Lag screw versus position screw techniques for rigid internal fixation of sagittal osteotomies: a comparison of stability.

Both lag screw and position screw techniques have potential advantages and disadvantages when used for securing sagittal osteotomies of the mandible. This study evaluated 56 patients undergoing bilateral sagittal split osteotomies for mandibular advancements. Osteotomies were fixed with either a position screw or lag screw technique using 2-mm self-threading screws. Five cephalometric points and two angles were used to evaluate skeletal changes. There were no statistically significant differences in the postsurgical movement of point B or the mandibular incisor. There were slight statistically significant differences in the horizontal and vertical movements of gonion. Overall, similar postoperative stability existed in both groups. Gonion and gonial angle changes were detected cephalometrically but had no effect on the clinical outcome.