RT 233 Skull Radiography

introducing

Zygomatic Arches

REVIEW: http://wn.com/Cranial_Facial_bones#/videos

Zygomatic Arches

This is just getting more and more fun ! ! !

AnatomAnatomy of y of

ZygomaZygomatic tic

ArchesArches

EssentiEssential al

ProjectProjectionsions

PatholoPathology of gy of

ZygomaZygomatic tic

ArchesArches

Anatomy of Zygomatic Arches

Bones Involved, anatomical landmarks

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) zygomatic process-temporal bone

2) Mandibular condyle

3) Articular tubercle

4) zygomatico-temporal sutures

5) zygoma

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

Essential Projections

SMV, Tangential, modified Townes

Submentovertical (SMV)TangentialAnteroposterior (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 (as much as possible)– 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)

SMV

SMV

SMV projection

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

CRPerpendicular to IOMLCentered to zygomatic arch at a point 1 inch (2.5

cm) posterior to outer canthusCentered to IR

Collimated field8 x 10 inches (18 x 24 cm)

AP Axial (Modified Towne) Zygomatic Arches

Patient positionSeated upright or supine

Part positionMSP perpendicular to midline of gridOML perpendicular to IR plane

• May use IOML and increase CR angle to ??°

AP Axial (Modified Towne) Zygomatic Arches

CR Angled 30 degrees caudad to enter glabella

approximately 1 inch (2.5 cm) above nasionIf IOML used, angle 37 degrees caudadCenter IR and CR

Collimated field8 x 10 inches (18 x 24 cm)

What about the beautiful images you’ve been seeing?

Exciting new transitions

It’s up to you.

Pathology of Zygomatic Arches

LeFort Fractures, Tripod Fractures,

FRACTURES SITES

TRIPOD FRACTURE

The tripod fracture, also called the zygomaticomaxillary complex or malar fracture, is composed of a set of three (actually 4) fractures. The first portion of the tripod fracture involves the maxillary sinus including the anterior and postero-lateral walls and the floor of the orbit. The second portion involves the zygomatic arch. The third portion involves the lateral orbital rim, usually including the lateral orbital wall, or the fronto-zygomatic suture. The term is actually not accurate as there is a fourth suture that can be involved: between the sphenoid and zygomatic bones.

LeFort Fractures

LeFort Fractures, Type I, Type II

Type III LeFort

___________ Fractures

_____________ Zygomatic Arches

Isolated Zygomatic Arch Fractures

Where is the fracture?

Waters view

What ???

Name this fracture:

Name this fracture:

Name this fracture:

What is the bone just posterior to the lacrimal bone?