Does shape affect function? Articulatory skills in babbling of infants with deformational plagiocephaly

The purpose of this study was to quantitatively analyse pre-speech/early language skills in healthy full-term infants with moderate or severe deformational plagiocephaly (DP) and in infants without any skull asymmetry.

At 6 and 12 months, 51 children with DP (41 moderate, 10 severe cases) were studied, along with 15 infants serving as control. Deformational plagiocephaly (DP) was objectively determined based on cranial vault asymmetry (CVA) using 3D stereophotogrammetry (3dMDhead System® and Analytics 4.0, Cranioform®). Articulatory skills in babbling were assessed using the articulatory skill (ART-index) and mean syllable number (MSN). At 12 months, standardized parental questionnaires were used to evaluate early language outcomes.

Overall, 3546 vocalizations were studied. Statistical tests did not reveal any significant differences of the ART-index between the three groups (ANOVA, F[2,63] = 0.24, p = 0.24). MSN likewise did not differ between the three shape groups (Kruskal-Wallis, p = 0.84). Among the children assigned to the at-risk group for language outcomes at 12 months were seven members of the symmetrical shape group (vs. seven assigned to the normally developing group), nine of the moderate DP group (vs. 27), and one of the severe DP group (vs. six). Fisher's exact test was used to analyse whether helmet therapy in the moderate DP group affected the results by influencing language outcomes, but did not reveal any significant influence (p = 0.712).

The results of this study do not support arguments suggesting that DP is a cognitive risk condition. The suggestion that a direct neurophysiological relationship exists between a DP condition and a cognitive developmental delay remains controversial.