Technique for Orthodontic Clinical Photographs Using a Smartphone

Smartphone cameras have advanced at a rapid rate. With this advancement, it is possible to take high quality orthodontic clinical photographs using a smartphone. The aim of this article is to describe the technique to take orthodontic clinical photographs using a smartphone.


Introduction
Within the field of orthodontics, high-quality clinical photographs are essential as a diagnostic tool, to monitor treatment progress, and for educational and medicolegal purposes. Orthodontic clinical photographs consist of extraoral and intraoral photographs [1]. Orthodontic clinical photographs may be taken by a professional medical photographer, orthodontist, or dental assistant [2].
Smartphones have become one of the most essential pieces of equipment in our daily lives. e latest smartphones are packed with features that make them much more than devices for making calls. In orthodontics, smartphones are known to be used for remote monitoring of treatment progress, cephalometric analysis, and taking orthodontic clinical photographs [3][4][5][6][7]. e current gold standard equipment for taking orthodontic clinical photographs is a DSLR (digital single-lens reflex) camera with a 100 mm macro lens and macro ring flash [8,9] (Figure 1). e high cost and large size of a DSLR camera and its lenses might deter certain dentists from using this equipment, and they might instead opt to use their smartphone camera [10]. Compared to a DSLR camera, a smartphone has the advantages of being smaller, lighter, cheaper, more user-friendly, and able to perform more tasks.
Taking personal photographs using a smartphone is relatively simple, but capturing high-quality orthodontic clinical photographs is harder. To produce acceptable orthodontic photographs that meet the standards of clinical records requires the dentist to have the proper equipment and use proper techniques. e purpose of this article is to explain and illustrate the technique of taking orthodontic clinical photographs using a smartphone.

General Settings.
In the preinstalled camera application (app), select the manual shooting mode. If the smartphone does not have a manual mode, a third-party app such as Adobe Lightroom Mobile can be installed which allows the camera to use manual mode ( Figure 2). e dentist should select the JPEG format picture quality if it is available. e larger RAW file type should only be selected if the dentist wishes to edit the photo. In the settings, the white balance setting should be set to Auto. e camera will then select the best white balance for the photo depending on the lighting conditions. e author uses autofocus to achieve focus. While the settings provide an option to use manual focus, in the author's experience, the current manual focus feature in a smartphone is not as accurate as autofocus, increasing the chances of out-offocus photographs. e focusing point for extraoral photos should be the eye, and for intraoral photos, the canine tooth. Finally, the exposure compensation should be set to zero.

Shutter Speed, Aperture, and ISO.
e author recommends a shutter speed faster than 1/100 second and suggests two methods to reduce the occurrence of camera shake, which may produce a blurred image ( Figure 3). First, hold the smartphone with both hands as close to your body as possible. Next, tuck in your arms. is will turn your body into a stable platform like a tripod. e author finds this method to be effective in reducing camera shake. Select the highest aperture value possible in the camera. A higher aperture number increases the depth of field. Most smartphones have shorter focal lengths. e shorter focal length results in the operator being closer to the patient, thereby reducing the depth of field. Hence, a higher aperture setting is required in smartphones. e ISO should be set at the lowest value available in the camera. Once all the camera settings have been made, the dentist can preview the exposure of the photograph. If the exposure is deemed too dark, the author suggests that the dentist first increase the light intensity of the continuous light. If the maximum intensity has been reached and the photograph is still underexposed, only then should the dentist increase the ISO value. Increasing the ISO is the last method to increase the exposure, because increasing its value will produce a noisier photograph.

Patient Positioning.
e extraoral view is taken either in the standing or seated position [1,11]. As a reference, the author uses the patient's interpupillary plane for the frontal view and the Frankfort plane in the profile and three-quarter view [12]. e plane should be parallel to the floor for every view. e intraoral view is taken in the dental chair. e patient is seated in a 45-degree angle for the anterior and buccal views, whereas the occlusal picture is taken in the supine position.
Modern smartphones are equipped with multiple lenses with different focal lengths. e author recommends that the dentist select the telephoto lens with the greatest focal length. Once the telephoto lens is selected, the author walks closer to the patient until the patient's image fills the frame. It is best to avoid zooming, if possible, as zooming will significantly reduce the quality of the photograph. If the camera is too close to the patient, only then will the author use the zoom feature of the camera until an acceptable distance from the patient is achieved.

Environment, Background, Lighting, and Accessory
Equipment. e environment where the photograph is taken plays a huge role in the quality of the image produced [13]. Extraoral photographs are best taken in a well-lit room with many windows and a daylight colour temperature light (5000 K-6500 K) [14]. e brighter the environment, the less additional external lighting is required.
A plain, nondistracting white or black background is typically used in orthodontic clinical photography [1]. Because of the limitations of mobile dental photography, the author does not recommend a white background due to the presence of shadows, especially in profile or three-quarter view. Instead, a darker background should be used to hide shadows.
One of the trickiest components of mobile dental photography is lighting. One method to overcome this shortcoming is to use a continuous light source [14]. e author recommends an affordable portable LED ring or box light (Figure 4). For intraoral photographs, the author uses a dedicated LED light to illuminate the teeth.   Accessory equipment such as a cheek retractor and mirror is essential for intraoral photography ( Figure 5). Various sizes of retractors and mirrors are available on the market. e size should be selected according to the patient. A transparent retractor and a mirror with a handle are recommended.

Discussion
In the hands of an experienced dentist, the picture quality of a DSLR camera system is far superior to that of a smartphone. Furthermore, there are certain technical differences between taking a picture with a smartphone and a DSLR. ese differences are summarised in Table 1. Hence, for a dentist who uses a DSLR daily, there is a need to get refamiliarized with the new settings. However, the inferior picture quality of smartphones does not mean that photographs taken with a smartphone are unacceptable for an orthodontic clinical record. Based on the author's experience, any modern-day smartphone, from the top-of-the-line to an average model, can capture quality orthodontic photos with the proper technique ( Figure 6). e author strongly believes that a photo taken with a smartphone is better than no photo at all. e author would like to emphasize the importance of data privacy when taking clinical photos with a smartphone [15]. Due to the connectivity of smartphones to the internet, the possibility of the picture being leaked online is significantly higher. e author recommends that clinical photos should not be kept together with personal photos. Using a separate phone or folder for clinical photos is best. To ensure that unauthorized personnel do not gain access to the photos, the folder should be password protected. Sharing of photos via messenger or social media is prohibited without the consent of the patient. e connectivity of smartphones does provide an advantage. Photos stored on the phone can be transferred immediately to a computer or cloud storage. is ensures that, in the unfortunate event of a lost phone or SD card failure, there is a backup file available. Finally, when a smartphone is no longer being used, its memory should be erased. International Journal of Dentistry    International Journal of Dentistry Smartphone photography not only benefits the dentist but also the patient [16]. With the current COVID-19 pandemic, more dentists have incorporated teledentistry in their daily practice [17]. e consultation can occur via live video feed or by the patient sharing their clinical photographs. e patient is unlikely to have a dedicated camera system with a macro lens and flash to provide the necessary photographs.
e only tool at their disposal is probably their smartphone. e techniques explained previously can be used at home with a few modifications. For instance, the author asks the patient to replace the cheek retractor with a spoon or their fingers and the intraoral mirror with a makeup mirror, if available ( Figure 7). If there is no continuous LED lighting, only then does the author recommend that the patient use the smartphone camera flash. e settings recommended to the patient will highly depend on the patient's knowledge of technology. If the dentist feels the patient is not well-versed in smartphone photography, more automatic settings will be recommended.

Conclusions
Orthodontic clinical photographs can be taken with a smartphone by using the correct methods. e dentist should ensure that the photographs are taken in the optimum environment with the optimum lighting and using the recommended settings.

Data Availability
No data were used to support this study.

Conflicts of Interest
e authors declare that there are no conflicts of interest regarding the publication of this study.