Regulating the role of bone morphogenetic protein 4 in tooth bioengineering

Purpose: Culture of the whole organ and regulation of its development using biologic and engineering principles can be used to produce structures and organs for reconstructing defects. The application of these bioengineering approaches in artificial tooth development may be the alternative way to replace missing dentition. Materials and Methods: For the artificial bioengineering of a mouse tooth, tooth buds were dissected and transplanted into the diastema of the developing mandible. The mandiblular primordia containing transplanted tooth buds were culture in vitro and in vivo using a bioengineering method. In addition, to regulate the development of tooth germs, bone morphogenetic protein 4 (BMP4) or its antagonist, Noggin was administered. Results: After the period of in vitro and in vivo culture, the transplanted tooth germ in the diastema showed tooth development with supportive structure formation. In the BMP-treated group, the bioengineered tooth was observed with increased maturation of cusp and enamel matrix. However, in the Noggin-treated tooth germs, the developing molar had a crater-like appearance with the immature development of the cusp and suppressed formation of the enamel matrix. Conclusions: This study confirmed that tooth germ transplantation in the diastema and culture with administration of BMP4 could lead to the mature development of the dental structures. in addition, these results suggest the possibility of bioengineering the tooth in morphogenesis and differentiation even in the toothless area. (C) 2007 American Association of Oral and Maxillofacial Surgeons.