Which of the following orbital structure is involved in blow out fracture of the skull: March 2010

Ans. D: Floor Critical signs of recent blow-out fracture include: Edema and ecchymosis of the lid tissues Restriction of ocular motility, especially with veical movements Orbital crepitus (subcutaneous emphysema) Hypoesthesia of the ipsilateral cheek, due to entrapment of the infraorbital nerve. There may also be an associated nosebleed due to communication between the orbit and maxillary sinus. Orbital edema initially surrounds and displaces the globe, in some cases causing the eye to appear proptotic. However, as the swelling subsides, the eye is likely to drop down and back, becoming enophthalmic. Associated traumatic uveitis and/or hyphema may be noted as well. Most commonly the orbital floor 'blows out', but it can also affect the medial wall of the orbit.