photography

PHOTOGRAPHY IN

ORTHODONTICS

CONTENTS• INTRODUCTION• EVOLUTION OF PHOTOGRAPHY• HISTORY OF PHOTOGRAPHY IN ORTHODONTICS• IMPORTANCE OF PHOTOGRAPHY IN ORTHODONTICS• ALL ABOUT DIGITAL PHOTOGRAPHY• CAMERA EXPOSURE• DIGITAL PHOTOGRAPHY (CLINICAL SCENARIO)• PHOTOGRAPHY LIGHTINGS• PHOTOGRAPHY AREA/SETUP• SOFTWARES USED IN CLINICAL PHOTGRAPHY• CONCLUSION

• It is often stated that Photography is the magic by which light is transformed in colour, space and time

• The three facets of the visual experience:

colour : a three dimensional entity consisting of hue, value,chroma

space : defines the depth, transparency, size, shape/form and texture

time : indicates movement, flicker, sparkle (vitality), fluctuation and glitter

Photographs are an essential part of clinical documentation. Current ‘the best practice’ is a full set of extra and intra-oral photographs, both at the start and completion of orthodontic treatment and ideally, some mid-treatment photographs showing key-stages in treatment.

Jonathan Sandler and Alison MurrayJournal of Orthodontics, Vol. 28, No. 3, 197-202, September 2001

EVOLUTION OF PHOTOGRAPHY

Camera obscura

 an image of a scene at the other side of a screen is projected through a small hole in that screen as a reversed and inverted image on a surface opposite to the opening. 

Joseph Niépce (1822)• the inventor of photography and a pioneer

in that field.• developed heliography, a technique he

used to create the world's oldest surviving product of a photographic process.

 Louis-Jaques-Mandé Daguerre (1837)• daguerreotypy

Title pages of Daguerre's 1839 manual, published soon after Arago's lecture to meet the intense public demand for more information about the photography.

Hercules Florence silver-salt-based paper process(1832)

Photographie

William Henry Fox Talbot 

salted paper and calotype processes

photography pioneer

The Pencil of Nature

George Eastman(1885)

Marketed the first flexible roll film.

Color Photography

Autochrome, the first commercially successful color process, was introduced by the Lumière brothers in 1907. 

Digital Photography

the first consumer camera (1981)

digital single lens reflex camera (1991)

 Digital imaging is a highly manipulative medium. It permits different communicative potentials and applications.

HISTORY OF PHOTOGRAPHY IN ORTHODONTICS

The history of dentistry and photography began in 1840

First dental school was opened

world's first photographic gallery was opened 

Dr. Edward Angle (Father of Orthodontics) was first known orthodontist to photograph his patients as part of his diagnostic workup

1960’s to 1970’s

 A limitation of 35mm film based photography became clear.

Invention of INSTANT film cameras.• while not the quality of 35mm film, offered the ability to take a photograph and see results within a couple of minutes. Film was processed inside the camera.

Lester Dine modified and affixed lenses and a flash creating the dental world’s first instant photographic system

1980’s

the most important invention in dentistry - DIGITAL PHOTOGRAPHY

Digital photography combines the best of all the three of the previous photographic concepts:

the quality of 35mm filmthe speed of instant photographythe computerized integration of video

Why go digital in orthodontics?

• No waiting time• Ability to enhance images• Can see images immediately• Allows immediate retakes• Can make exact duplicates• Images can be easily stored• Can be instantly forwarded or transmitted to patients, labs,

colleagues etc• Cost effective

How does digital camera work?

Why take orthodontic photographic records?

Case records (photo documentation)

Complement other orthodontic records

Important clinical and legal role

From a diagnostic point of view

Case presentations to study clubs and other groups

Academic research

Training of staff and students

Publications

Patient education

Presurical planning, and post operative analysis

All about digital photography

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CCD allows to view photographs on the spot, eliminating film and development costs, image manipulation and editing capabilites.

Digital Photography in Orthodontics; Journal of Orthodontics/Vol. 28/2001/197–201

1990s – typical CCD would comprise 640x480 pixels

1999 – first ‘Mega-pixel’ cameras ( over 1,000,000 pixels per image)

       The conventional 35mm slide is

thought to contain the equivalent

of 20-30 million pixels of

information.

Prosumer cameras• Image preview facility • Problems – – point flash(built-in) : shadows on most images– Not powerful enough to allow the photos to be taken on

very small aperture (f32)– Live display on LCD is inaccurate and are very power

hungry– Focusing system is problematic– Macro settings also sometimes gives disappointing results

Digital Photography in Orthodontics; Journal of Orthodontics/Vol. 28/2001/197–201

Professional camera

Parts of a typical digital camera

• Standard lensa camera lens giving a field of view similar to that of the naked eye.

• Wide angle lenswide-angle lens refers to a lens whose focal length  is substantially smaller than the focal length of a normal lens.

• Telephoto lensTelephoto lenses are especially handy when you can’t get physically close to your subject

• Macro lensA macro lens is one which allows you to take sharp, detailed, close-up photos of small subject

• Fisheye lensA fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic image

APS-C sensor

• Advanced Photo System type-C (APS-C) is an image sensor format

• APS-C variants are considerably smaller than 35 mm standard film.

• Because of this, devices with APS-C sensors are known as "cropped frame"

CCD• CCD image sensor is an analog

device ( passive-pixel sensor)

• CCDs is a more mature technology

• Prone to Blooming effect

CMOS• CMOS imaging chip is a type of Active

pixel sensor made using CMOS semiconductor process

• CMOS has fever components, use less power, provide faster readouts

• CMOS sensors are less expensive to manufacture

• Can combine the image sensor function and image processing functions within the same

integrated circuit

CROP FACTOR

• Most digital camera sensors are smaller than film, so any image you see from those cameras is created from a smaller area than film

• If a photo is made with the same lens, but a smaller sensor, it shows a smaller area.

• The smaller sensor is cropping the len’s image compared to a 35mm film frame

• JPG/JPEG (joint photographic experts group)most common file format used in digital photographyless compression=less data thrown away=larger file size

• RAW actual data taken directly from a digital camera’s image

sensorunprocessed image, purest image file possibleneed specific software

• TIFF (tagged image file format)larger size, good quality photographscan be compressed and uncompressed

IMAGE FORMATS

Camera Exposure

• Determines how light or dark an image will appear when it's been captured by your camera

• Determined by just three camera settings:apertureISO                         Exposure triangleshutter speed

Shutter speed

• Length of time during which the shutter is open

• Expressed as a fraction of a second (.. 1/60 , 1/125 , 1/200, .. , 1/500..)

• 1/4000 is a faster shutter speed

• Faster shutter speed freeze the action

• Good photography requires a balance between shutter speed and aperture

Shutter Speed Typical Examples

1 - 30+ seconds Specialty night and low-light photos on a tripod

2 - 1/2 secondTo add a silky look to flowing water

Landscape photos on a tripod for enhanced depth of field

1/2 to 1/30 second

To add motion blur to the background of a moving subject

Carefully taken hand-held photos with stabilization

1/50 - 1/100 second Typical hand-held photos without substantial zoom

1/250 - 1/500 second

To freeze everyday sports/action subject movement

Hand-held photos with substantial zoom (telephoto lens)

1/1000 - 1/4000 second To freeze extremely fast, up-close subject motion

Aperture setting

• The opening that controls the amount of light entering the lens.

• Aperture size is measured in “f-numbers”.• Every time the f-stop value halves, the

light-collecting area quadruples.

Depth of field• A camera's aperture setting is what determines a photo's depth of field

•  the range of distance over which objects appear in sharp focus.

Wide Aperturef/2.0 - low f-stop number shallow depth of field

Narrow Aperturef/16 - high f-stop number large depth of field

ISO SPEED• The ISO speed determines how sensitive the camera is to incoming light.• A lower ISO speed is almost always desirable, since higher ISO speeds

dramatically increase image noise.

Clinical scenario

Two main types of digital cameras

• Point & ShootAdvantages:- small and lightweight- lower cost

Disadvantages:- not upgradeable - inconsistent magnification

Recent Photography Trends in Orthodontics, TurkJOrthod.2016

Advantages:- highest image quality- upgradeable- various lighting options

Disadvantages:- heavy- expensive

• DSLR CAMERA

• An DSLR allows manual focus and can accommodate a variety of lenses• Virtually any digital SLR can produce excellent photographs.• Satisfactory depth of field + good illumination = high quality intra-oral

photos

The lens needed for dental photography is a Macro lens with a focal length of 85-105mm

Recommended camera settings

• Digital cameras automatically calculate exposures• To take the best possible shot, however, you may need to control the

settings manually

• Shutter speed – 1/125• ISO – 100• Mode – M• Aperture for Extra-oral – f-8 to f-11• Aperture for intra oral – f-32• Aperture for mirror view – f-19 to f-16

Digital dental photograph;British Dental Journal 207, 63 - 69 (2009) 

Exposure Mode: “M” Manual or “Av” Aperture Priority (Usually set on the dial on top of the camera)

Flash Mode: ETTL This is an automatic mode that works well for beginners. Advanced users may choose to experiment with manual flash exposure settings.

Focus Mode: “MF” Manual Focus Not to be confused with the exposure mode set above. This prevents the autofocus from changing the magnification setting. Focus will be achieved by moving the camera. This may initially seem more complex, but the mouth is generally too dark for autofocus to work properly.

Bister et al,

Ten current digital single lens reflex (SLR) cameras were tested for use in intra- and extra-oral photography as used in orthodontics.• Canon350D        Canon20D     Fujifilm S3Pro      Konica -Minolta7D• Nikon D100        Nikon D70     NikonD50             Olympus E1• Olympus E300   Pentax DS

No camera took acceptable images in factory default settings

over exposure, aperture and flash adjustment needed, good color fidelity

over exposure, once adjusted, were able to take intra- and extra-oral photographs without the need to change settings

poor DOF and aperture adjustment needed .

largest and brightest viewfinders

Nikon and Fujifilm

Olympus 

Canon, Konica-Minolta and Pentax

Konica-Minolta and Pentax

Comparison of 10 digital SLR cameras for orthodontic photography; Journal of Orthodontics, Vol. 33, 2006, 223–230

Photography lighting

There was one huge road block to taking dental pictures. There was no clear way to get light from the camera’s flash inside the dark cavern that is the mouth

1952

• Universal flash system for general macro photography

• A circular flash that attached to the end of the camera’s lens

• Ability to pinpoint light directly into patient’s mouth

• Providing full illumination from external anterior to posterior intra-oral quadrant pictures

To improve portrait photography, an additional flash called a “point light” was added to the ring flash system

Two distinct flashes - Ring for intra oral- Point for facials

Point flash

• Single strobe-light source mounted on one side of the camera lens• Flash can be moved around the lens to provide directional

lighting from different angles• Placed at 12, 9 , and 3 o’clock position for frontal, right lateral

and left lateral views respectively• Requires considerable experience and additional setup time

before each exposure

Twin flash

LED flash

Armamentarium

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Cheek retractors

• Larger end of the large retractors are used• Assistant should hold both retractors

pulling them both laterally, and forward• By pulling the lips forwards, towards the

photographer it makes it easier for the patient to bite together in occlusion and pulls the soft tissue away from the teeth

For anterior intra-oral shots

• Use the smaller end of the larger retractor on the side of interest

• The photographer should hold it themselves and pull it an extra 4-5mm both distally and away from the teeth to ensure at least the distal of first molar is captured

• The assistant passively holds the large end of the larger retractor on the opposite side

For the Buccal intra-oral shots

Mirrors

• Long-handled, front-silvered, glass mirrors are ideal

• Long handles are held by the photographer to allow complete control of the picture and keep assistants fingers out of the shot.

• reflection from the glass surface occurs when the silvering is on the back surface

• Prior to taking photographs the mirror should be either be warmed to prevent misting of the mirror when it is inserted into the patient’s mouth, or the patient should be instructed to hold their breath for 10 seconds or so

• During occlusal photography light is never reflected 100% and there is a tendency to be slightly underexposed.

What images to take

Extraoral

Intraoral

Frontal viewAt rest

With the teeth in maximal intercuspation and the lips closed

Dynamic smile

Close-up image of the natural smile

OBLIQUE VIEW (THREE-FOURTH , 45º)At rest

At smile

Close-up smile

Profile view At rest

At smile

Anterior view

Buccal view

Occlusal mirror view

Positioning the camera

• The distance from the camera to subject will be determined by the focal length of the lens

• Best way to standardize facial portraits is to keep focal length of the lens same ( ideally 100mm or 105mm) and maintain consistent subject-to-camera distance

• A line from the middle of the lens to the eye is parallel to the horizontal plane. If the camera is too high, the head will appear to have a forward tilt; if the camera is too low, the head will seem to tilt backward.

• Focus on the patient’s lower eyelid

Gage et al,

To compare the facial morphometric analysis using CBCT volumetric rendering and digital photography

3-D CBCT derived images were more accurate than 2-D photometric analysis when measuring upper and lower lip lengths in frontal view. Clinicians of different training backgrounds show higher consistency and accuracy in measuring the lower facial third from the frontal aspect with 3-D CBCT derived images than with 2-Dphotographs.

Comparison of facial morphometric analysis using CBCT volumetric rendering and digital photography; JOral Maxillofac Surg Med Pathol (2015)

Photography area

• A dedicated photography room can be as small as about 13x20 ft,

with a 13ft ceiling

• Enough space between the patient and the background

• White background - painted flat wall free of distractions

- custom-sized, motorized, light blocking shade or

a white roll-up screen

• Sunlight from a window should be shaded

• light can be diffused with either a Soft box or an Umbrella light

• Key light – used to highlight the form and dimension of the subject

• Fill light – may be used to reduce the contrast of a scene and provide some illumination for the areas of the image that are in shadow

• Fill flash – a photographic technique used to brighten the deep shadow areas, particularly in backlit subjects

• Back light – the process of illuminating the subject from the back

Softwares used in Digital photography

Dolphin imaging featuring 3D• Helps visualization and analysis of craniofacial anatomy

from data produced by cone beam computed tomography(CBCT), MRI, medical CT and 3D facial camera systems

• Features tools for onscreen manipulation and analysis of volumetric datasets

• Measurements and digitization can be performed in both 3D and traditional 2D

• 3D image capturing system for facial profile • 3D system – Photomodeler

• Photomodeler system measurements can be used to assess linear distances and angles

• Adobe Photoshop CS6• Adobe Photoshop lightroom 4

-Image editing , organizing and sharing

Sandler et al,

To assess the quality of photographs taken by orthodontists to see whether those taken by orthodontic auxiliaries and clinical photographers are of comparable quality.

Extraoral photographs showed no significant differences between the 3 groups.The results for intraoral photographs showed that, orthodontists produced significantly more good-quality intraoral photographs.

Quality of clinical photographs taken by orthodontists, professional photographers, and orthodontic auxiliaries; Am J Orthod Dentofacial Orthop 2009;135:657-62

Conclusion Clinical photography has been greatly improved with the advent of digital cameras, especially digital SLRs. To obtain high-quality, consistent photographs, the orthodontist must select an SLR that meets clinical requirements.It provides a diagnostic information that is easily recognized and understood by both professionals and laypersonsIn order to get the full diagnostic value out of digital photography, a systematic method and regimentation of clinical images must be adopted

References • Eder, J.M (1945) [1932]. History of Photography, 4th. Edition• Comparison of 10 digital SLR cameras for orthodontic photography; Journal

of Orthodontics, Vol. 33, 2006, 223–230• Digital dental photograph;British Dental Journal 207, 63 - 69 (2009) • Quality of clinical photographs taken by orthodontists, professional

photographers, and orthodontic auxiliaries; Am J Orthod Dentofacial Orthop 2009;135:657-62

• Jonathan Sandler and Alison Murray Journal of Orthodontics, Vol. 28, No. 3, 197-202, September 2001

• How to avoid common errors in clinical photography; Journal of Orthodontics, Vol. 32, 2005, 43–54