This study evaluated the transverse strength (rigidity) of three groups of sagittal split osteotomies performed in vitro in fresh sheep mandibles. Fixation was accomplished utilizing two different position screw techniques and a monocortical plate technique. Osteotomies fixed with three 2.0-mm screws in an inverted-L pattern and those fixed with on e monocortical miniplate were significantly more rigid than those fixed with two 2.7-mm screws placed in a line ar pattern. No significant difference in rigidity was noted between the inverted-L group and the miniplate group.