Most of the protruding lower jaw teeth in young people are caused by the external fan malformation of the teeth, in which case orthodontic treatment can be carried out to internalize the upper and lower jaw front teeth to achieve a more aesthetic lip protrusion to improve the problem of tooth protrusion. Most of the jaw teeth protrusion in older people is caused by periodontal disease. Patients with advanced periodontal disease will have larger and larger gaps between teeth, longer and longer clinical crowns, and fan shifting of teeth resulting in protruding, flared upper and lower jaw front teeth. In this case, periodontitis should be treated to control the periodontal inflammation to reduce and slow down the further shifting of the teeth. In this case, periodontal systemic treatment should be done, including ultrasonic scaling, periodontal scaling, root planing, etc. Patients should also pay attention to oral hygiene maintenance at home to prevent and avoid the recurrence of periodontitis.