The nostril sill is a structure which has been overlooked in both anat
omical and surgical texts. An understanding of the normal anatomy will
help in reconstruction of the nostril both in congenital and acquired
conditions, including cleft lip. In order to investigate this feature
100 normal Caucasian adults, with equal sex incidence, have been asse
ssed by direct measurement and photography. Three major variants of fo
rm were identified with significant differences in sill height and ang
ulation seen. A true nostril sill was found in only 62% of the study p
opulation and sex differences were noted among the variants. A relatio
nship was noted between each nostril sill variant and nostril type. Th
e implications for reconstruction are discussed.