Mandible, T M J

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