1. Supplemental Radiographic Technique
Chapter 28
Supplemental Radiographic Technique

2. Objectives Define the key words.
Demonstrate the ability to adapt standard techniques when necessary.
Demonstrate appropriate adaptations in image receptor placement to avoid overlap.
Explain the need to alter vertical angulation in the presence of a shallow palatal vault.

3. Objectives
Demonstrate knowledge of setting the exposure time based on patient characteristics.
Demonstrate the ability to place the intraoral image receptor in the presence of large maxillary or mandibular tori.
Discuss the procedures for image receptor placement in patients with edentulous areas.

4. Objectives
Discuss the procedures for image receptor placement during endodontic procedures.
List three methods of localization.
Use the buccal-object rule to identify the location of a foreign object.
Describe the difference between a standard molar periapical radiograph and a disto-oblique periapical radiograph.

5. Objectives List four reasons to duplicate radiographs.
Demonstrate the step-by-step procedures for duplicating radiographs.

6. Key Words Buccal-object rule Disto-oblique periapical radiographs
Duplicate radiograph
Duplicating film
Edentulous
Endodontic therapy

7. Key Words Hemostat Film duplicator Localization Root canal treatment
SLOB rule
Tori

8. Key Words Torus mandibularis Torus palatinus Tube shift method
Working radiograph

9. Introduction
Each patient presents with unique characteristics, some of which may require that the dental radiographer have the knowledge and skills to adapt procedures to best suit the circumstances.
What sets the skilled radiographer apart from the average is the ability to alter techniques and yet still produce diagnostic images.

10. Acceptable Variations in Technique
Avoiding overlap
Malaligned or crowded teeth
Altering vertical angulation
Exposure factors

11. Figure 28-1 Indicator ring not a dictator
Figure Indicator ring not a dictator. The radiographer has chosen to increase the vertical angulation to increase the periapical coverage on the resultant image.

12. Figure 28-2 Image receptor position to avoid molar overlap
Figure Image receptor position to avoid molar overlap. The anterior portion of the image receptor is placed a greater distance away from the lingual surfaces of the teeth.

13. Figure 28-3 Minimize canine and premolar overlap
Figure Minimize canine and premolar overlap. (A) The curve of the arches in this region superimposes the lingual cusp of the premolar onto the distal edge of the canine. (B) Shifting the horizontal angulation slightly to direct the x-ray beam to intersect the image receptor from the distal will help avoid overlap of these two teeth. (C) Note the elimination of overlap error in the radiograph on the right.

14. Figure 28-4 Different horizontal angluation is required when teeth are malaligned.

15. Figure 28-5 Shallow palate
Figure Shallow palate. The tissue edge of the image receptor is shown tipped away from the teeth. When the lack of parallelism is less than 15 degrees, the resultant radiograph will generally be acceptable.

16. Figure Increased vertical angulation recorded more of athe apical region imaging this supernumerary (extra) impacted premolar, while cutting off a portion of the occlusal region of the teeth.

17. Figure 28-7 Maxillary torus
Figure Maxillary torus. Image receptor placed on the far side of the torus away from the teeth.

18. Figure 28-8 Mandibular torus
Figure Mandibular torus. Image receptor placed between the torus and the tongue.

19. Figure 28-9 Partially edentulous mouth
Figure Partially edentulous mouth. Cotton rolls or polystyrene blocks can be used to substitute for missing teeth to help hold the image receptor holder in place. (A) Edentulous mandibular anterior region. (B) Edentulous maxillary posterior region.

20. Figure 28-10 Totally edentulous mouth
Figure Totally edentulous mouth. When all teeth are missing, cotton rolls, polystyrene blocks, or a combination of both can be used as substitutes for the crowns of the teeth. These will allow the patient to bite and stabilize the image receptor holder. The thickness of the cotton rolls or blocks will determine the amount of edentulous ridge recorded. (A) Maxillary anterior region. (B) Mandibular posterior region.

21. Figure Illustration of the bisecting technique for an edentulous patient. The central ray is directed perpendicular to the bisector, an imaginary line estimated to be halfway between the plane of the image receptor and a line drawn vertically through the ridge to substitute for the long axes of the teeth. (A) Maxillary edentulous ridge, (B) Mandibular edentulous ridge.

22. Figure 28-12 Endodontic film holder. (Courtesy of Dentsply Rinn.)

23. Figure 28-13 Modifying a film holder for use in endodontic therapy
Figure Modifying a film holder for use in endodontic therapy. Removing a portion of this disposable polystyrene image receptor holder will allow the endodontic materials placed in the tooth to remain in place during the exposure.

24. Figure 28-14 Rinn Snap-A-Ray image receptor holder.

25. Figure Hemostat as a film holder for endodontic procedures eliminates the need to occlude on on a biteblock.

26. Figure Hemostat facilitates holding the image receptor in a parallel position to the long axis of the tooth.

27. Methods of Localization
Definitive evaluation method
Right-angle method
Tube shift method (buccal-object rule)

28. Figure 28-17 Definitive method of localization
Figure Definitive method of localization. Note the barely visible supernumerary (extra) root on this first molar. Applying the definitive method of localization, it is most likely a buccal root. The buccal position would place this root a greater distance away from the image receptor, resulting in its magnified and less distinctly defined appearance.

29. Figure 28-18 Right angle method of localization
Figure Right angle method of localization. (A) A foreign object appears in the periodontal pocket between the second premolar and the first molar. It is impossible to tell from this periapical radiograph whether the object is located toward the buccal or the lingual. (B) The occlusal radiograph, placed at a right angle position to the tooth, clearly images the object on the buccal side of the pocket.

30. Figure 28-19 Horizontal tube shift
Figure Horizontal tube shift. (A) In the original radiograph, buccal and lingual objects are superimposed. (B) When the tube head is moved distally, the buccal object appears to move mesially, whereas the lingual object appears to move distally. (C) When the tube head is moved mesially, the buccal object appears to move distally, whereas the lingual object appears to move mesially.

31. Figure 28-20 Vertical tube shift
Figure Vertical tube shift. (A) In the original radiograph, buccal and lingual objects are superimposed. (B) When the tube head is moved superiorly, the buccal object appears to move inferiorally, whereas the lingual object appears to move superiorly. (C) When the tube head is moved inferiorly, the buccal object appears to move superiorly, whereas the lingual object appears to have moved inferiorally.

32. Methods of Localization
SLOB “Same on Lingual—Opposite on Buccal”

33. PROCEDURE 28-1 Disto-oblique periapical radiographs

34. Figure 28-21 Disto-oblique periapical technique
Figure Disto-oblique periapical technique. The horizontal angulation is shifted 10 degrees from the distal, and the vertical angulation is increased 5 degrees.

35. Figure Comparision of standard and disto-oblique periapical radiographs. (A) Standard periapical radiograph images a portion of the impacted third molar. (B) Disto-oblique periapical radiograph images more of the impacted third molar. Note that shifting the tube horizontally causes overlap error, and shifting the tube head vertically causes the crowns to be cut off the the image.

36. Film Duplicating Procedure
Duplicating film
Film duplicator
Procedures for film duplication

37. Figure 28-23 Radiograph duplicating machines
Figure Radiograph duplicating machines. Contain a built-in ultraviolet fluorescent light source and a timer to permit variations in density. These x-ray film duplicators accommodate duplication of multiple films at a time, with room for a full mouth series, or a panoramic radiograph. (Courtesy of Densply Rinn.)

38. Figure 28-24 Small radiograph duplicator accommodates film sizes #0, #1, and #2.

39. PROCEDURE 28-2 Film duplication

40. Procedure 28-2 (continued) Film duplication

41. Review: Chapter Summary
Anatomical conditions may require alterations in the radiographic technique.
A skilled radiographer can apply acceptable variations in aligning the horizontal and vertical angulations and still produce diagnostic quality radiographs.

42. Recall: Study Questions
General
Chapter Review

43. Reflect: Case Study
A patient has presented at your practice today for a consult regarding extensive dental work. This patient has several areas of missing teeth and has expressed an interest in dentures. The dentist has prescribed a full mouth series of radiographs and you are preparing to take the exposures.

44. Reflect: Case Study
After performing a cursory exam of the patient’s oral cavity you note the following:
Several missing and/or broken down teeth.
Malaligned and crowded teeth.
Partially erupted third molars.
Large torus palatinus and torus mandibularis.
A shallow palatal vault.

45. Reflect: Case Study Consider the following and write out your answers:
Describe the alterations in technique you will apply to obtain radiographs in the edentulous areas.
Describe the alterations in technique you will apply to avoid overlap error in the areas of malaligned and crowded teeth.

46. Reflect: Case Study
Identify and describe the technique you will use to best image the partially erupted third molars.
Describe the problems you anticipate facing with the presence of large tori and a shallow palatal vault.
Identify alterations in techniques that will help you overcome these obstacles.

47. Reflect: Case Study
If broken root tips or other foreign objects are identified on the radiographs, describe how the interpretation of these can reveal whether or not the objects in question are located on the buccal or the lingual.
Describe other methods of localization that can aid in making this determination.
Identify reasons why this patient’s radiographs may need to be duplicated.

48. Relate: Laboratory Application
Proceed to Chapter 28, Laboratory Application, to complete this activity.