AIM: The objective of this study was to compare tooth movement using platelet-rich plasma (PRP) and the conventional method in patients with moderate crowding during the leveling and aligning phase.

MATERIALS & METHODS: Fifty patients with moderate crowding in the maxillary arch were chosen. Split-mouth design was planned with one quadrant allotted as the experimental group (PRP side) and the other as the control group. Five injection sites were pre-defined: distal surface of the root of the central incisor, mesial and distal root surfaces of the lateral incisor and canine. After the extraction of the permanent maxillary first premolars, PRP was injected at various sites on the experimental side while the other side served as the control group. In each group, four times were studied: 0(T0), 21(T1), 42(T2), and 63(T3) days after injection. Tooth movement was measured using a digital Vernier caliper and statistical analysis was done using paired t-test.

RESULTS: Significant amount of tooth movement was seen at 21 days (p<0.001). No significant difference in tooth movement was found at 42 days (p=0.265) and 63 days (p=0.104) after injection.

CONCLUSION: Platelet-Rich Plasma is responsible for accelerating orthodontic tooth movement in patients with moderate crowding when injected during the leveling and aligning phase for the first 21 days after injection although it was non-effective after 42 and 63 days.