A 38-year-old man presented with hyperophthalmia, enophthalmos, and upper eyelid retraction 18 months following an osteoplastic flap and frontal sinus obliteration for mucocele. Computerized tomography confirmed the presence of frontal bone absorption in the roof of the orbit with traction and elevation of the orbital contents into the obliterated frontal sinus. A fracture of the orbital roof with penetration of periorbita at the time of original surgery was the suspected precipitating cause of the complication. Surgical management included lysis of the cicatrix between the orbit and frontal sinus and interposition of a silicone sheet between the orbit and sinus, which restored the appropriate anatomic relationships and prevented recurrence.