Teats adapted to be placed in an infant's mouth, comprising a nipple comprising at least one perforation adapted for the flow of a liquid, an areola, and an isthmus joining the nipple to the areola, wherein the nipple comprises asymmetrical palatine and lingual parts and the isthmus joins the nipple and the areola in a manner adapted for the correct positioning of lower and upper jawbones during use, and further wherein the teats are adapted to allow controlled expulsion and flow during use. Also disclosed are feeding bottles comprising such teats and feeding systems comprising such feeding bottles.