Zygomatic Arches Week 8 Zygomatic Arches Anatomy n

Zygomatic Arches Week 8

Zygomatic Arches: Anatomy n Prominent process called Zygomatic process n Squamous portion of temporal bone: n Projects anteriorly n Articulates with zygoma

Common Projections for Zygomatic Arches n SMV n Tangential: oblique inferosuperior n Modified Towne: AP Axial

Indications n Fractures n Trauma n Neoplastic / inflammatory processes

Le. Fort Fractures

Isolated Zygomatic Arches

Isolated Zygomatic Arch Fractures

SMV for Zygomatic Arches n Seated or supine n IOML parallel with IR n MSP perpendicular n If supine: n n n Flex knees Elevate trunk for full neck extension Relax abdomen n CR perp to IOML and entering 1” posterior to outer canthi

SMV Radiograph for Zygomatic Arches n Zygomatic arches free from overlying structures n No rotation as indicated by symmetric arches w/o foreshortening n Mandibular symphysis SI frontal bone

Tangential Projection for Zygomatic arches n Seated or supine n IOML parallel with IR n MSP 15 degrees toward side being examined n Tilt vertex 15 degrees away from side being examined n CR perp to IOML and centered to arch at a point 1” posterior to outer canthus

Tangential Anatomy

Tangential Radiograph for Zygomatic arches n Zygomatic arch free from overlying structures n Zygomatic arch not overexposed n Collimate tightly

Modified Towne: AP Axial for Zygomatic Arches n Seated or supine n MSP & OML perpendicular n CR to enter glabella approx 1” above nasion n OML: 30 caudad n IOML 37 caudad

Modified Towne Anatomy

Modified Towne Radiograph for Zygomatic Arches n No overlap of zygomatic arches by mandible n No rotation as evident by symmetric arches n Arches projected lateral to mandibular rami