Facial bones 2- NASAL BONES, ORBITS, AND ZYGOMAS

MAXILLAE articulations

Skull bones?

Facial bones?

Frontal & Ethmoid

7 facial bones - opposite maxillae, same side zygoma, lacrimal, nasal, palatine, inferior nasal conchae, vomer

ZYGOMA articulations

Skull bones?

Facial bones?

Frontal and Temporal

Maxillae

LACRIMAL articulations

Skull bones?

Facial bones?

Frontal and Ethmoid

Maxillae, inferior nasal conchae

NASAL articulations

Skull bones?

Facial bones?

Frontal and Ethmoid

Maxillae, opposite nasal bone

INFERIOR NASAL CONCHAE articulations

Skull bones?

Facial bones?

Ethmoid

Maxillae, lacrimal and palatine

PALATINE articulations

Skull bones?

Facial bones?

Sphenoid and Ethmoid

Maxillae, inferior nasal conchae, vomer, opposite palatine

VOMER articulations

Skull bones?

Facial bones?

Sphenoid and Ethmoid

Right and left Maxillae & right and left palatine

1. Frontal process of maxilla

2. Nasion

3. Lacrimal bone

4. Nasal bone

*in order→ nasal bone→ frontal process of maxilla→lacrimal

Nasal Bones radiographs

Waters

Bilateral nasal bones

What makes up the bony nasal septum?

Perpendicular plate of ethmoid

Vomer

1. Septal cartilage

2. Perpendicular plate of ethmoid

3. Vomer

Parietoacanthial (Waters) for Nasal Bones

MML & MSP perpendicular

Raise OML to form 37 degree perpendicular to IR

Petrous Pyramids below maxillary sinuses

Rotation- outer edge of orbit to lateral border of skull, looking for symmetry

View?

Label

Parietoacanthial (Waters) for Nasal Bones

1. Orbit

2. Zygomatic arch

3. Maxillary sinus

4. Maxilla

5. Petrous ridge

6. Mandibular angle

Lateral Nasal Bones

2 laterals

No grid, small focal spot, close collimation

-Interpupillary line perpendicular to IR
-MSP parallel to IR
-IOML parallel to top edge or perpendicular to side edge
-CR perpendicular, centered to ½ inch inferior to nasion
Include anterior nasal spine

What are the orbit orientations?

30° superior angle

37° medial angle

Important for the optic foramina positioning

Base of orbit

Label the 3 bones

1. Frontal (orbital plate)

2. Zygoma

3. Maxilla

Bony Composition of Orbits

7 bones

SPELMFZ- from apex to base
• Sphenoid
• Palatine
• Ethmoid
• Lacrimal
• Maxilla
• Frontal
• Zygoma

A. Frontal

B. Lacrimal

C. Ethmoid

D. Sphenoid (most posterior)

E. Palatine - vertical portion

F. Zygoma

G. Maxilla

H. Maxilla

Openings in the orbit

1. Optic foramen

2. Sphenoid strut - little line

3. Superior orbital fissure

4. Inferior orbital fissure

BLOW OUT Orbital Fracture

teardrop sign

blunt trauma to the eye, pressure builds up and floor collapse = bones break up

Orbit/Optic Foramina views

Parietorbital oblique (Rhese)

Parietoacanthial (Waters)

PA (Caldwell)

*Can replace waters with modified waters*

Parietoorbital Oblique Projection (Rhese method)

Orbits

Rotate head 37 degree toward affected side (3 point landing -chin cheek and nose)
-MSP will form a 53° to IR
-AML perpendicular to IR
-CR perpendicular to downside orbit
-Use grid 75-85 kVp
-Bilateral projections taken for comparison

Optic foramen in the lower outer quadrant

right orbit= right chin, cheek, nose

Modified Parietoacanthial (Modified Waters)

-kissing board (hint)

Orbits

-Raise OML to form a 55° angle to IR
-LML & MSP perpendicular to IR
-CR perpendicular, exits at acanthion

Petrous ridges projected in lower 1/2 of maxillary sinuses
Orbital floors not distorted

Zygomatic Arch Routine

Submentovertex (SMV) or Oblique inferosuperior (tangential)

AP axial (modified Towne)

Special (commonly part of facial bone study)
• Parietoacanthial (Waters)
• Lateral

SMV

Zygomatic arches

CR perpendicular to IOML , Center right below mentum
-IOML is parallel to IR
-Bilateral zygomatic arches

-if patient cant go all the way back= angle to match

Zygomatic arches well demonstrated in profile and symmetric

Oblique Inferosuperior (tangential)

Zygomatic arch

-Start in SMV -IOML parallel to IR
-Rotate and tilt skull 15° toward affected side
-CR perpendicular to IR and IOML
-CR to arch of interes

AP Axial (modified Townes)

Zygomatic arch

-Have patient tuck chin down
-OML perpendicular = CR 30° caudal
-Settle for IOML perpendicular = 37° caudal
-CR 1 inch superior to Nasion (to pass through mid arches)