Morphological Analysis of Foramen Ovale and Foramen Lacerum in terms of Percutaneous and Endoscopic Endonasal Approaches

Aims: It is clinically extremely important to determine the surrounding structures and variations of the foramen ovale, the region where mandibular nerve blockade is performed during percutaneous and endoscopic endonasal procedures. Therefore, this study was conducted to guide clinicians in determining and choosing the surgical method to be applied, especially percutaneous and endoscopic endonasal approaches, by investigating the relationship between foramen ovale, foramen lacerum and pterygoid processes on morphological basis.

Materials and Methods: The study was conducted with 56 skulls (right and left, 112 in total). In the lower view of the skull base, the horizontal relationship between the foramen ovale/foramen lacerum and the posterior border of the base of the lateral pterygoid processes was taken into account. Skulls with injuries to the lateral plate of the pterygoid process or foramen ovale and foramen lacerum on both sides were excluded.

Results: When the position of the foramen ovale relative to the processus pterygoideus lateralis was evaluated; the most common type II (medial type) was on the right with a rate of 30.3%, and type III (direct type) was on the left with a rate of 23.3%. The lowest rate was type IV. The foramen lacerum was in direct relationship with the medial pterygoid process posteromedially at a rate of 50%.

Conclusion: The fact that the foramen ovale is far from the foramen lacerum and pterygoid processes may make surgical procedures risky, as it will make it difficult to detect the origin of the mandibular nerve.