This article reports the influence of an autologous leukocyte-and platelet-rich plasma (L-PRP) injection as a minimally invasive method on supporting wound healing processes after a mandibular odontogenic cystectomy and double mandibular fracture fixation. 113 patients were enrolled into a control group (received no L-PRP injection) and 102 patients were enrolled into an L-PRP group with an oral mucosa incision. 18 patients after a double mandibular fracture were operated on using 2 external submandibular approaches receiving no fluids in the right site (a control group) and an L-PRP injection in the left incision (L-PRP group). Clinical observations showed that the oral mucosa healed faster in patients treated with L-PRP, in comparison to cases where inductive biomaterial was not added. Pain at the L-PRP injection site was relieved within few hours after an operation in patients with double mandibular fractures. However, there were no differences observed in the progression of the healing process. L-PRP possesses inductive properties that could stimulate healing processes and it seems to be one of the most promising methods in the future for the treatment of soft tissue defects