Blow out fracture of orbit most commonly involves:

Ans. a. FloorBLOW OUT ORBITAL FRACTUREUsually caused by a sudden increase in orbital pressure due to an object (fist/tennis ball), where object diameter is greater than diameter of orbital aperture.Orbital blow out fractureBlow out fracture usually involves the floor of orbit.OrbitPure blow out fracture does not involve orbital rim only floor fractureImpure blow out fracture involves orbital rim and/or facial bonesSIGNSPeriocular ecchymosis, edema, etc.Infraorbital nerve anesthesiaBlack eye (hematoma)Double vision- occurs due to mechanical entrapment of both inferior rectus and inferior oblique muscle.Enophthalmos-Sunken eye ballX-ray (Waters view): "Tear Drop" sign is seen in antrum.