Troubleshooting Improperly Aligned Photographs of the Dental Patient
By Robert Winter on September 20, 2017 | commentsEven though a photograph is worth 10,000 words, if the angle of the camera is not properly aligned, the image will provide you with incorrect information.
The article “Composing Photographic Images of Your Patient” provides you with information on how to compose a photographic image using the correct camera angulation. It is important to understand that the only attribute of a photograph that can be managed in Photoshop, Keynote, or PowerPoint is rotation. Manipulating the image in one of these programs can, for example, correct the level of the interpupillary line or the maxillary and mandibular occlusal planes relative to horizon.
Errors in composition that cannot be corrected are images that are:
1. Centered correctly but shooting down or up at whatever you are photographing
2. Off-center (taken from a side angulation)
3. A combination of up or down from level and off to one side
The key to getting the correct angle of the camera lens is having the patient stand with a natural head posture/position staring at the horizon so you can align your lens on a flat horizontal plane at the level of the upper teeth. This gives you a perspective of how all facial lines or planes compare to the horizon.
Portrait images of the patient in repose, smiling, with the lips retracted and the intraoral photographs, must be taken with the center of the camera lens at the level of the maxillary central incisors' incisal embrasure.
The patient's head must be in a posturally natural position, frontal plane and anterior-posterior (sagittal plane). With this established head position, the maxillary occlusal plane will be photographed correctly relative to horizon. The accuracy of the head position, and therefore the images captured, needs to be within one degree of level.
If it varies more than this, significant errors will be incorporated into the treatment plan. It may negatively impact tooth position (incisal edge) and gingival levels, impacting orthodontic, periodontal, and restorative procedures.
The series of photos shown are of a smile. You can face the same challenges with all other types of clinical photos.
Photo 1: All photographs are taken with the camera body (sensor), end of lens, facial plane, and background (if horizontal lines are visible) parallel to each other.
Photos 2 and 3: The photograph is taken with the correct angulation, centered on the maxillary incisor embrasure and level with horizon. The incisal edge position and level can be accurately assessed.
Photo 4 and 5: If the camera is rotated around the correct center of the image, it can be corrected if you have a reference of horizon.
Photos 6 and 7: If the level of the camera is held too high and the lens needs to be angled down to capture the ideal center of the image, the perspective of view changes. The maxillary anterior teeth will appear longer relative to the occlusal plane, and the incisal edges will appear to be following the curve of the lower lip. This may result in the maxillary anterior teeth being shortened unnecessarily to ‘level’ the incisal and occlusal planes.
Photos 8 to 12: If the camera is positioned too low, the camera lens needs to be angled up to capture the ideal center of the image. Now the maxillary anterior teeth appear shorter than ideal, resulting in unnecessary lengthening of the teeth to ‘correct’ the incisal and occlusal planes. The other option would be to intrude all the maxillary posterior teeth to ‘correct’ the occlusal plane. Neither thought process is correct because the perspective of view is incorrect.
Taking photographs slightly from the side (or a combination of too high or low and from the side) changes the perspective of view even more and cannot be corrected.
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Bob Winter, D.D.S., Spear Faculty and Contributing Author