<prompt> A teenager brought with blow out fracture of orbit. The fracture may involve mainly:Roof of the orbitPosterior wall of floor of orbitMedial wall of orbitMedial pa of floor of orbit  <response>: Blowout fractures mainly involve orbital floor and medial wall. When an external force is applied to the globe, intraorbital pressure increases to the point that one or more of the thin-walled bones of the orbit blow-out or fracture. The most common bone fractured is the maxillary bone which comprises the floor of the orbit. The orbital contents can be significantly displaced inferiorly after orbital blowout fracture. Ref: Shirakbari A.A., Hall M. 2011. Chapter 23. Maxillofacial Neck Trauma. In R.L. Humphries, C. Stone Eds, CURRENT Diagnosis Treatment Emergency Medicine, 7e. 