Which finding would you LEAST likely expect in a patient with an orbital floor fracture?

• A. Trapped Inferior Rectus
• B. Trapped Inferior Oblique
• C. Hypoesthesia of the Cheek
• D. Trapped Superior Oblique

Answer: (D)

In an orbital floor blow-out fracture, the floor is disrupted and contents can herniate into the maxillary sinus, so the structures occupying the floor are most at risk. The infraorbital nerve runs in the infraorbital canal within the floor, so injury here commonly causes hypoesthesia of the cheek. The inferior rectus muscle lies along the floor and is the muscle most likely to become entrapped in the fracture fragment, leading to limited upward gaze and diplopia, especially on upgaze. The inferior oblique also runs near the floor and can be entrapped, though this is less common. The superior oblique, however, sits in the superior orbit and through the trochlea, far from a floor fracture, making entrapment unlikely. Therefore, entrapment of the superior oblique would be the least likely finding.