Force-Induced Nitric Oxide Promotes Osteogenic Activity during Orthodontic Tooth Movement in Mice

Figure 1

Orthodontic force induces NO production and NOS expression. (a) The orthodontic appliance was fixed between the left maxillary first molar and the incisor. (b) After being applied with orthodontic force, the distal periodontal ligament of the upper first molar widened while the mesial was compressed, . (c) The representative images of micro-CT showed upper first molar moved mesially in the OTM group, . (d) The average distances of OTM were measured in HE and micro-CT images. (e) The concentration of NO₂^- in serum from mice applied with orthodontic force was increased compared with the control group, . (f) Injections of NOS inhibitor and NO precursor were performed every two days starting the day before the application of OTM. (g) The levels of endogenous NO in serum decreased but have no significant difference after interval injections of L-NMMA. The NO levels in serum were significantly upregulated after interval injections of L-arginine, . and . Bars and error bars show mean and standard error.