Objectives <p>This study evaluated bone healing in the maxillary anterior wall after Le Fort I osteotomy using a new cotton-like bone graft substitute (Rebossis^®), composed of beta-tricalcium phosphate and polylactic-co-glycolic acid, absorbable plates.</p> Materials and Methods <p>The anterior bony gap between maxillary segments was covered with Rebossis^®. Bone defect area and the area occupied by Rebossis^® were assessed using computed tomography immediately after surgery and at 1 year postoperatively.</p> Results <p>The study included 40 patients (80 sides) who underwent Le Fort I and mandibular osteotomies. Absorbable plates and screws were used to fix the maxillary segments in all cases. Cases were divided into a Rebossis^® group (40 sides) and a control group (40 sides). In the Rebossis^® group, graft area significantly decreased after 1 year (<i>p</i> &lt; 0.0001), and no residual bone defects were observed between segments. In the control group, although the bone defect area at 1 year was significantly smaller than that immediately after surgery in the frontal view (<i>p</i> &lt; 0.0001), complete bone healing was observed in only 5 of 40 sides. No postoperative infections and related clinical symptoms were observed in any patients.</p> Conclusion <p>Coverage of the intersegmental gap with Rebossis^® promotes new bone formation following Le Fort I osteotomy with absorbable plate fixation. This study was retrospective cohort study. This study was performed according to the Declaration of Helsinki, and was approved by the Ethical committee of the University of Yamanashi. Receipt number R06647.</p>