Facial Bones
Lateral IR Size: 8x10 LW SID: 40"" Page #'s: 2:325,292	Positioning:   • True Lateral with affected side to IR   • Upright if possible to demonstrate air / fluid levels	CR Entrance & Angle:   • _|_ to zygoma 1/2 way between outer canthus & EAM   • Collimation:   • Best to Determine:   • Entire facial bones in lateral position   • Zygomatic bone in the center	Eval Criteria:   • SI orbital roofs & mandibular rami   • NR by sella turcica in profile
Parietoacanthial (Waters) IR Size: 8x10 LW SID: 40"" Page #'s: 2:328,294	Positioning:   • Upright or prone facing bucky   • Nose should be ~3/4"" from grid   • Upright if possible to demonstrate air / fluid levels	CR Entrance & Angle:   • _|_ to exit acanthion   • Collimation:   • Best to Determine:   • Orbits, Maxillae & Zygomatic arches	Eval Criteria:   • NR by Equidistant lat borders of skull & orbits   • ***Must be met or need to repeat if Petrous ridges aren't immediately below the maxillary sinuses
PA axial (Caldwell) IR Size: 8x10 LW SID: 40"" Page #'s:	Positioning:   • Same as Cranium-Caldwell + added angle   • Pt prone or seated/upright in PA position:   • Pt forehead & nose: rest on bucky   • AP/AP axial may also be performed-Cephalad angles entering nasion (Orbits will be magnified ^ OID):	CR Entrance & Angle:   • CR exits Nasion.   • General study 15° caudad; if orbital floors of interest CR 30° caudad (Exaggerated Caldwell) Collimation:   • Best to Determine:   • Orbital rims, maxillae, nasal septum, zygomatic bones & anterior nasal spine	Anatomy to IR:   • MSP centered to IR & OML _|_ to IR, Nasion to crosshairs Eval Criteria:   • Entire cranial perimeter   • NR by Equidistant lat borders of skull & orbits   • Symmetric petrous ridges in lower 1/3 of the orbits