Introducing a new method for classifying skull shape abnormalities related to craniosynostosis

Abstract

We present a novel technique for classification of skull deformities due to most common craniosynostosis. We included 5 children of every group of the common craniosynostoses (scaphocephaly, brachycephaly, trigonocephaly, and right- and left-sided anterior plagiocephaly) and additionally 5 controls. Our outline-based classification method is described, using the software programs OsiriX, MeVisLab, and Matlab. These programs were used to identify chosen landmarks (porion and exocanthion), create a base plane and a plane at 4 cm, segment outlines, and plot resulting graphs. We measured repeatability and reproducibility, and mean curves of groups were analyzed. All raters achieved excellent intraclass correlation scores (0.994–1.000) and interclass correlation scores (0.989–1.000) for identifying the external landmarks. Controls, scaphocephaly, trigonocephaly, and brachycephaly all have the peak of the forehead in the middle of the curve (180°). In contrary, in anterior plagiocephaly, the peak is shifted (to the left of graph in right-sided and vice versa). Additionally, controls, scaphocephaly, and trigonocephaly have a high peak of the forehead; scaphocephaly has the lowest troughs; in brachycephaly, the width/frontal peak ratio has the highest value with a low frontal peak. Conclusion: We introduced a preliminary study showing an objective and reproducible methodology using CT scans for the analysis of craniosynostosis and potential application of our method to 3D photogrammetry. What is Known:• Diagnosis of craniosynostosis is relatively simple; however, classification of craniosynostosis is difficult and current techniques are not widely applicable. What is New:• We introduce a novel technique for classification of skull deformities due to craniosynostosis, an objective and reproducible methodology using CT scans resulting in characteristic curves. The method is applicable to all 3D-surface rendering techniques.• Using external landmarks and curve analysis, specific and characteristic curves for every type of craniosynostosis related to the specific skull deformities are found.

Quantification of Bilateral Coronal Synostosis: Anterior Brachycephaly

“…The methodology for the quantification of craniosynostosis developed in our previous study (UCSQ) is used ( Figure 1) (Kronig et al, 2020). The curves, generated by the UCSQ method, were analyzed for different variables (Table 1 and skull outline is followed clockwise.…”

“…A recently developed method for the classification and quantification of craniosynostoses is Utrecht Cranial Shape Quantifier (UCSQ) (Kronig et al, 2020). Utrecht Cranial Shape Quantifier is an outline-based method and has the advantage of capturing the actual skull shape variation with every 3-dimensional (3D) diagnostic system capturing the surface of the head.…”

New diagnostic approach of the different types of isolated craniosynostosis

“…External landmarks are located and marked (exocanthion left and right and porion left and right). [7]. In our previous study, we showed that these typical clinical findings in subgroups of craniosynostosis can be expressed quantifiably by extracting specific characteristics [7].…”

“…In order to create sinusoid curves, we used the described methodology of our previous study; a summary of the methods can be found in Fig. 1 [7]. Table 1 shows the extracted and calculated variables from the curves; these values are used for analysis of the curves for each type of craniosynostosis and the control patients.…”

“…[7]. In our previous study, we showed that these typical clinical findings in subgroups of craniosynostosis can be expressed quantifiably by extracting specific characteristics [7]. Based on the clinical features, we extracted the related specific characteristics of the created sinusoid curves of each simple craniosynostosis type (Table 1; Fig.…”