05 - Intraoral Radiographic Technique

full mouth series (FMX, FMS)

• 4 bitewings

• 8 posterior periapical radiographs

• 6-10 anterior periapical radiographs

• at Touro:

  • 6 PAs → 3 maxillary, 3 mandibular

steps for taking a radiograph

1. prepare the room

2. greet and seat the patient

3. review medical history

4. ask patient to remove glasses and head/neck jewelry

5. wash hands in front of patient

6. examine the oral cavity

7. place a lead apron and/or thyroid shielding

8. confirm exposure time

9. position the tube head to its approximate location

10. position the image receptor

11. complete the x-ray tube positioning

12. make the exposure

13. repeat steps 8-12 until radiographic examination is complete

paralleling technique

image receptor is placed further but parallel to the tooth

• eliminates foreshortening and elongation effects

• tooth is a little magnified, but long cone minimizes magnification

bisecting angle technique

x-ray beam is aimed perpendicular to imaginary line that bisects the angle formed by tooth’s long axis and image receptor

• amount of foreshortening equals the amount of elongation, resulting in tooth that is the correct length

• image is somewhat distorted

receptor-holding instruments

extension cone paralleling (XCP)

• instrument used to simplify the paralleling technique

• patient bites on the flat portion

• color-coded based on type of image

  • red → bitewing

  • blue → anterior periapical

  • yellow → posterior periapical

bitewing radiograph

goal to evaluate interproximal surfaces of teeth and periodontal bone height

• premolar and molar bitewings

  • align such that mesial part of image receptor captures distal half of the tooth mesial of what is to be captured

• vertical bitewing

  • used frequently for patients with significant periodontal bone loss

periapical radiographs

goal to evaluate apices of visualized teeth and evaluate periodontal bone height of anterior projections

• anterior

  • centrals → align such that it is centered at midline

  • left/right canine → center in image

• posterior 

  • premolar → aim such that mesial edge of image receptor captures distal portion of canine

  • molar → aim such that mesial edge of image receptor captures distal portion of second premolar

occlusal radiographs

• localize roots, supernumary teeth, unerupted teeth, and impacted teeth in buccal-lingual dimension

• localize foreign bodies and salivary gland stones

• evaluate maxillary sinus borders, patients with trismus (limited opening), fractures, and palate or floor of mouth

• maxilla → anterior or lateral

• mandible → anterior or lateral

SLOB

same lingual, opposite buccal

• if the x-ray is moved mesial and the object also shifts mesial, the object is on the lingual side

• if the x-ray is moved mesial and the object moves distal, the object is on the buccal side