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[Clinical study of stress shielding after mini-plate internal fixation for mandibular fractures].

OBJECTIVE
To investigate the stress shielding after mini-plate internal fixation for mandibular fractures.


METHODS
Eighteen patients with mandibular fractures were selected.X-rays were taken before operation and 3, 4, 6 months after operation when the plates were removed. The bone density of the mini plate area was examined and compared among different time interval groups.


RESULTS
The bone density before operation (125.41 ± 2.47) and 3 months after operation (120.19 ± 3.52) was not significantly different, but became lower 4 and 6 months after operation than before operation.


CONCLUSIONS
There appeared stress shielding after internal fixation for 4 and 6 months in mandibular fracture, and the mini plate should be removed at those times.