The chin generally refers to the lowermost part of the maxillofacial region, commonly known as the chin. The chin is located at the lower edge of the mandible and is formed by the horizontal branches of the mandible on each side, and its lower edge forms the chin-neck angle with the upper edge of the neck, which divides the maxillofacial region from the neck. The chin is the lowermost part of the face, and together with the cheeks, nose, lips and other organs, it constitutes the whole face, and the chin, together with the zygomatic arches and the angle of the mandible on both sides, form the basic skeletal contour of the face, and its shape determines the shape of the face. The position and shape of the chin has a great influence on the face, and its development determines whether the face is beautiful or not. If the chin is underdeveloped, it may result in a pointed or bird-shaped face. On the other hand, if the chin is overdeveloped, it may form a long face or a horse face, which also affects the aesthetics of the maxillofacial region.