Back sleeping can flatten babies' heads.
Black
Hilary
H
D001512:Bedding and Linens; D006801:Humans; D007223:Infant; D007224:Infant Care / Q000379:methods*; D049068:Plagiocephaly, Nonsynostotic / Q000209:etiology* / Q000517:prevention & control; D013398:Sudden Infant Death / Q000517:prevention & control*; D016683:Supine Position