Reconstructing Mandibular Defects Using Autologous Bioengineered Tooth and Bone

Objectives: Significant drawbacks to current dental and jaw reconstruction procedures include the necessity for multi-step surgical procedures and bone grafts. To improve these methods, we investigated the feasibility of reconstructing both teeth and jaw tissues using a tissue engineering approach.

Methods: Tooth and bone constructs were generated from 3 to 6 month old mini-pigs as follows. Unerupted mandibular M3 molars were harvested, and the pulp organ and enamel organ were dissected apart. Dental mesenchymal cells derived pulp organ cells were seeded onto a polyglycolide/poly-L-lactide (PGA/PLLA) scaffold sphere, which was then wrapped with a dental epithelial cell seeded gelform strip. Bone constructs were prepared by seeding iliac crest bone marrow derived osteoblasts, harvested from the same animal, onto a poly-DL-lactic-co-glycolic acid (PLGA) foam scaffold. The tooth and bone constructs were combined and implanted back into the same mini-pig mandible as an autologous reconstruction. After 12 and 20 weeks, the implants were harvested and evaluated by X-ray, ultra high resolution volume computed tomographic (VCT), histological, and immunohistochemical analyses.

Results: Organized bioengineered dental tissues closely resembling those of naturally formed teeth, and regenerated bone, were observed. Immunohistochemical analyses revealed the expression of tooth and bone specific markers on the bioengineered tissues.

Conclusion: The results of this pilot study suggest the feasibility of combined tooth and mandible reconstructions using tissue engineering approaches, using the clinically relevant autologous minipig model. Further optimization of this technique need to be considered, as guided by the results of this pilot study.

This research was supported by NIH/NIDCR Grant DE016370-01.