利用動態反應分析下顎骨外傷機轉

Since dynamic response analysis is an important basis for examining the mechanism of trauma, in order to evaluate the possibility of vibrational assessment of the mandible, in this study, resonance frequency (RF) was carried out as a parameter for assessing the relationship between the dynamic behavior of the mandible and mandibular fractures. Ten mandibles positioned on a soft cushion to provide free-free boundary conditions were tested using a model testing method. Each mandible was triggered to vibrate by an impact hammer at 7 points which were designated by clinical fracture sites. Then the RE values and vibrational mode were recorded. Our results showed that the RE values fell between 560 and 598 Hz with a mean cit 578.6±11.67Hz. Then, the RF value of the finite element (FE) model was calculated as 567.3 Hz which was only 1.9% smaller than the results of the in vitro test. That is, the EE model was validated as a credible model for dynamic response analysis. The RE value of a fresh mandible was then calculated as 501.4 Hz using the FE model. The result also indicated that the middle area of the mandibular body is probably a nodal position where bone fracture is less likely to occur. On the contrary, the greatest amplitudes were found in the parasymphysis of the mandible and in the subcondyle region where bone fractures are prone to occur The results obtained from this study provide insights into the basic dynamic properties of the human mandible.