Lec 5 Periapical Radiography, Paralleling, Bisecting-angle

Question 1

What are 2 techniques under periapical radiography?

Answer 1

1. Paralleling
2. Bisecting-angle

Question 2

Any medium used to capture an image, including film, charge-coupled devices (CCDs), complementary metal oxide semiconductor (CMOS) sensors, or storage phosphor plates

Answer 2

Image receptor

Question 3

Paralleling technique are also called as? (2)

Answer 3

Right-angle technique, long-cone technique

Question 4

The x-ray receptor is supported _______ to the long axis of the teeth and the central ray of the x-ray beam is directed at _______ to the teeth and receptor.

What technique?

Answer 4

• parallel; right angles
• paralleling technique

Question 5

Paralleling technique is made using a (short or long?) source-to-object distance.

Answer 5

Long

Question 6

• Facilitate the positioning of the receptor in the patient’s mouth.
• These holders stabilize the receptor to a bite block.

Answer 6

Receptor holding instruments (paralleling device??)

Question 7

PARALLELING TECHNIQUE (RECEPTOR PLACEMENT)

• The receptor should be positioned _____ to the teeth and deep into the ________ or __________.
• For maxillary projections:
  The ________ border of the receptor generally rests at the height of the ________ in the midline.
• For mandibular projections:
  The receptor should be used to displace the ______ posteriorly or toward the midline to allow the _____ border of the receptor to rest on the ___________ away from the _______ on the lingual surface of the mandible.
• Anatomic limitations: (4)

Answer 7

• parallel; lingual vestibule / palatal vault
• superior border; palatal vault (midline)
• displace the tongue; rest on the floor of the mouth; away from mucosa
• Shallow palate, shallow floor of the mouth, tori, multirooted tooth

Question 8

PARALLELING TECHNIQUE (Angulation of the Tube Head)

• Align the aiming ______ of the x-ray machine to the vertical and horizontal planes of the aiming ______.
• The ________ direction of the beam primarily influences the degree of ________ of the images of the crowns at the interproximal spaces.

Answer 8

• cylinder; ring
• horizontal; overlapping

Question 9

The receptor is positioned as _____ as possible to the ______ surface of the teeth, resting in the palate or in the floor of the mouth.

What technique?

Answer 9

• close
• lingual surface
• bisecting-angle technique

Question 10

The Bisecting-angle Technique is based on a simple geometric theorem, ______________ , which states that two triangles are equal when they share one complete side and have two equal angles.

Answer 10

Cieszynski’s rule of isometry

Question 11

The plane of the receptor and the long axis of the teeth form an angle with its apex at the ________ or ________. Consider an imaginary line that bisects this angle and direct the central ray of the beam at _________ to this bisector.

Answer 11

• incisal edge
• occlusal surface
• right angles

Question 12

BISECTING-ANGLE TECHNIQUE (Receptor-Holding Instruments)

The preferred method is to use a ________________ with an external device to ______ the x-ray beam and guide the appropriate ______ angle.

Answer 12

• receptor-holding bisecting angle instrument
• localize
• vertical angle

Question 13

BISECTING-ANGLE TECHNIQUE
(Positioning of Patient)

Maxillary projections.
- The patient should be seated ______ in the dental chair with the sagittal plane ____ and the occlusal plane ________.

Mandibular projections.
- The patient should be seated upright in the dental chair with the sagittal plane ______. The head is _________ to compensate for the changed occlusal plane when the mouth is opened.

Answer 13

• upright
• vertical
• horizontal
• vertical
• tilted back slightly

Question 14

BISECTING-ANGLE TECHNIQUE
(Receptor Placement)

• Similar to the paralleling technique, the receptor is positioned _____ the area of interest, with the apical end against the mucosa on the __________ surface.
• The __________ is oriented against the teeth with an edge of the receptor extending just beyond the teeth.

Answer 14

• behind
• lingual/palatal surface
• occlusal/incisal edge

Question 15

Diagnostic Objectives of Periapical Radiography
1. Assess extent of __________.
2. Detect presence and assess extent of __________.
3. Evaluate consequences of ____________ to the teeth and alveolar bone.
4. Assess periodontal _______.
5. Evaluate root ________.
6. Assess implant ______ and peri-implant _______.
7. Evaluate _______ and ______ teeth.
8. Evaluate external and internal ____________.
9. Assess pulp _______.
10. Determine length of ___________ during treatment.

Answer 15

• dental caries
• periapical inflammation
• traumatic injuries
• periodontal bone loss
• root morphology
• osseointegration & bone loss
• unerupted & impacted teeth
• root resorption
• pulp morphology
• endodontic instrumentation