clinical photography basic approach

1. WHAT IS PHOTOGRAPHY
• The word photograph comes from the greek words ‘Phos’ and
‘Graphien’.
– Phos – light
– Graphien- To draw
• Term was coined by Sir john Herschel in 1839.
• Photograph is a picture drawn with light.

2. WHY PHOTOGRAPHY IN DENTISTRY??
• Patient education
– Understand her/his condition
– Need for treatment
– Visualize potential improvements
– Improves confidence
– Evaluation of progress
• Interactive treatment planning
• Diagnostic aid ,Teaching
• Publication / Clinical research
• Communication with colleagues
• Record keeping
• Legal protection

3. SOME BASIC TERMS RELATED TO CAMERA
• RESOLUTION- it describes how much detail an image can
hold. It is determined by image’s pixel count.
• PIXEL- it is the smallest element in an image. Each pixel
displays one colour. Pixels are grouped together to create the
illusion of an image.
• FOCAL LENGTH The focal length of a lens is the distance
from the centre of the lens to the point at which the image of a
distant object is formed.
A long-focus lens forms a larger image of a distant object, while
a short-focus lens forms a small image.

4. FOCAL LENGTH

6. ISO SPEED
• ISO Speed determines how sensitive is the camera to the
incoming light. A lower ISO speed is better for clearer pictures.
The higher ISO settings can increase the noise in the pictures.
• In low light conditions however a higher ISO setting is
desirable.

8. SHUTTER SPEED
• The purpose of the shutter is to protect the film from light
until the chosen moment.
• Simply put, the shutter speed is the length of the exposure
time.
 Shutters have speeds ranging from ½ sec. to 1/8000 sec.
• A fast shutter speed, 1/2000 sec., 1/4000 sec., etc means that the
shutter is open only for a brief moment.
• A slower shutter speed, 1/30 sec., ½ sec. means the opposite;
the exposure is made for longer.

9. • Do not let the numbers on your camera confuse you.
• A shutter speed shown as ‘2000’ means 1/2000 – meaning very
fast.
• Usually, in Dental Photography, we have standard situations
which are static. Therefore, the shutter speeds are also
standard viz. 1/60
• The fraction indicator of 1/ is left out to ‘simplify’ things.

10. • If your shutter is adjusted to higher speeds as prescribed by
the manufacturer, you may end up with partially lit
photographs.
• The shutter speed that is synchronized with the flash is often
marked in red .
• The Shutter speed controls the duration of exposure ( 1/60 th
of a sec, 1/30 of a sec, ½ sec, 1 sec, etc)

11. APERTURE
• The aperture is an opening through which the light passes
from the subject to the film.
• The aperture size is a measure of the size of that opening.
• It controls the amount of light that is allowed to pass through
the lens, and eventually strike the film.

12. • The aperture does this either by opening or closing , and
allowing more or less light to pass through.

13. • Some lenses have a rotating
ring on the lens barrel called
the aperture selection ring.
• Other cameras have an
electronic dial to control
this setting.

14. • The various sizes of the aperture are called ‘f’ stops or ‘f’
numbers.
• The f-stops start from 1.4 and go up to 32.
• Easy calculation:
1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32
• These numbers refer to the size of the LENS aperture, but not
the diameter of the aperture.
• The f number is the number by which the focal length of the
lens must be divided to yield the diameter of the aperture

15. • For eg.
– In a 50mm lens the lens is set to f/2 aperture.
– Therefore the diameter of the aperture must be 50/2 i.e.
25mm.
– Similarly, in a 100mm lens an aperture setting of f/2
means a diameter of 100/2 i.e. 50mm

16. • Caution:
A 50mm lens set at f/8 will
allow exactly the same
amount of light that is
allowed to pass through as
does a 200mm lens set at f/8
200mm 50mm

17. • This can be expained on the
basis of the Inverse Square
Law.
• The intensity of light is
inversely proportional to the
square of the distance that it
travels.
200mm 50mm

18. • The 200mm is longer than
the 50mm lens.
• Therefore the light has to
travel further to reach the
film.
200mm 50mm

19. • Thus, on the 200mm lens the
opening has to be bigger, at
f/8, to allow the same
amount of light as a 50mm
lens set at f/8.
200mm 50mm

20. • Remember in this case too, the higher the number, the lesser
the amount of light that is allowed to pass through.
• Also one setting allows only half as much light as the
preceding one would.

22. CAMERA
• The term camera is shortened from camera obscura, literally
"dark room" in Latin.
• Camera was invented by Alexander wolcott, a New York city
dentist in 1839.
• The camera is basically a box , with small aperture or opening
where the lens is attached at one end and the film at the
other.
• The inside of the camera must be completely dark , so that the
rays of light reach the film only through the aperture.

23. PRINCIPLE
• The camera works in much the same way as your eye.
• The lens in the eye focuses the image on to the nerve cells in
the retina and this image is sent to the brain by the optic
nerve.

24. • This is the principle employed in the camera. The lens sharply focuses
the image on to the film.
• To keep the image sharp even when the distance varies, the lens has
to be moved either farther or closer to the film. This what we
commonly call ‘focussing’.

25. • The diaphragm of the camera is a variable aperture which
controls the amount of light allowed onto the film, much in
the same way that the iris of the human eye contracts in
bright sunlight but opens when the room is dark.

26. TYPES OF CAMERAS
• Single Lens Reflex (SLR)
• Twin Lens Reflex (TLR)
• Instant picture / Polaroid
• Point and Shoot
• Special cameras
– Panoramic
– Under water
– Stereoscopic
– Sub miniature (spy)

27. COMPONENTS OF A 35mm SLR CAMERA
Hot Shoe For Flash

28. LENS
• Lens is a piece of transparent material that has at least one
curved surface.
• The lens is the heart of the camera, the component that turns
the three dimensional world outside the camera into a two
dimensional image on the film inside.
• Its job is to take the beams of light bouncing off of an object
and redirect them so they come together to form a real image
-- an image that looks just like the scene in front of the lens.
– real--photographable or visible on a screen or
– virtual--visible only upon looking into the lens, as in a
microscope.

29. TYPES OF LENSES
• FISH EYE
• WIDE ANGLE
• TELEPHOTO
• ZOOM LENS
• MACRO LENS

30. •Dental Photography: 100-105mm Macro lens
• Some zooms can be set at a macro setting, although the
image magnification is not as great.
• In addition, because of the variable focal ability, it is almost
impossible to make zoom lenses as sharp as a fixed focal
length macro lens.

31. FLASH AND LIGHTING
• The two most important sources of light are
– Natural
– Artificial / Flash
• Using different combinations of the two can enable the
photographer to obtain a wide variety of results, often
with dramatic effects
 In dental photography, the flash gun is always
employed, irrespective of the type i.e. I/O or E/O
photography

32. TYPES OF FLASHES

33. BUILT-IN FLASH

34. DEDICATED POINT FLASH

35. RING FLASH

36. POINT FLASH
• It may producefairly good light distribution when used for
clinical photographs.
• However frequently distracting shadows, which can obstruct
important details do occur.
• These shadows are often irreparable using image editing
software.

37. RING FLASH
• It eliminates shadows by allowing a more even and thorough
distribution of light during extra and intra oral photographs
and thus the quality of image is enhanced.
• it is highly recommended to use point flash for orthodontic
photography.

38. RING + POINT COMBO

39. Ring flash Point flash
Advantages Shadowless Reveal topography ,shape and
contour
Disadvantages Low contrast Shadow
Specific use Intra oral photography Extra oral photographys

40. How many photographs do we need
•Generally 9 photographs are needed .
•4 extra oral and 5 intraoral

41. JCO,Volume 1997 Nov(729 - 739): Clinical Photography in Orthodontics JONATHAN SANDLER
Initial Progress Finish

42. EXTRA-ORAL PHOTOGRAPHY
Clinical Procedure
• Precede impressions, since alginate invariably remains on
the lips and cheeks and between the teeth.
• If possible, they should also precede radiographs, so that
any abnormal tooth postures, as in panoramic
radiographs, will not be repeated for the photos.
• Extraoral before intraoral photographs, because the
patient’s lips will be pulled and stretched during the
intraoral photography.

43. Hairstyle
Hairstyle can distract from
facial analysis.
• Hair should be pulled back,
in a ponytail, if necessary.
This allows for auricular
analysis and for relationship
between tragus and
infraorbital rim to be
evaluated.
• Same applies to hair down
over forehead.

44. Camera position for Extra-oral view

45. EXTRA ORAL PHOTOGRAPHS
• 1. face frontal (lips relaxed)
• 2 . face frontal ( smiling)
• 3 . profile(lips relaxed)
• 4 . Three quarter profile

46. EXTRAORAL PHOTOGRAPHY
• AS PER THE AMERICAN BOARD OF ORTHODONTICS (ABO)
REQUIREMENTS ARE:
• The background used in extra oral photographs,should either
be a solid white background or solid dark colour such as dark
blue.
• Quality standardized facial photographs either in black, white
or color
• Patient head oriented accurately in all three planes of space
and in frankfort horizontal plane.
• The clinician positioning for these photos would be standing a
few feet away from patient, and at the same level, if possible.
• Ear exposed for purpose of orientation.
• Eyes open and looking straight ahead, glasses removed.

47. Positioning of patient
• Both patient and clinician need to be positioned correctly in a
standardised manner.
• If there is a height difference between patient and clinician ,
any one of them can stand on a platform to raise them to
appropriate so that the camera level should be at the middle
of face.

48. • Eyes are open and looking
into camera.
• Ears exposed.
• No distracting eyewear or
jewllery.
• Inter-pupillary line
horizontal to the frame.
• Approximate center of
frame is the tip of the nose.
• The upper edge of
photograph must be just
above the top of the head
and the lower frame line
around the larynx.
ABO specification – Frontal
extraoral

49. ABO specification
frontal(smiling)
• The same guideline as for the face
frontal shot apply here ,with the
simple but important exception that
the patient should be smiling in a
natural way, with the teeth visible.
• The photo greatly aids in visualizing
the patients smile esthetics and soft
tissue proportions during smiling.

50. ABO specification
Profile ( lips
relaxed) • After taking the frontal face
photo, patient is asked to bodily
turn to their left ,thus having right
profile side facing the clinician.
• For patient with facial
asymmetry, both left and right
views should be taken.
• The head should be in natural
head position, with their eyes
fixed horizontally.
• Ideally whole of right side of face
should be clearly visible,with no
obstruction, such as hair, hat and
scarf .

51. ABO specification Three quarter extraoral view
• The patient’s body should
be at a right angle to the
camera, as in the profile
shot, but the patient should
turn the head about 45°,
until the opposite eyebrow
can be seen.
• Make sure that about half of
opposite upper lid eyelashes
show.
• Useful in examination of
midface deformities, surgery
of jaw etc

52. SMILE PHOTOGRAPHY

53. INTRA ORAL PHOTOGRAPHS
• The major purpose of intraoral photographs is to enable the
orthodontist to:
• Review the hard and soft tissues at clinical examinations.
• To record hard and soft tissue condition as they exist before
treatment.

54. ABO REQUIREMENTS FOR INTRAORAL
PHOTOGRAPHS
• As per American board of orthodontics (ABO)
requirements are:
• Patient dentition oriented in all 3 planes of space.
• Free of distractions, cheek retractor, labels , fingers.
• Tongue retracted.
• Free of saliva and bubbles.
• FIVE STANDARD VIEWS
• 1. frontal –in occlusion
• 2. right buccal –in occlusion
• 3. left buccal –in occlusion
• 4 upper occlusal
• 5 lower occlusal

55. SPECIAL CHEEK RETRACTOR
• 2 TYPES
• Regular and small size either end- used for intra-oral
photographs
• Narrow end and wide end- used for intra oral frontal and
buccal shots

56. Accessories:
Retractors

57. Dental photography mirror
• Many types of mirror ranging from front silvered to highly
polished stainless steel mirror.
• Front silvered mirror seem to offer best image quality and
light distribution over other mirrors.

58. Mirrors

59. ABO Specification – Frontal Intraoral
• Occlusal plane should be horizontal and bisecting the
photograph
• There should be equal display of the posterior dentition
• Teeth should be in occlusion

60. In intraoral anterior shot, assistant pulls larger ends of large
retractors laterally and as far forward as possible.

61. • PROCEDURE:
• Ask the patient to swallow before placing the retractors, and
aspirate excess saliva from the field of view if necessary.
• Pull the retractor laterally and as far forward as possible ,not
backward, which will compress the lips against the alveolus.
• For adequate depth of field, focus on the lateral incisor area
or the mesial of the canine by rocking gently backward and
forward
• The photo should be taken 90 to facial midline using the upper
frenal attachment as a guide

62. Right buccal – in
occlusion
• The assistant flips the right retractor
to the narrower side, while the left
retractor remains in place as for the
previous frontal shot.
• The patient is asked to turn their
head slightly to left, so their right
side will be facing the clinician.
• Clinician holds the right retractor
and stretches it the extent, that the
last present molar is visible, if
possible, while the assistant holds of
left retractor, without undue
stretching.
• Again the shot is taken 90 to canine
premolar area for best visualization
of buccal segment relationship.

63. • ABO SPECIFICATION RIGHT BUCCAL
• Anteriorly-should display the entire ipsilateral maxillary
central incisor at minimum.
• Posteriorly-include the entire first molars at minimum.
• All attached gingiva should be visible.
• Occlusal plane should be parallel to the frame.

64. • ABO SPECIFICATION LEFT BUCCAL
• For left side - same format as for the right lateral oblique
intraoral photograph.

65. For intraoral buccal shot, photographer holds
one retractor while patient turns head as far as
possible.

66. ABO specification – Occlusal View
• Mid-palatal raphe centered.
• Frame the entire arch with minimal lateral soft tissue
displayed.

68. ABO specification – Occlusal view
• Fill the frame with the entire mandibular arch at least
through the first molars.
• Labial surface of the central incisors should be parallel
to the bottom of the frame.
• Midline should be centered in the frame.

70. Co-ordinated U/L pics

71. Common Errors in Clinical
Photography

72. Backward tilt of head
Distorted view caused by
backward tilt of head.
The chin appears prominent,
particularly in the lateral view
.
• Try to get every patient into a
horizontal Frankfort plane or
“natural head position”.

73. Lack of symmetry

74. Some teeth out of focus.
In intraoral anterior shots, the focus should be on the lateral
incisors. In intraoral buccal shots, the focus should be on the
premolars. Depth of field is not an issue in mirror shots, since
all the teeth are on the same plane.

75. Foreshortening
• If the patient does not open wide
enough for the mirror shots,
foreshortening and arch distortion
will occur.
• The occlusal mirror should be rested
against the most distal tooth in the
arch being photographed, then placed
on the opposing incisor tips. When
ready to take the photograph, ask the
patient to “open twice as wide”

76. Misinterpretation of the sagittal
discrepancy
• Proper selection of retractors helps a great deal.
• Asking the patient to turn as far as possible to the left or right
against the pressure of the retractor.
• The patient must be warned that firm retraction will be
required, and the photographer must hold the retractor on
the side being photographed, since only he or she can pull
that extra 5mm distally immediately before the shutter is
snapped.

77. Saliva & tongue: Strict “No-No’s”

78. Tilting of occlusal plane

79. • Camera position too low,
giving the impression of an
open bite in the anterior
region

81. PNG- Portable Network Graphics
• Supports 16 million colors
• Preferable in largely uniform colors, e.g. high dynamic logos
• File extension .Png
• Not compatible with many soft wares

82. JPEG-Joint Photographic Experts Group
• It’s a compression method
• Lossy compression
• Extension .Jpeg/.Jfif
• Generation degradation, i.e. loses quality on repeated
saving
• Minimal file size
• Most popular file format, indicated for digital viewing and
web loading
• Contraindicated for printing

83. • Loss less compression formation i.e, no loss of quality occurs
when saving file in this format.
• It is preferred format for saving backup copies of original
image files.
• Downside of this format is that it results in very large sizes,
thus large capacity hard drives are required to maintain
storage.
(TIFF) TAGGED IMAGE FILE FORMAT

84. REFERENCES
Orthodontic Pearls: A Selection of Practical Tips and Clinical
Expertise; Eliakim Mizrahi. (2004) Taylor & Francis Group.
(Chapter 4: Orthodontic Samawi Photography, by PJ Sandler,
AM Murray)
A short guide to clinical digitlal photography in orthodontics. Shadi
S samawi bds MMedSci, MOrthRCS
Orthodontics current principles and Techniques Graber, Vanarsdall,
VIG FIFTH edition chapter2

85. THANK YOU
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