Only internal incision is considered for cleft lip. The repair of a labial occult cleft is not only a repair of the skin appearance, but the key is to restore the musculature of the lip and nose, including the subtle three-dimensional structure, otherwise the deformity will be pulled to a more pronounced deformity by abnormal muscular forces as it grows. Conversely, once the musculature is repaired, the form will become increasingly natural with balanced forces. This includes the surface skin, which can gradually form a natural human middle, so external excision is not recommended for removal.