Most common cause of fracture of roof of orbit-
Orbital-roof fractures are usually the result of high-energy injuries. They may be anteriorly continuous with an injury to the supraorbital rim or frontal sinus, or they may extend posteriorly to the superior orbitalfissure Ref khurana 6/e 402
Blow on back of head
Blow on parietal bone
Blow on the forehead
Blow on the upper jaw
Ocular trauma 