Effect of bone quality on the artificial temporomandibular joint condylar prosthesis

ObjectiveThis study evaluated the effect of bone quality on the stability of and stress in the artificial temporomandibular joint (TMJ) condylar prosthesis as well as on the stress and strain distributions in the bone.Study designThree-dimensional finite element models of the mandible and an artificial TMJ condylar prosthesis using 3 screws were established. Four types of bone were modeled by varying the elastic modulus of cancellous bone.ResultsIncreasing the bone quality from type IV to type I reduced the maximum relative micromotion between implant and bone, maximum von Mises stresses in the implant and surrounding cortical bone, and maximum von Mises strain in the surrounding cancellous bone by 17.5%, 10.5%, 12.0%, and 39.4%, respectively.ConclusionThe bone quality of the mandible has only a minor effect on the stability of and stress in an artificial TMJ implant and cortical bone, but it greatly affects the microstrain in cancellous bone.