Transplantation of human dental pulp stem cells: enhance bone consolidation in mandibular distraction osteogenesis

The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.

A randomized controlled trial was conducted. Eighteen skeletally immature New Zealand white rabbits were divided into 2 groups, with 9 in the control group and 9 in the SHED group. The SHED were isolated, expanded, and characterized. Six million cells were transplanted into the distracted area during the osteotomy period. After a 4-day latency period, a total of 6 mm was distracted for 6 days. The newly formed bone was analyzed radiologically, histologically, and histomorphometrically at 2, 4, and 6 weeks postoperatively. Nonparametric analysis of variance (Kruskal-Wallis test) was used for data analysis, and P < .05 was considered statistically significant.

The cell lineage was positive for the 2 mesenchymal stem cell markers tested (CD105 and CD166). More mature bone in the SHED transplanted group was observed radiographically and histologically. Histomorphologically, the percentage of newly formed bone after 2, 4, and 6 weeks was 18.41% and 41.53%, 31.68% and 59.78%, and 52.34% and 65.24% in the control and SHED groups, respectively. The difference between the groups was statistically significant (P = .012). The bone union and stage of bone maturity scores were significantly different between the control and SHED groups (P = .006 and P = .011, respectively).

Our findings suggest that SHED can serve as an additional cell resource for DO enhancement in rabbits and might be a promising model for the reconstruction of large mandibular defects in human oral maxillofacial surgery.