<prompt> Tear drop sign on X-ray PNS is seen inBlow out fracture of the floor of the orbitComminuted fracture of the maxillaFracture of the nasal boneFracture of the mandible  <response>: Ans. a Blow out fracture of the floor of the orbit Ref. Grainger Diagnostic Rad 4th2527; Ref . Q. 159. Of MH-2207BLOW-OUT FRACTURE is caused by fracturing of the orbital walls with herniation of orbital contents and subsequent tethering of the globe, resulting in pain and diplopia. It usually involves the orbital floor with trap-door deformity on skull AP view or characteristic Tear drop sign on X-ray PNS.Also Know: Tripod Fracture: zygomaticomaxillary fracture pyramidal fracture Le Fort II fracture fracture medial orbital and lateral maxillary walls. Bare orbit sign: Neurofibromatosis Coke-bottle sign: thyroid ophthalmopathy Mushroom-shaped posterior segment mass: choroidal melanoma Calcification is pathognomonic of: Retinoblastoma Most common intraorbital tumor in adults: Cavernous hemangioma. 