanic cavity and petrous bone cells below the cochlea. Three degrees of expression of this structure were discerned: I - 11/20 bones presented wide tunnel; II -- in 5/20 specimens only a small foramen was revealed under the finiculus; III -- in 4/20 cases this tunnel was not visualized. Learning outcome. A wide tunnel, which can be observed under the cochlea after the posterior tympanotomy, may mimic the round window niche. This can lead to the false electrode insertion. The potential risk of jugular bulb and carotid artery damage should be kept in mind as infracochlear pneumatization may serve as a pathway leading to these vessels. [ABSTRACT FROM AUTHOR]

Objectives: Dissection of cadaveric temporal bones (TBs) is considered the gold standard for surgical training in otology. For many reasons, access to the anatomical laboratory and cadaveric TBs is difficult for some facilities. The aim of this prospective and comparative study was to evaluate the usefulness of a physical TB prototype for drilling training in residency. Design: Prospective study. Setting: Tertiary referral centre. Participants: Thirty-four residents were included. Seventeen residents (mean age 26.7±1.6) drilled on only cadaveric TBs („traditional" group), in the traditional training method, while seventeen residents (mean age 26.5±1.7) drilled first on a prototype and then on a cadaveric TB („prototype" group). Main Outcome measures: Drilling performance was assessed using a validated scale. Residents completed a mastoid image before and after each drilling to enable evaluation of mental representations of the mastoidectomy. Results: No differences were observed between the groups with respect to age, drilling experience and level of residency. Regarding drilling performance, we found a significant difference across the groups, with a better score in the prototype group (P=.0007). For mental representation, the score was statistically improved (P=.0003) after drilling in both groups, suggesting that TB drilling improves the mental representation of the mastoidectomy whether prototype or cadaveric TB is used. Conclusion: The TB prototype improves the drilling performance and mental representation of the mastoidectomy in the young resident population. A drilling simulation with virtual or physical systems seems to be a beneficial tool to improve TB drilling. RW visualization during cochlear implantation Lobna E.F. ORL department, AIN Shams University, Cairo, Egypt Introduction: The clear visualization of the round window region through the facial recess is a prime requisite for the surgeon when inserting the electrode into the cochlea. Variations in the position of the round window can pose difficulty in the visualization of the round window niche by the surgeon. The variations in the position of the round window niche are caused by rotation of the cochlea in the horizontal and vertical axes, as well as the relation of the surrounding structures, namely the facial nerve. Various surrounding anatomical landmarks are very useful in accurate localization of the round window during cochlear implantation. Objectives: We hereby present 5 important landmarks for the easy and accurate localization of the round window niche and membrane. Results: The first is the relation between the round window and oval window, the second is the pyramid and the third is the fustis. The round window membrane itself should be seen in all cases and is considered the fourth landmark. Finally, as the aim is the proper positioning of the electrode inside the cochlea, the identification of the inside of the cochlea is considered the fifth landmark. We describe the detailed surgical techniques to identify these landmarks easily and in the most difficult situations of cochlear implantations. [ABSTRACT FROM AUTHOR]

In patients with residual hearing it is crucially important not to alter the fine structures of the cochlea. In this study we analyzed the anatomic variations of the "hook" region on 35 cadaveric temporal bones and tried to find out the optimal electrode insertion rout. Basing on the distance between the edges of oval and round windows all 35 cadaveric temporal bones were divided into two groups: "small" and "big" ones (on the ground of classification proposed by F. Atturo, M. Barbara, H. Rask-Andersen). It was revealed that this distance correlates with the position of the "hook" region structures: osseous spiral lamina, spiral ligament, basilar membrane, cochlear aqueduct and accessory aqueduct housing inferior cochlear vein. In the experimental study we compared 4 types of electrode insertion: via round window, with the use of anterior cochleostomy, anterior-inferior cochleostomy and enlarged round window. It was proved that the most nontraumatic approach in both "small" and "big" cochleae is the electrode delivery via round window membrane. This approach in all cases enabled electrode insertion without altering "hook" region structures. When anterior cochleostomy was performed in both "small" and "big" cochlea spiral ligament and lateral portion of the osseous spiral lamina were inevitably damaged in all the specimens. In 33% "big" cochlea cases basilar membrane was also altered. Whereas in temporal bones with anterior-inferior cochleostomy spiral ligament and osseous spiral lamina remained intact in 66% of "big" cochlea and in 50% of "small" cochlea and there was a significant risk especially in "small" bones (83 %) of damaging the cochlea aqueduct and accessory aqueduct. As for the enlarged round window approach we revealed alteration of cochlea aqueduct and its accessory canal in 75% cases ("small" cochlea) and 50% cases ("big" cochlea). [ABSTRACT FROM AUTHOR]

The most common indication for bone conduction devices (BCD) is conductive (CHL) or mixed hearing loss (MHL), or less frequently, single-sided deafness (SSD). Although chronic inflammatory diseases of the temporal bone with or without cholesteatoma are the underlying causes in the majority of CHL/MHL patients implanted with a Bonebridge device, a neuro-otologic disorder can be found in most SSD cases. This study aimed to evaluate the feasibility of transmastoid implantation with or without the addition of implant lifts in different pathologies, using a radiological simulation program. 240 temporal bones of 60 adult subjects with neuro-otologic diseases (NOD) and 60 subjects with chronic inflammatory diseases (CID) were enrolled. Complete implantation was possible in almost all cases with NOD as well as chronic otitis media without cholesteatoma (COM), requiring an implant lift in 50% of COM and 20% of NOD (p=0.025) cases. In contrast, in subjects with cholesteatoma, implantation required an additional tool in 95.5% of cases, leading to 59 % implantability rate in these temporal bones. Conclusion: Implant lifts increase the transmastoid implantability of the Bonebridge significantly in subjects with CID of the temporal bone. A preoperative radiological simulation to determine the ideal placement of the BC-FMT with regard to the position to the sigmoid sinus and the dura of the middle fossa is advisable in these cases. [ABSTRACT FROM AUTHOR]

Objectives: Bonebridge implantation is usually performed on a planned site of temporal bone with guidance of preoperative CT scan. However, planning of the exact site for BMT is difficult due to variations of anatomical structures. We present an implantation technique using common surgical landmarks of mastoid bones such as the tegmen mastoideum and the sigmoid sinus. Methods: A small hole in the mastoid bone was made first in keeping with the planned position for the BMT using preoperative CT scan, then the tegmen mastoideum and the sigmoid sinus through the hole were identified. After two structure were identified and then the cortical bones over the structures were removed. If the tegmen mastoideum and the sigmoid sinus displaced inferior and anterior. The bone bed was widen inferior to the tegmen mastoideum and anterior to the sigmoid sinus. Results: This technique allows exact positioning of the BMT by identifying the surgical landmarks first and minimizes the risk of complication. Conclusions: A surgical technique using landmarks such as the tegmen mastoideum and the sigmoid sinus for Bonebridge implantation is useful and safe. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the histopathology of human temporal bones with a history of cochlear implant to determine the localization of fibrosis and damage to cochlea. Background: This study addresses the histopathological findings of cochlear implantation in order to better guide the design of electrodes for cochlear implant and surgical approaches. Material and methods: Sixty celloidin embedded archival human temporal bone pairs from patients with unilateral cochlear implants were studied to understand the mechanism of cochlear damage following surgery and longterm implantation. The histopathological findings were compared between the implanted side and the contralateral unimplanted side. Results : The insertion of a cochlear implant electrode through the round window approach was associated with a significantly lesser degree of fibrosis compared with cochleostomy insertion. The temporal bone surrounding perilymphatic and endolymphatic compartments contained fibrous tissue that was in some cases, localized, and in other cases, widespread and ossified in proximity to the cochleostomy. There was fibrosis in areas where the electrodes encountered the anterior bend of the first cochlear segment and this was commonly present. Overall, the anatomy of the apical turns were better spared compared to the other areas. None of the specimen where the straight electrode was inserted through the round window demonstrated translocation. Seven temporal bones demonstrated erosive changes of the lateral wall consistent with secondary degeneration due to long term use of the electrode. Conclusion: The temporal bone histopathology findings implicate that the round window electrode insertion method is preferred over cochleostomy due to the apparent inciting of fibrosis and in severe cases, ossification near the cochleostomy site. In addition, the findings implicate that the midscala electrode design is recommended to avoid secondary changes to the lateral wall for long term use. [ABSTRACT FROM AUTHOR]