Normative ranges of anthropometric cranial indices and metopic suture closure during infancy

Abstract

OBJECTIVE Subjective evaluations typically guide craniosynostosis repair. This study provides normative values of anthropometric cranial indices that are clinically useful for the evaluation of multiple types of craniosynostosis and introduces 2 new indices that are useful in the evaluation and management of metopic and bicoronal synostosis. The authors hypothesize that normative values of the new indices as well as for established measures like the cephalic index can be drawn from the evaluation of CT scans of normal individuals. METHODS High-resolution 3D CT scans obtained in normal infants (age 0-24 months) were retrospectively reviewed. Calvarial measurements obtained from advanced imaging visualization software were used to compute cranial indices. Additionally, metopic sutures were evaluated for patency or closure. RESULTS A total of 312 participants were included in the study. Each monthly age group (total 24) included 12-18 patients, yielding 324 head CT scans studied. The mean cephalic index decreased from 0.85 at age 0-3 months to 0.81 at 19-24 months, the mean frontoparietal index decreased from 0.68 to 0.65, the metopic index from 0.59 to 0.55, and the towering index remained comparatively uniform at 0.64 and 0.65. Trends were statistically significant for all measured indices. There were no significant differences found in mean cranial indices between sexes in any age group. Metopic suture closure frequency for ages 3, 6, and 9 months were 38.5%, 69.2%, and 100.0%, respectively. CONCLUSIONS Radiographically acquired normative values for anthropometric cranial indices during infancy can be used as standards for guiding preoperative decision making, surgical correction, and postoperative helmeting in various forms of craniosynostosis. Metopic and towering indices represent new cranial indices that are potentially useful for the clinical evaluation of metopic and bicoronal synostoses, respectively. The present study additionally shows that metopic suture closure appears ubiquitous after 9 months of age.

Endoscopic surgery for patients with syndromic craniosynostosis and the requirement for additional open surgery

“…All patients underwent anthropometric measurements performed using calipers at the bedside, and 1 or more indices were calculated, including the cephalic index (CI), towering index (TI), and transcranial diameter difference (TDD). 18 The CI was measured for the patient with sagittal suture involvement and was defined as the eurion-to-eurion diameter divided by the glabella-to-opisthocranion diameter, multiplied by 100. 4 The TI was measured for the patients with bilateral coronal involvement and was defined as the coronal distance (measured from tragus to tragus) over the cranial vault divided by the occipitofrontal circumference, multiplied by 100.…”

“…4 The TI was measured for the patients with bilateral coronal involvement and was defined as the coronal distance (measured from tragus to tragus) over the cranial vault divided by the occipitofrontal circumference, multiplied by 100. 18 The TDD was measured for the patient with unilateral coronal involvement and was defined as the difference (in millimeters) between the occipital-frontal transcranial diameters on each side of the head (i.e., the left occipitalto-right frontal diameter subtracted from the right occipital-to-left frontal diameter). 6,17 Given the patients' young age at evaluation, all families in this series were counseled regarding both endoscopic surgery and open calvarial vault remodeling.…”

Smartphone-based video for 3D modelling: Application to infant’s cranial deformation analysis

“…Cranial deformation in infants is a group of conditions that affects a great percentage of new-borns (Rogers, 2011). Although its prevalence is high, there are no standards for its systematic evaluation.…”

“…Its use in infants usually requires the use of anaesthesia to put the patient to sleep. Another approach for the extraction of 3D data is the use of special 3D scanners such as the STARscanner (Plank et al, 2006). These tools are applied for the creation of the orthotic helmets used to correct the deformations as well as an analysis tool.…”

Development of a Photogrammetric Tool for Cranial Deformation Analysis in Infants

“…The ideal ellipsoid is the one which minimises the distances to the real head while meeting some constraints to assure that the head is normal, i.e. anthropometric cranial indexes considered normal according to medical literature (62). The ideal ellipsoid was obtained by least-square fitting using the mathematical model presented in Bektas (50).…”