[TA] the surface of a bone that contributes to the walls of the orbit. TA recognizes an orbital surface (facies orbitalis... [TA]) on the following bones: greater wing of the sphenoid bone (... alaris majoris ossis sphenoidale [TA]); the body of the maxilla (... corporis maxillae [TA]); the frontal bone (... ossis frontalis [TA]); the zygomatic bone (... ossis zygomatici [TA]). SYN: facies orbitalis [TA].