<prompt> Pneumocephalus is seen in fracture ofMaxillary sinusFrontal sinusSphenoid sinusMastoid antrum  <response>: Pneumocephalus is the presence of air or gas within the cranial cavity.Pneumocephalus is seen in fracture of frontal sinus Posterior table; may also be seen in ethmoid fracturesRef: Hazarika; 3rd ed; Pg 355 