mandible, t m j
TRANSCRIPT
Mandible, TMJRadiographs & Diagrams2009
MandiblePAPA AxialAxiolateral ObliqueTowne Method (AP Axial)Modified WatersSMVPanorex
TMJTowne MethodSchullerLawPanorex
PA Mandible Rest pt’s forehead &
nose against bucky Tuck in chin to bring OML
& MSP perp to IR 40” SID CR perp to IR to exit @
junction of lips Collimate to area of
mandible Shows mandibular rami
& lateral portion of body Rami s/b symmetrical Mentum superimposed
on C-spine
Lateral Facial Bones
a. Coronoid process
b. Mandibular fossa
c. Neck of condyloid process
d. Mandibular notch
e. Gonion
Axiolateral Oblique- Mentum 45°
Place pt in a true lateral w/ SOI against IR
Mouth closed, neck extended
To visualize mentum, oblique head 45° towards IR
Angle CR 25° cephalic to exit area of interest
CR will skim under the closest side of mandible to project the opposite side (area of interest) free of superimposition
Axiolateral Oblique – Body 30°Start from true
lateralOblique head 30°
towards IR25° CR angleCR will exit body on
opposite side of mandible
Collimate to mandible on all sides
Axiolateral Oblique- General Survey 10° - 15°
Oblique head 10°-15° towards IR
CR angled 25° cephalad
Area of interest should be demonstrated w/minimal superimposition & foreshortening
Axiolateral Oblique- Labeling1. Alveolar
process2. Gonion3. Ramus4. Condyloid
process
Panorex (Eagle’s Syndrome) Note extra
styloid processes lateral to gonions
Law - TMJ Head in true lateral IPL perp & MSP parallel to
IR IOML perp to front edge of
IR SOI against IR Rotate head 15° towards IR Angle CR 15° caudad Enters 1 ½ “ ↑ to upside EAM Exits downside TMJ SHOWS: TMJ Closed IR Closed mouth: Condyle in TM
fossa Open mouth: Condyle @ anterior
margin of TM fossa
PanorexPt is seated w/IOML
parallel to floor & MSP perp to IR
Teeth on bite piece, chin in bite block
Fixed CR & SIDShows: Flat image
of entire mandible; teeth, TMJ’s, body, rami, angles, symphysis, condyles & coronoid processes
Schuller - TMJ Pt’s head in true lateral
(body obliqued as needed for comfort)
IPL perp to IR, MSP parallel
Angle CR 25°-30° caudad Center ½ in anterior & 2
in superior to upside EAM Center IR to projected TMJ Collimate on all sides to
aprox 4 in square Closed mouth & open
mouth Shows TMJ closest to IR
Law Method- TMJ SOI closest to IR Head lateral body
obliqued as necessary for comfort
IPL perp to IR to avoid tilt From lateral, rotate face
15° towards IR Angle CR 15° caudad
centered to 1 ½ in ↑ to upside EAM
Center IR to projected CR Collimate on all sides to aprox 4
in square Shows TMJ closest to IR
Law vs Schuller’s-how do you tell?
Look for the hook
Condyloid process appears as a hook on Law Method radiographs.
Appears to hook around towards the mouth
PA Mandible (Bad) Taken on
phantom (no C-spine)
OML is not perpendicular
Law - TMJLaw- look for the
hook Condyle appears to
hook towards the face
This one could use more collimation
Modified Townes (Mandible) OML & MSP perp to IR CR angle 35°-40°
caudad Enter glabella (to pass
through EAM’s & B/T gonions @ MSP)
Shows: condyloid processes, TMJ fossae, Mandibular rami free from superimposition
SMV- Mandible• IOML parallel to IRCR enters ½ way B/T
gonions or 1 ½-2 in ↓ to mandibular symphysis
Shows mandible, coronoid & condyloid processes
Mandibular condyles anterior to petrosae
Mandibular symphysis superimposed on frontal bone
Modified Townes (Mandible) Note necklace in
anatomy
Panorex – Open/Closed
Townes - TMJ OML & MSP perp to IR CR angle 35° caudad
to pass 1” anterior to TMJ level
(Angle 42° caudad if IOML perp)
*Additional 5 ° may show TM fossae & joint best
Shows: Condyloid process & TMJ fossae (do 1 closed & 1 open view)
Review- Skull Landmarks
1. Mentum2. Acanthion3. Nasion4. Glabella5. Vertex6. Head7. Outer canthus8. Inion9. Tragus10. mandible
Review- Positioning Lines
1. EAM2. GML3. OML4. IOML5. AML6. MMLa. 8° b. 7°c. 10°d. 20°
1. Nasal bone
2. Frontal process of maxilla
3. Lacrimal bone
4. Superior nasal conchae
5. Inferior nasal conchae
6. Vomer
7. Alveolar process
8. Mandible
9. Maxilla
10. Zygomatic process of maxilla
11. Zygoma
12. Perpendicular plate of ethmoid
13. Temporal bone
14. Frontal portion of maxilla
15. sphenoid16. Parietal bone17. Frontal bone
Skull- Lateral View1. Vertex
2. Inion
3. Temporal bone
4. Mastoid process
5. Squamous portion of temporal bone
5a. Styloid process of temporal bone
6. Mandible
7. Maxilla
8. Zygomatic arch
9. Anterior nasal spine
Lateral Skull (Contd.)
10. Sphenoid bone
11. Lacrimal bone 12. Nasal bone 13. Zygoma14. Sphenoid15. Frontal bone16. Coronal
suture17. Squamosal
suture18. Lambdoidal
suture
Maxillae & Palatine Bones
A. Palatine Process of Maxilla
B. Palatine BonesC. Pterygoid
process of Sphenoid
Sinuses- Anterior View
1. Frontal Sinuses2. Ethmoid &
sphenoid Sinuses
3. Maxillary Sinuses
Sinuses – Lateral View
1. Frontal Sinuses2. Ethmoid
Sinuses3. Sphenoid
Sinuses4. Maxillary
Sinuses
Mandible – Lateral ViewA. Coronoid ProcessB. Manbidular NotchC. Neck of condyloid
processD. Head of condyloid
processE. Condyloid processF. RamusG. GonionH. BodyI. MentumJ. Alveolar Process