Background: The purpose of this study was to evaluate the relationship between age at initiation of helmet therapy for deformational plagiocephaly and the rate of correction.
Methods: Infants treated for deformational plagiocephaly with a helmet orthosis between 2009 and 2010 were included. Patients were stratified prospectively by the age at which treatment was initiated: group 1, younger than 20 weeks (n = 26); group 2, 20 to 23.9 weeks (n = 59); group 3, 24 to 27.9 weeks (n = 82); group 4, 28 to 31.9 weeks (n = 62); group 5, 32 to 35.9 weeks (n = 45); group 6, 36 to 40 weeks (n = 29), and group 7, older than 40 weeks (n = 43). Pretreatment and posttreatment calvarial asymmetry was measured using direct anthropometry and reported as a transcranial difference.
Results: Three hundred forty-six infants were included; initial transcranial difference was equivalent on all paired-group comparisons. Duration of helmet therapy positively correlated with age at initiation (r = 0.89, p < 0.05). The rate of change in transcranial difference correlated negatively with age at treatment onset (r = –0.88, p < 0.05): group 1, 0.93 mm/week; group 2, 0.64 mm/week; group 3, 0.59 mm/week; group 4, 0.56 mm/week; group 5, 0.41 mm/week; group 6, 0.42 mm/week; and group 7, 0.42 mm/week). At the conclusion of therapy, all groups had improved calvarial symmetry, albeit less completely in groups 6 and 7.
Conclusions: The correction rate of plagiocephaly with helmet therapy decreases with increasing infant age; after 32 weeks, there is a slow and relatively constant rate of change. Improvement can still be achieved in infants older than 12 months.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.