Effect of Local Use of Vitamin D on the Rate of Canine Distillization: a Split Mouth Randomized Control Trial

Orthodontic treatment (OT) is characterized as a lengthy procedure and enormous effort has been harnessed to shorten the OT duration using either surgical or non-surgical approaches. With the emerging concept of "accelerated orthodontics," scientific interest has been focused on chemical and electrical stimuli in combination with mechanical forces for rapid bone turnover and more stable results. Given the role of cytokines, parathyroid hormone, active vitamin D3 (1,25 dihydroxycholecalciferol) in bone regeneration, several studies have been conducted in which exogenous biological molecules have been locally administrated in order to stimulate orthodontic tooth movement. Vitamin D (Vit-D) plays a significant role in bone biology and remodeling.There are two primary forms of Vit-D: 25-OHD (25-hydroxyvitamin D) and 1,25 DHC (1,25-dihydroxycholecalciferol) which is the active form. 1,25 DHC is a potent stimulator of osteoclastic activity by inducing differentiation as well as increasing the activity of osteoclasts. It is also known to work in a dose-dependent way. Although it has a 2-3-hour plasma half-life, its effects on cells might last for days. Injecting the active form of Vitamin D can increase tooth movement, decrease the treatment time of fixed appliances and maintain the integrity of the bone. In the past researches have been done on cats and rodents on the effect of intraligamentary administration of vitamin D3 on tooth movement. Studies performed on human beings are few and inconclusive. Two out of the four studies done on humans were cross-sectional and investigated the role of active vitamin D on external apical root resorption. The other two clinical trials used split-mouth technique and examined the impact of local CTL administration on tooth movement rate, both demonstrating level 1 of evidence and high recommendation. Al-Hasani and colleagues reported that a low dose of 25 picogram/mL produced a higher rate of OTM, with no statistically significant difference between the study and control sides in 15 patients involved in the study. However, Iosub Ciur and colleagues reported 70% acceleration in the OTM when using higher 42 picogram/mL local dose of vit D, but the number of patients was extremely low and not adequate(n=4) in this study. The purpose of our study is to evaluate if higher doses of local vitamin D can accelerate tooth movement in adequate number of adult patients. If vitamin D in our population of adult patients can accelerate tooth movement, then it can allow for more predictable treatment outcome during fixed orthodontic therapy.