this is the seminar for Undergraduate students consisting of initial paralellelig and bisecting radiographic techniques, history, types, size, extraoral films, technical errors, radiographic examination in special children

1. PARALLELING AND BISECTING
RADIOGRAPHIC TECHNIQUES
Presented by:
Ritu Gupta
BDS- Final year

2. CONTENTS
 INTRODUCTION
 HISTORY
 TYPES OF
RADIOGRAPH
 SIZE OF INTRAORAL
FILMS
 EXTRAORAL FILMS
 INTRAORAL
PERIAPICAL
RADIOGRAPH
 PARALLELING
TECHNIQUE
 BISECTING ANGLE
TECHNIQUE
 PROBABLE
TECHNICAL
ERRORS
 RADIOGRAPHIC
EXAMINATION IN
SPECIAL CHILDREN
 GAG REFLEX
 BIBLIOGRAPHY

3. INTRODUCTION
 A conventional radiograph is a 2-D projection
image of a 3-D object in which an entire
volume of tissues between the X- ray source
and the film is projected onto the 2-D image.
 Radiographic examination plays a vital role in
the diagnosis and treatment planning of both
children and adult.

4.  In pediatric dentistry radiographs also plays a
significant role in assesment of growth and
development .
 It also helps in detection of
-dental caries
- diagnosis of cysts
-tumors

5. HISTORY
 The work of many scientists culminates in
discovery of X-rays by ROENTGEN on Nov-
8,1895.
 X-ray was named by ROENTGEN because of
simple fact that the nature of these rays was
not known at that time of discovery.

6. TYPES OF RADIOGRAPHS
 Radiographs of a pedo patient are
categorized in two groups-
1. Intra-oral radiographs
2. Extra-oral radiographs
 According to the films used in radiographic
examination it can be-
1. Intra-oral films
2. Extra-oral films

7. INTRAORAL FILMS
 They are meant for positioning inside the
mouth during exposure.
 There are three types of intraoral
radiograph projection-
1.Intraoral periapical radiograph (IOPA)
2. Bitewing radiographs
3. Occlusal radiographs

8. IOPA
BITEWING RADIOGRAPH OCCLUSAL RADIOGRAPH
TYPES OF INTRAORAL RADIOGRAPH PROJECTIONS

9. SIZE OF INTRAORAL FILMS
 Size 0(22x35 mm)- used for bitewing and
periapical radiographs of small children.
 Size 1 (24x40mm)-used for radiographing
anterior teeth in adults.
 Size 2 (31x41mm )- standard film
 Size 3 (57x76mm)- used for posterior bitewing
examination.
 Occlusal film (57x76mm)- used for visualizing
the entire maxillary or mandibular arch.

10. Size of intraoral films

11. EXTRAORAL FILM
 Extra-oral films used in dental practice vary in
their sizes depending on individual projection
for which they are employed.
 5x7 inches films-used for TMJ views and
lateral oblique views.
 8x10 inches films-uses for lateral
cephalometry and paranasal sinus view.
 6x12inches films

12. INTRAORAL PERIAPICAL
RADIOGRAPH (IOPA)
 IOPA radiographs are useful in the
evaluation of teeth and their
associated structures.
 IOPA radiograph can be taken by
using two techniques-
1. Short cone technique or bisecting
angle technique.
2. Long cone technique or paralleling
technique.

13. PARALLELING TECHNIQUE
 PRINCIPLE- X-ray film is
placed parallel to the
long axis of teeth and the
central ray is directed at
right angle to teeth and
film.
 Since the film is placed
farther away from the
object ,a film holder is
necessary.

14. ADVANTAGES
 Better dimensional accuracy.
 No superimposition of structure like zygomatic
arch.
 Head position is not critical .

15. DISADVANTAGES
 As the small size of mouth in children
precludes the placement of film beyond the
apical region of teeth.
 Less comfortable.
 More limited.

16. BISECTING ANGLE
TECHNIQUE
 PRINCIPLE-Based on simple geometric theorem-
cieszynskis “rule of isometry”.
 It basically states that two triangles are equal if they
have equal angles and a common side.
 The central ray is directed perpendicular to a plane that
bisects the angle created by long axis of teeth and film.

17.  In small children with primary dentition size-0
film should be used.
 Older children or in situation where large area
is visualized size-1 film should be used.

18. INDICATIONS
 To identify any pathology involving primary teeth such
as periapical pathology or internal resorption.
 In analysis of space in mixed dentition.
 To evaluate status of periodontal ligaments.
 To detect developmental anomalies-supernumerary or
un-erupted teeth
 To diagnose pulp calcification , root resorption and root
development.
 To diagnose traumatic injuries.

19. TECHNIQUE
OBTAINING CHILD’S COOPERTION FOR
RADIOGRAPH-
 Explain the child what you are planning to do.
 Obtain the confidence and cooperation of child.
 Talk to child to distract his attention and establish
confidence.

20. PROJECTIONS
 For maxillary teeth- head of the patient should
be upright.
 For posterior projection-film is kept on lingual
sulcus.
 For lower anterior projection-film is kept on
floor of mouth.

22. PROBABLE TECHNICAL
ERROR FOR A PEDIATRIC
PATIENT
 In general there is no scientific difference in technique
applied for children and adult radiograph , but some errors
can be commonly seen –
 Improper placement of film.
 Cone cutting.
 Overexposure.
 High exposure to patient to radiation because of repeated
radiographic examination
 Incorrect vertical angulation.
 Incorrect horizontal angulation.

23. RADIOGRAPHIC EXAMINATION
IN SPECIAL CHILDREN
 18 inch (46cm) length
floss is attached
through a hole made in
tab.
 The patient should
wear lead apron with a
thyroid shield and
anyone who helps hold
the patient and the
films.

24. GAG REFLEX
 The patient should be advise to breath rapidly through
nose.
 Stimulating the posterior closure of tongue or soft
palate initiate the gag reflex.
 In extreme case a topical anesthetic agent can be
applied.

25. BIBLIOGRAPHY
White S. , Pharoah M. Oral Radiology:
Principles and Interpretation. 1st South Asia
Edition. New Delhi (India) : Elsevier India ;
Sept 2014.
Tandon S. Textbook of Pedodontics. 2nd
edition. Hyderabad (India) : Paras Medical
Publisher ; 2009
Ghom AG. Basic Oral Radiology. 3/e. New
Delhi (India) : Jaypee Brothers Medical
Publishers (P) Ltd ; 2014