A Novel Prophylactic Device Against Head Deformity to Prevent Severe Positional Plagiocephaly.

: Preventing head deformity in the early postnatal period could avert positional plagiocephaly (PP). Accordingly, we developed a novel prophylactic device to prevent head deformity and examined its impact on the incidence of PP and prevention of severe PP at 3 months of age. : The newly developed prophylactic device was used immediately after birth or at the 1-month checkup, and cranial shape was measured before device application and at 3 months of age. The diagnostic threshold for PP was >5% for cranial vault asymmetry index (CVAI); cranial asymmetry (CA) of ≥13 mm was deemed severe. A database comprising cranial geometry of 3-month-old healthy Japanese infants ( = 110) served as the control. : This study included 42 infants who started using the novel prophylactic device immediately after birth or at the 1-month checkup. Measurements at 3 months of age revealed that the prophylactic device group had significantly lower CA and CVAI than the control group (CA [median]: 5.5 vs. 8.0, respectively, = 0.007; CVAI: 4.3 vs. 5.8, respectively, = 0.048). However, the PP prevalence did not differ significantly between the two groups (41% vs. 57%, respectively, = 0.094). The number of infants with severe PP was significantly lower in the prophylactic device group than in the control group (0% vs. 14%, respectively; = 0.012). At 3 months of age, no significant differences in CA or CVAI were observed between the immediate postnatal and 1-month groups. : The novel prophylactic device against head deformity could prevent severe PP.