AN IN VITRO BLUNT IMPACT EXPERIMENT UPON HUMAN CHINS

摘要

In order to investigate the mechanical relationship among the mandible -TMJ- skull during blunt impact, two fresh cadaver heads were impacted at the chins by a blunt body (about 6 kg) with velocity 1.1 m/s and 1.6 m/s. The impact forces were in the direction from the chin and vertically to the junction line of both sides of the condyles. It was found that the impact force-time curves were two peaks profiles. After the impact body contacting the chins, the impact forces rose rapidly to the first peaks (100.3/153.2 N, corresponding to 1.1/1.6 m/s of impact velocity) at 7.25/5.57 ms; then they slid for a while and rose again until reached the higher peaks (171.7/321.7 N) at around 21.1/20.1 ms; the total impact durations lasted about 46.1/42.6 ms. This paper obtained the dynamics characteristics of the mandible - TMJ - skull during blunt impact. It should be useful to further study the mechanical role in the genius TMJ disfunction resulted from facial trauma.