Objective: An investigation to determine the changing facial appearance of identical twins. Design: Clinical study. Materials and Methods: Two Minolta Vivid 900 3D optical laser scanners were placed as a stereo pair to capture the soft tissues of a pair of identical twins. Each scan took approximately 2.5 s. The scanned whole faces were superimposed to determine changes in facial morphologies at different time intervals. Outcome measures: The shell deviations between left and right scans of each patient were recorded and analysed for differences. Furthermore, final merged faces were overlaid to determine the changes in facial morphology over time. Results: The results showed that changes in height and weight correlated with changes in facial morphology. Conclusion: The 3D laser scanning device is a clinically useful tool in the study of facial growth and facial morphology in a pair of twins. © Blackwell Munksgaard 2005.