Holes in the head: parietal foramina, a developmental anomaly seen during a routine orthodontic assessment

Emissary Foramina of the External Occipital Protuberance: A Magnetic Resonance Imaging Study

OBJECTIVE

The posterior interparietal region is known to be a distinct area of the skull, predisposing to a variety of bony variants and congenital anomalies. The bony canals in this region have not yet been explored in detail. This study aimed to characterize them.

PATIENTS AND METHODS

Overall, 82 patients underwent thin-slice contrast magnetic resonance imaging. Coronal and sagittal images were used for the analysis.

RESULTS

At the rostral limit of the posterior interparietal region, the parietal foramen (PF) and transmitting emissary vessels were identified in 84% of cases, mostly delineated as single channels. They were located in the left parasagittal region (PS) in 26%, lateral to the left PS in 33%, right PS in 40%, lateral to the right PS in 12%, and midline in 16% of the cases. In 4% of the cases, the PF presented an obstruction around the outer opening. In the more caudal part of the posterior interparietal region, 51% of the patients presented with fine bony canals and transmitting emissary vessels, lying in the midline and parasagittal levels.

CONCLUSIONS

The frequency of PFs may be underestimated for superficially hidden outer openings of the canals. The midline posterior interparietal region may present fine bony canals for transmitting emissary vessels that function complementarily with PFs.

Unexpected artefacts and occult pathologies under CBCT

Purpose

To present the most frequent occult pathologies unexpectedly encountered via cone-beam computed tomography (CBCT), with particular reference to the diagnostic role of the dentist and that of the radiographer, with a view to clarifying where the diagnostic responsibility lies.

Material and methods

A narrative literature review on the most diffused occult pathologies under CBCT was conducted, with iconographical guide as an example for each category.

Results

The most frequent forms of unexpected pathologies encountered are: the presence of foreign bodies, airway anomaly, and the presence of radio-opacity or -transparency in the maxillofacial district.

Conclusions

The orthodontists must know that they are responsible to recognize these frequent, and potentially serious, pathologies of the head and neck. If the dentist feels unable to take on this responsibility, he or she should, however, be sure to have the scans read by a specialist radiologist.

Enlarged parietal foramina: a review of genetics, prognosis, radiology, and treatment

INTRODUCTION

Enlarged parietal foramina are variable ossification defects in the parietal bones that present as symmetric radiolucencies on skull radiographs. In contrast to the normal small parietal foramina, enlarged parietal foramina are a hereditary condition and genes associated with it have been identified.

METHODS

A literature review was performed to discuss the many known findings related to enlarged parietal foramina.

CONCLUSIONS

Even though they remain asymptomatic in the majority of cases, they may be associated with other pathologies and occasionally become symptomatic. This article provides a comprehensive review of the current knowledge of enlarged parietal foramina.