Histologic study of the cellular events during rat mandibular distraction osteogenesis.
OBJECTIVE
The cellular events, underlying bone regeneration through rat mandibular distraction osteogenesis (DO) was examined using micro computerized tomography (microCT), histology, and histochemistry.


METHODS
After 5-day latency, mandibles were distracted at 0.2 mm/12 h for 10 days, and fixed at latency 5 days (L5D), distraction 3, 6, 10 days (D3D, D6D, D10D), and consolidation 1, 3, 6, 10 weeks (C1W, C3W, C6W, C10W).


RESULTS
The microCT demonstrated radiopacity at the distraction gap (DG) during C1W, which was filled with new bone at C6W and C10W. At D3D, collagen fibers were aligned along the axis of the distraction vector. At D6D, alkaline phosphatase-positive osteoblasts and intramembranous ossification was observed. Collagen bundles became thicker with new bony trabeculae at D10D. Type II collagen-immunopositive areas first appeared at C1W. At C3W, cartilage tissue and endochondral ossification were found. By C6W, the entire DG had been bridged by new bone. The C10W specimens showed mature lamellar bone.


CONCLUSIONS
Mandibular DO produces bone through both intramembranous and endochondral ossification.
Ali
Mir Nowazesh
MN
Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Ejiri
Sadakazu
S
Kobayashi
Tadaharu
T
Anwar
Rezwana Binte
RB
Oda
Kimimitsu
K
Ohshima
Hayato
H
Saito
Chikara
C
D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology; D020219:Chondrogenesis / Q000502:physiology; D024022:Fibrillar Collagens; D017102:Fracture Healing / Q000502:physiology; D007124:Immunoenzyme Techniques; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery*; D010006:Osteoblasts / Q000166:cytology; D010010:Osteoclasts / Q000166:cytology; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D055114:X-Ray Microtomography
D024022:Fibrillar Collagens