Background: Short- and long-term evaluation of the aesthetic outcome of implant therapy has become a key research issue, intraoral photography is a frequently used tool for this purpose. Reproducibility of the shooting angle appears thus very important to obtain comparable photographs, in order not to change perspective and or dimensions of the region of interest. However, capturing with a reproducible angle may be challenging, in absence of complicated set-ups.

Aim/Hypothesis: To assess the effect of shooting angle variation on linear and planar measurements of the pink and white tissues on intraoral photographs, and to assess an easy-to-apply capturing method to obtain comparable intraoral photographs of the upper anterior teeth.

Material and Methods: Intraoral scans of the upper anterior teeth of 10 patients have been used to generate 99 ‘scan photographs’ of the same region of interest but in different shooting angles, i.e., starting from an ‘ideal’ position (i.e., 0° distortion), a picture was generated every 5° distortion in a horizontal or vertical direction, and in each possible combination thereof, until 15–25°distortion to the left, right, coronal, and apical direction. Additionally, a series of 11 intraoral photographs of the same patients and tooth sites were taken free-hand and in slightly varying perspective, at 3 time-points within 6 months, always attempting to achieve comparability. The papilla height (PH) and area (PA) and tooth crown area (TCA) were calculated on all scan- and intraoral photographs. For the intraoral photographs, the ‘best fitting’ photograph at each follow-up time-point, chosen by 6 evaluators, was compared to baseline.

Results: Linear and planar measurements on the ‘scan photographs’ did hardly deviate in a clinically relevant extent (i.e., > 0.5 mm for PH and > 10% for PA and TCA) within the first 10° distortion of the shooting angle at the horizontal or vertical plane, or any combination thereof. Further, the intraoral photographs taken at different time-points presented a high comparability, specifically, only 6 out of 100 photographs presented a PH with > 0.5 mm difference from baseline, none of the TCA measurements deviated > 10% compared to baseline, and only in 4 patients (one photograph each) a > 10% deviation of the PA was present compared to baseline. Poor to moderate inter- and intra-rater agreement, in terms of choosing the ‘best fitting’ photograph was achieved, most likely due to this high comparability. Nevertheless, photographs with clinically relevant changes were in general not chosen by the 6 evaluators.

Conclusions and Clinical Implications: Highly comparable intraoral photographs of the upper anterior teeth can be relatively easy captured by taking at each appointment a series of photographs in slightly varying perspectives, and then later on selecting the ‘best fit’ to baseline. In general, small distortions of the shooting angle (<10°) in all directions, except in apical direction, cause hardly any clinically relevant deviations for linear and planar measurements.