UCLA

Palatal expansion, frequently utilized for correcting transverse discrepancy, relief of crowding, and prior to bone grafting, is prone to significant relapse. With a need for treatment that improves the success of expansion, we hypothesized that estrogen (E2) will decrease relapse by increasing bone formation following expansion of the suture. Due to its short half-life and potential systemic effects, E2 was combined with nanodiamond (ND) and hydrogel (G). 18 rats underwent 7 days of palatal expansion and were divided into 5 groups (Control, E2, E2/ND, E2/G, E2/ND/G) for palatal injections. After 14 days of retention, expanders were removed for relapse. The addition of ND and G to E2 significantly reduced the relapse ratio and increased bone density. Staining showed greater mineralized area/total area, decreased number of osteoclasts, and increased osteoblasts in sutures in this group. These findings demonstrate local delivery of E2 may improve stability and predictability of palatal expansion.