Objective: The aim of the study was to evaluate the mechanical behavior of three different fixation methods used in the bilateral sagittal split ramus osteotomy. Materials and Methods: Three different three-dimensional finite element models were created, each corresponding to three different fixation methods. The mandibles were fixed with double straight 4-hole, square 4-hole, and 5-hole Y plates. 150 N incisal occlusal loads were simulated on the distal segments. ANSYS software ((v 10; ANSYS Inc., Canonsburg, PA) was used to calculate the Von Mises stresses on fixative appliances. Results: The highest Von Mises stress values were found in Y plate. The lowest values were isolated in double straight plate group. Conclusions: It was concluded that the use of double 4-hole straight plates provided the sufficient stability on the osteotomy site when compared with the other rigid fixation methods used in this study.