Use of stereophotogrammetry for measuring the volume of external facial anatomy: a systematic review

Introduction: Photographic documentation is important in several medical specialties, such as plastic surgery. Two-dimensional photography has limitations in capturing structure depth and volume, requiring other instruments to evaluate these changes. Several technologies have been developed for three-dimensional analysis of objects, of which stereophotogrammetry uses computerized analysis of two or more simultaneous photographs of the object to produce a three-dimensional geometric model. The advantages of stereophotogrammetry include lower cost, portability, absence of radiation, and speed of image capture. The aim of the present study was to perform a bibliographic review evaluating the use and accuracy of stereophotogrammetry for measuring the volume of facial structures. Methods: Using a combination of MeSH keywords and free terms, a search was performed in the Cochrane Library and MEDLINE databases. The search included all articles published on or before May 2018. Results: 2,213 studies were initially retrieved using this search strategy. Of these, 27 studies were selected based on the eligibility criteria, of which 21 were non-randomized case studies and 6 were randomized clinical trials. The methodological quality of the studies varied between 50 and 67%, on a grading scale from 0 to 100%. Conclusions: Stereophotogrammetry is a promising technology that is increasingly being used to check for facial volume variations with high accuracy and reproducibility. More studies with higher methodological quality are needed for evaluating the accuracy and use of stereophotogrammetry for facial volume evaluations.