SA2 - Cranial Orthotic Devices vs. Repositioning Techniques for the Management of Plagiocephaly: A Prospective Cohort Study

Abstract:

Introduction: Positional plagiocephaly, an oblique twisting or distortion of the head shape due to deformational molding, is a common occurrence in infancy. Historically, treatment has relied on repositioning techniques (moving the infant off flattened spots) to aid with remolding head shape, or cranial orthotic devices (CODs) to help direct favorable growth [1]. CODs are FDA-approved, but studies showing their advantage over less invasive or costly methods of correction are limited, and often do not extend follow-up past the initial treatment period. Thus, the purpose of this study is to compare the effectiveness of repositioning techniques versus cranial orthotic devices (COD) in correcting plagiocephaly in infants at least 6 months following initial treatment.

Methods: A prospective cohort study was conducted at a private clinic in Tampa, FL from 11/2017 to 01/2023. Inclusion criteria included infants ages 4-7 months presenting to the craniofacial clinic with a subsequent diagnosis of a positional head deformity, including asymmetric plagiocephaly or brachycephaly as measured by Cranial Vault Asymmetry (CVA) and Cephalic Index (CI), respectively [2]. Patients were excluded if they had plagiocephaly due to craniosynostosis, neoplasm, hydrocephalus, or isolated scaphocephaly. Based on caregiver choice, patients underwent a course of either COD therapy or were instructed to follow a home exercise program, including repositioning techniques and neck stretching exercises. Follow-up was maintained at 3-month intervals for at least 6 months. Multivariate linear regression analyses were conducted to evaluate the relationship between COD therapy vs. conservative therapy and changes to both CVA and CI. To control for potential confounders and effect modifiers, the following variables were included in the analyses: sex, age, initial CVA or CI respectively, and length of follow-up time. A post-hoc analysis was conducted to evaluate for the effect of the interaction between initial CVA and COD therapy via a multivariate linear regression analysis, to determine if patients with more severe asymmetries saw greater improvements.

Results: A total of 64 patients were included in this study. Of these, 35 underwent COD therapy, and 29 were treated with repositioning therapies. The mean follow-up times were 9.9 (SD 2.9) months for the COD group compared to 9.4 (SD 2.6) months for the repositioning therapy group (p = 0.50). Statistical analyses showed, when controlling for potential confounders and effect modifiers, that COD therapy was significantly associated with improved CVA, with a mean improvement of 3.09 mm (95% CI 1.70-4.47, p< 0.001). Conversely, COD was not significantly associated with improved CI (p=0.41). Post-hoc analysis evaluating the interactive effect between COD therapy and the initial CVA at the time of consult produced the following formula to predict the expected differential improvement in CVA (in mm) when COD therapy is pursued (compared to repositioning therapies alone): 0.5 x (initial CVA) – 2.

Conclusion: The results of this study demonstrated that COD therapy is significantly associated with improved CVA, when compared to conservative therapy alone, more notable differences in patients with more severe plagiocephaly. Further larger studies are indicated to corroborate the results of this study.

References:
1. Hillyar, C., A. Nibber, and J. Ong, A systematic review and meta-analysis of the evidence for association of potential risk factors with deformational plagiocephaly. Archives of Disease in Childhood, 2021. 106(SUPPL 1): p. A46.
2. van Vlimmeren, L.A., et al., Plagiocephalometry: a non-invasive method to quantify asymmetry of the skull; a reliability study. Eur J Pediatr, 2006. 165(3): p. 149-57.