抄録
[Purpose] In this study, we evaluated the usefulness of a PLLA bioabsorbable osteosynthetic plate (FIXSORB-MX®) for bone fixation after sagittal splitting ramus osteotomy (SSRO), and the postoperative stability of the PLLA plate and a titanium mini-plate was comparatively evaluated by lateral cephalograms.
[Subjects and methods] Seventy-three patients, who received SSRO using a PLLA plate, between June 1998 and February 2000, were clinically evaluated, and physical properties of the excised PLLA plates were analyzed. Also, the postoperative stability of PLLA plates was evaluated using lateral cephalograms obtained immediately after, 6 months after, and 1 year after sugery in 10 patients who had received surgery more than 1 year previously. In addition, 10 patients received a titanium mini-plate. Patients who showed severe open bite and asymmetry of the mandible were excluded.
[Results] Of the 73 patients who received surgery using a PLLA plate, 2 showed displacement of the proximal segment, 2 developed fistulation, and 2 cases had persistent tenderness over the plate, and the plate was removed in 4 of them. The viscosity molecular weight of the plate at the removal was 60, 000, 24, 000, and 16, 000, in 3 of the 4 patients. Concerning the stability, no clear regression was observed in either the titanium mini-plate group or the PLLA plate group. From these observations, PLLA plates are considered to be clinically useful, since they are as stableas titanium mini-plates, and they do not have to be removed after implantation.
