Maxillofacial bone regeneration with osteogenic matrix cell sheets: An experimental study in rats.
OBJECTIVE
Regeneration of maxillofacial bone defects, characterized by relatively small but complicated shapes, poses a significant clinical challenge. Osteogenic matrix cell sheets (OMCSs) have osteogenic ability and good shaping properties and may be ideal graft materials. Here, we assessed whether implantation of OMCSs could be used to repair maxillofacial bone defects.


METHODS
We adopted a rat mandibular symphysis model. The rat mandible is formed by a paired bone and the central portion consisting of fibrous tissue. There is no bone tissue at the site; accordingly, this site was interpreted as a physiological bone gap and was used for evaluation. Rat bone marrow cells were cultured in medium containing dexamethasone and ascorbic acid phosphate to create OMCSs. The OMCSs were implanted into the rat mandibular symphysis without a scaffold. Microcomputed tomography and histological analyses were conducted after 2, 4, and 8 weeks.


RESULTS
Two weeks after implantation, microcomputed tomography images and histological sections showed some sparse granular calcification tissue within the bone gap at the mandibular symphysis. At 4 weeks, the calcification tissue spread, and the gap of the mandibles were continued. At 8 weeks, this continuous new bone tissue was matured. The experimental group showed abundant new bone tissue in the group with OMCS implantation, but not in the group with sham implantation.


CONCLUSIONS
Our present results indicated that use of OMCSs may be an optimal approach towards achieving maxillofacial regeneration.
Department of Oral and Maxillofacial Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: ueyama@naramed-u.ac.jp.
Yoshihiro
Y
Ueyama
Department of Oral and Maxillofacial Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: t-yagyuu@naramed-u.ac.jp.
Takahiro
T
Yagyuu
Department of Oral and Maxillofacial Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: m-maeda@naramed-ua.c.jp.
Masahiko
M
Maeda
Department of Oral and Maxillofacial Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: mitsuhiko-imada@naramed-u.ac.jp.
Mitsuhiko
M
Imada
Department of Public Health, Health Management and Policy, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: makahane@naramed-u.ac.jp.
Manabu
M
Akahane
Department of Artificial Joint and Regenerative Medicine for Bone and Cartilage, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: kkawate@naramed-u.a.c.jp.
Kenji
K
Kawate
Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: yatanaka@naramed-u.ac.jp.
Yasuhito
Y
Tanaka
Department of Oral and Maxillofacial Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan. Electronic address: tkirita@naramed-u.ac.jp.
Tadaaki
T
Kirita
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001861:Bone Regeneration / Q000502:physiology*; D002454:Cell Differentiation; D003907:Dexamethasone / Q000494:pharmacology; D007150:Immunohistochemistry; D008334:Mandible / Q000000981:diagnostic imaging / Q000254:growth & development*; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D051381:Rats; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
D003907:Dexamethasone; D001205:Ascorbic Acid
Bone marrow-derived stromal cells; Bone regeneration; Cell sheet; Mandibular defect