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Congress: ECR25
Poster Number: C-26737
Type: Poster: EPOS Radiologist (scientific)
DOI: 10.26044/ecr2025/C-26737
Authorblock: H. Sasani1, M. Ozkan1, H. H. Celik2; 1Tekirdag/TR, 2Ankara/TR
Disclosures:
Hadi Sasani: Nothing to disclose
Mazhar Ozkan: Nothing to disclose
Hakan Hamdi Celik: Nothing to disclose
Keywords: Anatomy, Bones, Head and neck, CT, Computer Applications-3D, Computer Applications-General, Education and training, Forensics
Purpose The external occipital protuberance (EOP) is a bony projection on the occipital bone, serving as an attachment point for muscles and ligaments [1].It varies in shape due to mechanical forces, with an enlarged variant called the occipital spur or knob, which can cause symptoms like pain or remain asymptomatic. EOP is important in procedures such as nerve blocks, occipitocervical fusion, and sex determination [2].It can be classified into three types: flat (Type 1), crest (Type 2), and spine (Type 3),...
Read more Methods and materials This retrospective, cross-sectional descriptive study analyzed cranial CT scans of 1800 patients (909 males, 891 females) aged 20-79, conducted between January 2023 and March 2024. The study aimed to assess the external occipital protuberance (EOP) using morphometric measurements, such as base diameter, height, angle, diploe distance, and distance from the foramen magnum (FMAG) (Fig 2).Patients with optimal CT images and detectable EOP were included, while those with bone abnormalities or poor-quality images were excluded. Non-enhanced CT scans were performed, and...
Read more Results In our study, CT images of 1800 individuals (891 females, 909 males) aged 20-79 years were included and the values of 1590 individuals with prominent EOP were analyzed separately. In the study, morphological values were compared in 6 age groups including 300 individuals in deciles. The mean and standard deviation values of the measured parameters related to EOP in the cases included in the study are given in Table 1.In cases without significant EOP observed, EOP-related parameters could not be...
Read more Conclusion This study provides valuable insights into the occurrence and morphometric characteristics of EOP and its potential applications in age and sex estimation. It presents for the first time the measured values for EOP's angle, height, and base width, and highlights the significant differences in these parameters between age groups and genders. The study also explores the potential factors contributing to EOP enlargement, such as mechanical stress from head protraction, which could be linked to smartphone usage, though no definitive correlation...
Read more References Kadri PA, Al-Mefty O. Anatomy of the nuchal ligament and its surgical applications. Neurosurgery. 2007;61(5 Suppl 2):301-4. doi: 10.1227/01.neu.0000303985.65117.ea. Kim DI, Han SH. Non-metric study of the external occipital protuberance for sex determination in Koreans: using three-dimensional reconstruction images. Korean J Phys Anthropol. 2015;28(4):239-245. 10.11637/kjpa.2015.28.4.239. Shahar D, Sayers MG. A morphological adaptation? The prevalence of enlarged external occipital protuberance in young adults. J Anat. 2016 Aug;229(2):286-91. doi: 10.1111/joa.12466. Gülekon N, Turgut HB. The external occipital protuberance: can it be used as a criterion...
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