Object: Though positional posterior plagiocephaly (PPP) is considered common in infants since the pediatric recommendations of "Back to Sleep", several aspects of its natural history still remain unclear. The aim of this study is to understand the actual prevalence and severity of PPP in children and adolescents.
Methods: Head CT scans performed for head trauma during the period September 2016-September 2017 were retrospectively analyzed in a total of 165 children ranging from 0 to 18 years of age (101 boys). Cranial vault asymmetry index (CVAI) was calculated at the level of the superior orbital rim. CVAI values greater 3.5% was considered index of asymmetry. The results were analyzed according to different age groups: group I: 1 month to 1 year of age (37 children), group II: 2 to 4 years (32 children), group III: 5 to 8 years (36 children), group IV: 9 to 12 years (27 children), and group V: 13 to 18 years (33 children) and the severity of asymmetry according to CVAI values: mild group (CVAI range 3.5-7%), moderate group (CVAI range 7-12%), and severe group (CVAI > 12%).
Result: The total prevalence of PPP in the 165 children was 25%. While the prevalence in infants of group I was estimated to be 40.5%, it was 15.6% in group II, 30.5% in group III, 18.5% in group IV, and 12% in group V. The mean and maximum degrees of deformation were 3.5% and 15.1%, respectively. Most children had a mild asymmetry. One child (group II) presented a severe asymmetry. The degree of the asymmetry varied according to the groups but moderate asymmetry could be found at all ages even in groups IV and V.
Conclusion: This study analyzing PPP in an unselected unbiased pediatric population shows that PPP has a high prevalence in adolescents. It confirms that the prevalence of deformational plagiocephaly is more common than usually reported and that PPP may persist at a late age.
Keywords: Deformational plagiocephaly; Nonsynostotic plagiocephaly; Pediatric population; Positional posterior plagiocephaly.