Nitric oxide (NO) plays a role in regulating the rate of orthodontic tooth movement (OTM) in rat models; however, in humans this role remains less clear. In this study, samples of gingival crevicular fluid (GCF) were collected from each maxillary central incisor and first and second molar immediately before (T0), 1 hour after (T1), and 3-4 days after (T2) application of light orthodontic forces in thirteen male participants (ages 11-18 years) undergoing orthodontic therapy. NO levels were measured in each GCF sample, and significantly higher NO levels (p<0.05) were found at T1 at the buccal surfaces of the central incisors when compared to the posterior teeth. The results indicate a possible role for NO in OTM at the pressure sites of incisors at early time points. Further studies are required to determine whether NO levels in the PDL of human teeth are affected by the magnitude of an applied force.

Nitric oxide (NO) plays a role in regulating the rate of orthodontic tooth movement (OTM) in rat models; however, in humans this role remains less clear. In this study, samples of gingival crevicular fluid (GCF) were collected from each maxillary central incisor and first and second molar immediately before (T0), 1 hour after (T1), and 3-4 days after (T2) application of light orthodontic forces in thirteen male participants (ages 11-18 years) undergoing orthodontic therapy. NO levels were measured in each GCF sample, and significantly higher NO levels (p<0.05) were found at T1 at the buccal surfaces of the central incisors when compared to the posterior teeth. The results indicate a possible role for NO in OTM at the pressure sites of incisors at early time points. Further studies are required to determine whether NO levels in the PDL of human teeth are affected by the magnitude of an applied force.