Sulcus Lunate

The lunate groove is a small longitudinal depression on the facial tubercle of the lip, more noticeable on the medial side. There are small, thin grooves around the groove that give it the characteristic crescent appearance. It is an element of the surface morphometry of the lips. Occurs in both jaws. It can be easily palpated and easily visualized by ultrasound. Normally they are not visualized. It is formed by muscular-aponeurotic tissues, maintains tension during chewing, allows you to determine the tone of the orbicularis oris muscle, and determines the distribution of muscle tissue across the width of the face in the area where the teeth meet. It is a sign of facial wrinkles. Microscopy may reveal facial hyperemia on the outer side of the lips, stretching of the tip of the nose and lateral angles.