Timothy Zoltie discusses equipment used in one of the busiest dental photography departments in the UK
It’s easy to become overwhelmed when it comes to photography, when there are so many products to choose from. A clean and clear photo is important, so I’m going to share my own hints and tips to help you get to grips with dental photography.
I am often asked whether Nikon or Canon produce the superior camera systems, but to be honest, the differences are negligible. This is because 90% of the features aren’t utilised in dental photography.
You will require three main components of your camera: camera body, macro lens and a flash, with availability and user preferences varying with each. But what would I recommend?
When choosing a camera, a digital SLR is a solid choice, although mirrorless cameras now offer similar specifications while being smaller and lighter. Remember that the camera body you purchase has to be compatible with a suitable lens.
A 100mm/105mm macro lens is a must and offers a magnification ratio of 1:1. This keeps the user at a safe working distance from the subject while avoiding perspective distortion.
The third, but equally essential, tool is a ring flash, which will help to eliminate shadow and is ideal for intraoral photography. Alternatively, if you are conducting extraoral photography, I would then recommend an external Speedlight, with a flash off-camera cable. This enables a more powerful flash to be placed alongside the lens barrel to achieve adequate exposure and avoids background shadow.
There is no shortage of choice when picking a mirror for intraoral photography. You can choose from coatings such as chromium or titanium, different shapes, sizes and whether it has a handle.
We use two mirrors – a child palatal and a large palatal mirror from DB Orthodontics. We do not use a handle, as can be tempting to use it to lever the mouth open! Needless to say, this is uncomfortable for the patient, and can often result in the mirror resting on the distal surface of the molars.
Having a custom long-length large palatal mirror from DB Orthodontics enables the user to avoid unintentional fingers in the shot (Figure 1) and avoids resting the mirror on the area of interest.
It also offers the ability to switch mirror ends, allowing two options for varied mouth widths.
Ultimately, the choice of retraction equipment depends on the subject you are photographing. When undertaking anterior and oblique buccal views, we use the 3.5cm side of a large retractor. However, when undertaking upper and lower occlusal views, we switch to a small retractor.
This is due to horizontal versus vertical retraction. During anterior views, we require retraction all the way back to the molars, and a more horizontal lip retraction is preferable (unless focusing on the gingiva).
It is uncommon to achieve both vertical and horizontal retraction of the lips and so one must be prioritised over the other.
When undertaking mirror views, two small retractors allow for adequate retraction of the upper lip. Moving the retractors from a horizontal placement to a 45°angle helps to avoid the front lip covering the occlusal surface of the incisors.
Contrastors are a simple tool for eliminating unwanted detail and backgrounds, enabling direct focus on the subject.
Besides creating a more aesthetically pleasing image when using a plain black background, contrastors also help in portraying contour and shape by providing background separation. This can be useful in displaying the anatomy of the incisal edge, translucency, and extent of diastema.