Transcript of "Digital photography /certified fixed orthodontic courses by Indian dental academy "
INDIAN DENTAL ACADEMY
Leader in continuing dental education
Photographs are an essential
part of clinical records
1. Unreliable memories. Within a matter of months,
patients and parents tend to forget how severe the
original malocclusion was. Having slides available at
every visit reminds both the orthodontist and the
patient of the original situation, against which all
improvements can be judged.
2. Medicolegal requirements . It is critical to have
clinical photographs that indicate any preexisting
pathology or trauma to the teeth.
-Close-up photographs are strongly advised for any
marked decalcification or enamel fractures that are
evident from the outset.
The debonding appointment is often the
first time patients or parents really focus
in on the labial enamel, and it may be
the first time they actually notice surface
decalcification, fractures, or other
blemishes. Proper records will help
avoid any post-treatment disputes
3. Teaching needs. Slides are probably the
most important teaching aids in orthodontics.
If cases are to be used in lectures, posters,
papers, and presentations, a high standard of
clinical photography is required.
4. Treatment evaluations . A quick scan of
sequential slides with patients and parents
during treatment will save lengthy
explanations of biomechanics or tooth
A camera should be reliable and simple,
particularly in offices where there will be
Minimal adjustments should be required when
changing from intraoral to extraoral shots.
Any new camera should be calibrated by
running a test film to achieve the desired
frame fill for each of the three normal
orthodontic views—extraoral, intraoral, and
Digital photography has been generally
available since 1981.
In 1991 ‘Autotrader’ were the first mass
market publication to move completely
to digital recording of images.
Digital imaging, one of the innovative ,
popular fields in the computer world, is
attracting more and more interest
It is now possible, with a reasonable
investment, to digitally acquire, archive,
and easily retrieve clinical images of our
Special diagnostic software allow the
orthodontist to customize the presentation of
text, graphics, and photographs.
Faster processors such as the Pentium and
Power PC are being developed, while
additional capabilities that once required
auxiliary components are being built into the
Computerized Digital Photography
The term "computerized photography"
actually describes the blending of video
and digital photography, along with the
processing of those images.
It can be divided into three principal
functions: input, processing, and
The input procedure is the most techniquesensitive and has a dramatic impact on the
Digital images used in orthodontics are input
from one of three sources: video signal,
digital camera, or scanner.
Images from a video camera are usually
output as an analog signal, which is
converted to a digital image by a digitizer or
"frame grabber" built into the computer
A digital camera captures the image
directly from the CCD sensor and
requires no analog-to-digital
The digital images are stored in the
camera on small electronic "flash cards"
or on a miniature hard disk drive. They
can then be downloaded to a computer.
Bending Light- basic optics
The optical component of the camera is the
At its simplest, a lens is just a curved piece of
glass or plastic.
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
As light travels from one medium to another, it
Light travels more quickly through air than it does
through glass, so a lens slows it down.
When light waves enter a piece of glass at an angle,
one part of the wave will reach the glass before
another and so will start slowing down first.
This is something like pushing a shopping cart from
pavement to grass, at an angle. The right wheel hits
the grass first and so slows down while the left wheel
is still on the pavement. Because the left wheel is
briefly moving more quickly than the right wheel, the
shopping cart turns to the right as it moves onto the
The effect on light is the same -- as it enters the glass
at an angle, it bends in one direction.
It bends again when it exits the glass because parts
of the light wave enter the air and speed up before
other parts of the wave.
In a standard converging, or convex lens, one or
both sides of the glass curves out. This means rays
of light passing through will bend toward the center of
the lens on entry.
In a double convex lens, such as a magnifying
glass, the light will bend when it exits as well as when
The rays of light all start
at the same point -- the
candle's flame -- and
then are constantly
diverging. A converging
lens takes those rays
and redirects them so
they are all converging
back to one point. At
the point where the rays
converge, you get a real
image of the candle.
The nature of this real image varies
depending on how the light travels
through the lens.
This light path depends on two major
The angle of the light beam's entry into
The structure of the lens
The angle of light entry changes when
you move the object closer or farther away
from the lens.
The lens bends the light beam to a certain
total degree, no matter how it enters.
Light beams that enter at a sharper angle will
exit at a more obtuse angle, and vice versa.
The total "bending angle" at any particular
point on the lens remains constant.
The light beams
from the pencil point
enter the lens at a
sharper angle when
the pencil is closer
to the lens and a
more obtuse angle
when the pencil is
Therefore light beams from a closer
point converge farther away from the
lens than light beams from a point that's
In other words, the real image of a
closer object forms farther away from
the lens than the real image from a
more distant object
We can observe this phenomenon with a simple
Light a candle in the dark, and hold a magnifying
glass between it and the wall.
You will see an upside down image of the candle on
If the real image of the candle does not fall directly on
the wall, it will appear somewhat blurry. The light
beams from a particular point don't quite converge at
To focus the image, move the magnifying glass
closer or farther away from the candle.
This is what you're doing when you turn
the lens of a camera to focus it -- you're
moving it closer or farther away from
the film surface.
As you move the lens, you can line up
the focused real image of an object so it
falls directly on the film surface
Lens Shape and Image Size
A lens bends light beams to a certain total degree,
no matter the light beam's angle of entry. This total
"bending angle" is determined by the structure of
A lens with a rounder shape (a center that extends
out farther) will have a more acute bending angle.
Curving the lens out increases the distance between
different points on the lens. This increases the
amount of time that one part of the light wave is
moving faster than another part, so the light makes a
Light beams from a particular point will converge at
a point closer to the lens
In a lens with a flatter shape, light beams will
not turn as sharply and converge farther
away from the lens.
-Real image forms farther away from the lens
Increasing the distance between the
lens and the real image actually
increases the total size of the real
The light beams spread out more,
forming a larger real image exampleprojector
The magnification power of a lens is
described by its focal length.
The focal length is defined as the
distance between the lens and the real
image of an object in the far distance
A higher focal length number indicates
a greater image magnification
A rounder lens produces a smaller real
image with lesser magnification and a
flat lens produces larger image with
Label on lens barrel indicates positions for proper
magnification of intraoral, mirror, and extraoral shots.
A lens with an especially long focal length and is
used for distant photography.
This lens lets you zero in on specific elements in the
distance, so you can create tighter compositions.
For a close-up portrait- use a wide-angle lens.
This lens has a much shorter focal length, so it
shrinks the scene in front of you.
The entire face is exposed to the film even if the
subject is only a foot away from the camera
In a zoom lens, one can move
different lens elements back and forth.
By changing the distance between
particular lenses, we can adjust the
magnification power -- the focal length
-- of the lens as a whole
What is Autofocus?
Autofocus (AF) could be called power-focus,
as it often uses a computer to run a miniature
motor that focuses the lens for you.
Focusing is the moving of the lens in and out
until the sharpest possible image of the
subject is projected onto the film.
Depending on the distance of the subject from
the camera, the lens has to be a certain
distance from the film to form a clear image.
It is called "active" because the camera emits
something (in this case, sound waves) in order to
detect the distance of the subject from the camera.
Active autofocus uses an infrared signal and is
great for subjects within 20 feet (6 m) or so of the
Infrared systems use a variety of techniques to judge
the distance. Typical systems might use:
Amount of infrared light reflected from the
Infrared is active because the autofocus
system is always sending out invisible
infrared light energy in pulses when in focus
The subject reflects the invisible infrared light
back to the camera, and the camera's
microprocessor computes the time difference
between the time the outbound infrared light
pulses are sent and the inbound infrared
pulses are received.
Using this difference, the microprocessor circuit tells
the focus motor which way to move the lens and how
far to move it. This focus process repeats over and
over while the camera user presses the shutter
release button down half-way.
Infrared emitter and the receiver are on the front of
the camera, normally near the viewfinder.
To use infrared focusing effectively, emitter and the
sensor should have a clear path to and from subject
Subject should be centered.
Very bright subjects or bright lights can
make it difficult for the camera to "see"
the reflected infrared beam -- avoid
these subjects when possible.
Infrared sensing can have problems.
A source of infrared light from an open flame
can confuse the infrared sensor.
A black subject surface may absorb the
outbound infrared beam.
The infrared beam can bounce off of
something in front of the subject rather than
making it to the subject.
Advantage - it works in the dark, making
flash photography much easier.
Passive autofocus, commonly found
on single-lens reflex (SLR) autofocus
cameras, determines the distance to
the subject by computer analysis of
the image itself.
The camera actually looks at the scene
and drives the lens back and forth
searching for the best focus.
A typical autofocus sensor is a chargecoupled device (CCD) that provides
input to algorithms that compute the
contrast of the actual picture elements.
The CCD is typically a single strip of
100 or 200 pixels. Light from the scene
hits this strip and the microprocessor
looks at the values from each pixel
The microprocessor in the camera looks at
the strip of pixels and looks at the difference
in intensity among the adjacent pixels and
moves the lens,
The microprocessor then searches for the
point where there is maximum intensity
difference between adjacent pixels -- that's
the point of best focus.
Passive autofocus must have light and image
contrast in order to do its job.
The image needs to have some detail in it that
If you try to take a picture of a blank wall or a large
object of uniform color, the camera cannot compare
adjacent pixels so it cannot focus.
There is no distance-to-subject limitation
with passive autofocus like there is with the
infrared beam of an active autofocus system
Autofocus Speed and
The focusing system has been altered from a split
prism to a ground glass system, which improves ease
It is important to test the autofocus of a camera,
taking into account the magnification ratio, distance
from the subject, and illumination.
The availability of a manual focus is a plus.
A satisfactory autofocus for orthodontic
purposes will work properly at a distance of
12" from the subject with a 1:2 magnification
Digital images are made up of picture
elements (‘pixels’) comprising red, green, and
blue light, each set at a level between 0 and
If all three colours are set at 255 white is the
result, while if all are set at zero, black results
There are 256 grey shades that result from all
three colours being set at the same number.
Varying the level of each of the three colours
results in the gamut of 16·7 million colours.
Numerical values for each of these
colours are stored on the Charged
Couple device (CCD).
This is made up of pixels, the number of
which, combined with the degree of
compression, determines the quality of
the final output.
Resolution is dependent on the density of
The pixel depth determines the number of
possible colors per pixel.
Ideally, realistic images should be in 24-bit
color, which means that each pixel is
described from a palette of 16.8 million
At a minimum, the image should be described
in 16-bit pixel depth, or 65,000 colors.
In the 1990s a typical CCD would
comprise 640 * 480 pixels resulting in
acceptable images for snapshots, but
lacking the quality needed for high
quality clinical photographs
By 1999 the first ‘mega-pixel’ cameras
(over 1,000,000 pixels per image) were
Bearing in mind a conventional 35-mm
slide is thought to contain the
equivalent of 25–30 million pixels of
information there is still a long way to go
for digital images to be serious
The quality of the digital image depends on a
number of factors:
• Camera optics
• Pickup device (the CCD sensor in the camera)
• Analog signal quality (composite, S-video, or
• Digitizer resolution
Digital cameras can be divided into two
Compact digital cameras
Professional reflex cameras with
A professional reflex camera meets all
the requirements for clinical orthodontic
Optical System Quality for
For intraoral photography, the lens system
should allow adequate magnification at a
distance of at least 12" from the subject.
The optical quality depends on the camera's
focal length--the distance (in millimeters)
between the image sensor and the optical
center of the lens when the lens is focused on
Many compact digital cameras have lens systems
with a focal length of 35mm (equivalent to a 35mm
This value is inadequate for orthodontic intraoral
A 50mm focal length is sufficient, but a 100mm focal
length will completely satisfy the requirements for
A high focal length allows a reasonable
distance from the subject, minimizes
distortion, increases depth of field, and
permits adequate illumination of the subject.
Cameras with a zoom function have a variable focal length,
which is expressed as a range.
Focal length can be increased with a zoom lens or by the
addition of close-up lenses.
The best digital cameras have a zoom with a high magnification
ratio and the ability to add close-up lenses.
When the zoom is moved toward the maximum enlargement
position, or close-up lenses are added, it can become
impossible to focus from short distances, and the effectiveness
of the autofocus is reduced.
Thus, you may see an image in the viewfinder that has a high
magnification, but is out of focus. The balance of these factors is
what determines the macro capabilities of the system.
The macro quality of a digital camera is
acceptable when it is possible to capture a
70mm horizontal line at full screen, in sharp
focus, from a distance of 12".
This corresponds roughly to the 1:2
magnification on a conventional 35mm
A very good optical system allows a 35mm
line to be captured at full screen, which
corresponds to a 1:1 magnification ratio.
The amount of detail that the camera
can capture is called the resolution,
and it is measured in pixels.
The more pixels a camera has, the
more detail it can capture and the larger
pictures can be without becoming blurry
Some typical resolutions include:
256x256 - Found on very cheap cameras, this resolution is so low
that the picture quality is almost always unacceptable. This is
65,000 total pixels.
640x480 - This is the low end on most "real" cameras. This
resolution is ideal for e-mailing pictures or posting pictures on a
1216x912 - This is a "megapixel" image size -- 1,109,000 total
pixels -- good for printing pictures.
1600x1200 - With almost 2 million total pixels, this is "high
resolution." You can print a 4x5 inch print taken at this resolution
2240x1680 - Found on 4 megapixel cameras , allows even larger
printed photos, with good quality for prints up to 16x20 inches.
4064x2704 - A top-of-the-line digital camera with 11.1 megapixels
takes pictures at this resolution. At this setting, you can create
13.5x9 inch prints with no loss of picture quality.
How Many Pixels?
The number of pixels and the maximum resolution
don't quite compute.
For example, a 2.1-megapixel camera can produce
images with a resolution of 1600x1200, or 1,920,000
But "2.1 megapixel" means there should be at least
This isn't an error, there is a real discrepancy
between these numbers because the CCD has to
include circuitry for the ADC to measure the charge.
This circuitry is dyed black so that it doesn't absorb
light and distort the image.
CCD Resolution and Quality
Traditional film is replaced by a Charged
A CCD sensor has thousands of light
detectors, called "pixels", on its surface.
A high number of pixels ("optical resolution")
increases the quality and detail of the image,
but also increases the size of the file in which
the image will be saved.
File resolution can be increased by a
software interpolation, which does not
actually improve the image quality.
Therefore, when evaluating a camera's
optical resolution , only the actual CCD
The highest resolution is the full CCD
resolution, but the lower resolutions use only
a portion of the CCD pixels to describe the
Figure shows an intraoral
picture taken at a resolution of
832 X 624-- meaning that about
520,000 pixels are used to
describe the subject.
However, the clinically useful
area (shown by the yellow
rectangle) is displayed by only
If this image has been taken at
the maximum possible
magnification for the camera,
then the latter number
represents the "clinically useful
resolution" (CUR) for this
The CUR, a key factor in the choice of digital
The sensor resolution
Quality of the optical lens system.
Needs of the user.
A CUR of about 400,000 pixels is adequate
for orthodontic use.
Selecting a camera with a CCD resolution
close to the CUR is advisable.
Too great a difference will
Unnecessarily large files and thus will
require more memory and a longer
transfer time to the computer.
If the CCD resolution is larger, it will be
necessary to manipulate ("crop") each
file on the computer
Testing pixel quality
The sensor quality of a single pixel in
transmitting the luminance (brightness)
and chrominance (color hue) of the light
signal should be tested by observing
the images captured by the digital
camera on a properly tuned monitor.
By far the most significant improvement
which dramatically improves the
reliability of camera positioning are the
changes now seen through the
An optical reflex viewfinder is ideal, because
it provides an almost perfect correspondence
between the image seen in the viewfinder and
the captured image under all conditions.
An alternative is a Liquid Crystal Display
The LCD can be as small as .5", in which
case an optical system allows proper
magnification with the eye in close contact
with the viewfinder
An LCD can also be a small screen, 1.5-2.5"
in diameter, in which case the camera must
be held away from the eye when shooting
DISADVANTAGES- low "refresh rate ",
meaning that as the camera is moved to
frame the best picture, the image in the
viewfinder changes jerkily.
-LCD is hard to read in bright sunlight,
consumes a great deal of battery
For most indoor photography, where there is
relatively little ambient light, you need to
increase the light level to get a clear picture.
Increasing the exposure time doesn't work
well for most subjects, because any quick
motion, including the movement of the
camera itself, makes for a blurry picture.
Electronic flashes are a simple, cheap
solution to this inherent problem in
Purpose - is to emit a short burst of bright light
when you release the shutter. This illuminates the
room for the fraction of a second the film is exposed
Master and Slave
Flashes are often set up all around a subject to
achieve better lighting effects.
In this arrangement, one master flash may be
triggered by the camera shutter, while other flashes
are triggered by the master.
Some slave flash designs use the master flash's light
itself as a trigger. The slave flash has a small light
sensor that triggers the flash circuit when it detects a
sudden pulse of light
A synchronized ring flash is needed to obtain
uniform illumination of the subject in macro
Most compact digital cameras have built-in
flash units on one side of the lens which will
produce uneven light distribution in intraoral
photography and have no ports for external
synchronized flash units.
The subject illumination can be improved
1. Light deflectors -A mirror system can
effectively diffuse the flash light on both sides
of the subject
2. Light-activated external flash .- It may be
possible to mount an external flash on the
opposite side of the built-in flash.
The two flashes will operate simultaneously,
producing good illumination of the subject
Immediate Review of Recorded
This is one of the most important
advantages of digital cameras over
You can check the recorded image a
few seconds after taking the picture and
decide whether it is satisfactory.
Tuning of Exposition
In macro photography, it is important to
be able to manually adjust the
The size of the lens opening (aperture),
indicated by the f-number
The shutter speed, measured in
fractions of a second.
Batteries and AC
Some digital cameras use ordinary
alkaline batteries and have a battery life
of only 10-15 photographs.
Others have rechargeable LI ion
batteries that can last through more
File Format and Software
Once an image has been acquired by the
CCD, it is stored in the camera's memory as
Image files can be of different formats and,
more important, can be compressed.
Compression increases the number of
images that can be stored in memory, but it
also causes a decay of the image quality; the
higher the compression, the greater the
Images can be saved with or without
compression, and at which compression
Done by selecting the capture mode as
"FINE", "NORMAL", or "ECONOMY
The file storage format is not critical, but it is
preferable to use digital cameras that save
the acquired images as JPEG or TIFF files,
which can be read by virtually any imaging
Number of Images Stored
There are two types of image storage: built -in
(internal) memory and removable memory.
Four types of removable memory are currently
available for digital cameras:
Solid State Floppy Disk Card (SSFDC) or
Compact flash card
3.5" floppy disk
SSFDCs can store only as much as 8MB of data,
while miniature cards store as much as 24MB.
These two media need a converter that is inserted in
a floppy disk or PCMCIA
Compact flash cards can be found in sizes
from 2MB to more than 100MB and do not
need an adapter for insertion in a PCMCIA
The amount of space taken by one image
depends on its resolution and on the file
An uncompressed image with a resolution of
1,280 X 1,024 takes up 3.75MB, while an 800
X 600 image can be compressed to only
There are two different ways to transfer the images
from the camera to the computer:
1. Cable connection. Most digital cameras can be
connected to a PC or Macintosh computer through
a serial or parallel port.
This kind of connection is extremely slow, however, and
serial transfer is slower than parallel.
2. Transfer from removable memory through a
The time needed to transfer the images
depends on two factors:
The size of the image files
The transfer speed (in KB/second).
Since the file dimension is determined by the
resolution and compression of the image, a
reduction in size will have a negative
impact on image quality.
Therefore, transfer speed is the key
The ideal features of a compact digital
camera can be summarized as follows:
Lens system with a high focal length and a
powerful zoom, allowing intraoral
photography with at least a magnification
comparable to the 1:2 lens of 35mm cameras.
Optical resolution of at least 500,000 pixels.
Clinically useful resolution of at least 400,000
pixels (depending on the two previous
Both auto and manual focus.
Ability to use a ring flash.
Optical reflex viewfinder, or LCD with a high
Capability of reviewing the recorded image on
the viewfinder screen.
Ability to manually tune exposition
Rechargeable batteries and AC connection.
External memory that will store an adequate
number of images and speed up file transfer
to the computer.
Features to avoid include
Fixed focal length of 35mm (equivalent
to a 35mm camera).
Low optical resolution (640 X 480 or
Built-in memory only.
One type of digital camera (prosumer) falls into the
midrange price bracket £500–1500 and lies between
the consumer camera and the professional models.
They usually have a host of useful features including
macro-zoom lenses and potentially high image
The ‘piece de resistance’ of digital cameras is
undoubtedly the image preview facility in that images
can be immediately viewed on the LCD screen and
accepted or, if flawed, deleted and retaken.
Problems with the ‘prosumer’
The flash provided with most digital cameras is a
Ring flashes are essential to avoid unacceptable
shadowing on most of the images
Despite the use of deflectors and diffusers the results
with the built-in point flash tend to be disappointing.
The point flashes are also not powerful enough to
allow the photos to be taken on very small apertures
This is essential as it greatly increases the depth of
field and ensures most of the frame is in focus.
Taking the occlusal shots from much further away may
ensure adequate illumination, but will inevitably waste
pixels unnecessarily and focusing will also be problematic
The second problem involves the viewfinders; some
digital cameras are available with a ‘Galilean
telescope’ viewfinder that is very suitable for
snapshots, but totally unsuitable for high quality intraoral photography.
The problem is that the viewfinder, when close to the
subject, doesn’t accurately represent what the lens
Live display on the LCD screen is also possible, but
they are again inaccurate if the ‘refresh rate’ is slow,
and are very power hungry, making it an unsuitable
method unless a mains supply is utilized.
Thirdly, the focusing system can be
problematic as theauto-focus systems on the
‘prosumer’ cameras often take three or four
attempts to get the system to focus
All the area of interest is not always as sharp
as it might be.
The predetermined distance ‘macro’ settings
available on some of the digital cameras also
sometimes give disappointing results.
Kodak teamed up with Nikon in the late 1990s
to produce the Digital Camera System (DCS),
which was capable of very high quality
The problem with this system was that the
camera body alone was over £10,000
The Nikon Dl is one of the best digital
Another digital camera recently released is
the Fuji FinePix S1 Pro, which may be the
perfect digital camera for orthodontics .
The body is made by Nikon and is therefore
built to a high specification.
The lens system required is the Nikon 105
mm/2·8 AF Macro and the flash system is the
Nikon SB29 Speedlight.
The flash provides TTL metering and,
therefore, the intra-oral photos taken at F32
are invariably perfectly exposed and in focus.
The pictures are all taken on manual focus
just by setting the lens adjustment for intraoral shots, then moving backwards and
forwards to focus.
Using the ‘limit’ switch on the lens allows the
same magnification to be set for all intraoral
photos, thus allowing direct comparability
Images may be stored on a 64 Mb storage
The capacity of this card means that 330
images can be stored,using the lowest pixel
setting (1440) and maximum compression,
resulting in images of about 200 Kb.
The quality of these images is more than
acceptable for most clinical purposes.
The only adjustment the camera
requires is from F32 to F11 for extraoral shots and to switch off the flash
bulb behind the patients head on the
three-quarter and profile view to throw
the shadow behind the head.
Manipulation of digital
RequirementsA high quality digital camera, and a
sufficiently powerful computer to allow
easy viewing and subsequent
manipulation of the images
Exif viewer also allows inspection of
individual images ,
Most digital images are stored within the
camera on either a Compact Flash card (43*
38 * 3.5 mm in hard case) or a Smart Media
card (thinner, lighter, and more flimsy).
A 64Mb Compact Flash card will hold up to
330 images of more
Once the images have been captured they
need to be ‘read’ by the computer.
The most convenient method is use of an
adapter to allow the card to be inserted
directly into an empty PCMCIA port.
If a desktop computer is used, a variety of
multi-card readers are available that allow
connection through the serial ports (COM1 or
Transfer of images may be slower than using
the PCMCIA port.
It is provided with many cameras, and if loaded
correctly, the thumbnails’ (small representations of
each picture onthe computer screen) are
automatically loaded on the computer screen when
the memory card is accessed
It allows inspection of individual images, to check the
entire area of interest is included, as well as sufficient
depth of field was available to ensure the whole
picture is in focus
The instant preview facility, on all but the cheapest
digital cameras’ LCD screen, certainly gives an
overall impression of the image.
The top of the range cameras, such as the Fuji S1 Pro,
have a sufficiently high quality LCD screen combined with
the facility to scan the entire image easily with a powerful
This will allow quality verification by viewing on the
Images taken with mid-range cameras may need quality
confirming, using Exif viewer
Once all the images are all satisfactory Dentofacial
Showcase is opened alongside Exif viewer.
The ‘Restore Down’ button is now used (top right of the
screen, button next to Close Programme button) for both
programmes, to allow them to be visible on the screen at
the same time.
All of an individual patient’s images are now selected
in Exif viewer (left mouse button, whilst holding down
the Ctrl key) and these are dragged and dropped into
a previously opened new file in Showcase
With Windows 2000® it is possible to view files as
‘thumbnails’, as well as the previous options of large
icons, small icons, list, and details, available with
older versions of windows.
This is useful when a JPEG is to be imported into
To directly fill the screen with the image
and check the quality or manipulate the
It is necessary to double click the
thumbnail and take the JPEG into
Microsoft Photo Editor®, Adobe
Photoshop®, or other image
Showcase is a popular programme for storing,
manipulating, and showing orthodontic records of patients
Thumbnails are stored under each patient’s name, and
attributes such as type of photograph and stage of
treatment can be easily attached to individual images, or
groups of images using the ‘Speedway’ facility
The image may be rotated to compensate for poor camera
Using ‘Speedway’, images are now cropped to ensure
little or no retractor appears in the frame, and that the
‘background’ areas of black, produced as a result of
rotation of the image, are removed.
Slides of particular interest can be selected within
Showcase to run a slideshow to illustrate the features
of the patient’s malocclusion.
Individual slides can be presented in order to show
maximum detail of each view taken.
Comprehensive overview of the casecan be taken
Patients images can be stored within folders in
Showcase categorized in many ways
A limit of 64 to the number of images that can be
stored in each patients file
Radiographic information should also be imported in to the
The lateral cephalometric radiograph and OPG can be
photographed with the digital camera.
The flash is turned off and the camera aperture opened
sufficiently wide to reduce the shutter speed to 125 or
faster, to eliminate camera shake.
The ideal background is an outside window, using daylight
to trans-illuminate the film avoiding the greenish hue
inevitable when an X-ray viewer is used for illumination.
Alternatively once the image is within Showcase it can be
converted from colour to Greyscale (black and white)
Standard Orthodontic Views
For a complete photographic record, the recommended views
• Four extraoral— left profile (right profile only in cases of facial
asymmetry), three-quarter profile, full-face, and full-face grinning
• Five intraoral (in occlusion)—left and right buccal segments,
anterior view, and mirror images of both dental arches.
• Close-ups of any areas of concern—fractured, cracked, or crazed
teeth, nonvital teeth, or areas of hypoplasia or
Progress (during treatment or between
phases of treatment)
• Extraoral— if changes have occurred.
• Close-ups of any unusual or noteworthy
mechanics or problem areas. Removable
appliances used during treatment are often
photographed in cases to be presented.
End of treatment
• Same as initial.
Photographs of the retainers can also be
Functional occlusion (selected cases)
• Three intraoral (no mirror)—right lateral
excursion, left lateral excursion, and anterior
protrusion. These will demonstrate the
presence of desirable guidance and absence
of undesirable contacts
To obtain the highest quality photographs, the
Have consistent lighting exposure, focal length, and
Use the Frankfort horizontal line on lateral facial
Use 110V AC flash/flood units
Use a Synch cord between the camera body and one
of the 110V AC flash/flood units.
The other unit will trigger at the speed of light
(almost) and simultaneously flash. This gives a
balanced soft flood/flash lighting effect on both sides.
If the photography room is narrow, use
wall mounted flash/flood units
If the room is wide, then tripods should
be used to mount the flash/flood units
Be sure that the patient is properly
framed and focused.
110V AC Multiblitz Minilight has ring-type, highly
durable flash bulb and smaller centrally located, less
durable, bulb for floodlighting. Silver-lined umbrella
has been removed for this photograph.
Frontal projection in wider rooms, Multiblitz Minilights should be
mounted on tripods.
In so doing, extreme angles in flash presentation can be avoided.
There should be at least 2½ feet between the back of
the subject's head and the rear wall to prevent
A flat nonglare blue-green or medium green
background provides for good color prints.
It is important to aim the flood/flash umbrella or
(Photofex) soft box (Multiblitz Minilite 200) dual flash
boxes accurately at the patient.
A small electronic portable flashlight (pointer) taped
to the umbrella rod and aimed at the patient
Office photographer and subject, both standing. Base view.
Patient's previous photographs should be reviewed and should
be on counter behind photographer. Camera synch cord is
attached to closest Multiblitz Minilight. Subject is 2½ feet from
background and 5 feet from back of camera.
flat blue-green (painted) wallboard background, Hunter-Douglas Dwette
Eclipal "total darkness" window shade, and 8-inch lift.
Note optional indirect Lite Disc Reflector to provide soft light from
below,directly to chin and www.indiandentalacademy.com
front of face.
In addition, the photographer must:
Include more than just right lateral and frontal (AP)
views—left and right oblique views and a base view
should also be included.
Insure optimal patient positioning.
Insure correct lighting.
Avoid parallax distortion.
Previous photographs must be reviewed, just before
taking follow-up photographs, so that consistent
postoperative or posttreatment photographs can be
Full-Face Extraoral View
Objective: A symmetrical shot from the top of the patient’s head
to an inch or two below the chin.
Subject: Shine a dental light, if available, on the patient’s face.
This will constrict the pupils somewhat, reducing “red-eye”, and
throw the shadow behind the front of the face. Ask the patient to
avoid looking directly at the end of the camera, but to look into
the distance over the photographer’s shoulder.
Procedure: Set the camera to the extraoral mark on the barrel of
the lens. To ensure consistent magnification, rock backward
and forward until the patient’s eyes and cheekbones are in
Take one full-face view with the lips at rest and one with as
broad a smile as possible, fully exposing the teeth and gingivae
Sketch of ideal head position for frontal view. A, outer canthus to superior
attachment of the ear (C-SA line); B, interpupillary line; C, encompassing
area (crown to collarbone). The line from the outer canthus of the eye to
the hairline is superimposed over the C-SA line and is not specifically
labeled in this diagram.
Sketch of ideal head position for lateral view, showing
outer canthus to superior attachment of ear (A) and
encompassing area of crown to collarbone (C).
Frontal view. Note that patient is properly
aligned with regard to Frankfort horizontal line.
Profile Extraoral View
Objective: A photograph from the top of the patient’s
head to an inch or two below the chin.
The patient’s nose should be a short distance from
the edge of the frame;
The back of the head is not essential
Subject: Ask the patient to keep the lips at rest if at all
possible. If a dental light is available, it may be
possible to angle the light to throw the shadow
behind the patient.
Procedure: Same as with the full-face shot.
Extraoral profile view includes top of head, tip of nose,
and throat angle, with horizontal Frankfort plane.
Lateral view. Chin and about 40% of neck
should show. Use Frankfort horizontal line to be
sure that head is level.
Three-Quarter Extraoral View
Objective: A shot from the top of the head to one or
two inches below the chin.
Subject: 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.
As the shot is being taken, ask the patient to look
toward the camera while keeping the head in
position. This will produce a slightly more animated
shot and will allow the dental light to decrease the
amount of “red-eye”
Procedure: Focus on the cheekbone and the side of
the nose to ensure adequate depth of field.
Patient looks toward camera immediately before
three-quarter shot is taken
Oblique view. Use Frankford horizontal plane. (Horizontal line
through tragus and through infraorbital rim). Make sure that
about half of opposite upper lid eyelashes show. All of far side
pupil should not show.
Another oblique view, showing about half of subject's pupil, most
of her upper lashes, and none of her lower lashes. Also, note
how use of soft, indirect flash brings out this patient's delicate
flesh tones, pouting lips, and long eyelashes.
Base view. Include all of chin and small area of neck.
Interpupillary line should be horizontal. Photographer
should correct any habitual head tiring that subject
Hairstyle can distract from facial analysis. B, 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.
Central facial distortion is produced with 50 or
55 mm and is even more when a 28 mm lens
The best option is the 105 mm facial portrait
The 105 mm macrolens allows the
photographer to frame the head and neck
from 5 feet without parallax problems.
To do the same with a 55 mm lens would
require that the photographer be just 15
inches away from the subject.
Cheek retractors are available in many
shapes and sizes, but self-holding wire or
plastic retractors do not permit high-quality
The best retractors are the double-ended
kind, which come in two sizes
These allow patients of all sizes to be
photographed, maximizing soft-tissue
retraction and minimizing the amount of
retractor shown in the photo
Large and small retractors.
Intraoral Anterior View
Objective: To show the teeth in maximum
intercuspation, with the viewfinder completely filled
The occlusal plane should be horizontal, dividing the
frame in two, with the clinically correct midline as
close to the center of the frame as possible.
Subject: The patient should be seated in the dental
chair at a comfortable height for the photographer
and for the assistant retracting the lips and cheeks.
Ask the patient to keep the tongue back to provide
good contrast for the teeth
The dental light will aid in focusing.
Procedure: anterior intraoral shots require maximum
The larger ends of the large retractors must be used
on all patients except small children and severe lowangle Class II, division 2 cases.
Ask the patient to swallow before placing the
retractors, and aspirate excess saliva from the field of
Pull the retractor laterally and as far forward as not
backward, which will compress the lips against the
For adequate depth of field, focus on the lateral
incisor area or the mesial of the canine by rocking
gently backward and forward.
The line across the middle of the
viewfinder during intraoral photography
should, in most cases, be coincident
with occlusal plane and the shot should
be symmetrically composed.
In intraoral anterior shot, assistant pulls larger
ends of large retractors laterally and as far
forward as possible.
Intraoral Buccal View
Objective: To show the teeth in maximum intercuspation,
from the labial surface of the central incisor to the distal of
the first molar, or the second molar if possible
The occlusal plane should be parallel to the upper and
lower edges of the frame.
The frame should be filled with dental tissue, not with lips,
skin, fingers, or retractors.
Subject: The patient is seated upright in the dental chair,
with the head turned as far as possible to the left or right.
Ask the patient to keep the tongue away from the teeth to
help clear saliva from the photographic field and to provide
a dark background.
Intraoral buccal shots use both ends of the
The larger end of one retractor is held by the
assistant, pulling laterally away from the
teeth, on the side not being photographed.
The smaller end of another retractor is held
by the photographer, pulling as far distally as
possible, on the side being photographed
Pull the retractor firmly when you are about
to take the photograph.
For intraoral buccal shot, photographer holds one
retractor while patient turns head as far as possible.
Immediately before snapping the shutter, pull
the retractor another 5mm distally to make
sure the distal surface of the first molar can
Try to move perpendicular to a tangent
through the molar-premolar area, so that the
sagittal discrepancy will be fully represented
Careful use of the retractors can avoid the
need for buccal mirrors in almost all patients
Intraoral buccal view includes central incisors to distal
surfaces of first molars.
Upper Occlusal Mirror Shot
Objective: The entire viewfinder should be filled with
teeth, showing the maxillary arch from 1-2mm
anterior to the labial surface of the central incisors to
the distal of at least the first molars
If the second molars have erupted, try to include
The middle of the arch should be parallel to the
shorter dimension of the frame.
Subject: The patient should be seated upright in the
dental chair, with the head and body tilted back
The mouth should be wide open, and the chin
inclined slightly toward the floor. The tongue should
be held below the mirror to keep it out of view. The
dental light will again help focus
Procedure: Mirror shots are the hardest to take. At
least one pair of hands, and preferably two, are
needed to help.
Retractors are used to pull the upper lip upward,
laterally, and forward to set up a background of
sulcus mucosa for the incisors, while removing all
skin and most of the lips from view.
The retractors should almost touch in the
midline, and should be angled slightly
outward to ensure that the lips are well away
from the labial surfaces of the incisors.
assistants’ fingers and the retractors are
kept out of the shot, and avoid including a
direct view of the tips of the opposing teeth.
Warm the occlusal mirror in water for a few seconds, then dry it with
a paper towel.
The mirror must be held by the photographer to allow fine-tuning of
the shot at the last moment. Before inserting the mirror, ask the
patient to swallow to keep saliva away from the field of view; use an
aspirator if necessary.
Place the mirror in the mouth with the large end against the distal
margins of the terminal molars, adjust the dental light, and press
the mirror down onto the lower incisors.
Ask the patient to breathe through the nose for a moment to reduce
Angle the camera at 45° to the mirror, which in turn is angled at 45°
to the arch. Just before taking the picture, drop the mirror a couple
of millimeters away from the terminal molars.
Ask the patient now to “open twice as wide”, producing a further
For upper occlusal mirror shot, patient tilts head back
while photographer holds mirror and assistant pulls
lips upward, laterally, and forward.
Upper occlusal mirror shot includes incisors
and second molars.
Lower Occlusal Mirror Shot
Objective: To fill the viewfinder from just
anterior to the labial surfaces of the lower
incisors to the distal of the second molars.
The midline should be centered, if clinically
correct, to provide symmetry.
Subject: The patient should be seated with
the body tilted slightly backward and the head
tilted as far back as possible to minimize the
contortions required of the photographer.
Ask the patient to place the tongue above
and behind the mirror if possible
Lips are pulled downward, laterally, and slightly
forward with retractors to show the mucosa as a
background to the incisors
Try to avoid getting fingers, retractors, or opposing
incisor tips in the field of view
The photographer should hold the mirror from above
to allow slight adjustments in the position of the
Have the patient open as wide as possible, and at the
last moment move the distal end of the mirror slightly
away from the terminal molars.
For lower occlusal mirror shot, patient tilts head back
while photographer holds mirror and assistant pulls lips
downward, laterally, and forward.
Common Errors in Clinical
Misrepresentation of skeletal pattern.
This can occur if the patient tilts the
head too far backward or forward.
-Try to get every patient into a
horizontal Frankfort plane or “natural
2. Inconsistent magnification between stages of
- Marks on the barrel of the lens
- The lens can be locked at the required
magnification preventing accidental
movements that can occur if the camera is
lowered between shots.
- Final focusing is achieved simply by
rocking backward and forward until the
desired field appears sharp.
3. CAMERA LENS AND POSITION
Viewpoint (prespective) is determined by the
distance between the subject and the film plane.
The distance from camera to subject will be
determined by the focal length of the lens.
A wide-angle lens requires close subject-to-film
plane distances to fill the field and results in viewpoint
distortion known as barrel distortion, with
enlargement of the chin and nose, elongation in the
anteroposterior dimension, and excessive curvature
A slight telephoto lens (ideally 100 mm or 105 mm for
35 mm cameras) provides the best perspective
An extremely powerful telephoto lens creates
compression-type distortion, with nearer subjects
appearing smaller, shortening in the anteroposterior
dimension, and excessive flattening of features
The best way to standardize facial portraits is to keep
the focal length of the lens the same (100 mm or 105
mm) and have consistent subject-to-camera
Ideally, the camera should be mounted on a tripod
and the same distance used each time the patient is
Ideal camera position is one in which a line from the
middle of the lens to the eye is parallel to the
If the camera is too high, the head will appear to
have a forward tilt
If the camera is too low, the head will appear to
have a backward tilt
Centering the lens between both eyes will
result in equal space visible between hairline and
outer canthus of the eye on both sides.
Viewpoint distortion caused by a 35 mm wide-angle lens.
The camera-to-subject distance was diminished, causing
barrel distortion. B, Viewpoint distortion caused by 300
mm telephoto lens. The camera-to-subject distance was
increased, causing compression distortion.
Distorted view caused by incorrect camera
position. A, Camera too high; B, camera too
CHANGES IN MANDIBULAR POSITION
To illustrate the importance of standardizing
photographs and to simulate changes in jaw
position, vinyl polysiloxane occlusal records
were made and used to record jaw positions.
Five different occlusal positions from centric
relation to past end-to-end (extreme
protrusive position) were recorded and
photographed in frontal and lateral views.
These positions encompassed a range of 7.5
The photographs show that, in terms of recording
differences, the lateral view is far more sensitive
than the frontal view. It is possible to observe
differences of as little as 1.8 mm in the lateral
view , while differences of as much as 7.5 mm
were difficult to observe in the frontal view
An extreme protrusive position with a forward
head tilt, is somewhat difficult to distinguish from
a retruded jaw position with a backward head tilt
Actual changes in jaw position can be
accentuated through nonstandardized
An extreme protrusive jaw position with a
backward head tilt emphasizes a
prognathic appearance, whereas a
retruded jaw position with a forward head
tilt accentuates a retrognathic
Three mandibular positions shown in lateral views.
Differences between each of the positions are easily
discerned. A, Centric relation; B, centric occlusion; C,
extreme protrusive position.
Two mandibular positions shown in frontal view.
Differences between the two extremes are difficult to
discern. A, Centric relation; B, extreme protrusive
Variations in head position mask true changes in jaw
position. A. Extreme protrusive position with a forward
head tilt. B, cantric relation position with backward head
Variations in head position accentuate true changes in
mandibular position. A, Extreme protrusive position with
backward head tilt; B, centric relation position with
forward head tilt.
Other faulty techniques :
Positioning the patient too close to the background.
Background of wrong color.
No left and right flood/flash umbrella used for soft
Single frontal flash producing harsh facial wash and
Use of the wrong camera. The Olympus, Minolta,
Canon, or Nikon 35 mm, single lens reflex cameras
(SLR) are really logical choices today
Wrong lens: 28 or 55 mm lenses are totally inadequate when
compared with the 105 mm (facial portrait) macrolens
Use of the wrong film. The best choice is 35 mm color print film
Poor patient head positioning.
Diparity between the level of the camera lens and the patient's
face. Subject or photographer can stand on a stool (8 inch lift) to
compensate for any photographer-subject height disparity.
Use of battery-powered flash heads.
The cycle time in battery-powered flash units is too long.
Conversely, use of a 110V AC flash unit such as the Norman or
the Multiblitz Minilight, allows the flash to recycle to full charge
in 1 second.
Lack of symmetry
The occlusal plane should be horizontal and
bisecting the frame, and the clinically correct
midline should be right in the center of the slide.
---The viewfinder should be filled with teeth, with
first molars at the outer edges of the viewfinder.
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
Backdrop of oral mucosa not provided .
If the correct retractors are selected and the
lips are pulled not only laterally, but forward,
the oral mucosa, rather than skin, will form
the background for the teeth in all views.
Pulling the retractors backward will compress
the lips against the alveolus, producing a
When patient retracts tongue, background
has better contrast.
Marked tilting of occlusal plane and inadequate
retraction produce poor photograph.
Photograph with inadequate forward retraction and
incorrect magnification (teeth not filling frame).
If the patient does not open wide enough for the
mirror shots, foreshortening and arch distortion will
The occlusal mirror should be rested against the
most distal tooth in the arch being photographed,
then placed on the opposing incisor tips.
Always photograph the larger of the two arches first,
filling the frame with teeth, and keep the same
magnification for the smaller arch
Misrepresentation of the sagittal discrepancy
Proper selection of retractors and asking the patient
to turn as far as possible to the left or right against
the pressure of the retractor is helpful.
It is essential to include the distal surface of the first
molar, with the shot taken perpendicular to the
posterior segments if possible.
The photographer must hold the retractor on the side
being photographed, since only he or she can pull
that extra 5mm distally immediately before taking
Sagittal discrepancy misrepresented in shot with
inadequate retraction and poor camera position. B.
Shot repeated perpendicular to posterior segment
with proper retraction.
For more formal verbal presentations and for written case
reports for submissions to journals for publications or for
transferring patients to colleagues.
Images can be taken from Showcase directly into Powerpoint.
Both programmes are opened simultaneously on the screen
and the images are selected in Showcase, copied and the
cursor is moved to a Powerpoint slide into which the image is
The image will be resized within Powerpoint
The relative size and position of the individual images is
infinitely variable and maximum space can be occupied by
material of interest.
Five views can be incorporated into
one slide to give the ‘full picture’ of the
The size of each image within the slide
is controllable therefore areas of
particular interest can be enlarged to
allow detail to be seen
F / 30 yrs
Before the initial examination, the patient's facial and intraoral
photographs can be taken by an assistant with a digital camera.
These images can be displayed during the examination to help
review findings and recommendations with the patient or parent.
During the examination, appropriate images can be merged into
a Filemaker Pro document and sent to the printer.
An examination report is then brought for discussion.
This is a powerful communication and marketing tool
The same information is useful for the referring dentist or the
Quick Ceph Image is the cornerstone of our
diagnosis and treatment planning.
The cephalometric radiograph, after being
captured by a video camera, is traced on the
computer screen and then analyzed.
The analysis is incorporated into a diagnostic
report that is composed in FileMaker Pro.
A series of fields with predefined choices is
organized into a statement of existing
conditions, with the option of adding unique
text if the choices are inadequate. The same
process is followed for listing treatment goals.
A VTO is then performed and, when helpful, a
treatment simulation is carried out on the
These images are imported into FileMaker
Pro for the production of letters and reports to
referring dentists and other interested parties
Customized initial examination report created with Quick Ceph Image and FileMaker
Diagnostic report for referring dentist.
Any of the information stored in the computer system
can be formatted and printed on cardstock to produce
customized treatment cards
Clinical management is greatly improved by having
the patient's problems, treatment goals, treatment
plan, tracings, and photographs available on one
page, along with the ongoing treatment history.
At the conclusion of treatment, we can record our
results and send them to the patient and referring
Customized treatment card printed on
Treatment outcome report for referring dentist.
• Superior image quality
• Relatively inexpensive hardware
(camera, optics, lighting)
• Mature, stable hardware
• Availability of technical assistance
• Long processing time
• Delay in viewing
• Frequent need for retakes
• Ongoing film and processing expenses
• Physical storage requirements
• Possibility of lost or misplaced photographs
• Expense, time, and degradation of quality involved in
• Difficulty of remote transmission
Compared to traditional photography,
digital photography -advantages:
Immediacy of viewing
Infrequent need for retakes ("what you see is
what you get")
No film and processing expenses
Efficient retrieval by computer
Inexpensive and immediate duplication, with
no degradation of quality
Ability to transmit by modem
checkable exposure accuracy;
no ageing of photos;
dust and scratches are irrelevant;
built in white balance;
no film or processing costs;
transmission around the world in seconds is entirely feasible.
Disadvantages of digital photography
• Diminished image quality (this will
• Expensive hardware (camera, optics,
• Constantly improving hardware
• Difficulty of finding technical assistance
Facial photography for the orthodontic office George
Meredith, MD AJO-DO Volume 1997 May (463 - 470)
Stutts W. Clinical photography in orthodontic practice.
AM J ORTHOD 1978;74:1-31.
Standardized portrait photography for dental patients
- Claman, Patton, and Rashid.AJO Volume 1990 Sep
(197 - 205):
Ideal digital imaging system: A preliminary report
AJO-DO Volume 1997 Jul (111 - 112):
AJO-DO Volume 1984 Jan (89 - 93): Reliability of an
intraoral camera – Gholston
AJO-DO Volume 1997 Jun (657 - 658): Judging a
digital imaging system
JCO Volume 1967 Sep(34 - 36): Photography - PHILIP
JCO Volume 1969 May(239 - 246): Standardized Intraoral
Photography - HIELKE BROUWER, DDS, A. JAN VAN
HILLEGONDS-BERG, MD, D
JCO Volume 1972 Oct(570 - 573): Dental Photography: Some
JCO Volume 1996 Nov(639 - 639): Lip Retractor for Occlusal
Photography JOHN E. PAPPEL
JCO Volume 1997 Nov(729 - 739): Clinical Photography in
Orthodontics JONATHAN SANDLER, BDS(Hons), MSC, FDS
RCPS, MOrth R
JCO on Volume 1969 Apr(196 - 199): Orthodontic Photography
Procedure and Equipment - METROPOLITAN DISTRICT OF
COLUMBIA ORTHODONTIC STUDY GRO
JCO 1995 Aug 509 - 515
Management & Marketing
Computerized Photography: Practice Enhancement Strategies
MELVIN MAYERSON, DDS, MSD; MICHAEL ...
JCO 1992 Sep
539 - 550
JCO Roundtable: Computers
in Orthodontics - Robert G. Keim, DDS, Moderator; James K.
Economides, DDS, MSD; Paul Hoffman Jr., DD
JCO 97,98 NOV. digital photography in orthodontics
Journal of Orthodontics/Vol. 28/2001/197–201 Digital
Photography in Orthodontics JONATHAN SANDLER
Recent developments in clinical photography,British Journal of
Orthodontics, 26, 269–274. Sandler P. J. and Murray A. M.
Manipulation of digital photographs J. Sandler
A. Murray Journal of Orthodontics, Vol. 29, 2002, 189–194
HOW STUFF WORKS.COM
Leader in continuing dental education