Study on stress distribution of the condyle.
OBJECTIVE
To investigate the internal state of stress distribution in healthy human condyles and to offer some references for application of the temporomandibular joint (TMJ) biomechanics.


METHODS
Six male volunteers were selected to perform CT examination of the TMJ with 1.5 mm-thick sections at 1.5 mm intervals. Three dimensional image reconstruction of the joint was performed in the SUN workstation and the CT data were converted into the decimal system. The three dimensional finite element model mesh generation resulted from 1188 elements and 264 nodes in each condyle. Stress calculation was performed with SAP-V program, and the results were converted into mechanical density scalar. During the study, the internal state of stress distribution on each side condyle in every subject was analysed on the basis of loading on the anterior articular surface of the condyle.


RESULTS
Stress was concentrated in the anterior articular surface of the condyle and was highest at the loading point. The condylar cortical bone was the main load-bearing area. The level of stress distribution in the cancellous bone of the condyle was very low. Near condylar neck stress was well-distributed on the cortical. The internal state of stress was essentially symmetrical on the same cuts of both side condyles.


CONCLUSIONS
The results showed that three dimensional finite element analysis may indicate the internal state of stress distribution in the condyle, suggesting that a combination of the three dimensional finite element methods and the three dimensional imaging technique may be a useful means for diagnosis and treatment of TMJ diseases.
Hu
M
M
Department of Stomatology, General Hospital of PLA, Beijing, China.
Zhou
J
J
Hong
M
M
Ma
H
H
Tian
X
X
D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000502:physiology*; D013314:Stress, Mechanical; D013704:Temporomandibular Joint / Q000502:physiology*