Objectives: In this study, we designed a new technique for open septal reduction using a polydioxanone (PDS) plate and compared it with closed reduction. Design, Setting, Participants: This study included nineteen consecutive patients with nasoseptal fracture: ten receiving open reduction with a PDS plate (PDS group) and nine undergoing closed reduction (CR group). Open septal reduction was performed after closed reduction for nasal bone fracture. A mucoperichondrial flap was unilaterally elevated, and the deviated septal cartilage was reduced. The PDS plate was inserted horizontally above the vomerine suture. Surgical outcome was analyzed with three-dimensional volumetry and with a quality-of-life scale for nasal obstruction (NOSE scale). Results: Complications included one case of septal perforation in the CR group and one case of PDS exposure and septal hematoma in the PDS group. In the 3D volumetric analysis of the PDS group, the median value of the nasal cavity change significantly differed between 1.14 mL (interquartile range; 0.46 to 2.4) at the preoperative CT scan and 0.33 mL (interquartile range; -0.22 to 1.29) at the postoperative CT scan (**p = 0.0039). The NOSE scale revealed significant improvement in nasal obstruction postsurgically (median value, 42.5 to 7.5; *p = 0.0139) in the PDS group. Conclusion: PDS plates potentially present a new concept of open septal reduction in terms of septal reinforcement compared with the subtractive approach of open septal reduction.