Thierens LAM, et al. - For the quantification of facial morphology, symmetry, and appearance in cleft lip and palate, authors reviewed the current literature on the modalities of assessment of non-ionizing 3D images. They also evaluated the method error of these modalities. They conducted a systematic literature search using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials, Web of Science, and Embase. Findings suggested a wide usage of the non-ionizing 3D images in cleft research, but often methodologically suboptimal 3D analysis of the images is conducted. In order to quantify morphology, symmetry, and appearance, the content of 3D images ought to be fully utilized.