Helmet therapy efficacy and its prediction in Japanese infants with positional plagio- and brachycephaly.

PURPOSE: To provide additional information on optimal start times and therapeutic effectiveness based on treatment outcome of Japanese infants with positional plagio- and brachycephaly (PPB) receiving cranial molding helmet therapy (CMHT).

METHODS: In this retrospective cohort study, data from a 3D head scanning system was analyzed from 2173 Japanese infants who completed CMHT. Anterior and posterior symmetry ratio (ASR and PSR) and longitudinal to transverse diagonal ratios (LD/TDR) were calculated based on skull shape at helmet design and at completion of therapy. The outcomes were evaluated using the regression analysis and a predictive model using cranial parameters was developed.

RESULTS: The earlier the start of therapy, the greater the therapeutic effect on ASR, PSR, and LD/TDR (ASR, -0.134 percent points (ppt)/day; PSR, -0.086 ppt/day; and LD/TDR, -0.131 ppt/day). In the predictive model, in addition to starting age of the therapy, sex (male), the degree of deformity of the head (DoD) (moderate and severe), quadrant volume, PSR, and head circumference at the start of treatment also had a positive effect on changes in ASR, DoD (moderate and severe), ASR, LD/TDR and transverse diameter for PSR, sex (male), DoD (moderate), quadrant volume, PSR, and head circumference for LD/TDR.

CONCLUSION: The starting age of therapy had a relatively smaller contribution to outcome effects. Applying the cranial parameter obtained at the start of treatment to the predictive model helps to predict the effect of CMHT and whether PPB can be treated with CMHT in infants of older age.