Oral Radiology Week 2 Ppt Review

Front 1

What puts Limitations to perfect technique?

Back 1

• Rotated teeth
• Height of palate
• Presence of unerupted third molars
• Excessive root lengths
• Presence of tori
• Patient tolerance and cooperation
• Gag reflex
• Small mouth size - narrow arches

Front 2

What causes molar overlap?

How will overlapping result?

How is overlapping avoided?

Back 2

• Interproximal contacts are in the mesiodistal relationship to the midsagittal plane
• Paralleling the film to the buccal surfaces
• Place the film slightly diagonal with the front edge of the receptor a greater distance from the lingual surfaces of the teeth than the back edge

Front 3

What may be necessary in order to open the contacts of malposed or crowded teeth?

How would this be accomplished?

Back 3

• It may be necessary to take additional films at various horizontal angles
• The film must be positioned perpendicularly to the embrasure space between the two teeth.

Front 4

The radiograph will usually be acceptable if the difference between the angle of film and long axis of the tooth doesn't exceed ____ degrees.

Increasing the angle by up to ______ degrees of what is indicated will image more of the apical region.

More angulation than that may result in ?

Back 4

• 15 degrees
• 15 degrees
• distortion such as foreshortening

Front 5

What must be remembered when radiographing a patient with a shallow palate?

Back 5

The resulting radiograph will generally be acceptable if the lack of parallelism is less than 15degrees.

Front 6

Where should the film be placed when radiographing next to maxillary tori?

What should be remembered?

Back 6

• Place the film on the far side of the torus
• The oral mucosa covering tori may be thin and sensitive.

Front 7

Where should the film be placed when radiographing next to a mandibluar tori?

What should be done when taking bitewings in this area?

Back 7

• Place the film between the torus and the tongue
• A tab extender may be needed to make sure the film can be placed away from the torus

Front 8

When radiographing an edentulous patient, what can be used in place of the missing teeth?

Where is the PID aimed?

Back 8

• Cotton rolls
• Perpendicular to the mean tangent of the facial side of the ridge and to the plane of the film

Front 9

What should be bisected on an edentulous patient?

Back 9

The long axis of an imaginary tooth and the film

Front 10

What are methods for determining if an object or structure is located buccal or lingual to the teeth?

Back 10

• Definitive method
• Right-angle method
• Tube shift method or Buccal-object Rule or SLOB rule

Front 11

What is the definitive method for determining if an object or structure is located buccal or lingual to the teeth?

Is it a reliable method?

Back 11

• Uses a theory based on the shadow principle that because the film is placed lingual to the teeth, if an object is on the lingual, it will appear more clear and if on the buccal, it will appear less defined and magnified.
• It is not consistently reliable

Front 12

What is the right-angle method for determining if an object or structure is located buccal or lingual to the teeth?

How many radiographs are required?

Back 12

• A method using an occlusal film such as a cross sectional view to place the film at a right angle to the tooth.
• in this position the resultant radiograph will show if the object is on the buccal or lingual
• It requires two radiographs, one occlusal and one prependicular to the long axis of the tooth

Front 13

What is the tube shift method for determining if an object or structure is located buccal or lingual to the teeth?

How many radiographs are required?

Back 13

• A pariapical or bitewing receptor is exposed using proper technique and angulation, then a second periapical or bitewing receptor is exposed after changing the direction of the x-ray beam
• Two radiographs are required

Front 14

What is the buccal object (SLOB) rule for determining if an object or structure is located buccal or lingual to the teeth?

How many radiographs are required?

Back 14

• When the dental structure or object seen in the second appears to have moved in the same direction as the shift of the PID, the it is positioned to the lingual
• When the dental structure or object seen in the second appears to have moved in the opposite direction as the shift of the PID, the it is positioned to the buccal

--- Same Lingual Opposite Buccal ---

Two radiographs (from the tube shift method) are required

Front 15

What can the SLOB rule be used to detect?

Back 15

• Filling material in the root canals
• Impacted teeth

Front 16

What is the disto=periapical techique

What is it used to image?

Back 16

• Shift the horizontal angulation 10 degrees from the distal to project the image anteriorly
• Increase the vertical angulation 5 degrees
• ONLY Increase the exposure to the next highest impulse or timer setting to adjust for rays going through the zygomatic arch

Front 17

How can you tell the emulsion side of a duplicating film when viewing it under safelight conditions?

Back 17

The emuslion side appears more dull or lighter than the other side

Front 18

When duplicating radiographs, the emulsion side of the duplicating film should be placed up or down?

Back 18

emulsion side should be down

Front 19

How is the duplicating film processed?

Back 19

Same as normal radiograph film

Front 20

What should be done if you want darker or lighter duplicates?

Back 20

• Darker = decrease the exposure time
• Lighter = increase the exposure time

Front 21

What is the purpose of the occlusal radiograph?

Back 21

To view/examine large areas of the maxilla or mandible

Front 22

What types of occlusal radiographs are there?

Back 22

Topographical or cross-sectional

Front 23

How is the occlusal film placed in the patient's mouth?

Back 23

it lays flat on the occlusal plane and the patient bites on the film

Front 24

When can an occlusal radiograph be used?

Back 24

when the area of interest is larger than a pariapical film or when using a pariapical film is too difficult for the patient

Front 25

What is the topographical best used to image?

Back 25

• conditions of the teeth and supporting structures when you need to look at an area larger than a periapical
• more information in the alveolar crest and apical areas than pariapicals

Front 26

What does the cross sectional technique show, aid in, and help with?

Back 26

• it shows more area sublingually
• it aids in evaluation of conditions such as tori, impacted or malposed teeth, and calcifications of soft tissues such as salivary stones
• it can help locate foreign objects

Front 27

What can the occlusal radiograph be used to locate?

Back 27

• locating supernumarary, unerupted, or impacted teeth
• locating retained roots of extracted teeth
• detect the presence of lesions and their extent
• locating foreign bodies in the jaw

Front 28

what does the occlusal radiograph aid in?

Back 28

aid in evaluating fractures of the jaw

aids in examining patients who have limited opening

Front 29

What does the occlusal radiograph help show or evaluate

Back 29

• size and shape of mandibular tori
• the border of the sinus
• cleft palate patients
• children when a periapical is needed (size 2 film can be used)

Front 30

What are the most common occlusal exposures?

Back 30

• maxillary topographical anterior
• maxillary topographical posterior
• mandibular topographical anterior
• mandibular topographical posterior
• mandibular cross sectional

Front 31

What side of the film is placed facing the arch being exposed?

Back 31

The white side

Front 32

How much of the film should protrude out of the mouth? why?

Back 32

• about 1/4 inch
• to avoid cutting off part of the image

Front 33

what size of film is used on adults?

what size on children?

and where should the dot be?

Back 33

• size 4
• size 2 can be used
• dot goes out of the mouth

Front 34

How should the patient be prepared?

Back 34

• Explain the radiographic procedure to the patient
• position the patient upright in the chair
• adjust the headrest to support and position the patient's head
• place the lead apron with thyroid collar on the patient and secure it
• remove all objects from the mouth

Front 35

How should the head be positioned for the topographical occlusal radiograph?

Back 35

the head is positioned with the occlusal plane parallel to the floor and the midagital plane perpendicular to the floor

Front 36

How should the head be positioned for the mandibular cross-sectional occlusal radiograph?

Back 36

the patient is reclined in the char so the head can be tipped back with the occlusal plane and midsagital plane perpendicular to the floor

Front 37

What are the exposure factors (kVp, mA, and time)?

Back 37

the same as those for periapicals and bitewing radiographs

Front 38

What are the horizontal and vertical angulation principals?

Back 38

• Horizontal = same as periapicals and bitewings regarding opening contacts

• vertical = follow the bisecting angle principals

- observe the plane of the film and estimate the long axis of the teeth

- PID is angled to bisect the two planes

Front 39

What is the vertical angulation for maxillary tobographical anterior?

Back 39

+65

Front 40

What is the vertical angulation for maxillary topographical posterior?

Back 40

+45

Front 41

What is the vertical angulation for mandibular topographical anterior?

Back 41

-55

Front 42

What is the vertical angulation for mandibular topographical posterior?

Back 42

-45

Front 43

What is the vertical angulation for mandibular cross-sectional?

Back 43

0

Front 44

For a maxillary topographical anterior, how is the patient seated? what is the PID's angulation? where is the central ray directed? where is the point of entry?

Back 44

• with occlusal plane parallel to the floor
• +60
• through contacts of 8 and 9
• a point near the bridge of the nose

Front 45

For a maxillary topographical posterior, how is the patient seated? how is the film placed? what is the PID's angulation? where is the central ray directed? where is the point of entry?

Back 45

• with the occlusal plane parallel to the floor
• film is off to one side
• +45
• through the maxillary molars
• a point on the ala-tragus line below the outer canthus of the eye

Front 46

For a mandibular topographical anterior, how is the patient seated? what is the PID's angulation? where is the central ray directed? where is the point of entry?

Back 46

• with the occlusal plane parallel to the floor
• -55
• through the contacts of the mandibular centerals
• a point on the middle of the chin

Front 47

For a mandibular topographical posterior, how is the patient seated? where is the film placed? what is the PID's angulation? where is the central ray directed?where is the point of entry?

Back 47

• with the occlusal plane parallel to the floor
• off to one side
• -45
• through the mandibular posterior embrasures
• a point on the inferior border of the mandibule directly below the second mandibular premolar

Front 48

For a mandibular cross-sectional, how is the patient seated? what is the PID's angulation? where is the central ray directed? where is the point of entry?

Back 48

• reclined with occlusal plane perpendicular to the floor
• 0
• through a point 3 inches back from the tip of the chin
• a point 2 inches back from the tip of the chin

Front 49

For a maxillary pediatric occlusal projection, how is the patient seated? what is the PID's angulation? what size of film may be used?

Back 49

• seated with the occlusal plane parallel to the floor
• +60
• size 2