the midfacial skeleton is resolved into a series of geometric shapes : the pentahedral orbit resting on the tetrahedral maxillary sinus , the wedge-shaped ethmoid pyramid occupying the upper outer quadrant of the v-roofed naso-ethmoid box which is related anteriorly to the folded-disk frontal sinuses and external nasal wedge , and posteriorly to the sphenoid box and triangular pterygopalatine fossa wedge .
C0037253
skeleton
C0015027
ethmoid