All you need to know about digital photography

May 1, 2002
A candid pose and conversation with one of the profession's leading experts on digital imaging, Dr. Tom Hedge.

A candid pose and conversation with one of the profession's leading experts on digital imaging, Dr. Tom Hedge.

by Ekram Khan and Farah Malik-Kahn

Most of the articles written about digital dentistry are usually laden with techno jargon that has no relevance to dentists. I, too, am guilty of writing several of these technology articles. This time, I took a different perspective. Although a question-and-answer interview is not a novel concept, we decided to pick the brain of a leading expert and share his thoughts about how digital imaging and photography has impacted his dental practice. Dr. Tom Hedge teaches the digital photography program at the Las Vegas Institute (LVI) and has recently published a book on the subject.

The Kahns: What are the top digital cameras on the market, and why do you like them?

Dr. Hedge: The workhorse of digital cameras in dentistry since October 1999 has been the Olympus 2500. The key features of the camera at that time were the price and its ability to use TTL (through the lens) viewing. It was less than $2,400, and it allowed the operator to look TTL. There are three price ranges: high-end, mid-range, and entry level.

In regard to other options, the Canon D30 ($4,000) is a great high-end camera. Although it is a true digital SLR, it is very simple to use - almost like a point-and-shoot - has a broad depth of field, and can get a very tight shot. It really is the best camera I have worked with. The Canon D30 will be discontinued and replaced with the Canon D60 ($4,000). The only difference between the two Canon models is that it is going from a 3.11 to a 6.48 megapixel resolution.

The Canon G2 package is a point-and-shoot with 4 megapixel resolution that costs about $1,500. The good thing about this camera is that it has a hot shoe on it. So you can attach the Canon D30 flash, which is then TTL metered. This means the camera looks through the lens and adjusts the flash output based on what it sees through the lens, so you get perfect exposure. It is a great camera for staff members, because they tend to do better by using the LCD monitor to frame the picture. It's a nice rugged camera, takes excellent pictures, and can focus very tight on subjects.

The Olympus 4040 is a camera chosen by a number of after-market people such as PhotoMed and Lester Dyne. They are changing the flash or putting the diffusers on, and improving upon the quality of the camera to illuminate the mouth with the flash. The 4040 as a consumer version is a $700 camera, has 4 megapixels, and is a great little camera.

The Olympus D40 pocket-type camera has full manual controls for adjusting many settings. With it, I can get every shot in dentistry, including a quadrant. A quadrant shot is sort of what separates a very capable camera from one that is not.

The Kahns: Why is a quadrant shot so important?

Dr. Hedge: If you can get a full-screen quadrant shot that is well-lit and in focus, it is a great view to show to a patient. For years, we have been showing the patient a picture of one or two teeth at a time with an intraoral camera. We try to be comprehensive full-mouth dentists, but we show them single-tooth views. The quadrant view is so powerful because they get the whole picture. When you show one tooth at a time, the patients always ask, "What tooth is this, doc?" Whereas with a quadrant, they see the whole picture and understand the impact.

The Kahns: What is the ideal pixel resolution? There is an ongoing argument about that. What is your opinion?

Dr. Hedge: It really depends on whether you capture the shot the first time, just the way you want it. The Olympus 2500, a 2.5 megapixel camera, does not capture a quadrant shot; it captures further back and you can crop into a quadrant shot. The more you crop, the more pixels you need. Cameras such as the D40, C4040, G2, or D30 take the quadrant shot totally uncropped. So a 2.5 megapixel image or 2 megapixel image is enough.

What are you going to use it for? If you are going to email it to your lab using a 56k modem, then a 100 to 200 megabyte file is big enough, because it will tie up your lines. If your recipient is going to look at his monitor - which usually displays at 72 DPI on a 15-inch monitor set to 800 by 600 pixels of resolution - you only need half a megapixel to efficiently use the screen area. If you intend to print images at 8.5 by 11-inch size, then you need between 2.5 to 3 megapixels. More important than pixel resolution in a camera is ergonomics, ease of use, flash quality, quality of the optics, and quality of the illumination of the image.

The Kahns: What should be the standard lighting setup for taking images in the operatory?

Dr. Hedge: I shoot my series up to 20 images, and I start off with portraits in our portrait studio. I have a main, fill, and hair light with a nice backdrop, and I shoot my first portrait there. In the op, all of the shots are tight - extraoral or intraoral, with a smile or intro shot into the mouth. If you are using a ring flash with TTL metering, the ambient lighting in the op does not matter because the light from the ring flash overwhelms everything else.

The Kahns: Is the ideal location for these shots in the operatory?

Dr. Hedge: Yes, because you need the patient to lean back 45 degrees, and you want to be comfortable and not hunched over. You need air flow across the mirror to prevent fogging, and you need an assistant. The ergonomics in the op are very nice for shooting these shots. The most powerful shots I take are shot in a mirror. If you don't have air blowing across it, or if you don't warm the mirror in hot water first, you will get fogging.

The Kahns: Is there a standard set of images that should be taken for cosmetic imaging and clinical documentation purposes?

Dr. Hedge: There is no set standard such as an "AACD" series for digital photography. Olympus, Michael Maroon, and David Gane worked on one series, and I developed one for LVI. You should take the shots that are appropriate for the patient. For example, if I have a patient who is concerned about anterior aesthetics, he might present with neuromuscular problems, some bite and wear problems, but have virgin back teeth. I won't take the four quadrants because there is really nothing to show. What I start with on every patient is the portrait shot and a straight-on smile shot showing the teeth. Then, in the operatories, the first four shots I take are the nonretractive shots: lips at rest with the teeth showing; big smile shot; right and left smile shot.

I take the right and left smile shot because that is the view others see when looking at you. This is important for veneer or cosmetic cases, because it helps them decide whether they want to do veneers around to the first bicuspids or the second bicuspids.

After this, we put in the retractors and have the assistant hold them. I then take frontal shots, in occlusion and slightly open. The reason we do the in occlusion shot is that I want to see what the bite looks like and the slightly open shot shows the bottom teeth nicely.

Now that the patient understands how the retractor works, we have the patient hold the retractors while the assistant slides in a buccal mirror; then we take the four quadrants and the upper and lower occlusals.

Next I move to buccal views that are shot in the mirror where the patient holds the retractor on one side and the assistant holds the mirror on the other side. I shoot into the mirror taking left and right buccals in occlusion. That can be augmented with the tongue depressed with a mirror, shooting the oropharynx to evaluate the tonsils and airways. I sometimes shoot a submental view and several other shots on an individual-needs basis, including a shade shot and a shot of the Shimbashi measurement. I encourage everyone to take as many shots as they want because digital film is free.

The Kahns: Can you describe the techniques taught in your digital photography course at LVI and in your book on digital photography in dentistry?

Dr. Hedge: It's a two-day course, and it is basically everything digital - anything you can imagine. I go into every relevant aspect of digital dentistry during the two days. It is a comprehensive course that is well suited for beginners, but it also has plenty of content for advanced photographers. I cover all of the same topics in the book, which is titled Digital Dentistry, except that I go into more detail in the course at LVI. The book comes with a CD with 10 PowerPoint presentations on it. The book is for everybody - novice, intermediate, and advanced photographers.

The Kahns: Are these presentations templates?

Dr. Hedge: One is a template so that, when you build your own patient presentation, you can insert slides from files. In PowerPoint, you can insert all of these files with before-and-after procedures to show patients. I have sample patient presentations, and I also have health history and patient registration forms in PowerPoint. You can customize them by adding your own contact information and changing the questions. One of the problems of the paper forms we have in dentistry is that no one form has an exact fit for every practice. Every dentist has different needs than what's out there in preprinted forms. I have taken the time to do the layout for these forms. You can customize them to your needs and then you've got perfect health history forms for your practice.

The Kahns: Which imaging software applications have you tried, and which one do you use in your practice?

Dr. Hedge: It is interesting that a program like Photoshop Elements is only $99 and will do just about everything that the more expensive programs like ImageFX and DICOM will. But time is money. Frankly, most dentists wouldn't be able to master the features in the consumer-level photo-editing programs. There are some things that I can't even remember about how I did previously. The reason why ImageFX and DICOM are popular products is that they put image editing functions that are relevant to dentistry into easy-to-use macros that are simple to learn and reproduce consistent results. These companies figured out what dentists need to do on a daily basis and organized these functions into a simple user interface. I work with DICOM and ImageFX on a daily basis and get consistently excellent results from both. I use both programs because each program has specific features that I like.

The Kahns: In what ways has digital imaging affected or enhanced your practice?

Dr. Hedge: As I have learned and implemented new techniques into my practice, I have seen improvements in case presentation and communication with patients. I take a set of 10 to 20 digital images. As we sit in the consult room to review these images, the patients ask me questions. "What's that black mark over there?" "Why are my gums so receded?" "Oh gee, there's that crown that was done 30 years ago. It looks horrible. We need to redo that."

So instead of me telling them that they need 10 new crowns and having them look at me as if I just want to buy a new car, my patients are asking me the questions and saying that they want to deal with all of their dental issues. In my practice, digital imaging has brought in want-based dentistry rather than need-based dentistry.

The Kahns: Imaging software companies often make the claim that using their software will result in higher levels of case acceptance and increase your revenue from cosmetic procedures. Is this claim just marketing hype on their part, or have you realized a tangible increase in revenue?

Dr. Hedge: Using digital imaging to involve the patient in case planning has yielded better rates of case acceptance. Unquestionably, average rates of case acceptance have increased, because communicating the benefits and potential results of planned treatment is much easier.

The Kahns: What has been your experience with digital imaging's learning curve?

Dr. Hedge: One of the reasons I love teaching my course on digital imaging at LVI is the reaction I get from the doctors taking the course. I hand them a big, black, intimidating digital camera with lots of buttons and switches, tell them to frame the subject on the LCD screen or in the viewfinder, and push the shutter release button. When they see the image instantly appear on the screen, a contented smile of achievement appears across their faces. It truly isn't difficult at all. Most dentists are accustomed to taking pictures with SLR cameras like the Yashica Dental Eye with a through-the-lens viewfinder. But I think staff will find it easier to use the LCD to frame the shot.

As you can see, successful implementation of digital imaging and photography into the typical dental practice involves a keen selection of the appropriate tools, carefully establishing standard procedures for digital imaging with every patient, and consistent use of these procedures for enhancing patient communication and treatment planning. Digital imaging and photography isn't just for the enthusiasts anymore. During the past few years, the popularity of these technologies has increased as the price of entry has decreased. So get your cameras and software and jump into the era of digital dentistry!

Dr. Tom Hedge can be contacted via email at tomhedge@msn. com. His book is available at www.normancamera.com.

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