Radiology Flashcards
(60 cards)
1
Q
What is the selection criteria for Cephalometric Radiographs
A
- Evaluate growth and development of the cranium and face
- Evaluate the relationship betweeen orofacial and dental structures
- Monitor orthodontic/orthognathic treatment progression
- Evaluate other craniofacial abnormalities and trauma
2
Q
Imaging Technique
A
- Cephalostat: ear rods & nasion indicator help stabilize the patient
- Distances are maintained constant for comparison of sequential radiographs
- Structures furtheresst from receptor=most magnification
- Structures closest to receptor=least magnification
- Less discrepancy of (bilateral) midline structures (5-6% magnification)
3
Q
Source to object distance
A
5 Ft
* Minimizes image magnification
4
Q
Image Receptor Dimensions
A
20x25 cm (8x10 inch)
5
Q
Object to receptor distance
A
10-15 cm
6
Q
Lateral vs PA Cephalometric image:
1. Head Placement
2. Receptor Placement
3. Beam Direction
4. Beam centers at
A
Lateral:
* Beam: also directed perpendicular to midsagittal plane
7
Q
Patient Positioning for Cephalometric imaging
A
- Remove Jewelry and oral appliances
- Shielding (lead apron) and barriers
- Ear rods inside ear canals
- Ruler on Nasion
- NHP-look straight ahead into mirror, focus on eyes facilitates NHP
- Frankfort plane parallel to the floor
- Lips relaxed (no smile or grimace)
8
Q
Lateral Cephalometric: Indications
A
Most common
* Evaluate the AP relationships b/w maxilla, mandible, and cranial base
* Assess skeletal and soft tissue relationships
* Proceed with orthognathic sx tx planning
* Monitor progress of tx and tx outcomes
9
Q
Point A
A
- Deepest anterior concavity on the maxillary alveolus
10
Q
Point B
A
- Deepest anterior concavity on mandibular symphysis
11
Q
Sella (S)
A
- Midpoint of the sell turcica
- Pituitary Fossa
12
Q
Nasion(N)
A
- The most anterior point on the fronto-nasal suture
13
Q
Orbitale (Or)
A
- The most anterior, inferior point on the infraorbital rim
14
Q
Anterior Nasal Spine (ANS)
A
- Tip of the anterior nasal spine
15
Q
Posterior Nasal Spine (PNS)
A
- Tip of the posterior nasal spine
16
Q
Gonion (Go)
A
- Most posterior, inferior point on the mandibular angle
17
Q
Gnathion (Gn)
A
- Most anterior, inferior point on the mandibular symphysis
18
Q
Menton (Me)
A
- Most inferior point on the mandibular symphysis
19
Q
Pogonion (Pog)
A
- most anterior point on the mandibular symphysis
20
Q
Sn Line
A
Nasion to sella
21
Q
Frankfort Plane
A
orbitale and porion
22
Q
Mandibular Plane (MnPl)
A
- Gonion to Menton
23
Q
Maxillary Plane (MxPl)
A
- Anterior nasal spine to Posterior Nasal Spine
24
Q
SNA
A
AP Position of the maxilla to the cranial base
25
SNB
AP Position of the mandible to the cranial base
26
ANB
* AP postion of the Maxilla to the Mandible
* Skeletal Class
27
Maxillary-mandibular plane angle (MMPA)
Angle formed b/w the Maxillary plane and mandibular plane
28
Maxillary Incisal Inclination
Angle b/w the maxillary plane (MxPl) and maxillary incisors axis (UInc)
29
Mandibular Incisal Inclination
* Angle b/w the mandibular plane and mandibular incisors axis (LInc)
30
Posteroanterior Cephalometric: Indications
* Evaluate craniofacial asymmetry
* Assess Jawl Skeletal Relationships
* Proceed with orthognathic sx tx planning
* Monitor Progress of tx and tx outcomes
| SAME AS Lateral
31
What is circled in purple?
Ethmoid air cells
32
What is circled in green?
Frontal Sinus
33
What is circled in red?
Maxillary Antrum
34
Indicationos for CBCT in ortho
* Assess skeletal and dentofacial structures
* 3D Localization of impacted teeth
* Growth Assessment
* Pharyngeal airway analysis
* Cleft palate assessment
* Orthognathic sx planning
* Planning the placment of temporary anchorage devices
* custom ortho appliance fabrication
35
What is required to spatially localize pathology?
* Take at least 2 radiographs that are right angles to each other
36
What is the main anatomical landmark used in patient positioning during extraoral radiography?
Canthomeatal Line
37
Canthomeatal Line
* External auditory canal center to outer canthus of the eye
* 10 degrees from FP
38
What is the sequence for interpretation of Lateral Cephalometric projections?
1. Skull & Calvaria
2. Upper & Middle Face
3. Mandible
4. Cervical Spinne/airway/neck
5. ALveolar Bone/Teeth
39
What is the sequence for interpretation of Anteroposterior Cephalometric projections?
1. Calvaria & Sutures
2. Upper & Middle Face
3. Lower Face
4. Cervical Spine
5. Alveolar Bone & Teeth
40
Cephalometric Projections
Allow for reproducible imaging of the craninofacial region
Made w/a cephalostat
* maintains a constant relationship b/w skull, receptor, & x-ray beam
film or digital receptors
41
Lateral Cephalometric projections: Structures close to midsagittal plane
Structures close to midsagittal plane: Nearly Superimposed
* clinoid process
* inferior turbinates
42
Identify 1
Sella Turcica
43
Identify 2
Nasion (N)
44
Identify 3
Orbitale (Or)
45
Identify 4
Porion (Po)
46
Identify 5
Point A
47
Identify 6
Point B
48
Identify 7
Pogonion (Pog)
49
Identify 8
Menton (Me)
50
Identify 9
Gnathion (Gn)
51
Identify 10
Gonion (Go)
52
Identify 11
Mandibular Incisal Edge
53
Identify 12
Maxillary Incisal Edge
54
Identify 13
Upper Lip
55
Identify 14
Lower Lip
56
Identify 15
Subnasale
57
Identify 16
Soft Tissue Pogonion
58
Identify 17
Posterior Nasal Spine (PNS)
59
Identify 18
Anterior Nasal Spine (ANS)
60
Identify 19
Articulare
