Analysis of Cranial Type Characteristics in Term Infants: A Multi-center Study

Abstract

Background: Positional head deformity (PHD) is defined as a change in the shape of a baby's skull due to external force. In certain cases, it can lead to cosmetic deformities or even neurological issues due to its impact on the developing nervous system. We therefore conducted this study to investigate the incidence and characteristics of PHD in term infants in China and preliminarily establish a localized diagnostic reference standard. Methods: Overall, 4456 term infants from three medical institutions in Chongqing were recruited and divided according to age groups. Cranial vault asymmetry (CVA) and cephalic index (CI) were calculated in all infants. The current international diagnostic criteria were used to understand PHD incidence and analyze their CVA and CI distribution. Results: According to the current international standards, the total detection rate of PHD in Chongqing’s term infants was 81.5%, with brachycephaly alone being the most frequent (39.4%), followed by brachycephaly with plagiocephaly (34.8%), and plagiocephaly alone (6.2%). The detection rates of dolichocephaly were low: alone, 0.9% and combined with plagiocephaly, 0.2%. According to age, plagiocephaly (44.5%) and brachycephaly (82.0%) were most frequent in the 2-3-month group. The 75th/90th/97th percentiles and 3rd/10th/25th/75th/90th/97th percentiles of CVA and CIs were 0.4/0.7/1.0 and 76.4/78.8/82.3/91.1/94.6/99.2%, respectively. Conclusion: According to the current international standards, the PHD detection rate among term infants in Chongqing was high. Therefore, a new diagnostic standard for Chinese infants was proposed. CVA ≥0.4 cm indicates plagiocephaly. CI ≥91% indicates brachycephaly. CI ≤82% indicates dolichocephaly.