Advanced Dental Admission Test (ADAT)

Through which bone do the three divisions of the trigeminal nerve pass?

1. Frontal bone

2. Mandible

3. Sphenoid bone

4. Maxilla

The correct answer is: Sphenoid bone

The three divisions of the trigeminal nerve, which are the ophthalmic, maxillary, and mandibular branches, all pass through the sphenoid bone. This bone serves as a critical conduit for these divisions as they extend from the brainstem to various facial regions. The ophthalmic division exits the skull through the superior orbital fissure, while the maxillary division passes through the foramen rotundum. The mandibular division traverses through the foramen ovale, all of which are features associated with the sphenoid bone. This anatomical relationship highlights the importance of the sphenoid bone as a central structure in the pathway of the trigeminal nerve's branches, facilitating sensory innervation to the face and contributing to the understanding of craniofacial anatomy in dental practice. Therefore, the sphenoid bone is key in the orientation and course of the trigeminal nerve's three divisions.