ABSTRACT
Objective:To study the biomechanical characters of human mandible under compression load and to deduce the constitutive equation.Methods: Specimens taken from five mandible of fresh human cadavers were examined on INSTRON by a group of tensile tests at different strain rates (0.000 5,0.005,0.05 and 0.5 s-1).Bone mineral density of every individual mandible was measured.The effects of strain rate(**),bone mineral density (ρ) on Young'Modulus (E),strength(σu)and ultimate strain(εu) were studied and the constitutive equations were deduced using the following model:Y=aρb**c.Results:(1)σu=216.27ρ1.23**0.055（P<0.01），(2)E(Pa)=5 604.024**0.083（P<0.01）,(3)εu =0.045**-0.045（P<0.01）,(4)σu=1 798.87ρ-1.17**0.083ε0.82（P<0.01).Conclusions:Strain rate and bone mineral density are important factors for the biomechanical characters of human mandible under compression load.Based on the constitutive equations,the stress level,the possibility and degree of mandible injury may be estimated.