Oral Radiology Exam 2

Front 1

Which part of the tooth is most important forproper alignment of a bitewing radiograph, in order to reduce shape distortion?

Back 1

Crown

Front 2

What externally visible anatomical landmarks areused to approximate the location of the apices of:

(A) maxillary teeth?

(B) mandibular teeth?

Back 2

(A) Ala(Nose) & Tragus (Ear)... line between them

(B) Inferior Border of Mandible... ~1/2 inch above it

Front 3

Which 2 rules of the 5 basic rules of a goodshadow image are NOT possible to achieve when using bisecting positioning for an intraoral radiograph?

Back 3

(1) Beamperpendicular to the tooth/detector

(2) Detector parallel to tooth

Front 4

According to the American Academy of Oral & Maxillofacial Radiology, the goal of radiologic care is to produce high-quality images with a minimum of...

Back 4

Radiation exposure to the patient

Front 5

X-ray can damage cellular DNA by direct interaction of indirectly. What is the min mechanism of indirect degradation of DNA by X-rays?

Back 5

Free Radicals

Front 6

What is the best type of intraoral radiograph for examination of the lamina dura?

Back 6

Periapical

Front 7

Photostimulable phosphor detectors utilize “traps” to hold electrons that have been displaced from their ground states by x-rays. What portion of the electromagnetic spectrum is used to release theelectrons from these traps?

Back 7

Visible Light Portion

Front 8

Where are the mylohyoid ridge & oblique ridge in relation to the mental foramen?

Back 8

Posterior

Front 9

Arrange in order from most sensitive to leastsensitive to X-ray radiation: CT, Thyroid, Bone Marrow, Muscle

Back 9

Bone Marrow > CT > Thyroid > Muscle

Front 10

What types of x-rays occur in the cathode raytube?

Back 10

Bremsstrahlung and Characteristic

Front 11

True or False?

In licensed Clinical practice,you are required to keep each radiograph for 7 years after the image is firstobtained.

Back 11

FALSE

itis 7 years after patient is no longer a patient

Front 12

Correct technical term for carries that form atthe base of the tooth’s crown (near the alveolar crest)

Back 12

Root Caries or Cemental Caries

Front 13

Units of absorbed dose of radiation

Back 13

1Gray = 100 rads = 1 joule/kg

Front 14

In the bisecting angle technique, imaginary linebisects between what 2 objects?

Back 14

(1) The LongAxis of the Tooth

(2) Plane of the Detector

Front 15

In a cross-sectional mandibular occlusal set-up,the central ray from the BID is positioned perpendicular to the...

Back 15

Detectoror Occlusal plane

Front 16

Classical Shape of E1 Interproximal Caries Lesion

Back 16

Triangular

Front 17

Classical Shape of Buccal Surface Caries Lesion

Back 17

Round/Oval

Front 18

In a dental radiograph, the patient’s mandibular foramen should be closes to which teeth?

Back 18

Mandibular 3rd Molars

Front 19

Where are the largest medullary spaces seen indental radiography?

Back 19

Posterior Mandible

Front 20

In digital radiography, image resolution isrelated to pixel size. What controls image resolution in film radiography?

Back 20

Sizeof the silver halide crystals (grains)

Front 21

Curve of maxillary arch as usually presented ina topographical occlusal radiograph?

Back 21

Front 22

Coherent Light Scattering

Back 22

Relative E of Incident Photo? LOWER

Do Resulting Photons have enough E to Exit from Patient? NO or RARELY

Approximate % of Original Incident C-ray that Undergoes this Type of Scattering? 7%

Front 23

Compton Light Scattering

Back 23

Relative E of Incident Photo? HIGHER

Do Resulting Photons have enough E to Exit from Patient? YES

Approximate % of Original Incident C-ray that Undergoes this Type of Scattering? 57%

Front 24

Back 24

(A) mass or kVp

(B) kVp

(C) Object to Detector Distance

(D) Alignment

(E) Focal Spot Size

Front 25

What type of intraoral radiograph is the leastuseful for precisely locating supernumerary or impacted teeth?

Back 25

Bitewing

Front 26

What part of the tooth is the most important forproper alignment of a periapical radiograph, in order to reduce shapedistortion?

Back 26

Long Axis of the Root

Front 27

Change in electron binding energy as a functionof increasing distance from an atom’s nucleus?

Back 27

Decreases

Front 28

What is another accepted technical term for ”short-scalecontrast”?

Back 28

High Contrast

Front 29

What is the Cathode Ray?

Back 29

The Beam of Electrons in the X-Ray Tube

Front 30

Main purpose of the “fixing” stage ofradiographic film processing?

Back 30

To removethe unreacted silver halide crystals from the emulsion

Front 31

Who owns the dental radiographs of a patient?

Back 31

Dentist that Originally Took the X-ray

Front 32

What is another accepted name for the mylohyoidridge?

Back 32

Internal Oblique Ridge

Front 33

Two external structures on your patient’s headthat define the “Frankfort plane”?

Back 33

Orbitale (low point of inferior orbital margin)

Porion (external acoustic meatus)

Front 34

According to a minimal reading assignment, PSPdetectors have a property known as wide latitude:

What does wide latitude meanfor practical use of PSP detectors in Oral Radiography?

Back 34

PSPdetectors have a linear response to a wide range of X-ray exposure.

It is verydifficult to under/over expose a PSP detector

Front 35

Describe the main difference between theemulsion layers in standard radiographic film vs those in screen film?

Back 35

Maindifference is that the screen film emulsion includes visible light-sensitivedrugs & chemicals that are not present in the emulsions of standard radiographicfilm

Front 36

Type of ionizing radiation that causes the mostdamage per unit volume of tissue?

Back 36

Particulate Ionizing Radiation (alpha particles; beta particles; cathode rays)

Front 37

Define Ionizing?

Back 37

Have enough energy to displace electrons in tissue

Front 38

Compton scattering:

Back 38

High energy X-ray displaces an electron from a tissue atom.

C-ray’s path is divertedby the X-ray still has a relatively high energy (high enough to continue intothe tissue & penetrate to the detectors)

Front 39

FMX

Back 39

Full Mouth Series

Front 40

BID

Back 40

Beam Indicating Device

Front 41

mAs

Back 41

milli ampere-seconds

Front 42

HVL

Back 42

Half Value Layer

Front 43

3 Advantages of Digital Radiography Compared to Film-Based Radiography?

Back 43

(1) Less radiation exposure to the patient

(2) less environmental impact (less waste/chemicals)

(3) requires less storage space

Front 44

Main difference in the x-ray that initiate Compton scattering v. Coherent Scattering?

Back 44

Theenergy (wavelength) of the X-rays

High Energy >>> Compton Scattering

Low energy >>> Coherent Scattering

Front 45

What condition causes “image foreshortening” inan oral radiograph?

Back 45

(1) central C-ray is perpendicular to the detector, BUT...

(2) the tooth(object) and the detector are not parallel to each other

Front 46

5 steps of the PSP process for obtaining aradiographic image?

Back 46

(1) X-ray beam displaces valance electron fromsensor shell/orbit

(2) Displaced electron is captured in fluoride “trap”

(3) Scanning laser Light displaces trapped electrons

(4) Electrons fall back to ground state, giving off visible light

(5) Photo detector records light

Front 47

Who was Otto Walkhoff?

Back 47

Otto Walkhoff is credited with being the firstdentist to try Roentgen’s new discovery (X-rays) to form an image

Front 48

Current vs Early Units: Exposure

Back 48

Current: C/kg

Early: Roentgen (R)

Front 49

Current vs Early Units: Dose

Back 49

Current: Gray

Early: Rad

Front 50

Current vs Early Units: Equivalent Dose

Back 50

Current: Sievert (Sv)

Early: rem

Front 51

List Conditions that can look like cariouslesions on a radiograph

Back 51

(1) Mach Band Effect

(2) Cervical Burnout

(3) Non-Metallic Restorations

(4) Toothbrush Abrasion

Front 52

What is the geometry of the collimator openingused in panoramic radiograph?

Back 52

Slit

Front 53

3 normal anatomic structures that result in doublereal images on a panoramic radiograph

Back 53

(1) Hard Palate

(2) Hyoid Bone

(3) Spine

Front 54

3 factors that determine whether an atom will beionized by radiation?

Back 54

(1) Atomic Number

(2) Location of Electron being Displaced

(3) Energy of Incident Radiation

Front 55

Name 3 types of electromagnetic ionizingradiation

Back 55

(1) X-rays

(2) Gamma Rays

(3) UV rays (some)

Front 56

Ionizing radiation can damage somatic cells.

What characteristic of somatic cells determines their relative sensitivity toionizing radiation?

Back 56

Mitotic Rate

Front 57

The quantity of X-rays produced by an X-raymachine varies...

Back 57

Directly & Linearly with:

a) Exposure Time

b) Current

Front 58

The penetrating power of X-rays produced by anX-ray machine varies...

Back 58

Directly and Non-Linearly with:

a) Voltage

Front 59

3 anatomical conditions that are commonchallenges to correct placement of bitewing radiograph of the premolars

Back 59

(1) Tori

(2) Shallow Maxillary Palate

(3) High Muscle Attachments

Front 60

Difference between absorbed dose & effectivedose in ionizing radiation biophysics?

Back 60

AbsorbedDose: the amount of E absorbed by the tissue (units: Grays or joules/Kgof tissue)

Effective Dose: takes the type of tissueinto account by using a tissue weighting factor

• more sensitive tissue have a higher weightingfactor
  

Front 61

According to the reading assignment why shouldthe cost of a radiograph be included in the cost of the clinician’s diagnosticevaluation?

Back 61

So thatthere is no question that the dentist owns the radiographs

Front 62

The contrast of a radiograph is affected most by what variable of the X-ray machine?

Back 62

kVp

Front 63

Medullary Spaces in the mandible are __________ than in the maxilla.

Back 63

Larger

Front 64

Medullary Spaces in the anterior mandible are __________ than in the posterior mandible.

Back 64

Smaller

Front 65

True or False?

The American Academy of Oral 7 MaxillofacialRadiology regulates the maximum, cumulative absorbed does allowed per dentalpatient per year in the US.

Back 65

False

Front 66

What is the feature of the panoramic radiographthat indicates that the patient’s chin was too high during the exposure?

Back 66

Theteeth in the radiograph are aligned more in a straight line (left to right) oreven in a slight frown

Front 67

Occlusal carious lesions in posterior teethoften are not visible on intraoral radiographs until they are radiographicclass 3 lesions.

Why are they usually not visible before this?

Back 67

Becausethe large amount of enamel that the X-ray would have to go through (BL direction) to get to the detector

Front 68

In the electromagnetic spectrum, what is the specific type of ionizing radiation that has higher enerdy than X-rays.

Back 68

Gamma Rays

Front 69

Advantage of the bisecting angle techniquecompared to the parallel technique for a periapical radiograph?

Back 69

Thedetector (film) can be placed closer to the teeth (sharper images)

Front 70

True or False?

The US FDA requires that Cray machines in adental clinic be inspected every 3 years?

Back 70

False.

This is a NYS regulation.

Front 71

Follow Up for a failed Inspection in NYS...

Back 71

Every 60 days OR LESS

Front 72

FDA Regulations

Back 72

continue to be revised and slightly updated (important to know when an X-ray machine was FDA approved)

Front 73

Legal Risk Management

Back 73

• Patient Relations
• Informed Consent
• Liability
• Patient Record
• Ownership

Front 74

Approximate number of electron volts required togenerate a free radical in tissue?

Back 74

~ 10 eV

Front 75

Dense White Line Close to Tooth?

Back 75

Lamina Densa

Front 76

Cephalometric radiographs are used most oftenfor which dental specialty?

Back 76

Orthodontics

Front 77

In a radiograph, the image of the incisive foramen is high or low density?

Back 77

High Density

Front 78

A bitewing radiograph is the best way to detectwhat general type of caries?

Back 78

Interproximal

Front 79

What kind of restorative materials are mostradiolucent?

Back 79

Resin or Resin Composites

Front 80

Principle Quantum Numbers

Back 80

K = 1

L = 2

M = 3

N = 4

Front 81

Maximum Electrons Per Shell

Back 81

K = 2

L = 8

M = 18

N = 32

Front 82

For healthy teeth, how does the radiographicappearance of a young person’s periodontal ligament space differ from theradiographic appearance of an elderly person’s periodontal ligament space?

Back 82

PDL space on a young, healthy person isthicker than that on an elderly/healthy person

Front 83

In a periapical radiograph, what is the appearance of Trabeculae

Back 83

Radiopaque network (may exhibit step-ladder pattern)

Front 84

In a periapical radiograph, what is the appearance of Medullary Spaces

Back 84

Radiolucent Blocks between the trabeculae

Front 85

On a panoramic radiograph, where is the nasalseptum, relative to the image of the nasal spine?

Back 85

nasal septum is superior to the nasal spine

Front 86

Another accepted name for the external obliqueridge?

Back 86

Oblique Ridge

Front 87

And on a panoramic or periapical technique for aperiapical radiograph, how would you adjust the X-ray equipment in order to reduce the penumbra?

Back 87

Move the X-ray source further away from the patient

Front 88

True or False?

Screen film is a type of digital detector?

Back 88

False.

Front 89

Back 89

1. outline of nose
   
2. incisive foramen
3. lateral fossa
4. nasal fossa
5. nasal septum
6. border of nasal fossa
7. nasal spine
8. median palatine suture

Front 90

Back 90

1. incisive foramen (irregular, rounded radiolucent area)
2. outline of the nose
3. lateral fossa
4. nasal fossa (radiolucent)
5. nasal septum (radiopaque)
6. border of nasal fossa
7. nasal spine
8. median palatine suture

Front 91

1. Radiolucent line indicated by the two white arrows?

2. Radiolucent on both side of radiolucent line?

3. Radiolucent areas in mesial surface of the crowns?

Back 91

1. mid-palatine suture

2. incisive foramen

3. composite-resin restorations

Front 92

Back 92

1. border (floor) of maxillary sinus
2. maxillary sinus
3. septum in maxillary sinus
4. zygomatic process of maxilla
5. zygoma
6. lower border of zygomatic arch

Front 93

1. Identify the radiolucent structure in the upper right area.

2. Describe the radiograph in terms of area, restorations, and apparent periodontal health.

Back 93

1. Maxillary SInus

2. This is a periapical radiograph of the patients left posterior maxilla, showing the 1st & 2nd molars and both premolars (cropped). There are two restorations on the 1st molar. The periodontal health of the patient is fair to good. Bone height is even, although a bit low, and the PDLs are close to the roots of the teeth.

Front 94

Back 94

1. floor of maxillary sinus
   
2. maxillary sinus
   
3. zygomatic process of maxilla
   
4. zygoma
   
5. septum in maxillary sinus
   
6. lower border of zygomatic arch
   
7. hamulus
   
8. maxillary tuberosity
   
9. coronoid process
   

Front 95

Back 95

1. mental ridge
2. nutrient canal
3. nutrient foramen
4. genial tubercles
5. lingual foramen
6. inferior border of the mandible

Front 96

Back 96

1. nutrient canal
2. lingual torus

Front 97

Back 97

1. lingual torus
2. oblique ridge
3. mylohyoid ridge
4. submand. fossa (bone very thin/appears radiolucent)
5. mandibular canal
6. mental foramen

Front 98

What is the radiolucent area indicated by the white arrow?

Back 98

Mental Foramen

Landmarks: Near the apices of the mandibular premolars

Front 99

1. What structure is indicated by the black arrows?

2. Describe radiograph by type and location.

Back 99

1. Oblique Ridge or External Oblique Ridge

2. The is a periapical radiograph of the patients right posterior mandible.

Front 100

Back 100

1. oblique ridge
2. mylohyoid ridge
3. submandibular fossa
4. mandibular canal

Front 101

Type

Area

Notable Features

Description

Back 101

A Periapical Radiograph of the mandibular posterior left premolar/molar area [tooth # 19-22]showing a MO amalgam restoration on 2nd premolar [#20] and endodontic treatment with a full crown on 1st molar [#19]. Add sentence describing any carious lesions and there location/severity.

Front 102

4 Disadvantages of Digital Radiography

Back 102

(1) System Cost

(2) Detector Cost and Unpredictable Longevity

(3) Relatively New Technology (several competing systems)

(4) Digital Format requires Computer, etc.

Front 103

Size of the Detectors Shown?

Back 103

Front 104

Radiographic Features of Cancellous Bone vs. Cortical Bone

Back 104

Cancellous Bone: both radiopaque/radiolucent features:

• Radiopaque= ladder like trabeculae area
  
• Radiolucent= Areas of marrow (medullary spaces)
  

Cortical Bone: radiopaque, low density image

Front 105

1. What is the Green arrow pointing at?

2. What is the Radiolucent area that the Red arrows are pointing at?

Back 105

1. Inferior Border of the Nasal Fossa

2. Floor of the Maxillary Sinus

Front 106

Name the specific type of radiograph obtained with the devices pictured.

Back 106

1. Anterior Periapical

2. Posterior Periapical

3. Bitewing

Front 107

Describe

Back 107

This is a periapical radiograph of the patients left posterior mandible, showing both premolars and the 1st & 2nd molars. Bone Height is good, but the PDL space is widening at the mesial surface of the 2nd molar. Carious lesions are not visible in the radiograph.

Front 108

What kind of detector schematic is shown in this drawing?

Back 108

screen film

Front 109

Name the radiographic projection- be specific.

Back 109

Anterior Maxillary Occlusal

Front 110

Name the radiographic projection- be specific.

Back 110

Cross-Sectional Mandibular Occlusal

Front 111

A) What is the radiographic classification of this lesion?

B) What is the operative classification of this lesion?

Back 111

A) Class III

B) D1 or D2

Front 112

X-ray is set at 90 kVp, 15 mA, 2.5 mm aluminum filtration, and .2 sec exposure time with a distance of 8 inches. If you change 10 mA, what would be the new exposure time if you don't want to change the image density?

Back 112

Density = mA x s

(15 mA) x (.2 sec) = (10 mA) x (X sec)

X = .3 sec

Front 113

1) type of x-ray?

2) side of mouth?

3) teeth with restorations?

4) tooth with caries?

Back 113

1) Bitewing

2) Right

3) #2, #3, #5, #30, #31

4) Mandibular 2nd Premolar

Front 114

Which is set up wrong for a bitewing?

Why?

Back 114

Left.

Teeth would be positioned behind the detector, and not between the detector and source.

Front 115

1) What radiographic technique is indicated?

2) What radiographic projection is indicated?

Back 115

1) bisecting technique

2) anterior mandibular occlusal

(mandibular symphysis is included)

Front 116

Why is this a bad panoramic radiograph?

Back 116

Condyles are on different levels and not the same size.

The dentition is not all in focus.

Front 117

1) What structure is the arrow pointing to?

2) Describe the type and location.

3) Identify condition indicated by large radiolucent areas.

Back 117

1) Median Palatine Suture

2) This is a periapical radiograph of the patients maxillary incisors.

3) The large radiolucent areas indicate rampant caries.

Front 118

If a radiograph was produced using a source to film distance of 8 inches and an exposure time of 1 sec, what would be the correct exposure time to get the same image with a source to film distance of 16 inches?

Back 118

4 sec

[C] or [T] can be used in place of E.

Front 119

1) Red Arrow?

2) Green Arrow?

Back 119

1) Floor of the Nasal Cavity

2) Floor of the Maxillary Sinus

Front 120

What is the radiographic term used to describe the problem in this image?

Back 120

Cone-Cut or Partial Image

Front 121

Most Common Cause of Malpractice Suits is the Failure of the Dentist to use radiographs in the diagnosis or management of....

Back 121

1) pain

2) infection

3) swelling

Front 122

Back 122

1. Condyle 2. Sigmoid Notch

3. Coronoid Process 4. Mandibular Foramen

6. Mandibular Canal 7. Mental Foramen

10. Lingual Foramen

11. Genial Tubercles

12. Inferior Border of Mandible

14. Mylohyoid Ridge

Front 123

Draw the lines demonstrating the bisecting technique and explain what they are.

Back 123

A) Plane of the Detector

B) Bisecting Line

C) Long Axis of Central Incisors

Front 124

What is the main advantage of CMOS/APS over CCD for dental radiography?

Back 124

More Rapid Processing

Front 125

What X-ray detection mechanism is common to these techniques:

CCD, PSP, & CMOS/APS

Back 125

Detectors Electrons are displaced from their ground state

Front 126

Identify (1), (3),(4), & (5)

Back 126

(1) Genial Tubercles

(3) Mental Ridges

(4) Lingual Foramen

(5) Inferior Border of the Mandible

Front 127

X-Ray Interactions with Matter

Back 127

1. None

2. Coherent Scattering

3. Photoelectric Effect

4. Compton Effect

Front 128

Typical Equivalent Doses of Dental X-Rays?

Back 128

Front 129

What is a Joule?

Back 129

Front 130

Wave Theory

Back 130

c = velocity of "light"

v = frequency

l = wavelength

Front 131

Quantum Theory

Back 131

h = planck's constant

Front 132

Ionizing Effect on Biomolecules

Back 132

1) Direct

2) Indirect (via free radical formation)

Front 133

Cells sensitivity to ionizing radiation damage...

Back 133

Directly proportional to reproductive capacity.

Inversely proportional to cells degree of differentiation.

Front 134

Interactions associate with oral radiology...

Back 134

cathode rays interacting with targets = X-rays

X-rays interacting with your patient = scattering and radiographic

Front 135

Back 135

Image Foreshortening

Front 136

Back 136

Image Elongation

Front 137

Back 137

Image Enlargement

Front 138

Large or Small Crystals?

Back 138

Front 139

Fluorescence vs Phosphorescence

Back 139

Front 140

Radiographic Detection Mechanisms: Summary

Back 140

Front 141

Intensity

Back 141

Intensity = quality x quantity

quantity: determined by mAs

quality is penetrating ability (X-ray energy)

Inverse Square Law: Intensely is inversely related to distance SQUARED

Front 142

X-Ray Variables

Back 142

Front 143

Dose and Equivalent Dose: X-Ray

Back 143

Equivalent Dose (Sv) = Dose (Gy)

Front 144

Dose and Equivalent Dose: Alpha Particle

Back 144

Equivalent Dose (Sv) > Dose (Gy)