Does stinging nettle (Urtica dioica) have an effect on bone formation in the expanded inter-premaxillary suture?

•This study is the first to report effects of Stinging nettle (SN) extract on new bone formation in the midpalatal suture in rats.•Systemic administration of SN may accelerate bone formation at the expanded suture.•Systemic administration of SN may reduce the inflammation during the maxillary expansion procedure.•It may also be beneficial in preventing relapse after the expansion procedure.

ObjectiveTo determine whether systemically given stinging nettle (SN) has an effect on bone formation in response to expansion of the rat inter-premaxillary suture.Materials and methodsA total of 28 male Wistar albino rats were randomly divided into 4 equal groups: control (C), only expansion (OE), SN extract given only during the expansion and retention periods (SN group; a total of 17 days), and SN extract given during the nursery phase before expansion (a period of 40 days) and during the expansion and retention periods (N + SN group; a total of 57 days). After the 5-day expansion period was completed, the rats in the OE, SN, and N + SN groups underwent 12 days of mechanical retention, after which they were sacrificed, and their premaxilla were dissected and fixed. A histologic evaluation was done to determine the number of osteoblasts, osteoclasts, and capillaries, as well as the number and intensity of inflammatory cells and new bone formation.ResultsStatistically significant differences were found between the groups in all histologic parameters except the ratio of intensities of inflammatory cells. New bone formation and the number of capillaries were significantly higher in the SN groups than in the other groups. The statistical analysis also showed that the numbers of osteoblasts, osteoclasts, and capillaries were highest in the N + SN group.ConclusionSystemic administration of SN may be effective in accelerating new bone formation and reducing inflammation in the maxillary expansion procedure. It may also be beneficial in preventing relapse after the expansion procedure.