The purpose of this study was to determine whether, in fact, infants with deformational plagiocephaly, or plagiocephaly without synostosis, demonstrated cognitive and psychomotor developmental delays when compared with a standardized population. Through this study, we chose to expand upon our earlier findings from 2001 on patients with deformational plagiocephaly.
The study population includes a total of 110 consecutive patients, prospectively followed then retrospectively reviewed. Each infant was assessed using the Bayley Scales of Infant Development-II scoring system. The developmental analysis was categorized as either mental or psychomotor using the mental developmental index or the psychomotor developmental index, respectively. These infants were subcategorized into four groups: accelerated, normal, mild, or severely delayed. The groups were then compared with a standardized Bayley's age-matched population, using chi-square test goodness-of-fit tests.
Infants with deformational plagiocephaly were found to have significantly different psychomotor development indexes and mental developmental indexes when compared with the standardized population (p < 0.0001; p < 0.0001). With regards to the mental developmental index scores, none of the infants with deformational plagiocephaly were accelerated, 90 percent were normal, 7 percent were mildly delayed, and 3 percent were severely delayed. With regards to the psychomotor development index scores, none of infants were accelerated, 74 percent were normal, 19 percent were mildly delayed, and 7 percent were severely delayed.
This study indicates that before any intervention, infants with deformational plagiocephaly show significant delays in both mental and psychomotor development. Also of particular note is that no child with deformational plagiocephaly showed accelerated development.