Mandibular reconstruction simulation with osseointegrated titaniumu scaffold

Research Project

Project/Area Number	16K11758
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Surgical dentistry
Research Institution	Yokohama City University
Principal Investigator	Takasu Hikaru 横浜市立大学, 附属市民総合医療センター, 助教 (60647999)
Co-Investigator(Kenkyū-buntansha)	廣田誠横浜市立大学, 医学部, 准教授 (20347305)
Project Period (FY)	2016-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000) Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000) Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Keywords	インプラントシミュレーション / 顎骨再建 / 有限要素法
Outline of Final Research Achievements	This study was conducted to determine the secure mechanical stress distribution on the marginally resected mandible using implant simulation to assume reconstruction with bone-integrated scaffold. Three or four implants were placed at near, middle, or far position from the resected margin in a simulation model with a symmetric marginal defect in the mandibular symphysis. When the isolated implant was placed at the middle position, the von Mises stress was < 10 MPa irrespective of bone height and was significantly lower than at the far position and was generally equal to that of the symmetric pattern. These results suggest that the asymmetrically positioned three-implant-supported fixed denture is an alternative option without increasing the stress on both the resected and peri-implant bone, as compared to the symmetrically positioned four-implant-supported fixed denture, when an isolated long implant is placed neither too close to nor too far from the resected margin.
Academic Significance and Societal Importance of the Research Achievements	辺縁切除後の下顎ではインプラント埋入が困難であり、骨結合型スキャホールドなど新規材料の開発が望まれる。切除された下顎では咬合を４点で受ける場合には切除部から離れた後方に作用点（インプラント）を置くことで応力が減少し、切除部およびインプラント周囲にかかる応力が最小になると考えられた。また、3本埋入した場合は1本側のインプラントを切除部から離れた位置に埋入することで、インプラント周囲の応力が許容可能な範囲になることが実証され、解剖学的に作用点を4点おけない場合でも、3点で上部構造が固定されていれば安定した咬合負荷が可能になる可能性が本シミュレーションから示唆された。