{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T07:47:04Z","timestamp":1782200824800,"version":"3.54.5"},"reference-count":29,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T00:00:00Z","timestamp":1782086400000},"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: Paranasal sinus morphometry on computed tomography (CT) is of interest for forensic sex estimation, but many published predictive models rely on in-sample formulas without cross-validation, external testing, or release of model parameters. We aimed to characterize sex differences, pneumatization patterns, asymmetry, and age relationships of the paranasal sinuses in a Turkish adult population, and to develop, cross-validate, and transparently report a predictive model for sex estimation, explicitly benchmarked against the single best morphometric feature. Methods: In this single-center, STROBE-compliant retrospective cross-sectional study, maxillary, frontal, and sphenoid sinus volumes were measured by semi-automated active-contour segmentation in ITK-SNAP on CT scans of 499 adults (282 male, 217 female; 18\u201365 years). Between-sex differences were tested with the Mann\u2013Whitney U test with Bonferroni correction; effect sizes used Cliff\u2019s delta and the probability of superiority. L1-regularized logistic regression, random forest, and gradient boosting were trained with 10-fold stratified cross-validation and a held-out 20% test set, and compared with a univariate frontal-volume benchmark. Results: All three sinus volumes were larger in males (all Bonferroni-adjusted p &lt; 0.001), with the largest effect among the individual sinuses for the frontal sinus (Cliff\u2019s delta = 0.53; probability of male superiority = 0.77). The best classifier was L1-regularized logistic regression (10-fold cross-validated AUC 0.79 \u00b1 0.07; held-out test AUC 0.80; accuracy 70%). Because the area under the ROC curve of a single continuous marker equals its probability of superiority, frontal volume alone reached an AUC of approximately 0.77; the multivariable model therefore added little beyond this single feature. Age could not be reliably estimated (test mean absolute error \u2248 10.8 years; R2 \u2248 0). Conclusions: Paranasal sinus volumes show robust sex dimorphism, concentrated in the frontal sinus, but provide only moderate sex discrimination\u2014appropriate as one corroborating input in a forensic identification workflow rather than a stand-alone determinant. Age cannot be reliably estimated from sinus morphometry in this cohort. Full model coefficients are reported to permit independent replication.<\/jats:p>","DOI":"10.3390\/diagnostics16121928","type":"journal-article","created":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T06:13:37Z","timestamp":1782195217000},"page":"1928","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Paranasal Sinus Morphometry for Forensic Sex Estimation: A Computed Tomography Study of 499 Individuals with a Cross-Validated, Transparently Reported Machine Learning Model"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2853-0487","authenticated-orcid":false,"given":"Muhammet","family":"Can","sequence":"first","affiliation":[{"name":"Department of Forensic Medicine, Faculty of Medicine, Balikesir University, 10145 Balikesir, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cihangir","family":"I\u015f\u0131k","sequence":"additional","affiliation":[{"name":"Forensic Medicine Division, Bal\u0131kesir Atat\u00fcrk City Hospital, 10100 Bal\u0131kesir, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Burcu","family":"D\u00fczel As\u0131g","sequence":"additional","affiliation":[{"name":"Department of Radiology, Defne Hospital, 31000 Hatay, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1002\/ajpa.20116","article-title":"Assessing the variation in individual frontal sinus outlines","volume":"127","author":"Christensen","year":"2005","journal-title":"Am. 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