Detection of sexual dimorphism of the foramen magnum in cats using computed tomography

Abstract

The foramen magnum is a large round or oval opening surrounded by parts of the occipital bone. It connects the cranial cavity with the vertebral canal. The foramen magnum is an important structure having various applications in veterinary practice and forensic medicine. The variability of its shape and sexual dimorphism allow it to be exploited for sex and age identification in different species. This retrospective study used computed tomographic (CT) images of the caudal region of the 102 mixed-breed cat heads (55 males and 47 females). Eight linear measurements of the foramen magnum (FM) and occipital condyles were performed on CT images. The aim of the study was to find out if the linear measurements of the CT images of the foramen magnum showed variability between the sexes of the cats. In general, the values of the linear measurements in male cats were higher than in females. The mean maximum length of the foramen magnum (MLFM) was 11.18 ± 0.84 mm and 10.63 ± 0.72 mm in male and female cats, respectively. The mean maximum internal width of the foramen magnum (MWFM) was 14.43 ± 0.72 mm in males and 13.75 ± 1.01 mm in females. The difference between FM measurements in female and male cats was statistically significant (p value; FML: 0.001, FMW: 0.000). The MLFM confidence interval was 10.41 mm to 10.86 mm in female cats and 10.97 mm to 11.39 mm in males. The confidence interval of MWFM was 13.5 mm to 14.0 mm in female cats and 14.2 mm to 14.66 mm in male cats. With these intervals, we can predict the probability of sex in cats with 95% confidence. It was noted that measurements of the occipital condyles were not sexdetermining. The difference in foramen magnum index in female and male cats was statistically insignificant (p value; 0.875). As a result of the study, it was seen that the linear measurements of the foramen magnum were sex-determining.

Radiomorphometric analysis of the metapodial bones in the Scottish fold cats

“…The radiometry method as a useful, fast, cost-free and accurate method (Güzel et al, 2022: Koçyiğit & Demircioğlu, 2024) is used to visualize and measure different elements of skeletons from a large number of animal species like dog (Mutlu et al, 2023), dog and cats (Akbaş et al, 2023;Limmanont et al, 2019;Şenol et al, 2022), cattle, (Ince et al, 2015;Telldahl, 2015), sheep (Kahraman et al, 2022), horses (Erdikmen et al, 2021;Gündemir, Hadžiomerović, et al, 2021;Oheida et al, 2019), lions (Kirberger et al, 2005), New…”

“…In the practical veterinary clinic the method of radiometry is used to visualize and measured the different parts of the animal skeleton (Akbaş et al, 2023;Gunay et al, 2022;Gündemir et al, 2020;Gündemir, Hadžiomerović, et al, 2021). Many studies are made in this way to evaluate fetal head diameter in dogs and cats (Limmanont et al, 2019), the parameters of the foramen magnum in diferent cats breeds (Akbaş et al, 2023), carpal and phalanges morphometry in horses (Oheida et al, 2019), the morphometrical parameters of phalanges in arabian and throughbreeding horses (Gündemir, Szara, et al, 2021), variations of the distal phalanges in cattle (Manuta et al, 2024), linear paramters and angels on calcaneus in cats (Şenol et al, 2022) and horses (Erdikmen et al, 2021), description of the thoracic limbs in lions (Kirberger et al, 2005), pelvic limbs in New Zealand rabbit (Oryctolagus cuniculus) and domestic cat (Felis domestica) (El-Ghazali & El-Behery, 2018b), or to assess the sexual dimorphism in humans through calcaneus (Uzuner et al, 2016). This method is useful, fast, costless and has resulted in an accurate method from the study of Güzel et al (2022) and Koçyiğit and Demircioğlu (2024) where it has been proven that there is no statistical difference with the direct method of bone measurement with digital callipers.…”