Morphometric analysis of foramen ovale, foramen spinosum, and foramen rotundum of human skull using computed tomography scan: a cross-sectional study

Abstract

There is limited literature of objective assessments of foramina of skull base using computed tomography (CT) scan. This study was carried out to analyze the dimensions of foramen ovale (FO), foramen spinosum (FS), and foramen rotundum (FR) using CT scan imaging of the human skull and their associations with sex, age, and laterality of the body.

Materials and methods: A cross-sectional study was carried out in the Department of Radiodiagnosis and Imaging at BP Koirala Institute of Health Sciences (BPKIHS), Nepal using a purposive sampling method. We included 96 adult patients (≥18 years) who underwent CT scan of the head for any clinical indications. All those participants below 18 years, inadequate visualization or erosions of skull base foramina, and/or not consenting were excluded. Appropriate statistical calculations were done using the statistical package for social sciences (SPSS), version 21. The P-value of less than 0.05 was considered statistically significant.

Results: The mean length, width, and area of FO was 7.79±1.10 mm, 3.68±0.64 mm, and 22.80±6.18 mm², respectively. The mean length, width, and area of FS was 2.38±0.36 mm, 1.94±0.30 mm, and 3.69±0.95 mm², respectively. Similarly, the mean height, width, and area of FR was 2.41±0.49 mm, 2.40±0.55 mm, and 4.58±1.49 mm², respectively. The male participants had statistically significant higher mean dimensions of FO and FS (P<0.05) than the female participants. There were statistically insignificant correlations of dimensions of these foramina with age and between the left and right side of each foraminal dimensions (P>0.05).

Conclusions: The sex-based difference in dimensions of FO and FS should be clinically considered in evaluating the pathology of these foramina. However, further studies using objective assessment of foraminal dimensions are required to draw obvious inferences.

Keywords: human skull; morphometric analysis; objective measurement; sizes of foramina.

Figure 1

(A) Axial computed tomography image of the skull base (bone window) showing a method of measurement of foramen ovale (arrows), with calipers placed on length and width of left foramen ovale (solid lines). (B) Axial computed tomography image of the skull base (bone window) showing a method of measurement of foramen spinosum (arrows), with calipers placed on length and width of right foramen spinosum (solid lines). (C) Reformatted coronal computed tomography image of the skull base (bone window) showing a method of measurement of foramen rotundum (arrows), with calipers placed on the height and width of left foramen rotundum (solid lines).