One of the most obvious conditions requiring craniofacial reconstruction is the cleft lip and palate patient. This is the most common congenital craniofacial anomaly worldwide occurring in 1:300 - 1:2500 live births (Stanier and Moore 2004). At the moment, all craniofacial skeletal reconstruction, whether for a congenital or acquired defect, involves bone grafting which essentially transfers compressed bone marrow with its resident stem cells to a defect. Unfortunately, obtaining the bone graft requires a second surgical site, typically a second surgical team, prolonged anesthesia and hospitalization, and increased risks to the patient. Despite the magnitude of the problem, there has been very little progress in bone regeneration for the facial skeleton that reduces these risks. My research involves understanding and characterizing postnatal mesenchymal stem cells from two sources with the goal of clinical application, particularly in patients with craniofacial congenital anomalies.
Stem cells from human exfoliated deciduous teeth (SHED) have been shown to form a significant amount of bone when the stem cells are transplanted into immunocompromised mice (Miura, Gronthos et al. 2003). We have demonstrated that the same stem cells from pig deciduous teeth have similar bone forming capabilities. We intend to utilize these newly identified stem cells from deciduous teeth and determine whether they are clinically sustainable and sufficient in preclinical large animal models, such as the mini-pig.
The postnatal skeleton has limited regenerative capacity and very little is known about the regeneration that occurs and the factors that influence and regulate bone formation. In contrast to other skeletal sites, the costochondral graft site has been documented to regenerate completely. This model provides an opportunity to study the progression toward complete bone formation. We have quantified the regenerative capacity of patients of varying ages and are presently evaluating the differentiation capacities of their respective bone marrow mesenchymal stem cells.