The objective of this study was to provide morphometric analysis of an accessory spine that was found within the lumen of the foramen ovale, as well as to find out whether this structure could mechanically irritate the mandibular nerve. A bifid spine was perceived in the macerated skull of an adult individual. It was located in the anterior part of the left foramen ovale. The overall length of the spine was found to be 1.8 mm. The spine had a homogenous structure, and showed high levels of mineralisation. We conclude that the accessory spine did not compress the mandibular nerve, and that the foramen ovale provided enough space for passage of the nerve. In all likelihood, these structures remained in anatomical accordance without causing any neurological symptoms.