It is common for the infant trachea to deviate to the right, with a frequency of 50% at one year, 25% at two years, 15% at three years and 6% at four years (tending not to occur in the over fives), but it may be missed on inspiratory chest films with the head in extension. In a case report from India, authors point out that anaesthetists are often unaware of this normal variant. Since many tracheal tubes are designed with the bevel facing left, the angled tracheal wall may occlude the distal outlet of the tube, necessitating repositioning of the tube higher in the trachea above the bend.
Anaesth Intensive Care. 2009 Jan;37(1):144-5