University of Oulu

Aarnivala, H., Vuollo, V., Heikkinen, T., Harila, V., Holmström, L., Pirttiniemi, P., Valkama, A. (2017) Accuracy of measurements used to quantify cranial asymmetry in deformational plagiocephaly. Journal of Cranio-Maxillofacial Surgery, 45 (8), 1349-1356. doi:10.1016/j.jcms.2017.05.014

Accuracy of measurements used to quantify cranial asymmetry in deformational plagiocephaly

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Author: Aarnivala, Henri1,2,3; Vuollo, Ville2,4,5; Heikkinen, Tuomo2,4;
Organizations: 1Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland
2Medical Research Center Oulu, University of Oulu, Oulu, Finland
3PEDEGO Research Group, University of Oulu, Oulu, Finland
4Department of Orthodontics, Oral Health Sciences, University of Oulu, Oulu, Finland
5Department of Mathematical Sciences, University of Oulu, Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.8 MB)
Persistent link:
Language: English
Published: Elsevier, 2017
Publish Date: 2019-04-09


Objective: Various measurements are used to quantify cranial asymmetry in deformational plagiocephaly (DP), but studies validating cut-off values and comparing the accuracy of such measurements are lacking. In this study, we compared the accuracy of four different measurements in classifying children with and without DP diagnosed by visual assessment, and sought to determine their optimal cut-off values.

Study design: Two experts rated 407 3D craniofacial images of children aged between 3 and 36 months old using the Argenta classification. We then measured the following asymmetry-related variables from the images: Oblique Cranial Length Ratio (OCLR), Diagonal Difference (DD), Posterior Cranial Asymmetry Index (PCAI), and weighted Asymmetry Score (wAS). We created receiver operating characteristic curves to evaluate the accuracy of these variables.

Results: All variables performed well, but OCLR consistently provided the best discrimination in terms of area under the curve values. Subject’s age had no clear effect on the cut-off values for OCLR, PCAI, and wAS; however, the cut-off for DD increased monotonically with age. When subjects with discrepant expert ratings were excluded, the optimal cut-off values for DP (Argenta class \(\ge\) 1) across all age-groups were 104.0% for OCLR (83% sensitivity, 97% specificity), 10.5% for PCAI (90% sensitivity, 90% specificity), and 24.5 for wAS (88% sensitivity, 90% specificity).

Conclusion: We recommend using OCLR as the primary measurement, although PCAI and wAS may also be useful in monitoring cranial asymmetry. The threshold of relative asymmetry required for a deformation to appear clinically significant is not affected by the child’s age, and DD has no additional utility in monitoring DP compared to using only OCLR.

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Series: Journal of cranio-maxillo-facial surgery
ISSN: 1010-5182
ISSN-E: 1878-4119
ISSN-L: 1010-5182
Volume: 45
Issue: 8
Pages: 1349 - 1356
DOI: 10.1016/j.jcms.2017.05.014
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
Funding: The research was funded with a grant from the Oulu University Scholarship Foundation.
Copyright information: © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Published in this repository with the kind permission of the publisher.