Average Models and 3-dimensional Growth Patterns of the Healthy Infant Cranium

Abstract

Background: Treatment of cranial deformity is often performed during infancy in cases such as craniosynostosis and deformational plagiocephaly. To acquire morphologic standards for the treatment goals of these conditions, we created cranial average models and elucidated the growth patterns of the cranium of healthy infants in 3-dimension (3D) using homologous modeling. Methods: Homologous modeling is a technique that enables mathematical analysis of different 3D objects by converting the objects into homologous models that share the same number of vertices with the same spatial relationships. Craniofacial computed tomographic data of 120 healthy infants ranging in age from 1 to 17 months were collected. Based on the computed tomographic data, we created 120 homologous models. Six average 3D models (20 individuals each for 6 different age groups) were created by averaging the vertices of the models. Three-dimensional growth patterns of the cranium were clarified by comparing the 6 average models. Results: We successfully created 6 average models and visualized the growth patterns of the cranium. From 1-month-old to 5-month-old infants, the entire cranium except for the occipital region grows, and the cranium tended to be brachycephalic (cephalic index at 4–5 months: 87.1–97.3), but the growth was thereafter localized to specific areas. Conclusions: Three-dimensional growth patterns of the cranium of healthy infants were clarified. These findings will support the understanding and treatment of the conditions that cause cranial deformity. To our knowledge, this is the first report to visualize the growth patterns of the entire cranium of healthy infants in 3D.

Growth Curves for Intracranial Volume and Two-dimensional Parameters for Japanese Children without Cranial Abnormality: Toward Treatment of Craniosynostosis

“…Recently, 3D growth pattern of the cranium of healthy Japanese infants was reported. 20) They divided the period up to 17 months of age into six age groups and analyzed which parts of the cranium grew during the two adjacent age groups. They reported that up to 5 months of age, the entire area of cranium, except for the occipital region, undergoes rapid growth.…”

Review of Current Morphometric Standards in Craniosynostosis

“…10 This is likely contributed by the different measurement methods, as shown in this review, in addition to the inherent difficulty in locating standard anatomic landmarks, a common methodological step in many of the studies. 10-18…”

“…A unique methodology employed by Kuwahara et al 11,12 provides average models of healthy Japanese infants that were constructed via homologous modeling. Homologous modeling enabled the group to identify 7 principal components as to which part of the cranial shape each component was related to, allowing for easy characterization of cranial morphology noted in some clinical conditions that alter cranial morphology.…”

“…10 This is likely contributed by the different measurement methods, as shown in this review, in addition to the inherent difficulty in locating standard anatomic landmarks, a common methodological step in many of the studies. [10][11][12][13][14][15][16][17][18] A unique methodology employed by Kuwahara et al 11,12 provides average models of healthy Japanese infants that were constructed via homologous modeling. Homologous modeling enabled the group to identify 7 principal components as to which part of the cranial shape each component was related to, allowing for easy characterization of cranial morphology noted in some clinical conditions that alter cranial morphology.…”

The 3D skull 0–4 years: A validated, generative, statistical shape model

“…First proposed by Blanz and Vetter ( Blanz and Vetter, 1999 ; Booth et al, 2016 ) in 1999, 3DMMs have proven adept at modelling complex shape structures such as the human face, head, hand and ear ( Blanz and Vetter, 1999 ; Booth et al, 2016 ; Dai et al, 2018 ; Ploumpis et al, 2019 ; Dai et al, 2017 ; Zolfaghari et al, 2016 ; Khamis et al, 2015 ) despite limited input data. Paediatric skull models have also been constructed using 3DMMs, although the ability of these models to generate synthetic data has not yet been tested ( Li et al, 2015 ; Kuwahara et al, 2020 ; Libby et al, 2017 ).…”