Expression of MMP-1 and TIMP-1 in irradiated mandibles during distraction osteogenesis.
OBJECTIVE
The study aimed to evaluate the expression of MMP-1 and TIMP-1 in irradiated mandibles during distraction osteogenesis.


METHODS
Rabbits in the experimental group received preoperative radiation of 9 Gy for 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency. Three rabbits in the control and experimental groups were killed at days 7, 12, 18, and 25. Specimens were subjected to immunohistochemical examination and real-time polymerase chain reaction analysis.


RESULTS
At day 7, expression of MMP-1 and TIMP-1 was significantly suppressed in the radiotherapy group in contrast to the control group. At day 12, expression of MMP-1 was significantly higher in the control group. At day 18, expression of MMP-1 and TIMP-1 was significantly higher in the control than in the radiotherapy group.


CONCLUSIONS
Radiotherapy changes the expression pattern of MMP-1 and TIMP-1.
Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China.
Wen Biao
WB
Zhang
Li Wu
LW
Zheng
Daniel Tsin Tien
DT
Chua
Lim Kwong
LK
Cheung
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D006801:Humans; D007150:Immunohistochemistry; D008334:Mandible / Q000201:enzymology / Q000378:metabolism*; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D019857:Osteogenesis, Distraction; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
D017931:DNA Primers; D019715:Tissue Inhibitor of Metalloproteinase-1; D020781:Matrix Metalloproteinase 1