Extracranial cored method of human monobloc temporal bone harvest

Extracranial cored method of human monobloc temporal bone harvest | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Extracranial cored method of human monobloc temporal bone harvest Yann Lelonge¹’², Asimakis Asimakopoulos¹, Florian Bergandi², Alexandre Karkas¹, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7041372/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 13 Nov, 2025 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted 4 You are reading this latest preprint version Abstract Purpose Surgical skills requires a combinaison of anatomical knowledge and manual skills. Donated bodies remain an armament for teaching temporal bone dissection. Temporal bone skills courses are often organized with a single, massed block of practice, using head or temporal bones specimens. Ethical considerations limit body segmentation, and temporal bone harvesting can be difficult and time consuming. We describe a simple technique of harvesting temporal bone specimens from human cadaver called “the extracranial cored method” (CM). Then, we qualitatively validated the harvested specimens during a surgical training course Methods A 63mm hole saw and 63mm core drilling machine were used to harvest monobloc of two temporal bones without calvarium section. Then just two complementary bone cuts were necessary passing through the dorsum sellae and the posterolateral aspect of the foramen magnum. Subsequently, specimens harvested were evaluated during temporal bone surgical course by sixteen participants (senior and fellow group) Results The CM was assessed on 8 human cadavers. In all cases, two temporal bone specimens could be obtained in good macroscopic conditions. All sixteen temporal bones specimens were harvested in less than 60 minutes .No cosmetic deformities were noted after harvest. All temporal bones were found to be intact and in optimal condition for surgical course. For the qualitative, all items scored above 4 on a 5-point Likert scale, except for odor in the fellow group (mean score 3.3 ± 0.55 vs. 5 in the senior group; p = 0.0011). The macroscopic appearance was rated lower in the MD group compared to the fellow group (4.2 ± 0.95 vs. 4.8 ± 0.33; p = 0.036). All participants considered the presentation of the temporal bone to be ethical. In the MD group, the most preferred model was the fully segmented head, followed by the temporal bone ( p = 0.826). In the fellow group, the temporal bone was rated as the best model Conclusion The CM is a rapid, efficient, and reproducible harvesting technique that allows the extraction of two temporal bone specimens per cadaver with minimal bone cuts, without sectioning the calvarium and respecting cosmetic aspect. It is well-suited for use in otologic training courses, although it presents certain limitations for approaches involving the internal auditory canal temporal bone temporal bone removal embalming human body surgical training Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Surgical skills requires a combinaison of anatomical knowledge and manual skills. It has been demonstrated that trainee surgeons learn surgical techniques quickly and effectively using simulated surgical procedures [15]. Virtual simulators, phantom and animal models cannot reproduce perfectly the complexity and variability of the human anatomy [18]. Cadaveric training remains the gold standard before surgery on the live patient, although it is not new. The value of surgical rehearsal on cadavers before proceeding to supervised live patient surgery and ultimately independent practice is intuitively acknowledged [8]. Since the advent of the surgical microscope, otologic procedures have evolved into high-precision techniques. Although synthetic replicas of temporal bones made of acrylic resin have been developed for trainee surgeons, cadavers and donated bodies remain an armament for teaching temporal bone dissection [1,13]. Acquiring the dexterity to drill the temporal bone, as well as mastering its anatomy, is the stepping-stone to successful ear surgery. Dissection on cadaveric bones confers exposure to the myriad anomalies as well as confers the alertness to recognize an anomaly [7], and has been considered the gold-standard training method. However, during the recent decades, the number of temporal bones available for dissection has decreased due to stricter legislation as well as reduced number of specimens donated for scientific use. [2] Temporal bone skills courses are often organized with a single, massed block of practice, using head or temporal bones specimens. Total head required decapitation, questionable from the ethical point of view [14], and temporal bone harvesting could be difficult and time consuming. There are two techniques, with variations, described for intracranial temporal bone resection : the bloc method (BM) and the plug method (PM) [3,12,16,19], both requiring calvarium removal. The aim of this study was to describe a simple and novel technique of harvesting temporal bone specimens from human cadaver called “the extracranial cored method” (CM). Then, we qualitatively validated this harvesting method during a surgical training course. Material and Method Body Donors This study was conducted in the laboratory of anatomy of Saint-Etienne University according to the rules of the donation bodies program of the University, between Febrary 2025 to April 2025. All body donors provided informed consent for the use of their cadavers for research purposes, in accordance with the Declaration of Helsinki. The anatomical procedure was approved by the local ethics committee (Project No. 42-25-05) on febrary 2025. Fixation Fixation was achieved through embalming via intra-arterial injection through the carotid artery using a Frigid Fluid® embalming pump. A perfusion pressure ranging from 0.5 to 1.0 bar was applied, depending on the vascular condition of each cadaver, utilizing a Genelyn Ultra formaldehyde-based fixation solution. Photographic and Diagrammatic Documentation Images were captured with the integrated Iphone11 Full HD camera (resolution 9248 x 6936 pixels) Temporal bone harvest The equipment included a customized drill with 63mm hole saw and 63mm core drilling machine. Detachment of the temporal cored bone plug from soft tissue was done by a combinaison of forceps, scissors scalpels and towels. Section from skull base needed oscillating saw or circular saw. A single technician realized the procedure. The scalp was incised with coronal incision 6cm above the external auditory canal, which was transected. Zygomatic arch, mastoid and temporal fossa must be visualized. A first drill centered on external auditory canal was done bilaterally with hole saw. Then, the core drilling machine was directed toward the opposite. Saline irrigation was unnecessary because of brain matter. The two temporal bones were extracted in monobloc with Ferguson bone-holding forceps. Brainstem was carefully elevated from the bony vault, and all the cranial nerves were sharply cut with scissor. Then two osteotomies were made passing through the dorsum sellae and the posterior cranial fossa from the posterolateral aspect of the foramen magnum, respecting the petrous ridge and medial end of the internal acoustic canal (Figs. 1 , 2 and 3 ). Residual soft tissue attachment were removed with sharp dissection. The external auditory canal and scalp incisions were closed without cosmetic defect. Temporal bone dissection course In march 2025, the laboratory of anatomy of Saint-Etienne University held a one-day course in otologic surgery. The course was advertised for the benefit of senior and fellow trainees. There were 3 trainers and 13 participants. The feedback form was given to all 16 individuals involved in the course. The surgical procedures were : atticoantral mastoidectomy, posterior tympanotomy, ossiculoplasty with stapes transposition and partial ossicular reconstruction prosthesis placement, endolymphatic sac decompression, labyrinthectomy and translabyrinthine internal auditory canal approach. The surgical steps were realized on temporal bone haversted with the CM, hold in dissection bowl. (Fig. 4 ) At the end of the course all participants were asked, anonymously, to rate six items on a 5-point Likert scale ( 1 = strongly disagree, 5 = strongly agree) : macroscopical aspect, microscopical aspect, positioning, manipulation, drilling, structure identification, odor and ethical aspect. Finally, at the end of the course, participants were asked to score which model they potentially preferred for otologic courses : temporal bone harvested with CM, segmented head, body, virtual reality dissection or 3D-printed model. They associated point scale for each model : one point to the worst, five points to the best. Data were collected using Excel® software (Microsoft Corporation, USA). The evaluation items were pre-tested and validated by board-certified surgeons and residents not involved in the study. Statistical analysis Data are expressed as means. For qualitative dissection analysis, differences between groups were evaluated using the Mann–Whitney test, with a significance threshold set at p < 0.05. Data were analyzed using R software version 4.5.0 (R Core Team (2020). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria) for Windows Results Temporal bone harvest The extracranial cored method for temporal bone removal was assessed for efficacity and reproductibility on 8 human cadavers. In all cases, two temporal bone specimens could be obtained without disjunction. Each specimens was inspected and found to have all temporal bone components intact that we deemed necessary for training. This components included a complete external auditory canal, zygomatic process, squamous, mastoid and petrous apex, internal auditory canal. All sixteen temporal bones specimens were harvested in less than 60 minutes, including bone cuts and soft tissues removal. All temporal bones were found to be intact and in optimal condition for surgical course. Temporal bone dissection course All sixteen participants completed the questionnaire. All senior participants (MD group) had previously completed a temporal bone dissection course and were trained in otologic surgery. In contrast, none of the fellows (fellow group) had prior experience with temporal bone dissection. For the qualitative evaluation of temporal bones harvested with the CM technique, all items scored above 4 on a 5-point Likert scale, except for odor in the fellow group (mean score 3.3 ± 0.55 vs. 5 in the MD group; p = 0.0011). The macroscopic appearance was rated lower in the MD group compared to the fellow group (4.2 ± 0.95 vs. 4.8 ± 0.33; p = 0.036). All participants considered the presentation of the temporal bone to be ethical [Figure 5 ]. After the course, participants ranked and rated the different models they would have preferred to use, in ascending order of preference. In the MD group, the most preferred model was the fully segmented head, followed by the temporal bone ( p = 0.826). They noted the absence of dura mater and the temporal lobe as limitations for performing labyrinthectomy and the translabyrinthine approach. In the fellow group, the temporal bone was rated as the best model, followed by the complete head. In both groups, the 3D-printed model was ranked fourth, and virtual dissection was consistently ranked fifth [Figure 6 ]. Discussion Walvekar et al. describe two techniques for intracranial temporal bone resection: the block method and the bone plug method [19]. Both techniques require sectioning of the calvarium and removal of the brain, which increases harvesting time and the potential exposure to pathogens [17]. The block method is generally preferred, as it allows for comprehensive study of the mastoid air cells and the auditory tube. However, it requires multiple bone cuts and results in significant skull disfigurement, leading to poor cosmetic outcomes. Nadol et al. [12] recommend extracranial lateral temporal bone removal when a routine cranial autopsy is not planned. His technique involves the use of an autopsy saw to create a 5.75 cm bone plug extending to the midline. However, this approach requires disarticulation at the basisphenoid and basiocciput, which may compromise the integrity of the specimen. In contrast, our method uses a low-cost, customized saw to extract a monobloc of both temporal bones without sectioning the calvarium and with only three bone cuts. This approach minimizes macroscopic bone alteration, reduces harvesting time, and allows for a cosmetically acceptable suture without any visible facial distortion in the donor. A known disadvantage of using human cadaveric bones is the risk of transmission of infectious diseases. Although bones are typically preserved in formaldehyde or alcohol to reduce this risk, such preservation methods cause loss of natural coloration—an important factor when skeletonizing delicate structures such as the facial nerve. Frozen temporal bones offer improved color, tissue consistency, and contrast but present a higher risk of viral transmission [9]. To overcome the limited availability of human specimens, alternative training modalities have been developed, including Virtual Reality (VR) simulators and 3D-printed models. VR simulation offers a range of educational features such as on-screen guidance, integrated tutorials, and objective performance metrics, allowing trainees to track their progress and focus on areas requiring improvement. Many of these simulators incorporate haptic feedback to simulate the tactile sensation of otologic drilling; however, they do not permit the use of actual surgical instruments or microscope manipulation [1,10]. In contrast, 3D-printed models provide hands-on experience with the physical aspects of surgical procedures and more closely replicate the tactile feedback encountered during real surgery. '3D printing' refers to a range of technologies that produce physical models from digital 3D files through additive layering of materials. Despite the growing number of available printers and materials, standardized guidelines for selecting the most appropriate printing technology and material are currently lacking [4,6,11].". Nonetheless, while VR and 3D-printed models are increasingly utilized due to the declining availability of cadaveric bones, their lower cost, and evidence supporting their educational value [5], all participants in our study expressed a preference for cadaveric models over virtual ones. This may reflect selection bias, as participants voluntarily enrolled in a surgical cadaver dissection course. Other limitations of our study include the absence of a comparative technique for qualitative analysis, the lack of histological evaluation (particularly of the inner ear), and the use of a single operator to perform the CM procedure. Conclusion The extracranial cored method for temporal bone removal is a rapid, efficient, and reproducible harvesting technique that allows the extraction of two temporal bone specimens per cadaver with minimal bone cuts, without sectioning the calvarium and respecting cosmetic aspect. It is well-suited for use in otologic training courses, although it presents certain limitations for approaches involving the internal auditory canal Declarations Competing interests: The authors declare no competing interests. Funding Statement: No funding was received for conducting this study. Data availability : No datasets were generated or analysed during the current study. Ethical considerations: The procedures used in this study adhere to the tenets of the Declaration of Helsinki. Local approval committee « comité d’éthique scientifique et pédagogique de Saint-Etienne – Faculté de Médecine Jacques Lisfranc, université Jean Monnet » approve this study, number 42-25-05 Consent to participate: not concerned Consent to publish : not concerned Availability of data and materials : The data that support the findings of this study are available from the corresponding author upon reasonable request Acknowledging donor cadavers : The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase mankind’s overall knowledge that can then improve patient care. Therefore, these donors and their families deserve our highest gratitude Author contribution Y. Lelonge : Data collection or management, Data analysis, Manuscript writing/editing, figure design and photographs, Protocol/project development A. Asimakipoulos : data management, manuscript writing/editing F. Bergandi : Data collection or management A. Karkas : protocol development J-M Prades : Protocol/project development References Andersen SAW, Konge L, Cayé-Thomasen P, Sørensen MS (2015) Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice. JAMA Otolaryngol Head Neck Surg 141:913–918. https://doi.org/10.1001/jamaoto.2015.1563 Brenner E, Bleys RLAW, de Caro R, et al (2024) The legal and ethical framework governing body donation in Europe - 2nd update on current practice. Ann Anat 252:152195. https://doi.org/10.1016/j.aanat.2023.152195 Dinh C, Szczupak M, Moon S, et al (2015) Human Temporal Bone Removal: The Skull Base Block Method. J Neurol Surg B Skull Base 76:278–280. https://doi.org/10.1055/s-0034-1543972 Feigl G, Kos I, Anderhuber F, et al (2008) Development of surgical skill with singular neurectomy using human cadaveric temporal bones. 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Anat Histol Embryol 49:372–381. https://doi.org/10.1111/ahe.12539 Walvekar RR, Harless LD, Loehn BC, William Swartz (2010) Block method of human temporal bone removal: a technical modification to permit rapid removal. Laryngoscope 120:1998–2001. https://doi.org/10.1002/lary.21052 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 13 Nov, 2025 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted Editorial decision: Revision requested 05 Jul, 2025 Editor assigned by journal 04 Jul, 2025 Submission checks completed at journal 04 Jul, 2025 First submitted to journal 03 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7041372","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":481106836,"identity":"9acbf981-0666-44db-b194-980d982e4ba6","order_by":0,"name":"Yann Lelonge¹’²","email":"data:image/png;base64,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","orcid":"","institution":"CHU Saint-Etienne","correspondingAuthor":true,"prefix":"","firstName":"Yann","middleName":"","lastName":"Lelonge¹’²","suffix":""},{"id":481106837,"identity":"e2311394-44f5-4146-8692-dd559a7323c2","order_by":1,"name":"Asimakis Asimakopoulos¹","email":"","orcid":"","institution":"CHU Saint-Etienne","correspondingAuthor":false,"prefix":"","firstName":"Asimakis","middleName":"","lastName":"Asimakopoulos¹","suffix":""},{"id":481106838,"identity":"4c9f6f0b-246c-4380-892b-3d265998a0db","order_by":2,"name":"Florian Bergandi²","email":"","orcid":"","institution":"Laboratoire d’anatomie Faculté de médecine Jacques Lisfranc Saint-Etienne","correspondingAuthor":false,"prefix":"","firstName":"Florian","middleName":"","lastName":"Bergandi²","suffix":""},{"id":481106840,"identity":"f4eddc32-0b72-4ffe-8bf1-df46336559a2","order_by":3,"name":"Alexandre Karkas¹","email":"","orcid":"","institution":"CHU Saint-Etienne","correspondingAuthor":false,"prefix":"","firstName":"Alexandre","middleName":"","lastName":"Karkas¹","suffix":""},{"id":481106842,"identity":"e404ab39-3ab9-41a8-8665-b7755ec867a1","order_by":4,"name":"Jean-Michel Prades²","email":"","orcid":"","institution":"Laboratoire d’anatomie Faculté de médecine Jacques Lisfranc Saint-Etienne","correspondingAuthor":false,"prefix":"","firstName":"Jean-Michel","middleName":"","lastName":"Prades²","suffix":""}],"badges":[],"createdAt":"2025-07-03 21:08:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7041372/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7041372/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00276-025-03764-z","type":"published","date":"2025-11-13T15:57:28+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":87029796,"identity":"ba83a4fa-8b2c-440f-b1f1-6742035e0008","added_by":"auto","created_at":"2025-07-18 12:39:09","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":233780,"visible":true,"origin":"","legend":"\u003cp\u003ecustomized 63mm hole saw and 63mm core drilling machine required\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/92e29d1b83d84f0216d8f23a.png"},{"id":87029795,"identity":"8f704090-6d73-4a02-85f9-d81f4479883b","added_by":"auto","created_at":"2025-07-18 12:39:09","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":381060,"visible":true,"origin":"","legend":"\u003cp\u003eExtracranial Cored method steps; A = scalp and external auditory flap elevated; B = drilling with hole saw centered on external auditory canal; C \u0026amp; D = monobloc harvesting with core drill machine\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/cf6a84df069dec5ac62ddca9.png"},{"id":87029793,"identity":"ffd98569-696a-412c-ac8e-3ecb79439667","added_by":"auto","created_at":"2025-07-18 12:39:09","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":508200,"visible":true,"origin":"","legend":"\u003cp\u003eThe extracranial cored method monobloc ; A = before removal of brainstem and section of cranial nerves; B = black lines represent osteotomy area on skull base\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/c0964bee29bec63bffc6ecb8.png"},{"id":87029794,"identity":"10cc01e7-b258-4c59-ad35-d1ba51aa4a4a","added_by":"auto","created_at":"2025-07-18 12:39:09","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":351493,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal bone drilling\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/b50fa8c3ebb33540e2610df3.png"},{"id":87029789,"identity":"baea4555-9944-4c22-881b-13d3c02241eb","added_by":"auto","created_at":"2025-07-18 12:39:08","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":23106,"visible":true,"origin":"","legend":"\u003cp\u003eComparison between senior and fellow group during temporal bone dissection course\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/411cf17bb17598ba68ce0171.png"},{"id":87029792,"identity":"bebd7ea8-669d-4260-91b0-d265a4b33a70","added_by":"auto","created_at":"2025-07-18 12:39:08","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":22393,"visible":true,"origin":"","legend":"\u003cp\u003ePreferred model after temporal bone dissection course\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/6c2edf23c7c495bafdbb6760.png"},{"id":96105009,"identity":"a99703bc-1d37-4d42-a9ab-6ae84ab6fbe6","added_by":"auto","created_at":"2025-11-17 16:06:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2239201,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7041372/v1/c33483d9-3a90-47b5-8831-2433dc52cfb8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Extracranial cored method of human monobloc temporal bone harvest","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSurgical skills requires a combinaison of anatomical knowledge and manual skills. It has been demonstrated that trainee surgeons learn surgical techniques quickly and effectively using simulated surgical procedures [15]. Virtual simulators, phantom and animal models cannot reproduce perfectly the complexity and variability of the human anatomy [18]. Cadaveric training remains the gold standard before surgery on the live patient, although it is not new. The value of surgical rehearsal on cadavers before proceeding to supervised live patient surgery and ultimately independent practice is intuitively acknowledged [8].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSince the advent of the surgical microscope, otologic procedures have evolved into high-precision techniques. Although synthetic replicas of temporal bones made of acrylic resin have been developed for trainee surgeons, cadavers and donated bodies remain an armament for teaching temporal bone dissection [1,13]. Acquiring the dexterity to drill the temporal bone, as well as mastering its anatomy, is the stepping-stone to successful ear surgery. Dissection on cadaveric bones confers exposure to the myriad anomalies as well as confers the alertness to recognize an anomaly [7], and has been considered the gold-standard training method. However, during the recent decades, the number of temporal bones available for dissection has decreased due to stricter legislation as well as reduced number of specimens donated for scientific use. [2]\u003c/p\u003e\n\u003cp\u003eTemporal bone skills courses are often organized with a single, massed block of practice, using head or temporal bones specimens. Total head required decapitation, questionable from the ethical point of view [14], and temporal bone harvesting could be difficult and time consuming. There are two techniques, with variations, described for intracranial temporal bone resection : the bloc method (BM) and the plug method (PM) [3,12,16,19], both requiring calvarium removal.\u003c/p\u003e\n\u003cp\u003eThe aim of this study was to describe a simple and novel technique of harvesting temporal bone specimens from human cadaver called \u0026ldquo;the extracranial cored method\u0026rdquo; (CM). Then, we qualitatively validated this harvesting method during a surgical training course.\u003c/p\u003e"},{"header":"Material and Method","content":"\u003cp\u003e\u003cem\u003eBody Donors\u003c/em\u003e\u003c/p\u003e\u003cp\u003e This study was conducted in the laboratory of anatomy of Saint-Etienne University according to the rules of the donation bodies program of the University, between Febrary 2025 to April 2025. All body donors provided informed consent for the use of their cadavers for research purposes, in accordance with the Declaration of Helsinki. The anatomical procedure was approved by the local ethics committee (Project No. 42-25-05) on febrary 2025.\u003c/p\u003e\u003cp\u003e\u003cem\u003eFixation\u003c/em\u003e\u003c/p\u003e\u003cp\u003eFixation was achieved through embalming via intra-arterial injection through the carotid artery using a Frigid Fluid\u0026reg; embalming pump. A perfusion pressure ranging from 0.5 to 1.0 bar was applied, depending on the vascular condition of each cadaver, utilizing a Genelyn Ultra formaldehyde-based fixation solution.\u003c/p\u003e\u003cp\u003e\u003cem\u003ePhotographic and Diagrammatic Documentation\u003c/em\u003e\u003c/p\u003e\u003cp\u003eImages were captured with the integrated Iphone11 Full HD camera (resolution 9248 x 6936 pixels)\u003c/p\u003e\u003cp\u003e\u003cem\u003eTemporal bone harvest\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe equipment included a customized drill with 63mm hole saw and 63mm core drilling machine. Detachment of the temporal cored bone plug from soft tissue was done by a combinaison of forceps, scissors scalpels and towels. Section from skull base needed oscillating saw or circular saw.\u003c/p\u003e\u003cp\u003eA single technician realized the procedure.\u003c/p\u003e\u003cp\u003eThe scalp was incised with coronal incision 6cm above the external auditory canal, which was transected. Zygomatic arch, mastoid and temporal fossa must be visualized.\u003c/p\u003e\u003cp\u003eA first drill centered on external auditory canal was done bilaterally with hole saw. Then, the core drilling machine was directed toward the opposite. Saline irrigation was unnecessary because of brain matter. The two temporal bones were extracted in monobloc with Ferguson bone-holding forceps. Brainstem was carefully elevated from the bony vault, and all the cranial nerves were sharply cut with scissor. Then two osteotomies were made passing through the dorsum sellae and the posterior cranial fossa from the posterolateral aspect of the foramen magnum, respecting the petrous ridge and medial end of the internal acoustic canal (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eResidual soft tissue attachment were removed with sharp dissection. The external auditory canal and scalp incisions were closed without cosmetic defect.\u003c/p\u003e\u003cp\u003e\u003cem\u003eTemporal bone dissection course\u003c/em\u003e\u003c/p\u003e\u003cp\u003eIn march 2025, the laboratory of anatomy of Saint-Etienne University held a one-day course in otologic surgery. The course was advertised for the benefit of senior and fellow trainees. There were 3 trainers and 13 participants. The feedback form was given to all 16 individuals involved in the course.\u003c/p\u003e\u003cp\u003eThe surgical procedures were : atticoantral mastoidectomy, posterior tympanotomy, ossiculoplasty with stapes transposition and partial ossicular reconstruction prosthesis placement, endolymphatic sac decompression, labyrinthectomy and translabyrinthine internal auditory canal approach.\u003c/p\u003e\u003cp\u003eThe surgical steps were realized on temporal bone haversted with the CM, hold in dissection bowl. (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eAt the end of the course all participants were asked, anonymously, to rate six items on a 5-point Likert scale ( 1\u0026thinsp;=\u0026thinsp;strongly disagree, 5\u0026thinsp;=\u0026thinsp;strongly agree) : macroscopical aspect, microscopical aspect, positioning, manipulation, drilling, structure identification, odor and ethical aspect. Finally, at the end of the course, participants were asked to score which model they potentially preferred for otologic courses : temporal bone harvested with CM, segmented head, body, virtual reality dissection or 3D-printed model. They associated point scale for each model : one point to the worst, five points to the best.\u003c/p\u003e\u003cp\u003eData were collected using Excel\u0026reg; software (Microsoft Corporation, USA). The evaluation items were pre-tested and validated by board-certified surgeons and residents not involved in the study.\u003c/p\u003e\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eData are expressed as means.\u003c/p\u003e\u003cp\u003eFor qualitative dissection analysis, differences between groups were evaluated using the Mann\u0026ndash;Whitney test, with a significance threshold set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003cp\u003eData were analyzed using R software version 4.5.0 (R Core Team (2020). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria) for Windows\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cem\u003eTemporal bone harvest\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe extracranial cored method for temporal bone removal was assessed for efficacity and reproductibility on 8 human cadavers. In all cases, two temporal bone specimens could be obtained without disjunction. Each specimens was inspected and found to have all temporal bone components intact that we deemed necessary for training. This components included a complete external auditory canal, zygomatic process, squamous, mastoid and petrous apex, internal auditory canal.\u003c/p\u003e\u003cp\u003eAll sixteen temporal bones specimens were harvested in less than 60 minutes, including bone cuts and soft tissues removal.\u003c/p\u003e\u003cp\u003eAll temporal bones were found to be intact and in optimal condition for surgical course.\u003c/p\u003e\u003cp\u003e\u003cem\u003eTemporal bone dissection course\u003c/em\u003e\u003c/p\u003e\u003cp\u003eAll sixteen participants completed the questionnaire.\u003c/p\u003e\u003cp\u003eAll senior participants (MD group) had previously completed a temporal bone dissection course and were trained in otologic surgery. In contrast, none of the fellows (fellow group) had prior experience with temporal bone dissection.\u003c/p\u003e\u003cp\u003eFor the qualitative evaluation of temporal bones harvested with the CM technique, all items scored above 4 on a 5-point Likert scale, except for odor in the fellow group (mean score 3.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55 vs. 5 in the MD group; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0011). The macroscopic appearance was rated lower in the MD group compared to the fellow group (4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95 vs. 4.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.036).\u003c/p\u003e\u003cp\u003eAll participants considered the presentation of the temporal bone to be ethical [Figure \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAfter the course, participants ranked and rated the different models they would have preferred to use, in ascending order of preference.\u003c/p\u003e\u003cp\u003eIn the MD group, the most preferred model was the fully segmented head, followed by the temporal bone (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.826). They noted the absence of dura mater and the temporal lobe as limitations for performing labyrinthectomy and the translabyrinthine approach.\u003c/p\u003e\u003cp\u003e In the fellow group, the temporal bone was rated as the best model, followed by the complete head.\u003c/p\u003e\u003cp\u003eIn both groups, the 3D-printed model was ranked fourth, and virtual dissection was consistently ranked fifth [Figure \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eWalvekar et al. describe two techniques for intracranial temporal bone resection: the block method and the bone plug method [19]. Both techniques require sectioning of the calvarium and removal of the brain, which increases harvesting time and the potential exposure to pathogens [17]. The block method is generally preferred, as it allows for comprehensive study of the mastoid air cells and the auditory tube. However, it requires multiple bone cuts and results in significant skull disfigurement, leading to poor cosmetic outcomes. Nadol et al. [12] recommend extracranial lateral temporal bone removal when a routine cranial autopsy is not planned. His technique involves the use of an autopsy saw to create a 5.75 cm bone plug extending to the midline. However, this approach requires disarticulation at the basisphenoid and basiocciput, which may compromise the integrity of the specimen.\u003c/p\u003e\u003cp\u003eIn contrast, our method uses a low-cost, customized saw to extract a monobloc of both temporal bones without sectioning the calvarium and with only three bone cuts. This approach minimizes macroscopic bone alteration, reduces harvesting time, and allows for a cosmetically acceptable suture without any visible facial distortion in the donor.\u003c/p\u003e\u003cp\u003eA known disadvantage of using human cadaveric bones is the risk of transmission of infectious diseases. Although bones are typically preserved in formaldehyde or alcohol to reduce this risk, such preservation methods cause loss of natural coloration\u0026mdash;an important factor when skeletonizing delicate structures such as the facial nerve. Frozen temporal bones offer improved color, tissue consistency, and contrast but present a higher risk of viral transmission [9].\u003c/p\u003e\u003cp\u003eTo overcome the limited availability of human specimens, alternative training modalities have been developed, including Virtual Reality (VR) simulators and 3D-printed models. VR simulation offers a range of educational features such as on-screen guidance, integrated tutorials, and objective performance metrics, allowing trainees to track their progress and focus on areas requiring improvement. Many of these simulators incorporate haptic feedback to simulate the tactile sensation of otologic drilling; however, they do not permit the use of actual surgical instruments or microscope manipulation [1,10]. In contrast, 3D-printed models provide hands-on experience with the physical aspects of surgical procedures and more closely replicate the tactile feedback encountered during real surgery. '3D printing' refers to a range of technologies that produce physical models from digital 3D files through additive layering of materials. Despite the growing number of available printers and materials, standardized guidelines for selecting the most appropriate printing technology and material are currently lacking [4,6,11].\".\u003c/p\u003e\u003cp\u003eNonetheless, while VR and 3D-printed models are increasingly utilized due to the declining availability of cadaveric bones, their lower cost, and evidence supporting their educational value [5], all participants in our study expressed a preference for cadaveric models over virtual ones. This may reflect selection bias, as participants voluntarily enrolled in a surgical cadaver dissection course.\u003c/p\u003e\u003cp\u003eOther limitations of our study include the absence of a comparative technique for qualitative analysis, the lack of histological evaluation (particularly of the inner ear), and the use of a single operator to perform the CM procedure.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe extracranial cored method for temporal bone removal is a rapid, efficient, and reproducible harvesting technique that allows the extraction of two temporal bone specimens per cadaver with minimal bone cuts, without sectioning the calvarium and respecting cosmetic aspect. It is well-suited for use in otologic training courses, although it presents certain limitations for approaches involving the internal auditory canal\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eCompeting interests: The authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eFunding Statement: No funding was received for conducting this study.\u003c/p\u003e\n\u003cp\u003eData availability : No datasets were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003eEthical considerations: The procedures used in this study adhere to the tenets of the Declaration of Helsinki. Local approval committee \u0026laquo;\u0026nbsp;comit\u0026eacute; d\u0026rsquo;\u0026eacute;thique scientifique et p\u0026eacute;dagogique de Saint-Etienne \u0026ndash; Facult\u0026eacute; de M\u0026eacute;decine Jacques Lisfranc, universit\u0026eacute; Jean Monnet\u0026nbsp;\u0026raquo; approve this study, number 42-25-05\u003c/p\u003e\n\u003cp\u003eConsent to participate: not concerned\u003c/p\u003e\n\u003cp\u003eConsent to publish : not concerned\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials : The data that support the findings of this study are available from the corresponding author upon reasonable request\u003c/p\u003e\n\u003cp\u003eAcknowledging donor cadavers : The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase mankind\u0026rsquo;s overall knowledge that can then improve patient care. Therefore, these donors and their families deserve our highest gratitude\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eY. Lelonge :\u0026nbsp;\u003c/strong\u003eData collection or management, Data analysis, Manuscript writing/editing, figure design and photographs, Protocol/project development\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eAsimakipoulos\u003c/strong\u003e : data management, manuscript writing/editing\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eF. Bergandi\u003c/strong\u003e : Data collection or management\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA. Karkas :\u0026nbsp;\u003c/strong\u003eprotocol development\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eJ-M Prades :\u0026nbsp;\u003c/strong\u003eProtocol/project development\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAndersen SAW, Konge L, Cay\u0026eacute;-Thomasen P, S\u0026oslash;rensen MS (2015) Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice. \u003cem\u003eJAMA Otolaryngol Head Neck Surg\u003c/em\u003e 141:913\u0026ndash;918. https://doi.org/10.1001/jamaoto.2015.1563\u003c/li\u003e\n\u003cli\u003eBrenner E, Bleys RLAW, de Caro R, et al (2024) The legal and ethical framework governing body donation in Europe - 2nd update on current practice. \u003cem\u003eAnn Anat\u003c/em\u003e 252:152195. https://doi.org/10.1016/j.aanat.2023.152195\u003c/li\u003e\n\u003cli\u003eDinh C, Szczupak M, Moon S, et al (2015) Human Temporal Bone Removal: The Skull Base Block Method. \u003cem\u003eJ Neurol Surg B Skull Base\u003c/em\u003e 76:278\u0026ndash;280. https://doi.org/10.1055/s-0034-1543972\u003c/li\u003e\n\u003cli\u003eFeigl G, Kos I, Anderhuber F, et al (2008) Development of surgical skill with singular neurectomy using human cadaveric temporal bones. \u003cem\u003eAnn Anat\u003c/em\u003e 190:316\u0026ndash;323. https://doi.org/10.1016/j.aanat.2008.05.001\u003c/li\u003e\n\u003cli\u003eFrithioff A, S\u0026oslash;rensen MS, Andersen SAW (2018) European status on temporal bone training: a questionnaire study. \u003cem\u003eEur Arch Otorhinolaryngol\u003c/em\u003e 275:357\u0026ndash;363. https://doi.org/10.1007/s00405-017-4824-0\u003c/li\u003e\n\u003cli\u003eFrithioff A, Weiss K, Senn P, et al (2024) 3D-printed temporal bone models for training: Does material transparency matter? \u003cem\u003eInt J Pediatr Otorhinolaryngol\u003c/em\u003e 184:112059. https://doi.org/10.1016/j.ijporl.2024.112059\u003c/li\u003e\n\u003cli\u003eGeorge AP, De R (2010) Review of temporal bone dissection teaching: how it was, is and will be. \u003cem\u003eJ Laryngol Otol\u003c/em\u003e 124:119\u0026ndash;125. https://doi.org/10.1017/S0022215109991617\u003c/li\u003e\n\u003cli\u003eHolland JP, Waugh L, Horgan A, et al (2011) Cadaveric Hands-on Training for Surgical Specialties: Is This Back to the Future for Surgical Skills Development? \u003cem\u003eJ Surg Educ\u003c/em\u003e 68:110\u0026ndash;116. https://doi.org/10.1016/j.jsurg.2010.10.002\u003c/li\u003e\n\u003cli\u003eLeong AC, Aldren C (2007) \u0026ldquo;Bones of contention\u0026rdquo;: a donor register for temporal bone donation? \u003cem\u003eJ Laryngol Otol\u003c/em\u003e 121:932\u0026ndash;937. https://doi.org/10.1017/S0022215107005658\u003c/li\u003e\n\u003cli\u003eMikkelsen PT, S\u0026oslash;rensen MS, Senn P, et al (2025) Automatic Final-Product Assessment of Virtual Reality Mastoidectomy Performance: A Validity and Reliability Study. \u003cem\u003eOtol Neurotol\u003c/em\u003e 46:96\u0026ndash;103. https://doi.org/10.1097/MAO.0000000000004346\u003c/li\u003e\n\u003cli\u003eMowry SE, Jabbour N, Rose AS, et al (2021) Multi-institutional Comparison of Temporal Bone Models: A Collaboration of the AAO-HNSF 3D-Printed Temporal Bone Working Group. \u003cem\u003eOtolaryngol Head Neck Surg\u003c/em\u003e 164:1077\u0026ndash;1084. https://doi.org/10.1177/0194599820960474\u003c/li\u003e\n\u003cli\u003eNadol JB (1996) Techniques for human temporal bone removal: information for the scientific community. \u003cem\u003eOtolaryngol Head Neck Surg\u003c/em\u003e 115:298\u0026ndash;305. https://doi.org/10.1016/S0194-5998(96)70042-6\u003c/li\u003e\n\u003cli\u003eNaik SM, Naik MS, Bains NK (2014) Cadaveric temporal bone dissection: is it obsolete today? \u003cem\u003eInt Arch Otorhinolaryngol\u003c/em\u003e 18:63\u0026ndash;67. https://doi.org/10.1055/s-0033-1351681\u003c/li\u003e\n\u003cli\u003eNudeshima J, Kobayashi E (2022) Considering respect for the donated body: lessons from the scandal in France. \u003cem\u003eAnat Sci Int\u003c/em\u003e 97:313\u0026ndash;315. https://doi.org/10.1007/s12565-022-00654-x\u003c/li\u003e\n\u003cli\u003eNutt J, Mehdian R, Parkin I, et al (2012) Cadaveric surgery: a novel approach to teaching clinical anatomy. \u003cem\u003eClin Teach\u003c/em\u003e 9:148\u0026ndash;151. https://doi.org/10.1111/j.1743-498X.2012.00536.x\u003c/li\u003e\n\u003cli\u003eSagi V, Kosaraju N, Moore LS, et al (2023) Mortui vivos docent: a modern revival of temporal bone plug harvests. \u003cem\u003eFront Neurosci\u003c/em\u003e 17:1242831. https://doi.org/10.3389/fnins.2023.1242831\u003c/li\u003e\n\u003cli\u003eScott A, De R, Sadek SA, et al (2001) Temporal bone dissection: a possible route for prion transmission? \u003cem\u003eJ Laryngol Otol\u003c/em\u003e 115:374\u0026ndash;375. https://doi.org/10.1258/0022215011907901\u003c/li\u003e\n\u003cli\u003eVenne G, Zec ML, Welte L, Noel GPJC (2020) Qualitative and quantitative comparison of Thiel and phenol-based soft-embalmed cadavers for surgery training. \u003cem\u003eAnat Histol Embryol\u003c/em\u003e 49:372\u0026ndash;381. https://doi.org/10.1111/ahe.12539\u003c/li\u003e\n\u003cli\u003eWalvekar RR, Harless LD, Loehn BC, William Swartz (2010) Block method of human temporal bone removal: a technical modification to permit rapid removal. \u003cem\u003eLaryngoscope\u003c/em\u003e 120:1998\u0026ndash;2001. https://doi.org/10.1002/lary.21052\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"temporal bone, temporal bone removal, embalming, human body, surgical training","lastPublishedDoi":"10.21203/rs.3.rs-7041372/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7041372/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSurgical skills requires a combinaison of anatomical knowledge and manual skills. Donated bodies remain an armament for teaching temporal bone dissection. Temporal bone skills courses are often organized with a single, massed block of practice, using head or temporal bones specimens. Ethical considerations limit body segmentation, and temporal bone harvesting can be difficult and time consuming. We describe a simple technique of harvesting temporal bone specimens from human cadaver called “the extracranial cored method” (CM). Then, we qualitatively validated the harvested specimens during a surgical training course\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 63mm hole saw and 63mm core drilling machine were used to harvest monobloc of two temporal bones without calvarium section. Then just two complementary bone cuts were necessary passing through the dorsum sellae and the posterolateral aspect of the foramen magnum. Subsequently, specimens harvested were evaluated during temporal bone surgical course by sixteen participants (senior and fellow group)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe CM was assessed on 8 human cadavers. In all cases, two temporal bone specimens could be obtained in good macroscopic conditions. All sixteen temporal bones specimens were harvested in less than 60 minutes .No cosmetic deformities were noted after harvest. All temporal bones were found to be intact and in optimal condition for surgical course. For the qualitative, all items scored above 4 on a 5-point Likert scale, except for odor in the fellow group (mean score 3.3 ± 0.55 vs. 5 in the senior group; \u003cem\u003ep\u003c/em\u003e = 0.0011). The macroscopic appearance was rated lower in the MD group compared to the fellow group (4.2 ± 0.95 vs. 4.8 ± 0.33; \u003cem\u003ep\u003c/em\u003e = 0.036). All participants considered the presentation of the temporal bone to be ethical. In the MD group, the most preferred model was the fully segmented head, followed by the temporal bone (\u003cem\u003ep\u003c/em\u003e = 0.826). In the fellow group, the temporal bone was rated as the best model\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe CM is a rapid, efficient, and reproducible harvesting technique that allows the extraction of two temporal bone specimens per cadaver with minimal bone cuts, without sectioning the calvarium and respecting cosmetic aspect. It is well-suited for use in otologic training courses, although it presents certain limitations for approaches involving the internal auditory canal\u003c/p\u003e","manuscriptTitle":"Extracranial cored method of human monobloc temporal bone harvest","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-18 12:38:54","doi":"10.21203/rs.3.rs-7041372/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-05T15:59:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-04T12:10:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-04T05:13:41+00:00","index":"","fulltext":""},{"type":"submitted","content":"Surgical and Radiologic Anatomy","date":"2025-07-03T21:06:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e232fd84-f53c-4be5-ab07-6af817985656","owner":[],"postedDate":"July 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-17T16:00:31+00:00","versionOfRecord":{"articleIdentity":"rs-7041372","link":"https://doi.org/10.1007/s00276-025-03764-z","journal":{"identity":"surgical-and-radiologic-anatomy","isVorOnly":false,"title":"Surgical and Radiologic Anatomy"},"publishedOn":"2025-11-13 15:57:28","publishedOnDateReadable":"November 13th, 2025"},"versionCreatedAt":"2025-07-18 12:38:54","video":"","vorDoi":"10.1007/s00276-025-03764-z","vorDoiUrl":"https://doi.org/10.1007/s00276-025-03764-z","workflowStages":[]},"version":"v1","identity":"rs-7041372","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7041372","identity":"rs-7041372","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}