Transcript RADIOGRAPHIC TECHNIQUES

RADIOGRAPHIC TECHNIQUES
DR SAMY I AL-AGHA
A.PROFESSOR OF RADIOLOGY
AL-AZHAR –GAZA UNIVERCITY
RADIOGRAPHIC TECHNIQUES
CLASSIFICATION
A-Periapical
B-Bite-wing
C-Occlusal
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
1-BISECTING ANGLE TECNIQUE
A-Patient,s position
For maxillary teeth>>>ala tragus line is parallel
to floor
For mandibular teeth>>>line from tragus to
corner of mouth is parallel to floor
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
B-Film placement:
 Tube side of the film packetis towards the tube.
 The film(short dimension) is parallel to occlusal
plane(For anterior region)
 The film (long dimension) is parallel to occlusal
plane(For posterior region)
 Avoid over-bending of film packet
 The area of interest is in the center of film.
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
 2-3mm of film packet should be left beyond the
occlusal plane
 The patient holds the packet with finger
 Avoid movements of patient,film,or cone during
exposure.
C-Cone,s position:
1-Central ray(C.R)angulation
a-V.A
b-H.A
2-Point of entry
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
Vertical angulation
Denotes the angle between C.R&occlusal
plane
Vertical angle of maxillary teeth(+ve)
Incisors>>>>>>55-60
Canines>>>>>>45-50
Premolars>>>>35-40
Molars>>>>>>25-30
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
V.A for mandibular teeth(-ve)
Incisors>>>>>>15-20
Canines>>>>>>10-15
Premolars>>>>5-10
Molars>>>>>>0-5
Increase V.A 5 in a-shallow palate or floor of
mouth
b-flat ridges(edentulous pt)
c-inclined teeth
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
Decrease V.A 5 in case
a-high palate
b-deep floor of mouth
Horizontal angulation
It is the angle between CR&mid-sagittal plane
It control width(dimention of tooth)
CR must project through interproximal
surfaces of examined teeth
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
H.A
Incisor>>>>>zero
Canines>>>>45-60
Premolars>>>60-70
Molars>>>>>>90
Point of entry
The cone is positioned so that CR is directed
to apices of the teeth
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
For maxillary teeth>>>points of entry are
located on ALA TRAGUS LINE
Incisors>>>>>tip of the nose
Canines>>>>>0.2cm distal to ala of nose
Premolars>>>vertical line from eye pupil to
ala tragus line
1st Molar>>>>vertical line from outer canthus
to ala tragus line
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
2nd Molar>>>vertical line from 1cm distal of
outer canthus to ala tragus line
3rd Molar>>>>vertical line from 2cm distal
of outer canthus to ala tragus line
For mandibular teeth >>>the same as for
maxillary teeth but located on a line
0.5cmabove inferior border of the mandible
Time of exposure depends on area of
rediographed,KV,mA, film speed&age of Pt
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
Advantages of bisecting angle technique
1-Easy,quick &comfortable
2-Used in all patients
3-short object-source distance>decrese exp time
4-periapical area can be demonstrated
5-Speed technique
Disadvantages: 1-Not standerdized
2-error of
angulation>>>superimpositionof structures over
the area of interest
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
2-The paralleling technique(long cone tech) or
Right angle technique
 C.R is perpendicular to both film &tooth
 The film is placed in mid of oral cavity to get
parallism between tooth&film>>>image
magnification&unsharpness.
 Target-object distance is increased to avoid
unsharpness(16 inches)>>>increase KV,mA,s and
fast film(increase exposure time 4times)
 Film holders are used.
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
FILM HOLDERS:
1-Rinn instrument 2-Bite block
3-hemostat
4-Cotton rolls
5-Precision rectangular collimating instrument
Advantages of film holders
1-Provide parallism 2-Avoid exposure to Pt fing
Disadvantages
1-Closure of mouth before exposure
2-Cannot examin the periapical structures
3-Limited in small mouths or gagging sesation
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
ADVANTAGES OF PARALLELING TECHNIQUE
1-Standerdized>>>used in research
2-Accurate images
3-Avoids superimposition on apices
4-H.A&V.A detrmined by positioning devices
5-No overbending of films
PERIAPICAL RADIOGRAPHIC
TECHNIQUES
DISADVANTAGES OF PARALLELING TICHNIQUE
1-Difficult to image all parts of the mouth
2-Increased exposure time
3-Need long cones &film holders
4-Cannot image apical area in shallow palate
5-Discomfort of film holder
6-Time consuming
BITE-WING TECHNIQUE