Comparison of the effects of mandibular advancement and regression surgeries on temporomandibular joint in patients undergoing sagittal split ramus osteotomy with three-dimensional finite element analysis

SSRO is one of the most commonly used orthognathic surgical procedures for the correction of mandibular deformities. It has been reported that TMR may develop after correction of mandibular deformities with SSRO, and factors that may contribute to this situation have been investigated in various studies. The aim of this study is to evaluate and compare the stress changes in the TMJ with SEA after mandibular setback and advancement surgeries using SSRO. In the current study the stresses on the TMJs mandibular setback (5 mm and 10 mm) models, mandibular advancement (5 mm and 10 mm) models using SSRO and the control model without osteotomy were analyzed using the SEA method. In the study, in which the articular disc was modeled as non-linear and superelastic, the stresses on the articular fossa, disc and condyle were evaluated and compared. As a result of the findings; It was concluded that the increase in stress on the TMJ components in mandibular advancement models is significantly higher than in setback models, and this may contribute to the development of joint problems such as disc perforation and/or condyle resorption, especially in cases where the excessive mandibular advancement. In mandibular setback models, on the other hand, it is thought that higher stresses on the condylar cartilage may increase the risk of condyle resorption with the increase in the amount of setback.