1. The document discusses various intra-oral radiographic techniques including the paralleling cone technique and bisecting angle technique. 2. The paralleling cone technique provides accurate images with little magnification and no superimposition but is more difficult for patients. The bisecting angle technique is easier for patients but results in more image distortion. 3. Special considerations for intra-oral radiography include techniques for mandibular third molars, gagging patients, endodontic procedures, edentulous ridges, and pediatric patients. 4. Digital radiography provides advantages like automated measurements and image manipulation but has higher initial costs and bulkier sensors.

1. Navodaya Dental College
Department of Oral Medicine &
Radiology
Dr Shilpa R T
Professor
III Year

2. Intra-Oral
Radiography

3. Objectives of the presentation
• A step towards Evidence based Dentistry.
• Intra-Oral Radiographic techniques
• Film holders to make techniques easy.
• Modifications in difficult situations
• Highlights on Digital Radiography.
• Emphasis on Interpretation of Periapical
Lesions
Introduction

4. Intra-oral Radiography
Periapical Bitewing
Occlusal
Divided into three categories:

5. Indications of periapical Radiography
• Apical infection/inflammation
• Assessment of the periodontal status
• After trauma to the teeth and associated alveolar bone
• Presence and position of unerupted teeth
• Assessment of root morphology before extractions
• During endodontics
• Pre and post operative appraisal of apical surgery
• Evaluation of apical cysts and other lesions
• Evaluation of implants postoperatively.

7. Two fundamental rules of radiography:
1) The lowest level of distortion and the highest level of
image clarity will always be found in the region of the
central ray projection.
2) The image receptor should be as perpendicular as
possible to the central ray and as parallel as possible
to the tooth long axis in order to guarantee optimum
radiographic interpretability.

8. GENERAL STEPS FOR MAKING AN EXPOSURE
 Greet and seat the patient
 Adjust the x-ray unit setting
 Position the tube head
 Wash hands thoroughly
 Examine the oral cavity
 Position the film
 Position the x-ray tube
 Make the exposure

9. Intra-oral Periapical Projection
‘Bisecting - the angle’
Technique
(Short cone technique)
(Long cone technique)
‘Paralleling Cone’
Technique
Two Techniques

10. Paralleling Cone Technique of
Intra-oral Periapical Radiography
Patient Position: Patient can be either sitting upright
or reclined in the dental chair provided that the head
is not tilted to the side.
•First described by Edmund C. Kells in 1896
•Revived by Donald McCormack in 1937
•Perfected by Gordon Fitzgerald in 1947
Vertical
Horizontal

12. Long spacer cone
or
beam-indicating
device (BID)

13. Is It Easy ?

15. Bisecting - the Angle Technique of
Intra-oral Periapical Radiography
•First described by Weston Price in 1904
•Independently described by Cieszynski in 1907
•Also called as technique based on Principle of Isometric
Triangulation

16. Image size < Object size
Foreshortening
Image size > Object size
Elongation
Image size = Object size

17. Film Holding Instruments

18. PID Angulations: Bisecting Technique
Vertical angulation

19. Horizontal Angulation

20. Angulation in the vertical plane:
Teeth Angulation
Maxillary Mandibular
Incisors + 40 -15
Canines + 45 - 20
Premolars + 30 - 10
Molars + 25 - 05
Direction of the Central Ray: Central ray is directed
perpendicular to the teeth in the horizontal plane.

21. 11
12
13
16
17
18
14, 15
Maxilla : Imaginary ala-tragus line
Point of Entry of X Ray Central Beam

22. 41
42
43
47
48
44
46
45
Point of Entry of X Ray Central Beam
Mandible : Imaginary line 1 cm above the inferior border
of mandible.

23. Comparison of Parallel cone and
Bisected angle Techniques

24. Bisecting Angle Technique
Paralleling cone Technique

25. Paralleling cone Technique
Periodontal bone Status

27. 1. Accurate images with little magnification
2. No Superimposition
3. Well represented periodontal bone levels
4. Enable early detection of proximal caries
5. Angulations automatically determined by the film
holder
6. No cone cutting
7. Reproducible radiographs
8. positions of the film maintained irrespective of the
position of the patient's head
Advantages of the paralleling cone technique

28. 1. Anatomy of the mouth makes uncomfortable for the
patient may cause gagging.
2. Difficult to practice in Endodontics.
3. Lower third molar regions difficult.
4. Needs Long Cone.
Disadvantages of the paralleling technique

29. Advantages of Bisecting Angled Technique
1. Easy to master
2. comfortable for the patient
3. Easy to practice in endodontics
4. If all angulations are correct, the image will be
adequate (but not ideal)

30. Disadvantages of the Bisected angle technique
1. image distortion - foreshortening or elongation
2. Incorrect horizontal angulation - overlapping
3. Poor detection of proximal caries and the periodontal
bone levels.
4. superimposition of the zygomatic buttress
5. Cone cutting

31. Special Considerations
 Object localization techniques
 Mandibular third molars
 Gagging
 Endodontics
 Edentulous alveolar ridges
 Children

32. Object localization techniques

33. Mandibular third molars

34. Possible solutions:
1. REASSURANCE
2. local anaesthetic lozenge
3. Placing the film packet flat in the mouth (in the
occlusal plane) so it does not touch the palate.
Gagging

35. Endodontics

36. Edentulous Ridges
Partially Edentulous Ridges

37. Pediatric Patients
1. Exposure factors (milliamperage,
kilovoltage, time) must be
reduced because of the smaller
size of the pediatric patient.
2. Euphenisms

38. Digital Radiography

39. The digital radiograph: A digital image actually
corresponds to the reduction of a conventional
image into a prepared grid work of image points,
the so-called pixel (picture element).

41. Why should we go Digital ?

42. Automated measurement Inversion
Magnification

43. Alteration in contrast Pseudocolourization

44. Embossing or pseudo 3-D

45. Limitations:
 Very high initial cost.
 Sensor is bulkier compared to an x-ray film
making it difficult to place in some parts
of the mouth and in children.

46. Thank You