A detailed descriptive seminar on clinical photography in orthodontics for PG students and Orthodontic clinicians

1. ORTHODONTIC CLINICAL
PHOTOGRAPHY
Dr. KUNAAL AGRAWAL
BDS, MDS Orthodontics and Dentofacial Orthopaedics
Senior Lecturer, Department of Orthodontics and
Dentofacial Orthopaedics, RCDS&RC Bhopal

3. Why Take Orthodontic
Photographic Records?
• Study Models
• Radiographs
• Clinical Photographs

4. Camera? Why Go Digital..?
• Running cost issue
• More cost effective
• No ‘physical’ photographs
• ‘Post process’ or ‘enhance’ your photographs

8. BASIC TERMINOLOGY
• RESOLUTION:
• Determined by image’s pixel count & bit depth of each
pixel
• A pixel is the smallest discernible element in an image
• Camera’s resolution is determined by the number of
MEGAPIXELS
• Display’s resolution is expressed in pixels per inch (ppi)
• The minimum camera resolution suitable for
orthodontic purposes is around 3-4 Megapixels

13. • FOCAL LENGTH:
• Distance from the part of the optical path where the
light rays converge to the point where the light rays
passing through the lens are focused on to the image
plane – or the digital image sensor
• Measured in millimetres
• The longer the focal length, the more the lens magnifies
the scene

18. • SHUTTER SPEED:
• Refers to the amount of time the shutter is open or the
digital image sensor is activated
• Displayed as fractions of seconds, like 1/8 or 1/250
• Shutter speed increments are similar to aperture
settings, as each incremental setting either halves or
doubles the time of the previous ones
• For example, 1/60 of a second is half as much exposure
time as 1/30 of a second, but about twice as much as
1/125 of a second

19. • ISO
• International Standards Organization
• The ISO rating, which ranges in value from 25 to 6400 (or
beyond), indicates the specific light sensitivity
• The lower the ISO rating, the less sensitive the image
sensor is and therefore, the smoother the image will be,
because there is lesser digital noise in the image
• And vice-versa

20. • LIGHTING
• Studio electronic flash is recommended for
photographing a patient’s facial and head and neck
views
• Intra-oral photography requires the use of a portable
electronic flash unit. Most recommended is ring flash

24. • MACRO FUNCTION/LENS:
• Refers to ‘close up photography’
• The image projected on the ‘film
plane’ (ie. Film or a digital sensor)
is the same size as the subject
• Point and Shoot Digital Cameras
• Or, Dedicated Macro Lens
Assembly attached to DSLR
camera

34. Photography Retractors

35. Photography Mirrors
• Front coated silvered mirrors seem to offer the best
image quality & light distribution over other types
of intraoral mirrors
• With front coated silvered mirrors, no ‘double
layering’ or ‘ghost images’ occur
• Also, light reflection is not on par with front coated
silvered mirrors, leading to a ‘dimmed, darkened
image’ as an end result
• Highly recommended

38. • Preferable to use long-handled mirrors as they
allow better control and handling by the clinician
during the occlusal shots
• Usage depends on age and degree of mouth
opening of the patient
• Medium-handled mirrors are generally used in
dental practice

40. HOW MANY PHOTOGRAPHS..?
4 Extra-Oral 5 Intra-Oral
Total 9
Photographs

41. General Guidelines
• Remove all extra wearables
• Remove glasses, jewelry, and body piercings
• Hair shouldn’t obscure face and ears
• Patient’s eyes should be open
• Suitable seating/standing
• Face & lips should be in natural relaxed position
• Teeth should be in occlusion for i/o photographs
• Camera is positioned with lens axis horizontal

42. • Patient’s head shouldn’t be tilted; median plane
should be vertical
• Patient’s head should be level, with Frankfurt Plane
or Reid’s Plane being parallel to the floor
• Use camera viewfinder grid to align head in FOV
• Patient should be sitting/standing upright and
looking directly ahead, in natural head position

44. Extra-Oral Photographs
• Face Frontal (lips relaxed)
• Face Frontal (smiling)
• Profile, right side preferably (lips relaxed)
• 45o Profile (also known as 3/4th Profile, smiling)

48. Intraoral Photographs
• Front – in occlusion
• Right buccal – in occlusion
• Left buccal – in occlusion
• Upper occlusal (using occlusal mirrors)
• Lower occlusal (using occlusal mirrors)
• Overjet (optional)

61. IMAGE EDITING/ENHANCEMENT
• Flipping/Mirroring & De-Rotating
• Cropping
• Colour, Brightness, ‘Gamma’ Control and Contrast
• ‘Scratch’ Removal

66. MISCELLANEOUS
On-Screen Presentations 72-96 PPI, .JPEG Format
Printing &
Publications
150-300 PPI, .JPEG/.TIFF Format
A Short Guide to Clinical Digital Photography in
Orthodontics, 2e; Shadi S. Samawi

67. MOBILE DENTAL PHOTOGRAPHY
• Unlike a DSLR, a mobile phone can only have a tiny
sensor inside due to its form factor. This affects two
main issues:
• The overall image quality that it’s able to reproduce in
comparison to a DSLR in terms of resolution, Pixel
sharpness, and accurate color reproduction
• The focal length distortion problem

68. • THE FOCAL LENGTH DISTORTION PROBLEM
• In basic terms, when light comprising an image passes
through a certain lens, it bends in certain directions
depending on the type of lens and focal length it’s
passing through, before falling onto the image sensor to
produce the electrical signals that result in the end-
processed image. There are basically two types of
“distortion” possible depending on the type of lens
used:
• Pincushion distortion
• Barrell distortion

69. • Mobile phone lenses are designed for specific
purposes, namely taking pictures of every-day
scenes and selfies!
• In order to do that, manufactures have to fit wide-
angle lenses (short focal lengths ranging between
24-32mm) onto all mobile phones to be able to
incorporate the entire scene from “an arm’s
length”, as they say.
• Otherwise, only a small part of your face would
show up in the picture if a longer focal length was
used from this short “arm distance”.
• This leads to what is termed as Barrell Distortion;
the face and nose appear enlarged and clown-like,
for example.

71. • Looking at a DSLR with interchangeable lenses, this
problem is non-existent as we can fit any focal
length lens available to us from the shortest to the
longest available without any issues

72. Mobile Phone and DSLR Intraoral comparisons of the same patient, shot
successively. The distortion in arch dimensions, form of the dentition
and color representation in the mobile shots is obvious!

73. How can the smartphone
version of the above image be
accurately used and relied
upon as an accurate
representation of the the
clinical situation when used
for Digital Smile Design
planning through DSD
software? Even if the above
shot was taken using any of
the recent specialized light
and shade calibration
attachments, and even with a
higher resolution smartphone
camera, the distortion will
remain as it is a physical
function of the built-in
smartphone camera lens

74. • And so mobile phone manufacturers try to
counteract these shortcomings mainly through
clever programming of the camera software
parameters, as they cannot overcome such physical
limitations.
• Some companies have started creating Add-On
Macro lenses and flash lights attachments for
mobile phones but this has simply negated the
initial appeal of the mobile phone as a smaller,
lighter, easier and quicker to use setup for dental
photography!
• This also has raised the budget needed for a proper
dental photography setup to levels almost
equivalent to a DSLR setup, so there goes the
“money savings” argument as well!

75. • The ideal focal length for Dental photography has
traditionally been around 100mm, and for good
reason
• This focal length produces the least amount of
distortion in either dimension, and that’s why
professional portrait photographers work within
that 85-135mm focal length range – even up to
200mm – to produce the most accurate
proportions and pleasing results of their subjects
• Currently, the best, most consistent method to
produce true 1:1 Macro magnification with
accurate proportions for Dental Photography is
through using a 100mm equivalent Macro lens on
a DSLR

76. CONCLUSION & RELEVANCE