Parietal foramen: incidence and topography

Computed-tomography evaluation of parietal foramen topography in adults: a retrospective analysis

BACKGROUND

The parietal foramen (PF) of the skull is a variable anatomic feature with important implications for venous drainage, infection, and injury. Its topography is clinically relevant for neurosurgeons for intracranial navigation and preoperative planning.

METHODS

PF topography was investigated in a series of 440 head computed-tomography scans of Omani subjects at Sultan Qaboos University Hospital. The mean age of the patients was 52 ± 17 years and there were 160 males and 280 females. The topography features of the PF, including frequency, diameter, patency, and relative position in relation to the superior sagittal sinus (SSS), were recorded. Additionally, sex and laterality differences in PF parameters were analyzed using a Chi-square test.

RESULTS

The overall prevalence of PF was 72.3% (318/440). The bilateral presence of PF was identified in 34% of skulls. Unilateral right-side prevalence was 18.2%, while left prevalence was 13.2% (p = 0.62). The prevalence of unilateral accessory PF on the right side was 1.8%, while it was 1.1% on the left (p = 0.69). PF within the sagittal suture/or intra-sutural PF was observed in 6.8% of skulls, with a frequency of 9.4% in men and 5.4% in women (p = 0.29). The diameter of the PF was 1.45 ± 0.74 mm on the right side, and 1.54 ± 0.99 mm on the left side (p = 0.96). There were 2% of incomplete PF. The PF was located over the SSS in 70.3% on the right side and 53.8% on the left side. No significant differences were observed between the PF topography parameters and sex or laterality.

CONCLUSION

The present study for the first time reports the baseline data of PF topography in a large sample of CT scans in the Arab population. The geography and race influence the PF topography differences. PF may be used as a reliable landmark of SSS. The morphological characteristics and distribution of PF reported in this study have clinical implications for imaging diagnosis, intracranial navigation of vascular disorders, and treatment.

ANATOMICAL VARIATIONS OF THE PARIETAL FORAMEN AND ITS RELATIONS TO THE CALVARIAL LANDMARKS: A CROSS-SECTIONAL CADAVERIC STUDY

OBJECTIVE

The aim: Estimate the prevalence of the parietal foramen in the adult human skulls of Ukrainian origin, and study its morphology and relationships to main anatomical landmarks of the skull.

PATIENTS AND METHODS

Materials and methods: A cross-sectional observational study of PF was conducted with 42 random cadaveric adult human skull roofs (calvaria) collected from the laboratory and museum of Human Anatomy Department, Kharkiv National Medical University, Ukraine. The patency and the length of the PF canal were determined, and PF external/internal diameters and the distance to the calvarial landmarks from PF were measured using the caliper. Mean and standard deviation were calculated to compare with the existing data.

RESULTS

Results: In the present study 85.7% (n = 36) of the calvaria had the PF, 54.8% (n = 23) had bilateral location of PF, 30.9% (n = 13) had unilateral presence of PF (right side: 23.8%, n=10 and left side: 7.1%, n=3), and 14.3 % (n = 6) demonstrated bilateral absence of PF.

CONCLUSION

Conclusions: An anatomical variation in parietal foramen is not uncommon, and the differences can be based on multiple factors like geography and race. It is important to have detailed information on anatomical variations in different population groups to facilitate surgical and radiological interventions.

Trigonocephaly and Cranium Bifidum Occultum Treated Simultaneously Using the Split-Bone Technique and Piezosurgery

Cranium bifidum occultum (CBO) is a rare congenital disease characterized by the anomalous ossification of parietal bones, which presents with a midline bone defect with no extrusion of intracranial content. Its association with craniosynostosis has been reported only a few times to date. The aim of this case report was to describe, for the first time, the association between presumed non-syndromic trigonocephaly and CBO, as well as the treatment of both conditions using the same surgical approach. This was done by performing fronto-orbital advancement and the split-bone technique using piezosurgery, in order to achieve an autologous sample to cover the bone defect. To the best of our knowledge, this approach was proven to be safe and able to treat both diseases without a heterologous bone graft.