The purpose of this study was to investigate the stress distribution and the biomechanism of mandibular condylar fracture, because the condyle is one of the sites predisposed to fracture. Clinical and experimental studies on the fracture mechanism have so far been undertaken by a number of our precedessor. It’s possible that fracture pattern of condylar process was influencend by the morphological characteristies of the condylar head.
In this analysis, loading was applied to four directions in the model of the mandibular body, and three directions in the model of the condylar head.
The results obtained were as follows:
1. Lange stress arised on the condylar head in simulated model with the loading on the mandible symphysis rather than mandible angle, and maximal principal stress arised on the articular eminence.
2. It were supposed that fracture arised on the condylar neck with tendency of the maximal stress on the condylar neck with the all 4 types when the 45 degree and horizontal loading was directed into condylar head. Especially, the tendency was remarkable on the horizontal load of convex type. The stress was remarkable on the pole area in the vertical loading.
3. With the same loading these were supposed that comminuted fracture on the condylar head arised on convex and round type. Especially, the tendency was remarkable in the convex type.
4. The size of displacement was observed in the direction of horizontal, 45 degree and vertical to the descending parameter. The direction of displacement was observed on the upper area of the mandibular head to the internally to the horizontal and 45 degree loading with the all cases, and externally to the vertical loading with the flat and angled cases. Especially, the internal displacement tendency was observed on the condylar head to the all derectional loading with the convex type.
Above results suggest that condylar fracture is supposed with the loading on the mandible. Especially, frequency of the fracture is remarkable on the condylar neck area.
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