Investigation Of Retention And Relapse After Orthodontic Treatment And The Effect Of Indomethacin And Salvia Miltiorrhiza Bunge (SMB)on Orthodontic Tooth Movement

Relapse after orthodontic treatment is a common problem and is closely associated with retention.It is therefore of qreace significant to study the retention and relapse of post-orthodontic tooth movement. Indomethacin is a kind of non-steroidal anti-inflammatory drug, which can inhibit synthesis of body prostaglandin(PG)and resist orthodontic tooth movement. SMB can dilate ending blood vessels, improve microcirculation, and promote orthodontic tooth morement. However, little is known about the effect of SMB on the periodontal tissue during active tooth movement .The changes of the dental arch in shape and size, and occlusal relation during and after orthodontic treatment can be reflected by measuring dental-occlusal models.Modelmeasurement is considered as a primary method in evaluating the effect of retention and the extent of relapse after the treatment. However, few of domestic investigations about dental arch stability during posttreatment and postretention are performed.A series of experimental and clinical investigations were performed with focus onthe aforementioned problems.The present investigation consists of three parts:In the first part,experiments were performed in rat or dog. Observations were made about the rearrangment and reconstruction of periodontal tissue after active tooth movement, the effect of retention and Circumferentiol supracrestal fiberotomy ( CSF) on dental relapse, the regularity of tooth movement and changes of periodontal tissues during dental relapse, and. the results are as follows:...