OBJECT
LOCALIZATIO
N
TECHNIQUES
Presented by Anjali S
Dept of Oral Medicine &
CONTENTS
INTRODUCTION
INDICATIONS
CLASSIFICATION
INTRA
ORAL LOCALIZATION TECHNIQUE
CONCLUSION
INTRODUCTION
INDICATIONS

IMPACTED TOOTH.

FOREIGN BODIES.

RETAINED ROOT /ROOT POSITIONS

UNERUPTED /SUPERNUMERARY TEETH

SALIVARY STONES.

JAW FRACTURES

ENDODONTIC PROCEDURES- ACCESSORY CANALS

BROCKEN NEEDLES & INSTRUMENTS
CLASSIFICATION

INTRA ORAL LOCALIZATION TECHNIQUE
STEREORADIOGRAPHY
TUBE SHIFT TECHNIQUE
RIGHT ANGLE TECHNIQUE
MAGNIFICATION RADIOGRAPHY
 EXTRA ORAL LOCALIZATION TECHNIQUE
RIGHT ANGLE TECHNIQUE
TOMOGRAPHY
SIALOGRAPHY

LOCALIZATION TECHNIQUE BY COMBINATION OF
INTRA ORAL & EXTRA ORAL RADIOGRAPHS
INTRA ORAL LOCALIZATION
TECHNIQUES
STEREOSCOPIC RADIOGRAPHY
• 1896
• Stereoscope - optical instrument for viewing
photograph/roentgenogram which produce binocular
vision
PRINCIPLE : work as eye – brain merges them into one.
INDICATION:
location of small intracranial calcifications & multiple
foreign bodies in a dense or thick section


relationships of margins of bony fracture
PROCEDURE
2 exposure – one for each
eye with definite distance
apart called interpupillary
distance
Exposed film is viewed with stereoscope that use
mirror/ prism to co-ordinate & converge the
image to fuse one image.
Drawback :
Requires high level of skill
PARALLAX METHOD
TUBE SHIFT TECHNIQUE
PRINCIPLE
The relative position of the radiographic images of two
separate objects changes when the projection angle at
which the projection was made is changed.
METHOD
Moving the tubehead mesially/distally or superiorly/infeiorly and changing the
direction of the x-ray beam will result in the movement of the object of interest
on the film in relation to the reference object.
ERROR
tubehead is moved, but there is no change in direction of the xray beam, which results in no change in location of the object
of interest in relation to reference object
HORIZONTAL PARALLAX METHOD
 Clark’s Rule
 Described in 1910
 Used 2 periapical radiographs
 Keur used 2 OR rather than periapical radiographs
 Locate vertically aligned images eg:root canals
HORIZONTAL MOVEMENT
•Patients head stabilized
•A conventional intraoral
radiographic image of area of
interest
•Second radiograph by shifting
the PID either mesially or
distally
DISTAL
MESIAL
Horizontal movement
mesialesial
tubehead is moved distally and the
beam is directed mesially.
distaltal
buccal object of interest moves
mesially (opposite to tubehead
movement) in relation to the
second molar
• lingual object of interest moves
distally (same direction as
tubehead) in relation to the
second molar.
•
distal
mesial
VERTICAL PARALLAX METHOD
Richards
in 1953 & 1980-BUCCAL OBJECT RULE
Shift the tube in vertical plane
Used to locate horizontally aligned image.
Eg-mandibular canal
Radiographic localization of unerupted maxillary anterior teeth using the vertical tube shift
technique: The history and application of the method with some case reports Stanley G. Jacobs
American Journal of Orthodontics and Dentofacial Orthopedics October 1999
Vertical movement
Vertical movement of the tubehead and x-ray beam
Maxillary PA
BW
Mandibular PA
In moving from the maxillary periapical to the bitewing and
from the bitewing to the mandibular periapical, the tubehead
moves down and the beam is redirected upward (opposite
direction; decreased vertical angulation).
APPLIED ASPECT
OF
TUBE SHIFT
TECHNIQUE
INCISOR FILM
CANINE FILM
The maxillary left canine is impacted. Is it located more to
the buccal or the lingual?
MOLAR BITEWING FILM
MOLAR PERIAPICAL FILM
The amalgam particle
indicated by the arrows is
located bucally or
lingually?
1st radiograph : radiolucency at
the apex of the lower second
premolar
2nd : (disto-mesial)
angulation
To differentiate mental foramen
from peri-apical lesions
3rd: corono-apical angulation
RIGHT ANGLE TECHNIQUE
MILLER’S TECHNIQUE
PRINCIPLE
2 projections are taken at right angles to each
other
PROCEDURE
1 periapical radiograph  superio-inferior &
antero-posterior relationship
1 occlusal radiograph  buccolingual & anteroposterior relationship
Together gives 3D of area and location of
object
APPLIED ASPECTS
1.periapical + Occlusal
two projections are taken at right angles to one another
to localize the impacted tooth in or about the maxilla.
Periapical + Occlusal
two projections are taken at right angles to one
another to localize the impacted tooth in or about the
mandible.
TECHNIQUE FOR MANDIBULAR 3RD MOLAR
1.X-ray beam projected perpendicular to the
occlusal film
2. Variation in technique- occlusal film placed in a
slanting manner with its posterior border resting on
ascending ramus
MODIFICATION OF MILLER’S TECHNIQUE
FOR MAXILLARY 3RD MOLAR
Superimposition
of multiple skeletal structures in
maxilla
Occlusal
film horizontally placed with central ray
passing through the zygomatic arch
-another periapical film.
MAGNIFICATION RADIOGRAPHY
 PRINCIPLE OF IMAGE SIZE DISTORTION
 Focal spot – film distanceobject away from film
more magnified and more distorted
APPLIED ASPECTS