cueFlash

Glossary of Procedures Test 4-Facial bones and sinuses

Start Studying! Add Cards ↓

Created by Study

Skull is __ bones divided into 2 groups: __ cranial bones + __ facial bones
22; 8; 14
Functions of facial bones
-Provide support, structure, and shape for face
-Form protective housing for upper ends of respiratory and digestive tracts
-With several of the cranial bones, form the orbital sockets for protection of the eyes

Names of facial bones
2 nasal, 2 lacrimal, 2 maxillary, 2 zygomatic, 2 palatine, 2 inferior nasal conchae (turbinate), 1 mandible, 1 vomer
Articulations of facial bones, including joints between roots of teeth and jawbones, are ________ _______ and are __________ EXCEPT for ____, which are ______ joints of the ____________ type and are ______
fibrous gomphoses; immovable; TMJs; synovial; hinge and gliding; freely movable
TMJ is articulation of ____________ with _____________ of temporal bone
mandibular condyle; mandibular fossa
Nasal bones form...
superior bony wall of nasal cavity (bridge of nose)
Nasal bones are small, thin, and can vary in ____ and _____
size; shape
Nasal bones articulate with each other in _______ and also articulate with...
MSP; perpendicular plate of ethmoid bone, frontal bone, and maxillae
What are the smallest bones of the skull?
Lacrimal bones
Lacrimal bones are very thin and are situated...
anterior to medial wall of the orbits between the labyrinth of the ethmoid bone and the maxilla
Lacrimal bones and maxillae form ___________, which accommodate lacrimal sacs
lacrimal fossae
Each lacrimal bone has a ____________ through which a tear duct passes
lacrimal foramen
Each lacrimal bone articulates with...
frontal, ethmoid, maxilla, and inferior nasal concha bones
Lacrimal bones can be seen on ______ and _______ projections of the skull
PA; lateral
What are the largest of the immovable bones of the face?
Maxillary bones
Each maxillary bone articulates with...
all other facial bones except mandible, as well as frontal and ethmoid bones of cranium
Maxillary bones form part of the lateral walls and most of the floor of the _________, part of the floor of the ______________, and 3/4 of _______________
nasal cavity; orbital cavities; roof of mouth
Maxillary bones have _____________ that articulate with ______________ and assist in formation of prominence of cheeks
zygomatic processes; zygomatic bones
Large, pyramidal cavity in the body of each maxilla that empties into nasal cavity
Maxillary sinus
_______________ on maxillary bone under each orbit serves as a passage through which the infraorbital nerve and artery reach the nose
Infraorbital foramen
On what bones are the infraorbital foramina located?
Maxillary bones
Thick, spongy ridge at inferior borders of maxillae that supports roots of teeth
Alveolar process
Pointed, forward-projecting prominence at junction of maxillary bones in MSP
Anterior nasal spine
Midpoint of anterior nasal spine
Acanthion
Zygomatic bones form...
prominence of cheeks and part of orbital cavities (form part of floor and most of lateral wall of orbital cavities)
___________ of zygomatic bone extends posteriorly to unite with ____________ of temporal bone to form ___________
Temporal process; zygomatic process; zygomatic arch
Zygomatic bones articulate with...
frontal, maxilla, temporal, and sphenoid bones
What bones are L-shaped?
Palatine bones
Palatine bones are composed of ________ and __________ plates
vertical; horizontal
Horizontal plates of palatine bones articulate with _________ to complete the posterior __________
maxillae; 1/4 of bony palate (roof of mouth)
Superior tips of vertical portions of palatine bones assisting in forming the posteromedial bony ________
orbit
Inferior nasal conchae extend diagonally and inferiorly from lateral walls of ________ at approximately its lower ____
nasal cavity; 1/3
Which bones are long, narrow, extremely thin, and curl laterally (giving them a scroll-like appearance)?
Inferior nasal conchae (turbinate)
The upper 2 nasal conchae are processes of the _______ bone
ethmoid
The 3 nasal conchae divide the sides of the nasal cavity into ________, __________, and _________ _________
superior, middle, and inferior meatuses
What is a thin plate of bone in the MSP of the floor of the nasal cavity?
Vomer
Vomer forms...
inferior part of nasal septum
Nasal conchae are covered with a ___________ to warm, moisten, and cleanse inhaled air
mucous membrane
Vomer articulates with...
sphenoid and perpendicular plate of ethmoid bone
The posterior border of the _______ is free
vomer
What is the largest and densest bone of the face?
Mandible
3 parts of mandible
Body, rami, and symphysis
Curved horizontal portion of mandible from angle to symphysis
Body
2 vertical portions of mandible, from condyles to angles
Rami
Mandibular rami unite with body at __________
angle of mandible (gonion)
Lateroposterior aspect of mandible
Gonion
The surface of the rami form an ______ angle of...
obtuse; 110-120 degrees
Each ramus has 2 processes at its upper extremity that are separated by ____________. ___________ is anterior, and ___________ is posterior
mandibular notch; coronoid process; condylar process
Condylar process consists of a constricted area (______) and broad, thick, almost transversely placed _________ that articulates with ____________ of temporal bone
neck; condyle; mandibular fossa
TMJ slants posteriorly __ degrees and inferiorly and medially __ degrees
15; 15
TMJ is immediately in front of ____
EAM
At birth, the mandible consists of bilateral pieces held together by a fibrous symphysis that ossifies in...
1st year of life
Triangular prominence at bottom of ridge of ossification
Mental protuberance
Midpoint of mental prominence; anterior aspect of mandible where the 2 mandibular bodies join together
Mental point
Most anterior and central point of mandible, where right and left halves of mandible have fused
Symphysis
Superior border of body of mandible; consists of spongy bone and supports roots of teeth
Alveolar portion
2 ____________ in mandible allow transmission of nerves and blood vessels
mental foramina
U-shaped bone at base of tongue
Hyoid
Where is hyoid located?
At base of tongue
Hyoid is an accessory bone of the ______ skeleton
axial
Hyoid is made of _____, 2 __________, and 2 __________
body; greater cornua; lesser cornua
________ serves as an attachment for certain muscles of the larynx and tongue
Hyoid
Hyoid is easily palpated just above...
larynx
Cone-shaped, bony-walled cavities on each side of MSP of head
Orbits
Bony sockets that hold the eyeballs and structures associated with them, as well as blood vessels and nerves
Orbits
What 7 bones make up each orbit?
Lacrimal, maxillary, zygoma, palatine, frontal, ethmoid, sphenoid
(LET MAD ZEBRAS PLAY FOR EVERY SPORT)
Circumference of orbit (outer rim area) is made of...
frontal, zygoma, and maxilla bones
Each orbit has a ___, a ______, a _________, and a ______
roof; medial wall; lateral wall; floor
Easily palpable, quadrilateral-shaped anterior circumference of orbit
Base
Apex of orbit corresponds with...
optic foramen
Long axis of each orbit is directed obliquely, posteriorly, and medially at an angle of __ degrees to MSP of head and also superiorly at an angle of about __ degrees from OML
37; 30
The major and frequently radiographed openings of the orbits are...
optic foramina and superior and inferior orbital sulci
Cleft between greater and lesser wings of sphenoid bone
Superior orbital fissure
Narrow cleft extending from lower anterolateral aspect of sphenoid body anteriorly and laterally between floor and lateral wall of orbit
Inferior orbital fissure
Walls of orbits are _____ and subject to ______
thin; fracture
When struck on eyeball, eyeball is forced into orbit and "______ ___" the thin bony _____ of the orbit
blows out; floor
Eye consists of ________, _________, _______, and accessory organs such as _______, _________, and ________
eyeball; optic nerve; blood vessels; extrinsic muscles; lacrimal apparatus; eyelids
What connects eyeball to brain?
Optic nerve
Optic nerve connects _______ and ______
eyeball; brain
Eyeball is situated in _______ part of orbital cavity
anterior
Thin mucous membrane that covers the exposed part of the eyeball and lines part of the eyelids
Conjunctiva
Conjunctiva is kept moist by ________ from ________
tear secretions; lacrimal gland
Outer supporting coat of eyeball is a firm, fibrous membrane consisting of anterior segment called ________ and posterior segment called _______
cornea; sclera
What is known as the "white of the eye"?
Sclera
________ is in front of iris, with its center point corresponding to the pupil
Cornea
Inner coat of eyeball; is contiguous with optic nerve
Retina
Is composed of nervous tissue and several million receptor organs (rods and cones)
Retina
What do rods and cones do?
Transmit light impulses to brain
What may be used to locate foreign bodies in the eye, and what is NOT used?
US and CT, and sometimes radiography are used. MRI is not used
In what bones are the paranasal sinuses located?
Frontal, ethmoid, sphenoid, and maxillary bones
Air-containing cavities in the frontal, ethmoidal, and sphenoidal bones of cranium and maxillary bones of face
Paranasal sinuses
Functions of paranasal sinuses
-Serve as a resonating chamber for voice
-Decrease weight of skull by containing air
-Help warm and moisten inhaled air
-Act as shock absorbers in trauma
-Possibly control immune system



Which sinuses are usually well developed and aerated enough at birth to be demonstrated radiographically?
Maxillary sinuses
By what age are the frontal and sphenoidal sinuses distinguishable from ethmoidal air cells?
6-7
When do ethmoidal air cells develop?
Puberty
At what age are the sinuses completely developed?
17-18
When fully developed, each of the sinuses communicates with...
the others and with the nasal cavity
Which are the largest sinuses?
Maxillary sinuses
There are generally __ of each type of sinus (sinuses are _________)
2; paired
Where are maxillary sinuses located?
In body of each maxilla
Maxillary sinuses appear _________ in lateral image, but are ___________ in shape and have only __ walls
rectangular; pyramidal; 3
Maxillary and frontal sinuses drain into _________. Anterior and middle ethmoidal air cells drain into ________. Posterior ethmoidal air cells drain into _________. Sphenoidal sinuses open into ____________.
middle nasal meatus; middle nasal meatus; superior nasal meatus; sphenoethmoidal recess of nasal cavity
What are the second-largest sinuses?
Frontal sinuses
Where are frontal sinuses located?
Between tables of vertical plate of frontal bone
Which sinuses have several elevations on their floors which correspond to the roots of the subjacent teeth?
Maxillary sinuses
Which sinuses are occasionally absent?
Frontal sinuses
Because ___________ is usually deviated from the midline, _________ are rarely symmetric
intersinus septum; frontal sinuses
Where are ethmoidal sinuses located?
Within lateral masses of labyrinths of ethmoid bone
Ethmoidal sinuses are composed of a varying number of air cells that are divided into 3 main groups: _____________________
anterior, middle, and posterior
Anterior and middle ethmoidal cells vary in number from ____; posterior ethmoidal cells vary in number from ____
2-8; 2-6
Where are sphenoidal sinuses located?
Body of sphenoid bone
Often, only 1 sphenoidal sinus is present, but there are never more than __ sphenoidal sinuses
2
Sphenoidal sinuses lie immediately below ___________ and extend between _________ and ____________
sella turcica; dorsum sellae; posterior ethmoidal air cells
Paranasal sinuses should be radiographed with patient in _______ position
upright
Why should be sinuses be radiographed with patient upright?
To demonstrate presence or absence of fluid and differentiate between fluid and other pathologic conditions
What size FS should be used for sinuses?
Small
When head is repositioned for sinuses, __________ should be allowed to pass before exposure is made to allow exudate to shift position
several minutes
What are the breathing instructions for all headwork?
Suspend respiration
Gowning for all headwork
Remove everything from upper shoulders up, including necklaces, hair accessories, pins, jewelry, glasses, weaves, teeth, retainers, etc.
History questions for headwork
-Any trauma? When?
-Any pain? Where? Sharp or dull pain?
-Headaches or congestion?
-Dizziness?
-Any surgery?
-Any teeth problems?
-Etc.





Routine for facial bones
PA axial (Caldwell), regular Waters, lateral
Position for PA axial (Caldwell) facial bones
Prone or seated. Rest forehead and nose on table or upright Bucky. OML and MSP perp to IR, IP parallel to IR
IR for PA axial (Caldwell) facial bones
10x12 LW
CR for PA axial (Caldwell) facial bones
15 caudal, exiting nasion
Structures shown for PA axial (Caldwell) facial bones
Orbital rims, maxillae, nasal septum, zygomatic bones, and anterior nasal spine
When CR is angled 15 caudad, petrous ridges appear...
in lower 1/3 of orbits
When CR is angled 30 caudad, petrous ridges appear...
below inferior margins of orbits
For PA axial (Caldwell) facial bones, where should petrous pyramids appear?
In lower 1/3 of orbit
Eval criteria for PA axial (Caldwell) facial bones
-Symmetric petrous pyramids in lower 1/3 of orbits
-Entire cranial perimeter showing 3 distinct tables of squamous bone
-Equal distance from lateral border of skull to lateral border of orbit on both sides
-Penetration of frontal bone without excessive density at lateral borders of skull, which will then demonstrate facial bones


IR for parietoacanthial (PA; regular Waters method) facial bones
8x10 LW
CR for parietoacanthial (PA; regular Waters method) facial bones
Perp, exiting acanthion
Structures shown for parietoacanthial (PA; regular Waters method) facial bones
-Axial image of facial bones
-Orbits, maxillae, zygomatic arches
Eval criteria for parietoacanthial (PA; regular Waters method) facial bones
-Distance between lateral border of skull and orbit equal on each side
-Petrous ridges projected immediately below (inferior to) maxillary sinuses
Position for lateral facial bones
Semiprone or obliquely seated, in PA oblique body position with affected side closest to IR. IOML and MSP parallel to IR (IOML perp to front edge of IR). IP perp to IR
IR for lateral facial bones
8x10 LW (clinically, 10x12 LW)
CR for lateral facial bones
Perp, entering lateral surface of zygomatic bone midway between outer canthus and EAM
Structures shown for lateral facial bones
-Lateral projection of face, with right and left halves superimposed
Eval criteria for lateral facial bones
-All facial bones in their entirety, with zygomatic bone in center
-Almost perfectly superimposed mandibular rami
-Superimposed orbital roofs
-No rotation of sella turcica


Position for modified ("shallow") Waters facial bones
Prone or seated. Nose and chin on table or upright Bucky. Extend neck so OML forms a 55 degree angle with IR. MSP perp to IR
CR for modified ("shallow") Waters facial bones
Perp, exiting acanthion
Structures shown for modified ("shallow") Waters facial bones
-Demonstrates facial bones with less axial angulation than Waters
-Good for demonstrating floor of orbits and blowout fractures. Places orbital floor perp to IR and parallel to CR, demonstrating inferior displacement of orbital floor and the commonly associated opacified maxillary sinus
What projection is good for demonstrating floor of orbits and blowout fractures?
Modified ("shallow") Waters
Eval criteria for modified ("shallow") Waters facial bones
-Petrous ridges immediately below inferior border of orbits and at a level midway through (in lower half of) maxillary sinuses
Position for acanthioparietal (reverse Waters) facial bones
Supine. Extend neck so OML forms a 37-degree angle with IR. MML and MSP perp to IR
IR for acanthioparietal (reverse Waters) facial bones
10x12 LW
CR for acanthioparietal (reverse Waters) facial bones
Perp, entering acanthion
Structures shown for acanthioparietal (reverse Waters) facial bones
-Demonstrates superior facial bones
-Appears similar to Waters, but facial structures are considerably magnified
Eval criteria for acanthioparietal (reverse Waters) facial bones
-Distance between lateral border of skull and orbit equal on each side
-Petrous ridges below maxillary sinuses
Routine for orbits
PA axial (CR angled 30 degrees caudal), modified Waters, and lateral. Tomographic study may be included after routine series
All orbits projections are done ______, except for RHESE which is done ________
TT; in table Bucky
What are patient instructions for exams of orbits?
Gently close eyes and keep eyes still. Hold your breath
IR for all orbits
8x10 or 10x12 LW
Position for parietoorbital oblique (RHESE method) optic canal and foramen
Semiprone or seated upright. Center affected orbit to unmasked half of IR. Rest zygoma (cheek), nose, and chin on table or upright Bucky. AML perp to IR. MSP at 53-degree angle with IR
CR for parietoorbital oblique (RHESE method) optic canal and foramen
Perp, entering 1" superior and posterior to upside TEA, and exiting through affected orbit closest to IR
Structures shown for parietoorbital oblique (RHESE method) optic canal and foramen
-Demonstrates optic canal "on end" and optic foramen lying in inferior and lateral quadrant of projected orbit
-Lateral deviation indicates incorrect head rotation. Longitudinal deviation indicates incorrect angulation of AML
-Both sides are examined for comparison
-Shows parietoorbital projection of ethmoidal, sphenoidal, and frontal sinuses


Eval criteria for parietoorbital oblique (RHESE method) optic canal and foramen
-Optic canal and foramen visible at end of sphenoid ridge in inferior and lateral quadrant of orbit
-Entire orbital rim
-Supraorbital margins lying in same horizontal line
-Close beam restriction to orbital region


Position for PA axial eye
Rest forehead and nose on IR. OML and MSP perp to IR. IP parallel to IR
CR for PA axial eye
30 caudal, entering outer canthus and directed through center of orbits, exiting 3/4" distal to nasion
Eval criteria for PA axial eye
-Petrous pyramids below inferior orbital rim (orbital shadows)
-No rotation of cranium
-Close beam restriction centered to orbital region

Position for parietoacanthial (modified/"shallow" Waters) eye
Rest chin on IR holder. MSP perp to IR, and OML forming a 55-degree angle with IR
CR for parietoacanthial (modified/"shallow" Waters) eye
Perp through midorbits (outer canthus)
What is parietoacanthial (modified/"shallow" Waters) projection of eye good for demonstrating?
Blowout fractures
Eval criteria for parietoacanthial (modified/"shallow" Waters) eye
-Petrous pyramids well below orbital shadows and halfway filling maxillary sinus
-Symmetric visualization of orbits, indicating no rotation of cranium
-Close beam restriction centered to orbital region

Position for lateral eye
Semiprone or seated. Outer canthus of affected eye adjacent to and centered over midpoint of IR. IOML perp to front edge of IR. MSP parallel to IR. IP perp to IR
CR for lateral eye
Perp, entering outer canthus of side up
Eval criteria for lateral eye
-Density and contrast permitting optimal visibility of orbit and eye for localization of foreign bodies
-Superimposed orbital roofs
-Close beam restriction centered to orbital region

For lateral eye, patient should be told to...
Look straight ahead for the exposure with eyes open or gently closed
Routine for sinuses
PA axial (Caldwell), regular Waters, lateral
Position for PA axial (Caldwell) sinuses
Upright. OML forming an angle of 15 degrees with horizontal CR. MSP perp to IR
OR
Can tilt vertical grid device down so a 15-degree angle is obtained. Rest nose and forehead on IR. OML and MSP perp to IR

CR for PA axial (Caldwell) sinuses
Perp and horizontal, exiting nasion
Structures shown for PA axial (Caldwell) sinuses
-Frontal sinuses superior to frontonasal suture
-Anterior ethmoidal air cells lying on each side of nasal fossae and immediately inferior to frontal sinuses
-Sphenoidal sinuses projected through nasal fossae just inferior to or between ethmoidal air cells
-Petrous pyramids extending from inferior 1/3 of orbit inferiorly to obscure superior 1/3 of maxillary sinus


Eval criteria for PA axial (Caldwell) sinuses
-Symmetric petrous pyramids in lower 1/3 of orbits
-Frontal and anterior ethmoidal air cells
-Equal distance from lateral border of skull to lateral border of orbit on both sides, indicating no rotation
-Frontal sinuses lying above frontonasal suture and anterior ethmoidal air cells lying above petrous ridges
-Clearly visible air-fluid levels, if present
-Close beam restriction of sinus area




Position for parietoacanthial (Waters) sinuses
Upright. Hyperextend neck and rest chin on grid device. MSP and MML perp to IR. OML forming a 37-degree angle with IR
CR for parietoacanthial (Waters) sinuses
Perp, exiting acanthion
If neck is not extended enough for parietoacanthial (Waters) sinuses...
petrosae are projected over inferior parts of maxillary sinuses
Structures shown for parietoacanthial (Waters) sinuses
-Axial image of facial bones, orbits, maxillae, and zygomatic arches
-Parietoacanthial projection of maxillary sinuses, with petrous ridges inferior to floor of sinuses
-Frontal and ethmoidal air cells distorted
-Foramen rotundum


Eval criteria for parietoacanthial (Waters) sinuses
-Petrous ridges just beneath antral floor, inferior to maxillary sinuses
-Equal distance between lateral border of skull and lateral border of orbit on both sides, indicating no rotation
-Orbits and maxillary sinuses symmetric on each side
-Maxillary sinuses
-Close beam restriction of sinus area
-Clearly visible air-fluid levels, if present




Position for lateral sinuses
Seated in RAO or LAO position. Head in true lateral position. IOML perp to front edge of IR. MSP and IOML parallel to IR. IP perp to IR
CR for lateral sinuses
Perp, entering midway between outer canthus and EAM (book says 1/2-1" posterior to outer canthus)
What is the only projection that shows all 4 sets of sinuses?
Lateral
Structures shown for lateral sinuses
-AP and superoinferior dimensions of paranasal sinuses, their relationship to surrounding structures, and thickness of outer table of frontal bone

When used for preoperative measurements, lateral sinuses should be done at __" to reduce magnification and distortion
72
Eval criteria for lateral sinuses
-All 4 sinus groups, but sphenoidal sinus is of primary importance
-No rotation of sella turcica
-Superimposed orbital roofs
-Superimposed mandibular rami
-Clearly visible sinuses
-Close beam restriction of sinus area
-Clearly visible air-fluid levels, if present





CR for parietoacanthial (open-mouth Waters; Pirie) maxillary and sphenoidal sinuses
Perp, exiting acanthion
Breathing instructions for parietoacanthial (open-mouth Waters; Pirie) maxillary and sphenoidal sinuses
"Say ahh and hold your breath" (to immobilize tongue at floor of mouth during exposure)
Structures shown for parietoacanthial (open-mouth Waters; Pirie) maxillary and sphenoidal sinuses
-Sphenoidal sinuses within the open mouth
-Maxillary sinuses
Eval criteria for parietoacanthial (open-mouth Waters; Pirie) maxillary and sphenoidal sinuses
-Petrous pyramids immediately inferior to floor of maxillary sinuses
-Equal distance between lateral border of skull and lateral border of orbit on both sides, indicating no rotation
-Orbits and maxillary sinuses symmetric on each side
-Maxillary sinuses
-Close beam restriction of sinus area
-Clearly visible air-fluid levels, if present
-Sphenoidal sinuses projected through open mouth without overlap of upper dental arch
-Shadow of tongue not superimposing sphenoidal sinuses






Position for submentovertical (SMV) ethmoidal and sphenoidal sinuses
Seated. Hyperextend neck and rest head on vertex. Mouth closed. IOML parallel to IR (vertical). MSP perp to IR
CR for submentovertical (SMV) ethmoidal and sphenoidal sinuses
Perp to IOML through sella turcica, entering midway between zygomatic arches at a level of 1.5-2" inferior to mandibular symphysis (according to book, entering MSP 3/4" anterior to level of EAM)
Structures shown for submentovertical (SMV) ethmoidal and sphenoidal sinuses
-Symmetric image of anterior portion of base of skull
-Sphenoidal and ethmoidal air cells
Eval criteria for submentovertical (SMV) ethmoidal and sphenoidal sinuses
-Mandibular condyles anterior to petrous ridges
-Equal distance from lateral border of skull to mandibular condyles on both sides, indicating MSP is perp (no tilt)
-Anterior frontal bone superimposed by mental protuberance, indicating IOML is parallel (full extension)
-Clearly visible air-fluid levels, if present


Routine for nasal bones
PA axial (Caldwell), exaggerated Waters, both laterals
Position for PA axial (Caldwell) nasal bones
Rest forehead and nose on table or upright Bucky. OML and MSP perp to IR. IP parallel to IR
CR for PA axial (Caldwell) nasal bones
15 caudal, exiting nasion
Position for exaggerated Waters nasal bones
Chin on table or vertical bucky. Hyperextend neck to place OML at 30-degree angle with IR. Nose comes off IR about 2-2.5" or so
When OML is at a 30-degree angle with IR for exaggerated Waters projection, petrous ridges appear...
1.5-2" below maxillary sinuses
CR for exaggerated Waters nasal bones
Perp, exiting acanthion
Position for lateral nasal bones
Semiprone, with body in PA oblique position. IOML and MSP parallel to IR (IOML perp to front edge of IR). IP perp to IR
IR for lateral nasal bones
8x10 or 10x12 CW, 2 on 1. Lead off 1/2 the IR, make 1 exposure, then flip the lead strip to lead off the other 1/2 and make the 2nd exposure. Mark each side for 2 on 1
CR for lateral nasal bones
Perp to bridge of nose, entering 1/2" distal to nasion
Structures shown for lateral nasal bones
-Demonstrates side nearer IR and soft structures of nose
-Both sides are examined for comparison
Eval criteria for lateral nasal bones
-No rotation of nasal bone and soft tissue
-Anterior nasal spine and frontonasal suture
Position for submentovertical (SMV) bilateral zygomatic arches
Supine or seated. Hyperextend neck so IOML is parallel to IR (vertical). MSP perp to IR
CR for submentovertical (SMV) bilateral zygomatic arches
Perp to IOML, entering MSP of throat 1" posterior to outer canthi (midway between zygomatic arches at a level of 1.5" inferior to mandibular symphysis)
-May have to angle CR to be perp to IOML
Structures shown for submentovertical (SMV) bilateral zygomatic arches
-Bilateral symmetric SMV images of zygomatic arches, projected free of superimposed structures
-Unless very flat or traumatically depressed, arches are projected beyond the parietal eminences by the divergent x-ray beam
Eval criteria for submentovertical (SMV) bilateral zygomatic arches
-Frontal bone and mandibular symphysis superimposed
-Zygomatic arches free from overlying structures
-Zygomatic arches symmetric and without foreshortening
-No rotation of head


Position for AP axial (modified Towne) bilateral zygomatic arches
OML or IOML perp to IR. MSP perp to IR
CR for AP axial (modified Towne) bilateral zygomatic arches
30 caudal if OML perp, 37 caudal if IOML perp, entering glabella (1" above nasion)
Structures shown for AP axial (modified Towne) bilateral zygomatic arches
Symmetric AP axial projection of both zygomatic arches, free of superimposition
Eval criteria for AP axial (modified Towne) bilateral zygomatic arches
-No overlap of zygomatic arches by mandible
-Zygomatic arches lateral to mandibular rami
-No rotation evident because arches are symmetric

Position for tangential unilateral zygomatic arch
Hyperextend neck and rest head on vertex. IOML parallel with IR. Rotate MSP 15 degrees toward side being examined, and tilt top of head 15 degrees away from side being examined
CR for tangential unilateral zygomatic arch
Perp to IOML, centered to zygomatic arch at a point 1" posterior to outer canthus of affected side
Structures shown for tangential unilateral zygomatic arch
-Tangential image of one zygomatic arch free of superimposition
-This projection is useful in patients with depressed fractures or flat cheekbones
Eval criteria for tangential unilateral zygomatic arch
-Zygomatic arch free from overlying structures
-Zygomatic arch not overexposed
Routine for mandible
For area of interest: PA, axiolateral, and lateral (?)
Position for PA mandibular rami
Rest forehead and nose on IR. OML and MSP perp to IR
CR for PA mandibular rami
Perp, exiting acanthion
Eval criteria for PA mandibular rami
-Mandibular body and rami symmetric on each side
-Entire mandible
Position for PA axial mandibular rami
Rest forehead and nose on IR. OML and MSP perp to IR
CR for PA axial mandibular rami
20-25 cephalad, exiting acanthion
Eval criteria for PA axial mandibular rami
-Mandibular body and rami symmetric on each side
-Entire mandible
-Condylar processes

Position for PA mandibular body
Rest head on nose and chin so anterior surface of mandibular symphysis is parallel with IR. AML nearly perp to IR
CR for PA mandibular body
Perp to level of closed lips
Eval criteria for PA mandibular body
Mandibular body symmetric on each side
Position for PA axial mandibular body
Rest nose and chin on IR. AML nearly perp to IR. MSP perp to IR
CR for PA axial mandibular body
30 cephalic, exiting midway between TMJs
Eval criteria for PA axial mandibular body
-TMJs just inferior to mastoid process
-Symmetric rami
Position of head for axiolateral oblique mandibular ramus
True lateral
Position of head for axiolateral oblique mandibular body
Rotate head 30 degrees toward IR
Position for axiolateral oblique mandibular symphysis
Rotate head 45 degrees toward IR
CR for axiolateral oblique mandible
25 cephalic, passing through mandibular region of interest
Eval criteria for axiolateral oblique mandibular ramus and for axiolateral oblique mandibular body
-No overlap of ramus by opposite side of mandible
-No elongation or foreshortening of ramus or body
-No superimposition of ramus by C-spine

Eval criteria for axiolateral oblique mandibular symphysis
-No overlap of mentum region by opposite side of mandible
-No foreshortening of mentum region
Routine for TMJs
Open and closed axiolateral and open and closed axiolateral oblique
What looks similar to AP axial TMJs?
AP axial (modified Towne) bilateral zygomatic arches
Position for AP axial TMJs
OML and MSP perp to IR. One with mouth closed and one with mouth open (do NOT try open-mouth position in trauma patients)
CR for AP axial TMJs
35 caudal, centered midway between TMJs, and entering a point 3" above nasion
Eval criteria for AP axial TMJs
-No rotation of head
-Minimal superimposition of petrosa on condyle in closed-mouth exam
-Condyle and TMJ below pars petrosa in open-mouth exam

How many projections are done for axiolateral TMJs?
4. Right and left, open and closed
Position for axiolateral TMJs
Oblique body position. MSP parallel with IR and IP perp to IR
CR for axiolateral TMJs
25-30 degrees caudal, entering 1/2" anterior and 2" superior to upside EAM
Eval criteria for axiolateral TMJs
-TMJ anterior to EAM
-Condyle lying in mandibular fossa in closed-mouth exam
-Condyle lying inferior to articular tubercle in open-mouth exam for normal patients

How many projections are done for axiolateral oblique TMJs?
4. Right and left, open and closed
Position for axiolateral oblique TMJs
Oblique body, with head in true lateral position. MSP of head rotated 15 degrees toward IR. AML parallel with IR
CR for axiolateral oblique TMJs
15 caudal, entering 1/2" anterior and 1.5" superior to upside EAM, exiting TMJ closest to IR
Eval criteria for axiolateral oblique TMJs
-TMJ
-Condyle lying in mandibular fossa in closed-mouth exam
-Condyle lying inferior to articular tubercle in open-mouth exam for normal patient

Add Cards

You must Login or Register to add cards