[Study on the changes of TMJ stress before and after sagittal split ramus osteotomy by 3D finite element method].
OBJECTIVE
To investigate the characteristic changes of the TMJ stress distributions, before and after SSRO for treating the skeletal class III malocclusion, being during centric occlusion.


METHODS
CT scan was used to obtain 2-D transverse image of maxilla and mandible. Finite element models were established before and after SSRO. An analysis of the stress, strain, and displacement of TMJ configurations was done by three-finite element method. Paired t test was used to compare the stress before and after operation.


RESULTS
The Von Mises stress on TMJ configurations was found to decrease significantly after mandibular set-back SSRO; The maximal and minimal principal stress and maximal displacement were also found to decrease after surgery; The stress of both sides of the TMJ was found to distribute symmetrically.


CONCLUSIONS
Oral and maxillofacial deformity was treated by orthognathics surgery, jaws were repositional that induce the changes of the TMJ stress, the upper and lower further study should be done to determine the stress changes effecting the function and health of TMJ.
Joint Orthodontics-Orthognathics Center, Ninth People's Hospital, School of Stomatology, Shanghai Second Medical University, Shanghai 200011, China. judy63fb@yahoo.com
Bing
B
Fang
Qi
Q
Zhou
Guo-fang
GF
Shen
Zhong
Z
Cai
D020342:Finite Element Analysis; D006801:Humans; D019248:Jaw Fixation Techniques; D008313:Malocclusion, Angle Class III / Q000601:surgery; D008334:Mandible / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000379:methods*; D010027:Osteotomy / Q000379:methods*; D013314:Stress, Mechanical; D013704:Temporomandibular Joint / Q000503:physiopathology*