Using a 3D asymmetry index as a novel form for capturing complex three-dimensionality in positional plagiocephaly

• Published in: Scientific reports 2022-12, Vol.12 (1), p.20831-20831, Article 20831
• Main Authors: Linz, Christian, Faber, Julian, Schmid, Reiner, Kunz, Felix, Böhm, Hartmut, Hartmann, Stefan, Schweitzer, Tilmann
• Format: Article
• Language: English
• Subjects: 692/700/139/1735; 692/700/1421/2025; 692/700/3032/3145/3146; Asymmetry; Classification; Classification systems; Humanities and Social Sciences; Humans; Infant; multidisciplinary; Pancreas; Photogrammetry; Plagiocephaly, Nonsynostotic - diagnostic imaging; ROC Curve; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-24555-1

Positional plagiocephaly (PP) is the most common skull deformity in infants. Different classification systems exist for graduating the degree of PP, but all of these systems are based on two-dimensional (2D) parameters. This limitation leads to several problems stemming from the fact that 2D parameters are used to classify the three-dimensional (3D) shape of the head. We therefore evaluate existing measurement parameters and validate a newly developed 3D parameter for quantifying PP. Additionally, we present a new classification of PP based on a 3D parameter. 210 patients with PP and 50 patients without PP were included in this study. Existing parameters (2D and 3D) and newly developed volume parameters based on a 3D stereophotogrammetry scan were validated using ROC curves. Additionally, thresholds for the new 3D parameter of a 3D asymmetry index were assessed. The volume parameter 3D asymmetry index quantifies PP equally as well as the gold standard of 30° diagonal difference . Moreover, a 3D asymmetry index allows for a 3D-based classification of PP. The 3D asymmetry index can be used to define the degree of PP. It is easily applicable in stereophotogrammetric datasets and allows for comparability both intra- and inter-individually as well as for scientific analysis.