A baby’s upper lip protruding more than the lower lip may be related to genetic factors, bad habits, and broken lip tie. 1. Genetic factors: when both parents have a protruding upper lip, it may be passed on to the child, and as the baby grows older, the upper lip appears to be more prominent than the lower lip. 2. Bad habits: If the baby often purses his lips, it may cause some stimulation to the upper lip area, which may also cause the upper lip to protrude more than the lower lip. 3. Lip tie rupture: after the baby’s lip area is scratched by objects, impact, extrusion, there may be lip tie rupture, when the lip tie rupture, there may be uncontrolled lips, upper lip than the lower lip protruding situation. There may also be other reasons why your baby’s upper lip protrudes more than the lower lip. If your baby has any of the above conditions, it is recommended that you seek prompt medical attention, and under the guidance of your doctor, complete the relevant examinations to clarify the cause of the condition and treat it appropriately.