Anatomical Variations of the Foramen Ovale and Trigeminal Neuralgia

The foramen ovale (FO) is a prominent foramen situated in the middle cranial fossa, allowing passage for a branch of the trigeminal (Vth cranial) nerve, along with the accessory meningeal artery, an emissary vein, and potentially other anatomical features. Initially, it develops as a ring-shaped foramen, but upon complete ossification, its shape varies, with potential differences in size and form as well. This research aims to investigate the diverse anatomical variations of the FO and their implications for the structures traversing it, particularly the third branch of the trigeminal nerve, which may lead to neuropathies such as trigeminal neuralgia. The study utilized databases like PubMed and Scopus, employing the sentence "Anatomical variations of the foramen ovale and trigeminal neuralgia," along with supplementary retrieval from the bibliographies of relevant articles. In addition to the bibliography retrieved from the bases, a secondary search of articles from the selected bibliographies was also performed. A total of 84 articles were found, of which our study includes 19 articles that meet the selection criteria. The examination revealed numerous possible variations, not only in shape but also in the morphometric properties of the FO. These variations in dimensions and the presence of additional bony formations may influence the anatomical structures passing through it, potentially leading to their entrapment or compression, and resulting in neurological symptoms, specifically trigeminal neuralgia. Consequently, there are documented instances of trigeminal neuralgia linked to vascular compression and the entrapment of the trigeminal nerve. However, further investigation into the various hypotheses surrounding its etiology is essential to elucidate the specific mechanisms underlying the neuropathy, thereby enabling medical specialists to better manage patients with trigeminal neuralgia.