Mouth is the most expressive part with the largest range of facial movements.
The oral cavity is attached to a semi-cylinder composed of the upper and lower jaws and teeth, and is arc-shaped and located directly below the face. It is one of the important organs for swallowing and speaking, and it is also one of the important factors that constitute facial beauty. Can produce rich expressions, and the shape is particularly eye-catching. In medicine, the range of upper lip and lip includes facial tissue around upper lip and cleft palate, from the bottom line of nostril to the frontal and labial sulcus, and from both sides to nasolabial sulcus.