[The post-injury regenerating ability of temporomandibular joint of rats exposed to the repeated + Gz forces].
OBJECTIVE
To observe the post-injury regenerating ability of temporomandibular joint of rats exposed to the repeated + Gz forces.


METHODS
One hundred and eight male rats were randomly assigned to 9 groups, with 12 rats in each group. Group A was normally fed serving as the blank control group. Group B was only fixed with rat-kept devices for 5 minutes as the fixed control group. Group C was borne +1 Gz for 5 minutes. In the same position as group C, group D, E, F, G, H and I were repeatedly exposed to +10 Gz for 30 seconds each time with 5 times a day and +1 Gz for 1 minutes as a interval. The 6 groups were treated in the condition above for 4 days a week and 4 weeks in total. The rats in group A, B, C and D were killed on the next day after the centrifuge. The rats in group E, F, G, H and I were killed at 1, 2, 4, 8 and 12 weeks after the centrifuge, respectively. After the rats were killed, temporomandibular joint were taken for observation under optical microscope, scanning electron-microscope (SEM) and transmission electron-microscope (TEM).


RESULTS
There was no significant difference observed in group A, B and C. But in group D, E, F, G, H and I pathologic injuries and self-regeneration were seen in TMJ in different degrees.


CONCLUSIONS
The injury of TMJ could regenerate gradually with time.
Ma
Liang
L
Department of Scientific Research, General Hospital of PLA, Beijing 100853, China.
Hu
Min
M
Sun
Zhen-yu
ZY
Chen
Hua
H
Li
Chun-hai
CH
Xie
Zhong-chen
ZC
D000054:Acceleration / Q000009:adverse effects*; D000818:Animals; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013704:Temporomandibular Joint / Q000293:injuries* / Q000473:pathology* / Q000648:ultrastructure