Modified Cephalic Index Measured at Superior Levels of the Cranium Revealed Improved Correction With Helmet Therapy for Patients With Sagittal Suture Craniosynostosis.

OBJECTIVE: Historically, studies have shown that cranial remolding therapy improves surgical correction and protects against regression for patients with sagittal suture craniosynostosis. This study aimed to define the most responsive cranial height for measuring cephalic index (CI) following cranial remolding therapy for infants with sagittal suture craniosynostosis. METHODS: The authors performed a retrospective analysis of data between January 2018 and August 2019. The outcomes measured were CI-3 (level of glabella) through CI-7 (superior to eurions), where each value was defined as the width at levels 3 through 7 divided by the length at level 3. Differences between baseline- and post-treatment measurements were assessed using a 5 × 2 repeated measures analysis of variance. RESULTS: Data from thirty-four patients (19 males, 15 females, and mean age 2.79 months) were analyzed. Mean treatment duration was 4.59 ±â€Š1.86 months. There was a significant increase between baseline and posttreatment measurements (baseline: 72.60% ±â€Š0.70%, post: 76.30% ±â€Š0.80%; F1,33 = 27.74, P < 0.001). The interaction effect for CI level ∗ baseline-post was also significant (F1.43,47.16 = 6.75, P = 0.006). Post hoc analyses revealed the posttreatment measures were significantly greater than baseline measures at every CI level. The magnitude of the measured differences systematically decreased from CI-7 to CI-3, with a greater effect size at the most superior level (ie CI-7) of 0.961 compared to 0.778 at the traditional level (ie CI-3). CONCLUSIONS: The CI measurement at level 7 demonstrated the greatest responsiveness to treatment, whereas the traditional CI measurement taken at level 3, the current standard, proved the least responsive.