Positional Brachycephaly

GENESIS

Brachycephaly translates literally to “short head” and refers to a head that is shortened in the anteroposterior dimension and wide between the biparietal eminences when viewed from above. The most frequent cause of brachycephaly is constant supine positioning during infancy ( Fig. 27.1 ). The increasing prevalence of brachycephaly in recent years is a consequence of the success of efforts to prevent sudden infant death syndrome (SIDS). The “Back to Sleep” campaign was initiated by the American Academy of Pediatrics in June 1992, with the initial recommendation to place infants to sleep on their sides or backs to prevent SIDS. After 1996, the more stringent recommendation for only supine sleep positioning was made because it was recognized that some side-sleeping infants were still dying from SIDS after assuming a prone sleeping position during the night. The end result of this public education effort was a decline in the prevalence of prone sleeping position from 70% in 1992 to 13% in 2004, with a concomitant reduction in the rate of SIDS from 1.2 per 1000 in 1992 to 0.56 per 1000 in 2001 (a decrease of 53% over this 10-year period). Unfortunately, strict supine sleep–positioning campaigns have also increased the rate of positional head deformities by 400–600%. When infants remain in a persistently supine position without any preferential head turn because of torticollis and without the developmental benefits of turning their heads from side to side during regular periods of “tummy time” while awake and under direct adult observation, their heads become progressively flattened through the impact of gravity and persistent occipital mechanical pressure.

A 1995 study of 7609 Dutch infants, who were screened for positional preference before 6 months of age, revealed that 8.6% manifested positional preference with resultant deformational plagiocephaly; an additional 10% manifested occipital flattening, 45% of whom showed persistent asymmetric occipital flattening at 2–3 years of age. Among 181 otherwise normal New Zealand infants whose head shapes were followed at regular intervals from birth through 2 years of age in 2002, the prevalence of plagiocephaly or brachycephaly peaked at 4 months at 20% (associated with male gender, first born, limited neck rotation, and inability of caregivers to vary the infant’s head position when putting the infant down to sleep) and then fell to 9% by 8 months of age and 3.3% by 2 years of age. Despite continued advice by family doctors and community child health nurses to encourage neck rotation, tummy time, and repositioning, 33% of the 8-month-old infants with abnormal head shapes were still abnormal at 2 years of age. The supine-sleeping infants in this 2002 cohort were significantly more brachycephalic at each assessment interval (cephalic index 4–5%), greater than a 1977 cohort of prone-sleeping infants, and these investigators used a cephalic index cutoff of 93% as the point at which the abnormal head shape was obvious. A follow-up study of 129 of these children at 3 and 4 years of age revealed that 61% of abnormal head shapes had reverted to normal, whereas 4% remained severely abnormal at follow-up, with 13% categorized as having poor improvement with continuing parental concern over their child’s head shape.

Among 1045 high school students (37% male, 63% female) ranging from 12 to 17 years old (average age, 15.7 years), the prevalence of plagiocephaly was 1.1% and the prevalence of brachycephaly was 1.0%, with an overall prevalence of a deformational cranial abnormality of 2.0%. This study was limited by having fewer males, who are affected more often and more severely, and by assuming helmets were not available before 1998, when they were clearly in use after 1980 (but not regulated by the US Food and Drug Administration). Among the adolescents with plagiocephaly or brachycephaly, 38.1% were noted to have abnormal facial characteristics. Note that Hutchinson found a 4% prevalence of severe brachycephaly or plagiocephaly at 3 and 4 years of age in her longitudinal study that included an excess of males (71% male, 29% female).

Taking all of these data together, it is clear that the “Back to Sleep” campaign has been a major success in reducing the incidence of SIDS by more than 50%, but primary care providers also need to emphasize the importance of tummy time to parents. It is essential to place infants on their backs for sleep, except in cases of prematurity, gastroesophageal reflux, or obstructive sleep apnea. Infants should be placed on their stomachs whenever they are awake and under direct adult supervision so as to develop their prone motor skills and to encourage the full range of neck rotation. The development of positional brachycephaly, with or without plagiocephaly, is an indication that parents may not be providing their infants with adequate tummy time.