The effect of screw size and insertion technique on the stability of the mandibular sagittal split osteotomy

The effect of screw size and insertion technique on the stability of sagittal split osteotomies was evaluated on 10 cadaver mandibles. The mandibles were osteotomized, and stabilized with either 2.0- or 2.7-mm stainless steel screws inserted as lag screws or position screws. All specimens were tested on an MTS servohydraulic testing machine (MTS Systems, Inc, Minneapolis, MN) to determine the strength and stability of the fixation. There were no statistically significant differences between the strengths achieved with the different screw sizes or fixation techniques. The primary variable that determined stability seemed to be the quality of the underlying bone.