dynamics of gene expression of matrix metalloproteinase-8 and tissue inhibitor metalloproteinase-1 on removable orthodontic appliance wearers

The teeth will move if subjected to pressure through orthodontic appliances which causes a remodeling of periodontal ligament and alveolar bone. MMP-8 plays an important role in the remodeling process during orthodontic movement. The expression of MMP-8 gene is regulated by a natural inhibitor namely TMP-1. The purpose of this study was to observe the MMP-8 and TIMP-1 gene expressions in the gingival crevicular fluid [GCF] of patients with removable orthodontic appliance. A sample of 8 patients wearing orthodontic appliances was obtained. The finger springs were activated with 75 grams of force to produce canine distalization. GCF samples were collected from the distal side of upper canines before force application, 1-, 2-, 3-, and 4 weeks after application consecutively. The samples were analyzed by using RT-PCR. Statistical univariate analysis was used to show the distribution and percentages of the gene expressions. The gene expression of MMP-8 at t[0] was 28.1% but the force application elevated its expression to 62.5% at t[1], and then decreased continuously at t[2] [37.5%], t[3] [34.4%], and t[4] [31.3%]. The gene expression of TIMP-1 at t[0] was 40, 6% but the force application elevated its expression to 59,4% at t[1], and then decreased continuously at t[2] [43,8%], t[3] [40.6%], and t[4] [37.5%]. In conclusion, there was a dynamic gene expressions of MMP-8 and TIMP-1 before and after force application and the pattern was similar, i.e. the highest level happened on the first week, but it declined continuously in the following weeks

Expression of matrix metalloproteinase-8 [MMP-8] gene in patients with fixed orthodontic appliances

Orthodontic treatment with fixed appliance produces structural and biochemical changes and breaking the balance between the synthesis and the breakdown of the collagen in the periodontium. MMP-8 plays an important role in the remodeling of periodontal ligament during orthodontic movement. The purpose of this study was to observe the expression of MMP-8 gene in the gingival crevicular fluid [GCF] of fixed orthodontic patients. It is expected that the result can be used as a reference to decide the proper time for elastomeric chain to be reactivated. Orthodontic fixed appliances were placed on 8 patients and elastomeric chains exerting a force of 75 grams were attached to produce canine distalization. GCF samples were collected from the distal side of upper canines before force application, 1-, 2-, 3-and 4 weeks after application consecutively. The samples were analyzed by using RT-PCR. Statistical analyses used were univariate analysis and Mann-Whitney U test. The expression of MMP-8 in the GCF at t0 was 31.3% but the force application elevated its expression of 65.6% at t1, and then decreased continuously at t2, t3, and t4. There was no statistically difference of MMP-8 gene expression between to and t3. The highest level of MMP-8 gene expression due to orthodontic forces happened in the first week, but it declined continuously in the following weeks. The proper time to reactivate an elastomeric chain was 3 weeks after application