Clinical Manifestation of Congenital Unilateral Lower Lip Palsy: A Study of 111 Patients

OBJECTIVES: Congenital unilateral lower lip palsy (CULLP) is a congenital disorder characterized by an asymmetric lower lip while opening the mouth. CULLP is not well known for its concept of disease. We investigated the clinical appearance of this congenital disorder. METHODS: We retrospectively reviewed the clinical records of patients with congenital unilateral lower lip palsy and compared them with other case series reports. We investigated the following items: the number of CULLP patients who decided to have an operation, the age at the operation, sex, the associated side of the lower lip, the associated disorders, and the family history of CULLP. RESULTS: Left-sided predominance was seen in our case series and other reports. However, the female-male ratio and the associated abnormalities could not be concluded as their tendencies. CONCLUSIONS: The study type and the facilities would be important sources of bias. A unified assessment of CULLP patients and a prospective study are inevitable to investigate the pathology of CULLP.