Caliper Measurement a Reliable Assessment Tool Following Pediatric Cranial Reconstruction

by Linda Kossoff •

How reliable is the caliper compared to computed tomography (CT) when measuring cranial dimensions in children?

BOTTOM LINE: Caliper measurements are a simple and reliable way to assess cranial vault proportionality with growth after cranial vault reconstruction.

BACKGROUND: The birth defect craniosynostosis restricts skull growth, leading to head shape abnormalities and, potentially, elevated intracranial pressure. Successful surgery corrects head shape abnormality, allowing for normal growth. Calipers are the main craniometric tool used in craniosynostosis, while CT is thought to be more precise. However, CT causes unacceptably high radiation exposure.

STUDY DESIGN: Retrospective chart review.

SETTING: Department of Otolaryngology–Head and Neck Surgery, State University of New York Upstate Medical University, Syracuse.

SYNOPSIS: Researchers identified 89 patients (64 males, 25 female) who received CT head scans between 2010 and 2019 to evaluate for head shape abnormality and had documented caliper measurements of anterior-posterior (AP) and transverse head dimensions. Researchers analyzed the data and compared the measurements taken with caliper to the CT measurements. Of the AP caliper measurements, 73% were within 1 cm of the CT measurement, and 88% of the transverse caliper measurements were within 1 cm of the CT measurement, both below the standard deviation of 1.6 cm. Given that craniofacial surgery is frequently necessary to manage craniosynostosis and that patients are generally young and growing rapidly, craniofacial changes need to be followed postoperatively. Although a CT scan delivers the more precise measurements for this purpose, it is a time-consuming process that involves radiation exposure and possibly anesthesia. The study’s findings suggest that caliper measurement can reliably be used to assess cranial proportionality with growth following craniofacial reconstruction. Limitations included retrospective data collection, differing planes between caliper and CT measurements, and an inability to include caliper measurements of diagonal and vertical cranial dimensions.

CITATION: Wu GT, Audlin JR, Grewal JS, et al. Comparing caliper versus computed tomography measurements of cranial dimensions in children [published online ahead of print September 12, 2020]. Laryngoscope. doi:10.1002/lary.29086.