1. 1 Partial tooth dislocation: it should be reduced under local anesthesia and then ligated and fixed for 4 weeks. 3, 6, 12 months after operation, if pulp necrosis is found, root canal treatment should be done in time.

1.2 dislocation of impacted teeth: root canal therapy should be performed 2 weeks after reduction, because these teeth are usually accompanied by pulp necrosis and are prone to root resorption. Young permanent teeth with impacted dislocation should not be forcibly removed and reset, so as not to cause more trauma and induce the absorption of root and marginal alveolar process. Therefore, symptomatic treatment, continuous observation and natural eruption are the most ideal treatment methods. Generally, teeth can sprout to the original position after half a year of tooth replacement.

1.3 completely dislocated teeth: replanted within 0.5 hours, 90% of teeth can avoid root resorption. Therefore, after the teeth are dislocated, they should be put back to their original positions immediately. If the teeth have been contaminated, they should be cleaned with normal saline or sterile water and then put back to their original positions. If it cannot be repaired immediately, the affected tooth can be placed under the patient's tongue or in the vestibule of the mouth, or in a cup filled with milk, normal saline or tap water. Don't hide it in a dry place. Go to the hospital as soon as possible.

For complete tooth dislocation, specific treatment plans should also be made according to the patient's age and the length of time in vitro:

(1) Dislocated teeth with fully developed apices: If the treatment is rapid or the reduction is timely, root canal treatment should be performed 3-4 weeks after operation. Because after this kind of tooth replantation, it is impossible for the pulp to rebuild blood circulation, and it will inevitably be necrotic, which will cause inflammatory root resorption or periapical lesions. If root canal therapy is done before replantation, the time in vitro will be prolonged, which will lead to root resorption. Generally, after 3-4 weeks of replantation, the looseness will decrease, and inflammation absorption will just begin. Therefore, 3-4 weeks after replantation is the best time for root canal therapy.

If the dislocated patient goes to see a doctor 2 hours later, the cells in the pulp and periodontal ligament are necrotic, and the periodontal ligament cannot be expected to be reconstructed, so the root canal treatment can only be completed in vitro, and the affected tooth can be implanted and fixed after scraping the root surface and alveolar fossa.

(2) Complete dislocation of young permanent teeth: If the patient is treated quickly or reset on his own in time, the dental pulp can continue to survive, and the general curative effect is good. Animal experiments showed that after replantation for 3 months, 93% of dental pulp was completely filled with contrast agent, and only 7% of dental pulp was necrotic. The regeneration of pulp blood vessels mainly consists of newly formed blood vessels growing into the pulp cavity from the broad root end, and some of them coincide with the original blood vessels, which shows that replanted teeth have quite strong restoration ability.

Of course, if you don't see a doctor in time or delay the reduction time, you can only complete root canal treatment in vitro, scrape the alveolar fossa and replant the root surface, and the prognosis is not good.

2. Loose tooth fixation

2. 1 steel wire ligation was simple, but the fixation was stable at that time. Because the front teeth are single teeth and the root is wedge-shaped, the steel wire will exert wedging force on the root along the long axis of the teeth after tightening, which will make the teeth easy to be squeezed out, make the front teeth prone to lip tilt, sometimes make the dislocated teeth unable to be completely reset, and also easily damage the gingival papilla, resulting in great periodontal trauma, oral cavity difficult to clean, poor hygiene and prone to gingivitis. When changing teeth, the crown of deciduous teeth or newly erupted permanent teeth is short, the undercut is small, it is not easy to ligate, and it is difficult for patients with irregular dentition to keep it. Patients who are engaged in special occupations such as actors and teachers are consciously unsightly and unwilling to accept them.

2.2 When light-cured resin or enamel adhesive is fixed, it should be fixed at the proximal and distal ends of teeth. The soft tissue of the affected tooth is injured, edema and exudation are more, and saliva may enter or blow dry incompletely, which will reduce the cohesive force of the adhesive, loosen the resin and affect the fixation of the tooth. Moreover, the resin will stimulate the adjacent gingival papilla, leading to gingivitis, but it will not affect the dentition replacement period and the fixation of dislocated teeth, and the oral foreign body sensation is small, which will not affect the appearance and is easy for patients to accept.

2.3 Fixing loose teeth with edgewise arch can change the crown-root ratio of loose teeth and disperse the bite force. To reduce the damage of lateral force to periodontal tissue, because there are brackets on the injured teeth and healthy teeth of adjacent tissues, and the arch wire is embedded in the groove and then ligated and fixed, this section of dental arch is connected into a whole by the arch wire, and has appropriate elasticity, so that the biting force is evenly distributed on all teeth, which has certain physiological mobility, conforms to physiology and is beneficial to the recovery of periodontal tissue. The bracket is in surface contact with the tooth surface, which is easy to bond and does not stimulate or damage the periodontal tissue. For the case of uneven dentition and dentition, sufficient retention can be obtained by bending the arch wire. The appearance of porcelain brackets can avoid affecting the appearance, and the clinical installation and disassembly are simple and comfortable, and it is easy to clean. The reasons for the failure of extraction in this group are poor periodontal health, apical absorption and tooth loosening, which may be related to serious local injury and inflammatory reaction.