[TA] the slight projection on the free edge of the center of the upper lip at the lower extent of the philtrum. Synonym(s): tuberculum labii superioris [TA], labial tubercle, procheilon, prochilon
procheilon
(prō-kī′lŏn) [Gr. pro, before, + cheilon, lip] A prominence in the central portion of the upper lip.