Bioengineering of the Teeth and Jaws to Clinical Practice

Pill-Hoon Choung, DDS, MSD, PhD
Department of Oral and Maxillofacial Surgery
Tooth Bioengineering National Research Laboratory
BK21 Dental Research Institute, School of Dentistry
Seoul National University, Seoul, Korea.

To bioengineer the mandible, we used a whole mandibular culture system via in vitro and in vivo organ culture in mouse. The whole mandibular explants were cultured and investigated whether artificial and controlled development of mandibular structures could be possible. In addition, to investigate the tooth development in the none-tooth bearing area, the tooth germs were transplanted into the toothless gap, diastema of the developing mandible. Also to study the effect of growth factors on the tooth development, some proteins were added during culture period. In this preliminary study, a combination of in vitro and in vivo culture techniques to attempt to fabricate the mandible could lead to the growth of the mandible, development of its supporting structures, and formation of the dental crown and root. The results of this study indicate that artificial development of mandibular structures is possible and in the future might be applied to jaw reconstruction. Furthermore, we isolated and cultured 4 dental stem cells from human teeth. As an in vivo study, a combination of calcium hydroxide and autologous dental pulp stem cells (DPSCs) was applied for the treatment of intentionally created tooth defects in beagle dogs. It was evident that calcium hydroxide increased recruitment, migration, proliferation, and mineralization of the DPSCs. Such results are valuable for future availability of DPSCs, which are recently focused as the stem cell reservoir for regeneration of dentin upon tooth injury. These dental stem cells seem to be applied to alveolar bone and periodontium reconstruction.

As a clinical practice, “the novel bioengineering methods for the maxillo-mandibular reconstruction” based on “auriculo-mastoid osteo-fascio-cutaneous flap” system will be introduced in this presentation. When vascularized skin and bone flap were required simultaneously, we designed a new method of auriculomastoid fascio-cutaneous (AMFC) island flap (J. Oral and Maxillof. Surg. 54:559-567, 1994) combined with the parietal osteofascial (POF) flap (J. Cranio-Max.-Fac. Surg. 19:235-242,1991) pedicled on a single base and named it “the auriculomastoid osteo-fascio-cutaneous (AMOFC) flap”. Also a new bioengineering method of maxillo-mandibular cutaneous reconstruction based on the principle of the AMOFC flap system (11 cases, which have been followed-up for 10 years) will be presented compared with 63 vascularized bone grafts. These bioengineered composite flaps seem to be very useful in reconstruction of maxillofacial soft tissue and bony defects. It is reliable and does not require microvascular anastomosis, with many additional advantages and various modifications of compound designs. The potentials and opportunities of nanotechnology in this important and exciting field of research will also be discussed.

Biography of Professor Pill-Hoon Choung (DDS, MSD, PhD)

1979. 2:  Graduated from College of Dentistry, MSD (1982), PhD (1987),

Seoul National University, Seoul, Korea

1985.6 ~ 1989.1: Associated Professor, Chairman

Dept. of Dentistry, College of Medicine, Choongnam National University

1989.1 ~ present:  Professor

Dept. of Oral & Maxillofacial Surgery, College of Dentistry,

Seoul National University

1998.10 ~ present: President

Korean Association of Research and Charity on Cranio-facial Deformity

2004.6 ~ present: Vice President

Korean Tissue Engineering and Regenerative Medicine Society

2004. 8 ~ present: Member

The Korean Academy of Science and Technology

2004.12 ~ 2006.12:  Dean

School of Dentistry, Seoul National University

2006.8 ~ present: Director of Tooth Bioengineering National Research Lab.

2007.10 ~ present:  Vice President

Korean Association of Sports Dentistry

2009.12 ~ present:  President,

Korean Society for Stem Cell Research

2008.12 ~ Present:  Dean

School of Dentistry, Seoul National University