**2. Characteristics of stem cell research**

Mesenchymal stem cells are characterized by the capability of osteogenic, adipogenic, and chondrogenic differentiation [7]. Previously, the stem cells derived from the periosteum and bone marrow of the jaw bone (mandible) and long bone (tibia) were compared in order to determine a suitable cell source [8]. A bone marrow-derived mesenchymal stem cell sheet with platelet-rich plasma could promote bone regeneration [9]. Bone marrow is an attractive source of stem cells, but gaining stem cells from bone marrow may produce greater pain and morbidity [10]. Stem cells can also be achieved intraorally, and gingiva may serve as a more feasible source for stem cells because obtaining gingival-derived stem cells can be done under local anesthesia with less pain and morbidity [11].
