Occlusal and Skull Radiography

Question 1

what size is an occlusal film size

Answer 1

4

Question 2

what are the indications/advantages for occlusal radiography

Answer 2

• larger size receptors allow larger segments of the jaw to be examined
• for use when patients are unable to open mouth wide enough for peri apicals due to pain, trismus, etc

Question 3

what are the clinical indications for occlusal radiography

Answer 3

• roots, impactions, supernumeraries
• foreign bodies
• localization of stones in ducts
• alteration to cortical bone
• sinus and nasal integrity
• fractures
• extent of pathoses

Question 4

what are the maxilla views of occlusal radiography

Answer 4

• standard cross sectional
• lateral (right/left) cross sectional
• anterior topographical

Question 5

what are the mandibular occlusal views

Answer 5

• standard cross sectional
• lateral (right/left) cross sectional
• anterior topographical

Question 6

what is the standard cross section of maxilla

Answer 6

• vertical angle (+) 65 to 70 degrees pointed downward
• central ray (CR): bridge of nose and center of PSP plate

Question 7

what is the lateral cross sectional view of maxillary arch

Answer 7

• vertical angle (+): 55-60 degrees pointed downward
• central ray: posterior maxilla

Question 8

describe the anterior topographical view of the maxilla

Answer 8

• vertical angle (+): 55 to 60 degrees pointed downward
• central ray: 1/4 to 1/2 inches above tip of nose

Question 9

describe the standard cross sectional view of the mandible

Answer 9

• vertical angle: perpendicular to PSP
• central ray: between mandibular first molars; along mid sagittal plane; move beam away about 2 inches or 5 cm

Question 10

describe the lateral cross sectional view of the mandible

Answer 10

• vertical angle: perpendicular to PSP plate following long axis of first molar
• central ray: center of PSP plate @ apex of first molar

Question 11

describe the anterior topographical view of the mandible

Answer 11

• vertical angle (-): 55 to 60 degrees pointed upward; bisecting angle between PSP plate and long axis of incisor teeth
• central ray: below apices of incisors 1 cm above tip of chin, along midline of chin, direct at center of PSP plate

Question 12

what are the occlusal exposure settings

Answer 12

1 or possibly 2 exposure settings higher than posterior maxillary periapical exposures

Question 13

describe pediatric occlusal radiography

Answer 13

-technique is same as adult occlusal radiographic technique
- use number 2 plate

Question 14

what is skull radiography used for

Answer 14

• orthodontic evaluations
• orthognathic evaluations
• pathology beyond coverage of standard dental images

Question 15

what are the skull projections

Answer 15

• lateral cephalogram/cephalometric
• PA cephalogram/cephalometric
• Waters’ PA
• Reverse- Towne (PA)
• SMV

Question 16

what are the image enhancers

Answer 16

• grids
• air gaps

Question 17

what are the types of grids

Answer 17

-standard
- focused
- grid ratios

Question 18

what do grids with PSPP do

Answer 18

reduce amount of scatter radiation exposing film and improves image contrast

Question 19

what are the types of lateral skull radiography

Answer 19

• standard
• cephalometric

Question 20

describe lateral skull projections skull/film alignment within cephaostat

Answer 20

• beam is 90 degrees to mid sagittal skull plane and sensor
• mid sagittal skull plane and sensor are parellel
• frankfort plane parallel to horizontal

Question 21

what is the most common skull projection

Answer 21

lateral skull

Question 22

what is cephalometric radiography used for

Answer 22

taking measurements and evaluatig the effect of growth or disease on a skeletal profile

Question 23

cephalometric radiography positioning is standardized for

Answer 23

retrospective or predictive evaluation of skeletal changes

Question 24

what is the standard focal distance for cephalometric radiography and why

Answer 24

60 inches
- to standardize magnification and improve resolution

Question 25

what are the soft tissue filters

Answer 25

• at source
• at receptor: over grid, over intensifying screen

Question 26

what is the lateral cephalometric radiograph used for

Answer 26

orthodontic and orthognathic surgery
and to see soft tissue outline

Question 27

describe PA skull radiograph

Answer 27

• beam is 90 degrees to sensor and parallel to mid sagittal skull plane
• coronal (frontal) skull plane is 90 degrees to sensor

Question 28

describe Waters’ (occipitomental) skull radiograph

Answer 28

• beam is 90 degrees to sensor and parallel to mid sagittal skull plane
• mid sagittal skull plane is 90 degrees to sensor but chin is raised to touch sensor

Question 29

describe submentovertex (basilar) skull radiograph

Answer 29

• beam is 90 degree to sensor and axial skull plane
• mid sagittal skull plane is 90 degrees to sensor but vertex is adjacent sensor