{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T05:05:36Z","timestamp":1784178336511,"version":"3.55.0"},"reference-count":26,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T00:00:00Z","timestamp":1783987200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: The anatomical relationship between the oval window (OW) and the facial nerve (FN) is of significant importance in the context of stapes and middle ear surgery. However, the influence of mastoid pneumatization on OW morphology and FN proximity remains to be elucidated. Methods: This retrospective study included 220 radiologically normal temporal bones from 110 adults. OW width, OW height, OW niche width, FNt\u2013OW distance, FNm\u2013OW distance, OW\u2013mastoid cell distance, and OW\u2013FNm\u2013FNt corridor area were measured on HRCT images. Mastoid pneumatization was classified using a sigmoid sinus-based grading system. RASCI was developed by integrating OW morphology, OW niche width, and mastoid pneumatization. Results: The mean width of the OW, the height of the OW, and the width of the OW niche were 2.41 \u00b1 0.92 mm, 1.38 \u00b1 0.36 mm, and 1.03 \u00b1 0.38 mm, respectively. The mean FNt\u2013OW and FNm\u2013OW distances were recorded as 0.93 \u00b1 0.33 mm and 2.78 \u00b1 0.94 mm, respectively. It was established that larger OW dimensions and FN-OW distances were associated with higher levels of mastoid pneumatization. The radiological\u2013anatomical constraint was categorised as low in 21.4% of cases, moderate in 69.5%, and high in 9.1% of the temporal bones (RASCI). Conclusions: Mastoid pneumatization appears to be associated with OW morphology and FN\u2013OW spatial relationships. The RASCI could provide an initial HRCT-based framework for grading the constraints of the OW-FN corridor; however, prospective surgical validation is required.<\/jats:p>","DOI":"10.3390\/diagnostics16142200","type":"journal-article","created":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T01:05:58Z","timestamp":1784077558000},"page":"2200","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Assessment of the Oval Window\u2013Facial Canal Corridor and Mastoid Pneumatization: A Preliminary HRCT-Based Radiological\u2013Anatomical Framework"],"prefix":"10.3390","volume":"16","author":[{"given":"Burak","family":"Bileceno\u011flu","sequence":"first","affiliation":[{"name":"Department of Anatomy, Faculty of Medicine, Ankara Medipol University, Ankara 06570, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6745-4814","authenticated-orcid":false,"given":"Tu\u011f\u00e7e","family":"Ak\u0131n","sequence":"additional","affiliation":[{"name":"Department of Anatomy, Faculty of Medicine, Ankara Medipol University, Ankara 06570, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8301-9257","authenticated-orcid":false,"given":"Berin","family":"Tu\u011fta\u011f Demir","sequence":"additional","affiliation":[{"name":"Department of Anatomy, Faculty of Medicine, Ankara Medipol University, Ankara 06570, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hilal Melis","family":"Alt\u0131nta\u015f","sequence":"additional","affiliation":[{"name":"Department of Anatomy, Faculty of Medicine, Ankara Medipol University, Ankara 06570, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali","family":"K\u00f6ksal","sequence":"additional","affiliation":[{"name":"Department of Medical Services and Techniques, Vocational School of Health Services, At\u0131l\u0131m University, Ankara 06530, Turkey"},{"name":"Department of Radiology, Private Ac\u0131badem Bay\u0131nd\u0131r Hospital, Ankara 06250, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S\u00fcha","family":"Beton","sequence":"additional","affiliation":[{"name":"Department of Ear, Nose, Throat Surgery, Faculty of Medicine, Ankara University, Ankara 06230, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1258\/002221504772784540","article-title":"Positional relationship between the facial nerve and other structures of the temporal bone","volume":"118","author":"Dai","year":"2004","journal-title":"J. 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Otol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/14\/2200\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T04:36:41Z","timestamp":1784176601000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/14\/2200"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,14]]},"references-count":26,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["diagnostics16142200"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16142200","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,14]]}}}