RAD 233 Facial Bones

How many facial bones?

14

what are the facial bones

2 nasal

2 lacrimal

2 maxillary

2 zygomatic

2 palatine

2 inferior nasal conchae

vomer

mandible

2 small thin bones that vary in size and shape in individuals

Nasal bones

nasal bones form superior bony wall of nasal cavity commonly called

bridge of nose

w/ what bone does the nasal bone articulate w/ at MSP

with each other

w/ what bone does the nasal bone articulate w/ superiorly

frontal bone

w/ what bone does the nasal bone articulate w/ posterosuperior?

perpendicular plate of ethmoid bone

w/ what bone does the nasal bone articulate w/ on each lateral side?

maxillae

what’s the 2 smallest bones in the skull?

lacrimal bones

Located in anterior part of medial wall of orbits between labyrinth of ethmoid and maxilla

lacrimal bone

Each lacrimal bone contains a lacrimal foramen which what passes through it?

tear duct

The lacrimal bone forms the lacrimal fossae which holds what?

lacrimal sacs (tear sacs)

the lacrimal bone articulates w/ what?

frontal

ethmoid

maxilla

inferior nasal concha

What’s the largest immovable bone of the face?

Maxillary

the maxillary articulates w/ all other facial bones except for…

mandible

what cranial bones does the maxillary articulate w/?

frontal and ethmoid

Form part of lateral walls and most of floor of nasal cavity and also forms part of the floor of orbit

maxillary

How much of the maxillary forms the roof of the mouth?

3/4

what part of the maxillary articulates w/ the zygoma to form part of the cheek?

zygomatic process

The maxillary bone contains large, pyramidal cavity known as?

maxillary sinus

Found in the maxillary bone located under each orbit for passage of infraorbital nerve and artery

Infraorbital foramen

inferior borders of spongy bone that support roots of teeth

Alveolar process

forward, pointed process at midline junction of the 2 maxillary bones

Anterior nasal spine

midpoint of the junction between the 2 maxillary bones

Acanthion

Form prominence of cheeks and part of side wall and floor of orbits

Zygomatic bone

What of the zygoma extends posteriorly to join zygomatic process of temporal bone?

Temporal process of zygomatic bone

formed by union of temporal process of zygoma and zygomatic process of temporal bone

Zygomatic arch

What does the zygoma articulate w/ superiorly?

frontal bone

What’s lateral to sphenoid

Zygoma

What does the zygoma articulate w/ laterally?

zygomatic process of temporal bone

What does the zygoma articulate w/ anteriorly?

maxilla

What does the zygoma articulate w/ posterior?

sphenoid

Two L-shaped bones composed of vertical and horizontal plates

Palatine bones

what part of the palatine bone articulate with maxillae to
complete the posterior fourth of bony palate (roof of mouth)?

Horizontal plate

what part of the palatine extend upward between maxillae and pterygoid processes of sphenoid in posterior nasal cavity

Vertical portions

What part of the palatine bone assist in forming posteromedial orbits?

Superior tips of vertical plates

Long, narrow, very thin bones with a lateral
curl that give gives scroll-like appearance

Inferior nasal conchae

How do the inferior nasal conchae project from the nasal cavity

Extend diagonally and inferiorly from lateral walls at its lower third

The inferior nasal conchae divide nasal cavity into:

Superior, Middle, and inferior meatus

what’s the function of the Inferior Nasal Conchae

warm, moisturize and clean inhaled air

the upper two nasal conchae are processes of which bone?

ethmoid

The inferior nasal conchae forms part of what?

Nasal cavity and lateral orbits

Thin plate of bone situated in MSP of floor of nasal cavity

Vomer

what part of the nasal septum does the vomer form?

inferior part

the superior border of the vomer articulates w/ what?

body of sphenoid bone

Superior part of anterior border of the vomer articulates with what?

perpendicular plate of ethmoid bone

What border of the vomer is free of articulation?

Posterior border

what’s the largest densest bone of the face?

mandible

curved horizontal portion of mandible

body

What’s the only movable bone in the skull

Mandible

two vertical portions on each side of body of mandible

Rami

junction of body and ramus in the mandible

angle of mandible (gonion)

anterior, triangular prominence in the mandible

Mental protuberance

most anterior and central part where left and right halves of mandible fuse

symphysis

superior border of mandible body; consists of spongy bone that supports roots of teeth

Alveolar process

small openings on each of side the mandible below the second premolar; transmit nerves and blood vessels

Mental Foramina

anterior process on top of ramus (mandible)

coronoid process

posterior process on top of ramus

condylar process

what part of the mandible articulates with mandibular fossa of temporal bone to form temporomandibular joint (TMJ) (mandible)

condyle

How much does the TMJ slants posteriorly and how much does it slant inferiorly and medially?

15 degrees

concave area at top of ramus between coronoid and condylar processes (mandible)

Mandibular notch

The rami project superiorly at an obtuse angle to the body of the mandible, and their broad surface forms an angle of approximately how much?

110-120 degrees

Which process of the mandible projects higher the anterior or posterior process

Anterior (coronoid process)

Small U-shaped bone situated at the base of the tongue

Hyoid bone

Accessory bone of axial skeleton – not a facial or cranial bone

hyoid bone

which is the only bone in the body that doesn’t articulate w/ another bone

hyoid bone

the hyoid bone helps as an attachment for certain muscles of what?

larynx and tongue

The hyoid consist of what?

body

2 greater cornua

2 lesser cornua

What are the essential projections of the facial bones

lateral

Parietoacanthial (Waters method)

Acanthioparietal (reverse Waters method)

Posteroanterior (PA) axial (Caldwell method)

How is the IR set up for all the facial projections?

10×12 LW

How is the MSP to the IR for the lateral facial bones?

parallel

How is the IPL to the IR for the lateral facial projection

perpendicular

For the Lat facial projection how is the IOML to the front edge of the IR?

perpendicular

CR for lateral facial projection

Perpendicular to IR enters lateral surface of zygomatic
bone halfway between outer canthus and external
acoustic meatus (EAM)

collimation for the lat facial projection

6×10 in

PT position for waters

prone or upright facing bucky

For the waters projection the head should rest where?

tip of extended chin

For the waters projection the OML should form angle of how much to the plane of the IR

37 degrees

For the water projection the Mentomeatal line (MML) and MSP should be how to the iR

perpendicular

Where are the petrous ridges shown for the waters and reverse waters?

below maxillary sinuses

for the waters projection the IR should be centered where?

Acanthion

CR for Parietoacanthial (Waters) Facial Bones

perpedicular to exit acanthion

collimation for Parietoacanthial (Waters) Facial Bones acanthioparietal(reverse waters)?

8×10 in

For the modified waters (shallow waters) the OML forms how much of an angle from the IR

55 degrees

for the Modified Waters (Shallow Waters) Petrous ridges at:

inferior orbital margin

mid-maxillary sinus

The Modified Waters (Shallow Waters) is best for ?

Blowout fractures

• Orbital floor displacement

• Opacified maxillary sinus

The reverse waters is similar to the waters except for?

It comes out more magnified

PT position for the Acanthioparietal (Reverse Waters) Facial Bones

Supine or upright facing x-ray tube

For the Reverse Waters the chin and neck should be extended to place the OML how many degrees to the plane of the IR?

37 degrees

For the reverse waters the MML should be how to the IR?

Almost perpendicular

For reverse waters the MSP is how to the IR?

perpendicular

CR for reverse waters

Perpendicular to enter acanthion, center IR and CR

Acanthioparietal (Reverse Waters) is used when

Patient cannot lie prone (trauma cases)

PT position for PA axial (caldwell) for facial bones

seated upright or prone w/ forehead and nose resting on upright bucky

For the Caldwell facial bones the OML and MSP are how to the IR

Perpendicular

For the Caldwell facial bones the IR is centered where?

Nasion

CR for the Caldwell facial bones

15 degrees caudad exiting nasion

For the Caldwell where are the petrous ridges

lower third of orbits

for the exaggerated Caldwell where are the petrous ridges

below orbital floors

For the “exaggerated” Caldwell for the orbital rims what CR angulation is used

30 degrees caudad