Facial and ear dimensions in term Nigerian neonates

A study of selected facial and ear dimensions in 200 term and appropriate-for-gestational age neonates delivered at the University College Hospital, Ibadan, Nigeria, was carried out with the aim of describing their normal range of variation and providing reference values for clinical use. The features studied included inner canthal distance, outer canthal distance, palpebral fissure length, nasolabial distance, oral intercommissural length, total ear length and ear length above the eyeline. The inner canthal distance ranged from 1.6 to 2.5 cm with a mean of 2.1 (SD 0.2) cm while the outer canthal distance ranged from 5.2 to 7.2 cm with a mean of 6.1 (SD 0.4) cm. The oral intercommissural length ranged from 2.5 to 4.0 cm with a mean of 3.1 (0.3) cm and the total ear length ranged from 2.4 to 4.0 cm with a mean of 3.2 (SD 0.3) cm. Three per cent of the neonates had the whole ear located completely below the eye line. No significant sex differences in the mean values of any of the dimensions studied were found. The findings of the study are consistent with those of other workers who have documented shorter ears in the Negro neonate compared to his Caucasian counterpart. It is suggested that local values derived from well-defined populations be used as reference in the evaluation of the child with dysmorphic features in order to avoid errors of classification due to racial variations in the range of normal.