Reliability of three-dimensional anterior cranial base superimposition methods for assessment of overall hard tissue changes: A systematic review

Objective: The purpose of this systematic review was to synthesize the available literature concerning the reliability of three-dimensional superimposition methods when assessing changes in craniofacial hard tissues. Materials and Methods: Four electronic databases were searched. Two authors independently reviewed potentially relevant articles for eligibility. Clinical trials, cohort, case-control, and cross-sectional studies that evaluated the reliability of three-dimensional superimposition methods on the anterior cranial base were included. Results: Six studies fulfilled the inclusion criteria. Four studies used the voxel-based registration method, one used the landmark-based method and one used the surface-based method. Regarding reliability, the voxel-based studies showed on average a difference of 0.5 mm or less between images. The optimized analysis using a six-point correction algorithm in the landmark-based method showed 1.24 mm magnitude of error between images. Conclusions: Although reliability appears to be adequate, the small sample size and high risk of bias among studies make available evidence still insufficient to draw strong conclusions.