Experimental study of mineralization in mandibular bone distraction with irradiation during the consolidation phase.
BACKGROUND
This study aimed at assessing the effect of radiotherapy on regenerated bone mineralization and consolidation obtained by mandibular bone distraction. The planned application was a new immediate mandibular reconstruction technique in defects following surgery for oral cavity tumours requiring postoperative radiotherapy.


METHODS
Ten sheep underwent bilateral mandibular bone distraction (control group). A second group of 6 sheep (study group) had bilateral mandibular bone distraction followed by irradiation on the 21st postoperative day. The animals were sacrificed on the 60th postoperative day. Radiographic and histomorphometric studies were performed.


RESULTS
In the control group, 9 distraction sites out of 20 were consolidated. In the irradiated group, 9 out of 12 were consolidated. Histomorphometric analysis did not demonstrate any statistically significant difference between the osseous and cartilaginous samples, the trabecular thickness of the new bone, or the osteoid surface of basal bone in the control and test groups (p=0.126, 0.247, 0.792, 0.082). However, the osteoid surface of the regenerated bone in the test group was statistically smaller (p=0.017) than in the control group.


CONCLUSIONS
In this experiment, radiotherapy did not hinder bone mineralization or consolidation following distraction of mandibular bone receiving irradiation on the 21st postoperative day. Bone distraction could be proposed for the repair of mandibular defects following surgery for oral tumours which require early postoperative radiotherapy.
Girod
Angélique
A
Department of Oral and Maxillofacial Surgery, Centre Hospitalier Lyon-Sud, Pierre-Benite, France. angelique.girod@curie.net
Roger
Thierry
T
Breton
Pierre
P
Bouletreau
Pierre
P
D000818:Animals; D001857:Bone Matrix / Q000473:pathology / Q000528:radiation effects; D001861:Bone Regeneration / Q000528:radiation effects; D016723:Bone Remodeling / Q000528:radiation effects; D002113:Calcification, Physiologic / Q000528:radiation effects*; D003094:Collagen / Q000528:radiation effects; D008334:Mandible / Q000473:pathology / Q000528:radiation effects / Q000601:surgery*; D010006:Osteoblasts / Q000473:pathology / Q000528:radiation effects; D010010:Osteoclasts / Q000473:pathology / Q000528:radiation effects; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods; D011878:Radiotherapy; D012756:Sheep; D013997:Time Factors; D014945:Wound Healing / Q000528:radiation effects
D003094:Collagen