Study of characteristics and correlation of the head shape of infants with plagiocephaly

Objective To study the characteristics of the head shape and correlations among the shape para-meters in infants at the plagiocephaly. Methods One hundred and four infants at the age of 4-12 months from Department of Rehabilitation, Guangzhou Women and Children′s Medical Center with plagiocephaly or normal head shape from January to October 2016 were selected for head shape characteristic analysis.Seventy-four males and 30 females were included.Seventy-three infants (53 males and 20 females) with plagiocephaly were plagiocephaly group with age of (7.07±2.23) months.Thirty-one infants (21 males and 10 females) with normal head shape were control group with age for (8.29±2.81) months.The Spectra scanner 2.0 was applied to acquire head shape parameters including cephalic ratio (CR), radial symmetry index (RSI), oblique diagonal difference (ODD), and cranial vault asymmetry index(CVAI). The correlation between the head shape characteristics and shape parameters of infants in different month ages and gender with plagiocephaly were analyzed through independent sample t-test and Pearson correlation analysis.Among all the enrolled infants, there were 46 infants in 4-7 months (36 cases with plagiocephaly and 10 cases with normal head shape), 34 infants in >7-10 months (24 cases with plagiocephaly and 10 cases with normal head shape), and 24 infants in >10-12 months (13 cases with plagiocephaly and 11 cases with normal head shape). Results CR in 4-7 months group and >7-10 months of plagiocephaly group were all significantly higher than that in control group [(91.32±5.60)% vs.(80.73±2.68)%, (90.31±6.22)% vs.(84.14±3.57)%], and the differences were all statistically significant (t=-5.765, -2.924, all P 10-12 months plagiocephaly group compared with that in control group (t=-1.917, P=0.060). RSI, ODD, and CVAI of plagiocephaly group in all ages were significantly higher than those in control group [(46.40±13.59) mm vs.(16.13±4.18) mm, (11.84±3.58) mm vs.(3.44±1.59) mm, 7.92±2.43 vs.2.34±1.07], and the differences were all statistically significant (t=-17.210, -16.579, -16.304, all P 0.05). Pearson correlation analysis revealed that there was no correlation between CR and RSI, ODD, CVAI in any age of plagiocephaly group (all P>0.05). There was a positive correlation among RSI, ODD, and CVAI in the plagiocephaly group in any age (r=0.940, 0.912, 0.973, all P<0.001). Conclusions In the infants with plagiocephaly may exist asymmetric head shape and the shorter length of head at the same time.When one of the values of RSI, ODD and CVAI increases, the other two values increase too with more serious level of plagiocephaly. Key words: Plagiocephaly; Infants; Head shape; Laser scanning; Gender