Objectives: To evaluate the effect of vitamin D3 local injections on apical root resorption, alveolar bone integrity, and chair-side time following three and six months of canine retraction. Subjects and Methods: Seventeen adult patients (18-35 years old) of class I and II malocclusions were recruited, who required bilateral maxillary 1st premolars extraction before starting maxillary canines retraction. The experimental side received 25 pg dose of vitamin D3 injected locally into the distal periodontal sulcus of the canine (before force application) every three weeks, while the control side received retraction force only. Periapical radiographic evaluation was conducted after 3 and 6 months of the start of canines' retraction. Results: At both time points (3 and 6 months), radiographic findings revealed uniform alveolar bone contour with non-sig-nificant differences (p> 0.05) between the experimental and control sides regarding canine root resorption scores. The experimental side exhibited better alveolar bone turnover as indicated by well-defined periodontal ligament widening. However, vitamin D3 injection entailed four minutes extra chair-side time. Conclusion: Enhancement of canine retraction by local injection of vitamin D3 induced better periodontal response, does not impose detrimental apical root resorption nor adversely affect the alveolar bone integrity, and the procedure does not entail significant extra chair-side time.
