Craniofacial growth in infants with deformational plagiocephaly: does prematurity affect the duration of head orthosis therapy and the extent of the reduction in asymmetry during treatment?

Objective Although prematurity is a risk factor for developing deformational plagiocephaly (DP), to our knowledge, there are no studies that have analyzed the impact of a premature birth on the duration of head orthosis therapy and the extent of the reduction in asymmetry during treatment. Materials and Methods We examined 239 patients with DP who were undergoing head orthosis therapy. Depending on the gestational age, they were assigned to either a premature (gestational age of < 37 weeks) or a full-term (gestational age of ≥ 37 weeks) group. Head shape was analyzed using 3D-stereophotogrammetry at the start and end of treatment. We performed multiple linear regression analyses to evaluate the impact of prematurity on the duration of therapy and the extent of the reduction in asymmetry, taking age and the initial asymmetry of an infant’s head into account. Results Head orthosis therapy led to a significant reduction in asymmetry in both groups. Using multiple linear regression analyses, we demonstrated that age at the start of treatment, the initial asymmetry and prematurity, significantly influenced the duration of therapy. Patients who were born at an earlier gestational age experienced a shorter treatment length. However, prematurity did not affect the extent of the reduction in cranial asymmetry that was achieved. Conclusions Along with age at the start of treatment and the initial asymmetry, prematurity is significantly correlated with the duration of head orthosis therapy, but not with the extent of the reduction in asymmetry achieved. Clinical Relevance Knowledge of these findings is important for clinicians when planning treatment and discussing the effectiveness of head orthosis therapy with the parents of premature infants with DP.