Thursday, 14 July 2016

Think before your clicks part 2

This article has been co - authored by Dr. Bernie Villadieg0
Dr. Bernie B. Villadiego- DDS, graduated from Creighton University School of Dentistry in 1989 and went on to complete a general practice residency program at Los Angeles County/USC Medical Center. He established a private practice with an emphasis in esthetic and reconstructive dentistry in Chatsworth, California in 1993. An Accredited member of the American Academy of Cosmetic Dentistry, Dr.Villadiego is a graduate of several cosmetic residency dental programs at the Esthetic Professionals Dental Education Center in California. He is also a visiting faculty/clinical instructor with the Spear Education at Scottsdale Center for Dentistry in Arizona. He has also completed a functional/occlusal residency program at Texas Center for Occlusal Studies in Texas. An avid photographer, Dr. Villadiego has lectured on the use clinical photography for diagnosing and record keeping as well as the use of glamour photography in dental marketing

In part 1 of “THINK BEFORE YOUR CLICKS” we addressed a few reasons like DISTORTION, NOISE, LACK OF RECORDING ACCURATE COLORS/SHADE, LACK OF RECORDING IN RAW FORMAT etc. as to  why mobile phone photography is considered as substandard for dental documentation.This article in association with Dr. Bernie shall put light on other problems related to mobile dental photography. 

Apart from high quality images a DSLR gives us a huge flexibility when it comes to attaching a wide range of lenses and accessories like high end flash systems and diffusers which have become an integral protocol to record high quality dental images.
Many clinics are now equipped with STUDIO LIGHTS (STROBES) which you might have seen in a professional photo studio while making family portraits. Yes the ones with a big black and white softbox attached to it. (Yes they are now being highly recommended for dental photography!!) Every wondered why they keep 2 Studio lights 1 on either side at 45 degree? It is because this gives the best possible natural effect to your skin tones and the light looks much more natural.
It is a good idea to remember one golden rule:
When the light source is upfront the images are always FLAT and loose dimension as well as a 3 D effect.
Examples of such light sources are: In built flash of a DSLR, RING FLASH etc.
A good image is not just a play of Light, but light and SHADOWS play a vital role in giving the subject a third dimension. Without shadows the image is too flat to appreciate depth.
Why this is important in dentistry?
Well, even in dentistry we want light and shadows and NOT LIGHT ALONE.
Line angles, point angles and buccal convexities are supposed to have a good light reflection whereas embrasures (especially gingival embrasures) are supposed to have shadows in them so as to give a good 3 D effect to our images. 

This is where a TWIN LIGHT system comes into picture for dental professionals.
Be it Canon (MT24EX) or Nikon (R1C1) Twin light is the IDEAL light source for dental documentation because they are positioned laterally which give a more natural and pleasant effect to our images. They illuminate the line angles sharply and give subtle shadows in embrasures. Moreover they can be twisted and turned in 3 axes so that the light source can illuminate the area of concern accurately.

We can also add diffusers/ soft boxes/ reflectors/ bouncers onto the flash to make the light more soft so that we can even appreciate the surface textures and shades better.
It is time to ask can we do this in MOBILE PHONE PHOTOGRAPHY. Certainly not!
Mobile phones give you NO SPACE to add accessories. Now a days we have seen macro lens attachments for mobile phones which are nothing but a piece of poorly designed glass and it just deteriorates the image quality even further. 


It is practically impossible to record the colors/ shades accurately if you do not have custom white balance settings in your camera. Together with the help of a NEUTRAL GREY CARD and custom white balance settings in a DSLR we can come extremely close to the actual Hue, Value & Chroma of a tooth which is impossible in a mobile phone.

Besides like already discussed in PART 1 LED lights in a mobile phone aren’t color corrected and hence they make the worst light to use for dental documentation.
They are too feeble and hence ambient (available) light effects are easily recorded. Available light like the chair light of your set up can badly affect your images in mobile dental photography.
One may buy extra LED panels but even they can be mounted and is to be hand heled or mounted on light stands making the use very cumbersome.


Almost all international journals and associations/ institutes are extremely careful about privacy. They not only want to confirm that the documentation is your own but they need all the METADATA (EXIF) data which now a days also has your GPS coordinates that confirm the case / documentation has been done by yourself.
AACD uses raw images to prevent fraud in documentation protocols and examination.

There is NO provision for recording a RAW file in mobile phones.
RAW files are digital negatives and can be opened by specific software’s only hence much more protected.
RAW files are lossless compressions of the original image captured by the sensor. JPEG files on the other hand are compressed to more than 5 times and hence do not have adequate details.

A DSLR when used can shoot both RAW+JPEG files at one go. This is in fact the recommended setting for documenting our dental cases. 


The BIGGEST drawback of using a mobile phone for dental documentation is the lack of a STANDARD called magnification ratio.
This function is ONLY available with MACRO lenses where in you set the magnification first ( e.g. in anterior aesthetic cases as per AACD guidelines we have to set a magnification of 1:1 or 1:2 first and then record our pre and post-operative shots)

In the above image of a 100 mm macro lens MAGNIFICATION ratio is seen in YELLOW font and when the focusing ring is rotated the magnification ratio changes. One can set the desired magnification first and then shoot. This gives greater standardization with respect to image composition which is impossible using a mobile phone. When one standardizes the magnification ratio he also standardizes the distance from which the image has to be taken.
This increases the chances of pre and post-operative images looking same. 
An example of standardization of composition using a single magnification ration of 1:1A picture collage makes it easier for the viewer to relate to the case and summarize the entire protocol. Watermarking with your name is a must to prevent theft of images and prevent copyright issues. 


It is not a good choice to use mobile phone documentation in dentistry for all the reasons discussed in the article THINK BEFORE YOUR CLICKS.
It might have limited use to communicate a surgical procedure to your patients/ colleagues, short margin of crown to your lab etc. but it is to be kept at an informal level among peers only.
There is NO COMPARISON of a DSLR and a mobile phone for documentation.
Aesthetic dentistry has NO ROLE of mobile phones in documentation.
A valid advice would be “Use your phones for communication not documentation.”