Date: October 2021.
Source: American Journal of Orthodontics and Dentofacial Orthopedics, DOI:
• Evidence on three-dimensional facial photograph superimposition was assessed.
• Seven high and 1 low risk of bias studies were included, with high heterogeneity.
• The studies tested various landmark- and surface-based methods.
• The surface-based seems to be superior to the landmark-based registration.
• Further research in the field is mandatory.
Introduction: Superimpositions of 3-dimensional photographs enable a thorough and risk-free assessment of facial changes over time. However, the available methods and the evidence supporting them have not been assessed systematically. The paper summarizes and assesses the current evidence on superimposition methods of serial 3-dimensional facial photographs available in the literature.
Materials and Methods: The following databases were searched without time restriction (last updated December 2020): MEDLINE via PubMed, EMBASE, Cochrane Library, and Google Scholar. Unpublished literature was searched on Open Grey and Grey Literature Report. Authors were contacted if necessary, and reference lists of relevant papers were screened. All studies with sample size ≥6 that tested the accuracy or precision of a superimposition technique, or agreement between different techniques regarding facial surface changes, were considered. The 2 authors performed data extraction independently using predefined forms. The risk of bias was assessed through the Quality Assessment and Diagnostic Accuracy Tool 2 tool.
Results: Eight studies fulfilled the inclusion criteria. The total risk of bias of 7 studies was high and of 1 low. Seven studies had high total applicability concerns, and 1 was unclear. There was high heterogeneity among studies, which tested constructed planes through manually selected landmarks, a configuration of 9 landmarks, various surface areas, and the entire facial surface as superimposition references. A small rectangular area on the forehead combined with one on the middle part of the nose and the lower wall of the orbital foramen showed promising results.
Conclusions: The limited available evidence suggests that surface-based registration is superior to landmark-based registration. Further research in the field is mandatory.

Article: Superimposition of serial 3-dimensional facial photographs to assess changes over time: A systematic review.
Authors: Jonathan Johannes Wampfler, Nikolaos Gkantidis. Department of Orthodontics and Dentofacial Orthopedics, School of Dental Medicine, University of Bern, CH-3010, Freiburgstrasse 7, Bern.