1. 0
Bitewing Technique
The following slides describe techniques
used in taking bitewing films.
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2. Patient Preparation
Prior to starting to take films, the patient must be
positioned properly. Seat the patient and ask them
to remove their glasses and any removable partial
dentures or orthodontic appliances. Adjust the
headrest to support the head while taking films.
Raise or lower the chair to a comfortable height for
the operator. Place the lead apron and thyroid collar
on the patient. You are now ready to begin taking
films.
It is a good idea to inform the patient about the
number of films you will be taking so they know
what to expect, especially when doing a full-mouth
series.

3. Bitewing Technique

4. Bitewing Film
This film gets its name from the tab (“wing”) that the
patient bites on to hold the film in place. The
bitewing film is used for the detection of
interproximal caries and the condition of the alveolar
bone. This film shows the crowns of both the
maxillary and mandibular teeth and a portion of the
roots.
A premolar film and molar film are normally taken on
each side for a total of four posterior bitewing films.

5. Head Position
The head is normally positioned so that the maxillary
arch is parallel to the floor and the midsagittal plane
(MSP) is perpendicular to the floor. This is a definite
requirement when using bitewing tabs to hold the film in
position; it is not as important when using the Rinn
Bitewing Instrument.
MSP
head supported by headrest

6. Bitewing Film Placement
Tabs
The traditional method of bitewing placement uses tabs. The
tab in the photo below left is attached to a sleeve through
which the film is inserted. The disadvantage to this type of
tab is that the film can move forward or backward as the
patient closes. The preferred type of tab, below right, sticks
to the white side of the film and does not allow the film to
move during closure.

7. Bitewing Film Placement
Bitewing Instrument
The Rinn Bitewing Instrument pictured below is
frequently used instead of tabs. The instrument
facilitates placement and the ring insures correct
alignment of the PID.

8. Rinn Bitewing Instrument
Instrument set-up
The prongs on the bar are aligned with the holes in
the biteblock and the two are attached. The ring is
placed on the bar so that it is centered on the
biteblock.

9. Rinn Bitewing Instrument
Before placing the film in the biteblock, the film
should be bent gently around a finger (white
side down, long axis in line with finger).

10. Rinn Bitewing Instrument
Place the film, white side facing ring, under one
tab, centered front to back, and then gently place
the opposite edge of the film under the other tab.
The film may curve slightly away from the ring. The
location of the identifying dot on the film is not
important.

11. Rinn Bitewing Instrument
Make sure the all-white side of the film is visible
through the ring (White-in-sight). You are now ready
to place the film in the mouth. This set-up works for
both sides of the mouth (Instrument does not need
to be changed).

12. Bitewing Technique
Film Position
(Same for tabs or Rinn BW instrument)
The premolar bitewing film is approximately centered on
the 2nd premolar; the front edge of the film should be at
least in the middle of the canine. The molar film is
centered on the 2nd molar if the third molars are present.
The long axis of the film is horizontal.
The position of the film dot doesn’t matter; it will be
beyond the crowns of the teeth on the film.
long axis
premolar molar (3rds)

13. Bitewing Technique
Film Position
If the third molars are not erupted into the mouth, it is not
necessary to position the film to cover the third molar
region. It is better to move the film slightly forward,
centered on the contact between the first and second
molars. This gives you duplicate information in the second
premolar/first molar areas, which may aide in making a
diagnosis in these areas.
molar (no 3rds)

14. Bitewing Technique
Film Placement
It is important to always start with the premolar bitewing.
This allows apprehensive patients or those with active
gag reflexes to somewhat get used to the film before
proceeding to the more posterior molar film. Both films
on one side should normally be completed before
moving to the other side. However, if a patient has
problems with gagging on the premolar film, I
recommend immediately going to the other side and
taking the premolar film. Once the two premolar films are
taken, you can attempt to take the molar films.

15. Vertical Angulation (with tabs)
When the film is positioned in the mouth, the upper
portion of the film is angled approximately +20° as it
contacts the palate. In the mandible, the film is upright
(0° angle). The average between these two angles is
+10°. This +10° is the vertical angulation selected
when using bitewing tabs.
+20º
0º

16. Vertical Angulation (with tabs)
Adjust tubehead so that the 10° mark is opposite the
position guide. The 10° setting may be above or below the
zero mark, depending on which way the tubehead is
rotated around the supporting yoke (see photos middle
and right below). The PID must be angled downward for
all positive angulations; if it is angled upward it is a
negative angulation.
10°
position guide

17. Make sure the maxillary arch is parallel to the floor and the
midsagittal plane is perpendicular to the floor before
aligning the tubehead. In the photo below left the PID is
angled downward at 10 degrees as recommended, but the
patient’s head is tipped to the side. Rotating this same
picture (below right) to position the maxillary arch parallel
to the floor (dotted line) shows that the true angle of the
PID is upward in relation to the film. This will give a
distorted image.
+10°

18. Vertical Angulation (with instrument)
When using the Rinn BW instrument, align the PID
with the ring. This automatically aligns the x-ray
beam with the correct vertical angulation, no matter
how the head is positioned.

19. Horizontal Angulation (with tabs)
The horizontal angulation is adjusted so that a line
connecting the front and back edge of the PID (yellow line
below) is parallel with a line connecting the buccal surfaces
of the premolars and molars (green line below). The x-rays
will then pass straight through the contact areas between the
teeth. The front edge of the PID should be ¼” anterior to the
front edge of the film to keep the beam centered on the film.
correct incorrect

20. Horizontal Angulation (with instrument)
When using the Rinn BW instrument, align the PID
with the ring. This automatically aligns the x-ray beam
with the correct horizontal angulation, assuming the
film was positioned properly in the mouth. (See
following slide).

21. The film should be equidistant from the teeth in an anterior-
posterior direction (the distance from the front edge of the
film to the lingual surface of the teeth should be the same as
the distance from the back edge of the film to the lingual
surface of the teeth). The film should be positioned in this
manner for both the premolar and molar radiographs. This
helps to avoid overlap (see “Errors”).
correct incorrect incorrect

22. When aligning the PID, have the patient “smile big” with their
teeth together; this allows you to see the buccal surface of
the posterior teeth when using tabs. When using the Rinn
instrument, this helps you make sure the patient is biting
completely, not just tightening their lips around the
instrument. The center of the x-ray beam (dotted line) should
be directed at the occlusal plane; this centers the beam top
to bottom.

23. Where teeth are missing, it is often necessary to use a
cotton roll to help support the tab or instrument. Position
the film in the mouth and then slide the cotton roll into the
edentulous area. Make sure the cotton roll does not rest
on top of the occlusal surface of the teeth that are
present.
cotton roll

24. In the film at left, a cotton roll was
not used and the tab and film
dropped down into the edentulous
area, resulting in a tipped film.
In the film at left, a cotton roll was
used, keeping the tab and long
axis of the film parallel with the
occlusal plane.

25. 0
Another thing to consider when there are edentulous areas
is to position the bitewing tab forward or backward on the
film so that the tab comes in maximum contact with the
teeth that are present. In the premolar placement below, the
tab was moved forward for maximum contact with the
mandibular premolars. For the molar film, the tab would be
moved toward the back end of the film to contact the 2nd
molar.

26. The film may be angled in the mouth to
facilitate anterior placement when using
the tabs. As long as the horizontal
angulation is aligned properly, the teeth will
not be overlapped.
When using tabs, make sure the
film clears the palatal gingiva as
the patient closes to keep the film
from being pushed down into the
mandible.

27. 0
If lingual tori are present, the film must be placed lingual to
the torus (both with tabs and the instrument). When using
tabs, it is often helpful to attach another tab to the one
attached to the film; this lengthens the portion you hold on
to, making it easier to position the film more toward the
tongue and lingual to the torus.
film
torus
extra tab
extra length
tab on film

28. Bitewing Films 0
Premolar Bitewing: covers Molar Bitewing: covers
both premolars, first molars molars. In this patient,
and at least a portion of with no third molars, the
second molars. film was positioned too far
posteriorly.

29. Bitewing Films
If third molars are not erupted into the mouth, the molar
film should be positioned more anteriorly, as seen above.
Make sure ¼” of film extends posterior to second molar
so that the distal aspect of both upper and lower second
molars, including the bone, can be seen.

30. Bitewing Films
In some patients, one film may cover all posterior teeth
if the third molars are not present. This can often be
determined during film placement or by looking at
previous films. If you’re not sure, take both premolar
and molar films.

31. Bitewing Films
If the first premolars are missing (often seen
with orthodontic patients) and the third molars
are not present, one bitewing per side is
enough.

32. Bitewing Films
If it is determined that bitewing films are needed on
a patient that is completely edentulous in one arch,
a complete denture may be left in the mouth to help
support the bitewing tab or bitewing instrument. The
maxillary complete denture is used in the film
above.

33. Vertical Bitewing
For the routine bitewing film, the long axis of the film is
horizontal (side-to-side). In patients with advanced
periodontal involvement, the bone loss may be so
extensive that it does not show up on the normal
bitewing. For these patients, some dentists prefer to have
the bitewing film positioned with the long axis placed
vertically (up-and-down). This is called a vertical bitewing.
long axis

34. Vertical Bitewing
Two bitewings (premolar and molar) are normally taken on
each side posteriorly, just as with regular bitewings, for a total
of four posterior films.
If indicated, vertical bitewings can also be taken in the
anterior region. A total of three anterior films would be used:
one centered on the midline to show the incisors and one on
each side to image the canine regions.
right right right incisor left left left
molar premolar canine canine premolar molar

35. Vertical Bitewing
Vertical bitewing films can be taken using tabs or a
bitewing instrument, just as with regular bitewings.
The vertical angulation is +10° with tabs; the PID is
aligned with the ring when using the instrument.
The horizontal angulation is determined in the same
manner as it is with regular bitewings. The object is
to open the contacts between the teeth on the film.

36. Bitewing Technique Errors
The following slides identify some of the most
common errors seen when using the bitewing
technique.

37. Overlap
If the horizontal angulation is not aligned correctly, so that
the x-rays pass through the teeth contacts at an angle, the
contact areas will be overlapped (see arrows on film
below).
Overlap is the superimposition of part of one tooth with
part of the adjacent tooth (dotted circles below left). The
red arrow represents the direction of the x-ray beam; the
x-ray beam should be perpendicular to the dotted line
below. (See discussion of horizontal angulation on earlier
slide).

38. Overlap
Sometimes overlap is unavoidable due to the malposition
of some teeth. One or more teeth may be more buccal or
lingual than the adjacent teeth, resulting in crowding and
changing the angle of contact between these teeth. The
arrow in the film below points to an example of this type
of overlap.
If the majority of contacts are open on a film, with only a
few areas overlapped, this would not be considered an
error.

39. Improper Film Placement
Improper film placement is a common error seen in
the bitewing technique. In the premolar film below
left, the film was placed too far back, cutting off the
mesial of the first premolar. In the molar bitewing,
below right, the film was not back far enough,
cutting off the distal aspect of the third molars.

40. Improper Film Placement
If the top edge of the film contacts the palatal gingival
ledge, the film may be pushed down into the floor of
the mouth as the patient closes. This results in a
bitewing that looks more like a periapical film, as
seen in the two films below. This is more likely to
happen when using tabs.

41. Cone Cutting
If the x-ray tubehead is not positioned properly, the x-ray
beam may not cover the entire film. This is known as
conecutting, which results in a clear (white) area on the film
where the silver halide crystals were not exposed to x-rays
(see films below). In the diagram below right, the dotted
circle represents where the x-ray beam should have been
positioned; the solid circle shows the actual position of the x-
ray beam (too posterior).

42. Patient Movement
If the patient moves or opens the mouth slightly
during exposure, a blurred or distorted image may
result. The film below was produced when the
patient opened the mouth partway through the
exposure. It looks similar to a double exposure.

43. Reversed Film 0
If the tab is placed on the colored side of the film or the
film is placed in the bitewing instrument with the
colored portion facing the ring, the lead foil in the film
packet will be between the teeth and the film. This
results in the pattern stamped on the lead foil
appearing on the film (see small dark squares on right
side of film below). The film will also be lighter than the
other films taken at the same time.

44. Unnecessary Films
The patient below has no second or third molars on
the right side. The premolar film is all that is needed
on this patient. The patient received uneccessary
exposure by taking the molar film.
M PM

45. Unnecessary Films
This patient had a complete upper denture and a
lower partial denture which replace all the molars on
the left side. This film showing only denture teeth
should obviously not have been taken.

46. Full Mouth Series
The paralleling and bisecting angle techniques are used to
take periapical films and have nothing to do with the
bitewing technique. When taking a full mouth series on a
patient with a full compliment of teeth, four bitewing films
are normally taken. These are combined with 15
periapicals (# 1 films used anteriorly) when using the
paralleling technique or 14 periapicals (# 2 films used
anteriorly) when using the bisecting angle technique.
Paralleling full mouth series of periapicals + 4 bitewings =
19 films
Bisecting angle full mouth series of periapicals + 4
bitewings = 18 films