Different conditions can affect the nerves serving the lip muscles. These include the facial nerve (cranial nerve 7) and the trigeminal nerve (cranial nerve 5) which run along both sides of your face.

Ouardi, K. , Hamama, J. , Harbili, M. , Ouraini, S. , Benariba, F. and Errami, N. (2025) Silent Growth: 18-Year History of an Upper Lip Schwannoma. Voice of the Publisher, 11, 128-135. doi: 10.4236/vp ...