RT 233 Skull Radiography introducing Zygomatic Arches
Zygomatic Arches This is just getting more and more fun ! ! ! 1 Anatomy of Zygomatic Arches 2 Essential Projections 3 Pathology of Zygomatic Arches
Anatomy of Zygomatic Arches Bones Involved, anatomical landmarks 1
The squamous portion of the temporal bone is the thin upper portion. It forms a part of the side of the cranium and has a prominent arched process called the zygomatic process. The zygomatic process projects anteriorly articulating with the zygomatic facial bone, this completes the zygomatic arch. On the inferior border of the zygomatic process is the rounded eminence called the articular tubercle. The articular tubercle forms the anterior boundary of the mandibular fossae. The mandibular fossa receives the condyle of the mandible to form. Anatomy of Zygomatic Arches
Anatomy of Zygomatic Articulations 1) _________________ 2) _________________ 3) _________________ 4) _________________ 5) _________________
Possible Indications for Zygomatic Arch Imaging 1.Car accident 2.Sports injury 3.Domestic violence, child or elder abuse 4.Blunt trauma 5.Fall 6.Gunshot
2 Essential Projections SMV, Tangential, modified Townes
Submentovertical (SMV) Tangential Anteroposterior (AP) axial (modified Towne) Essential Projections: Zygomatic Arches
Submentovertical Zygomatic Arches Patient position – Seated upright or supine – If supine, elevate thorax Part position – Hyperextend neck to place IOML parallel with IR plane – Rest head on vertex – MSP perpendicular to IR plane
Submentovertical Zygomatic Arches CR – Perpendicular to IOML – Enters MSP of throat at level 1 inch (2.5 cm) posterior to outer canthi – Center IR and CR Collimated field – 8 x 10 inches (18 x 24 cm)
Tangential Zygomatic Arches Patient position – Seated upright with back against vertical Bucky – Supine with trunk elevated
Tangential Zygomatic Arches Part position – Hyperextend neck and rest head on vertex – IOML as parallel with IR plane as possible – Rotate MSP of head 15 degrees toward side being examined – Tilt top of head 15 degrees away from side being examined – Center zygomatic arch to IR
Tangential Zygomatic Arches CR Perpendicular to IOML Centered to zygomatic arch at a point 1 inch (2.5 cm) posterior to outer canthus Centered to IR Collimated field 8 x 10 inches (18 x 24 cm)
AP Axial (Modified Towne) Zygomatic Arches Patient position Seated upright or supine Part position MSP perpendicular to midline of grid OML perpendicular to IR plane May use IOML and increase CR angle
AP Axial (Modified Towne) Zygomatic Arches CR Angled 30 degrees caudad to enter glabella approximately 1 inch (2.5 cm) above nasion If IOML used, angle 37 degrees caudad Center IR and CR Collimated field 8 x 10 inches (18 x 24 cm)
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3 Pathology of Zygomatic Arches LeFort Fractures, Tripod Fractures,
FRACTURES SITES
TRIPOD FRACTURE Radiographic signs of facial fractures Indirect Signs The most common mechanism producing facial fractures is auto accidents. About 70 % of auto accidents produce some type of facial injury, although most are limited to soft tissue. The face seems to be a favorite target in fights or assaults, which are the next most common mechanism. The remainder of facial fractures are produced by falls, sports, industrial accidents and gunshot wounds. Less than 10 % of all facial fractures occur in children, perhaps because of the increased resiliency of a child's facial skeleton. The most common patterns of midfacial fractures are summarized in the table below. Probably the most common facial fracture is the tripod or zygomaticomaxillary complex fracture, so called because it involves separation of all three major attachments of the zygoma to the rest of the face.
LeFort Fractures
LeFort Fractures, Type I, Type II
Organize with Sections Type III LeFort
___________ Fractures
_____________ Zygomatic Arches
Isolated Zygomatic Arch Fractures
Where is the fracture?
Name this fracture:
What’s Your Message? ZYGOMATIC ARCHES