A Review of Cranial Remolding Orthosis Treatment for Babies with Combinational Deformational Plagiocephaly with Brachycephaly and Development of a New Classification Scale

Background/objectives: This comprehensive study of infants with combinational deformational plagiocephaly with brachycephaly (cDPB) and combinational deformational brachycephaly with plagiocephaly (cDBP) examined the effectiveness of a custom, thermoplastic vacuum-formed cranial remolding orthosis and identified clinical predictive factors that affect treatment outcomes. In addition, a standardized classification scale for babies with combinational head shapes was developed for this study. Methods: This was a retrospective study of patients who were treated by Cranial Technologies between January 2014 and March 2025 and met the following inclusion criteria: (a) presented with a Cranial Vault Asymmetry Index (CVAI(S)) > 3.5 AND Cephalic Index (CI) > 90, (b) were compliant with the treatment protocol, (c) were nonsyndromic, and (d) did not have craniosynostosis. Infants with isolated plagiocephaly or isolated brachycephaly were excluded. Multiple linear regression (MLR) analyses and paired t-tests were used to model the effects of clinical predictive factors on CVAI(S) and CI outcomes and determine the change between pre- and post-treatment cranial anthropometric measurements, respectively. Results: N = 82,326 infants met the inclusion criteria for this study. The mean overall reduction in CVAI(S) was −3.64 (p < 0.001) and for specific age groups it was as follows: 3–4 months −5.274 (p < 0.001), 4–6 months −4.074 (p < 0.001), 6–8 months −3.262 (p < 0.001), 8–11 months −2.692 (p < 0.001), and >11 months −2.247 (p < 0.001). The mean overall reduction for CI was −3.84 (p < 0.001) and was not related to age. In terms of clinician-rated outcomes, 95–100% of babies who entered treatment at less than 6 months of age had a “good” or “great” outcome, while the “good” or “great” success rate dropped to less than 19% for babies who started treatment after 11 months of age. MLR (Adj. R2: 0.582) identified the following factors as significant predictors (p < 0.001) for change in CVAI(S): entry age (β = 0.008), left-sided plagiocephaly (β = −0.420), initial cephalic index (β = −0.056), initial CVAI(S) (β = −0.479), prematurity (β = −0.189), and the presence of torticollis or neck muscle involvement (β = 0.053). A second MLR for change in CI (Adj. R2: 0.217) observed significance (p < 0.001) for the following predictors: initial CI (β = −0.335), left-sided plagiocephaly (β = −0.332), multiple birth (β = −0.290), male sex (β = −0.158), initial CVAI(S) (β = −0.049), premature (β = −0.086), and neck muscle involvement (β = −0.106). Conclusions: CRO treatment for cDPB/cDBP resulted in highly significant improvement in both CVAI(S) and CI across all age groups with the youngest babies requiring the shortest treatment durations and demonstrating more favorable results, especially in correcting asymmetry. Overall, the mean reduction in CVAI(S) varied significantly between age groups, with younger babies experiencing greater change in CVAI(S) scores, whereas CI did not demonstrate the same relationship with entry age. This study proposed new terminology for infants who present with elements of both plagiocephaly and brachycephaly. The use of standardized terms such as cDPB/cDBP to describe a combinational head shape will enhance comparability across future studies, thus enabling better outcome reporting.