Lower lip sinuses are usually seen in association with congenital anomalies. The anomaly is usually a sac like depression in the lower lip, somewhat lateral to the midline. The sinus is usually in the middle of the conical protrusion. It ends in the blind pouch lined by squamous epithelium and encircled by the mucous glands which open into the sinus. Apart from the cosmetic handicap, the anomaly causes the patient no actual subjective distress.
There may be, at most, annoying secretion of mucous from the sinus extra orally.Much has been written about the congenital lower lip sinuses being associated with other congenital anomalies and there treatment. However, i could not find any case due to trauma which made me more peculiar about its reporting.