The usefulness of poly-L-lactide acid (PLLA) screws for fixation in sagittal splitting ramus osteotomy (SSRO) was discussed.<BR>The subjects were 10 patients with mandibular prognathism who underwent SSRO with rigid fixation by PLLA screws between February 1998 and August 1999. The clinical symptoms and X-ray findings of the mandible around screws were evaluated. The postoperative changes of point B, Pogonion and Menton at 3 months following surgery were measured on lateral cephalograms. Thirty patients who underwent SSRO fixed by stainless steel screws were selected as a control group.<BR>X-ray findings revealed osteosclerotic changes around 12 PLLA screws. Concerning the change in the position of measuring points on the mandible, no significant difference was observed between the PLLA group and the control group. No complications were observed clinically.<BR>The results suggested that the PLLA screw is useful for fixation in sagittal splitting ramus osteotomy.