Background: Minimally invasive cochlear implant surgery by using a microstereotactic frame demands solid connection to the bone. We aimed to determine the stability of commercially available orthodontic miniscrews to evaluate their feasibility for frame's fixation. In addition, which substitute material most closely resembles the mechanical properties of the human temporal bone was evaluated.
Methods: Pull-out tests were carried out with five different types of orthodontic miniscrews in human temporal bone specimens. Furthermore, short fiber filled epoxy (SFFE), solid rigid polyurethane (SRPU50), bovine femur, and porcine iliac bone were evaluated as substitute materials. In total, 57 tests in human specimens and 180 tests in the substitute materials were performed.
Results: In human temporal bone, average pull-out forces ranged from 220 N to 285 N between screws. Joint stiffness in human temporal bone ranged between 14 N/mm and 358 N/mm. Statistically significant differences between the tested screws were measured in terms of stiffness and elastic energy. One screw type failed insertion due to tip breakage. No significant differences occurred between screws in maximum pull-out force. The average pull-out values of SFFE were 14.1 N higher compared to human specimen.
Conclusion: Orthodontic miniscrews provided rigid fixation when partially inserted in human temporal bone, as evidenced by pull-out forces and joint stiffness. Average values exceeded requirements despite variations between screws. Differences in stiffness and elastic energy indicate screw-specific interface mechanics. With proper insertion, orthodontic miniscrews appear suitable for microstereotactic frame anchoring during minimally invasive cochlear implant surgery. However, testing under more complex loading is needed to better predict clinical performance. For further pull-out tests, the most suitable substitute material is SFFE.
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http://dx.doi.org/10.1177/19160216241248669 | DOI Listing |
Head Neck
January 2025
Department of Otolaryngology, Head and Neck Surgery, Princess Alexandra Hospital, Queensland Skull Base Unit, Brisbane, Queensland, Australia.
Background: Standardized surgical approaches to advanced pre-auricular cutaneous squamous cell carcinomas (cSCC) are lacking.
Methods: Fifty-four patients who underwent lateral temporal bone resection (LTBR) for pre-auricular cSCC were grouped into "Levels" of increasing disease spread. Surgical approaches to achieve negative-margin resection were designed for each Level and replicated on cadaveric specimens.
Zhonghua Yi Xue Za Zhi
January 2025
Otology Medical Center, the First People's Hospital of Foshan, Foshan528000, China.
This study aimed to investigate the efficacy of inverted door flap (IDF) combined with transcanal approach to the tympanic antrum (TCAA) technique under the endoscope for treatment of middle ear cholesteatoma. Outcomes of patients treated with combined techniques at the First People's Hospital of Foshan City between March 2021 and March 2023 were evaluated. A total of 31 patients (33 ears, 16 males and 15 females) aged (42.
View Article and Find Full Text PDFWorld Neurosurg
January 2025
Department of Anatomy, Federal University of Pernambuco, Recife, Brazil. Electronic address:
Jacob Fidelis Ackermann was a German Medical Doctor born in 1765 in the city of Rüdesheim. Between 1789 and 1815 years he was professor of medicine at the universities of Mainz and Heidelberg, teaching the disciplines of anatomy, physiology, botany, and natural history. In his famous work on basilar invagination, Ackermann described and illustrated the cranial base flattening in two skulls from Italy.
View Article and Find Full Text PDFEur Arch Otorhinolaryngol
January 2025
Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
Objective: Intraoperative systems for monitoring facial nerve function, in which temporal electrical stimulation is applied to the facial nerve through electrodes, are used in many surgeries requiring facial nerve preservation; however, continuous stimulation or quantitative evaluation of facial nerve function is difficult with this approach. We examined the usefulness of a continuous and quantitative facial nerve-monitoring system for temporal bone lesions by using our experience to modify the existing methods used for cases involving vestibular schwannomas.
Study Design: Retrospective observational study.
Eur Arch Otorhinolaryngol
January 2025
Guilloz Imaging Department, Central Hospital, University Hospital Center of Nancy, Nancy, 54000, France.
Background And Purpose: To evaluate various anatomical parameters and their relationship to chorda tympani nerve (CTN) injury and round window (RW) access during cochlear implantation.
Materials And Methods: Ultra-high-resolution CT images of 66 patients were retrospectively reviewed and compared with operative reports. The facial recess and the round window were analyzed, mainly using the chorda-facial angle (CFA), the width of the facial recess, the CTN-tympanic annulus distance, the RW-mastoid portion of the facial nerve angle, and the type of RW.
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