Sir: Far and away the commonest cause of an unusual head shape in an infant ('Now Sam looks as nature intended', 13 July) is the distortion of the skull brought about by an habitual sleeping position (plagiocephaly). This may originate soon after birth and may be associated with a tendency to hold the head more to one side than another due to tightness in the neck muscles on one side. Neither condition requires treatment as, with time, the child will spend more time upright and the asymmetry will straighten.
The incidence of these conditions has increased considerably since the guidelines on sleep position in infancy have stressed the benefit of the child lying on the back, which seemingly has been associated with a major fall in the incidence of cot death but more of these minor but initially worrying conditions.
M. F. M. BAMFORD
Department of Child Health
The Ipswich Hospital