The problem of loose teeth is now not only exist on the elderly, more and more young people also have loose teeth, so what are the causes of loose teeth? 1, external impact factors external impact teeth were bruised, bruised or overbite, can make the teeth shake. This is because the external excessive force causes the periodontal membrane to be injured, and the elastic fiber between the teeth and periodontal membrane is damaged, making the teeth loose. 2, periodontal disease caused by periodontal disease caused by tooth loosening. The periodontal membrane is subjected to chronic inflammatory stimulation for a long time, so that the periodontal membrane fibers are gradually degenerated and destroyed. When these periodontal tissues supporting the teeth are gradually destroyed, the teeth will become loose. 3, periodontal degeneration periodontal degeneration can cause most teeth to loosen. Periodontal degeneration occurs mostly in young people due to degenerative changes in periodontal tissues, destruction of periodontal fibers and resorption of alveolar bone, resulting in loosening and displacement of teeth. The loosening of teeth caused by periodontal degeneration occurs first in the upper and lower front teeth and the first molar, as the teeth are shifted, the previously aligned teeth become thinner, the upper front teeth protrude outward, and gaps are created between the teeth. Although periodontal degeneration is rare clinically, it is very harmful and can often make young people lose all their teeth at an early stage, so attention should be drawn to it. 4, acute periapical periodontitis Acute periapical periodontitis, osteomyelitis of the jaw bone, tumors in the jaw bone can cause loosening of the teeth of the diseased teeth. Some diseases that can affect the gums and periodontal support tissues, such as necrotizing gingivitis, vitamin deficiency, diabetes, etc., can also cause loosening of teeth. Loose teeth should be treated promptly for the cause and most patients can be cured. Therefore, when the problem of loose teeth occurs, it is important to go to the clinic for examination and treatment in a timely manner.