Bioabsorbable plates and screws for bone fixation system have been used owing to many advantages over conventional metallic devices. This study investigated the effects and safety of recently developed modifiable bioabsorbable plate and screw made of 100% poly (L-lactic acid) in the healing process of mandible fracture in arabbit model. In vitro extract test for cytotoxicity and bacterial reverse mutation test for genotoxicity were carried out. Any cytotoxicity caused by extract from experiment sample was not observed. In genotoxicity test, increase in the number of revertants was not observed. As an in vivo test, plates and screws were used for rigid fixation of exper-imental mandible fracture in twenty rabbits. Tissue specimens with plate were taken from the rabbits after 4, 6, 8,10 weeks and histological analysis was studied. After 4 weeks, the plate was covered by connective tissue and severe chronic active inflammation in soft tissue was observed. After 6 weeks, absorbed part in plate and new bone forma-tion around periostium and decrease in inflammation were detected. After 10 weeks, new bone formation was observed in all samples and the thickness of bone increased. The remodeling was not complete yet. This study dem-onstrates that recently developed biodegradable plate and screw system made of poly(L-lactic acid) was effective in mandible fracture regions known as high load-bearing areas. This indicates that bioabsorbable poly (L-lactic acid) plates and screws are available for most of bone fractures, although the adjustment process and long-term follow-up study are necessary for clinical application.