Abstract
INTRODUCTION: The study aimed to determine the influence of palatal injection of platelet-rich plasma (PRP) on the rate and type of orthodontic tooth movement (OTM) during the en-masse retraction of upper anterior teeth. MATERIALS AND METHODS: Two-arm parallel-group trial, in which 30 class II division 1 adult patients (7 males and 23 females) aged 16 to 27 years were recruited. The sample was randomly divided into two groups: the experimental group, in which PRP was injected in the palatal mucosa of the maxillary six anterior teeth immediately before starting the en-masse retraction of upper anterior teeth, whereas in the control group, traditional treatment was employed. Following the first premolar extraction, space closure was accomplished using frictionless mechanics for the en-masse retraction of upper anterior teeth. In both groups, a rigid segmented arch made of stainless steel with a diameter of 0.021 x 0.025 inch and an 8-mm power arm was used for the upper anterior teeth, and mini-implants were inserted between the upper second premolar and first molar at 8 mm apical from the archwire line. NiTi coil springs were used for retraction. Measurements were recorded at the onset of space closure (T0) and every 40 days till the middle of the en-masse retraction of upper anterior teeth (T1). RESULTS: Thirty patients completed the trial, and no patients were lost to follow-up in both groups. The OTM rate in the PRP group was similar to that of the control group (P = 0.596). The upper anterior teeth in the two groups were retracted mostly by controlled tipping and partially by translation. Statistically insignificant differences were observed between the two groups regarding the rest of the cephalometric variables. No serious harms were observed in either group. CONCLUSIONS: PRP was ineffective in accelerating the OTM rate during the en-masse retraction of upper anterior teeth and it did not affect the type of tooth movement.