Experimental investigation using hypofunction model following botulinum neurotoxin injections on developmental disorders of the craniofacial morphology and the masticatory function

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K20649
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Orthodontics/Pediatric dentistry
• Research Institution: Nagasaki University
• Principal Investigator: FUJISHITA Ayumi 長崎大学, 病院(歯学系), 医員 (30755723)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: マウス / 機能低下 / 咀嚼運動メカニクス / ボツリヌストキシン

Outline of Final Research Achievements

In this study, we use the mice model for evaluating the effect of muscle hypofunction following botulinum neurotoxin injections on the craniofacial growth. We took the CT data for morphological analysis. In addition, three-dimensional jaw movements and EMG of the masseter and temporalis muscles were recorded while mice were chewing. Hypofunction group showed unstable jaw movement and their jaw movement trajectories were changed. Besides, in morphological analysis, hypofunction group showed changes of the mandible shape compared with the control group.
These results suggest that a part of functional disorders affect the all mechanisms of mastication. Furthermore, it appears to have a great effect on craniofacial morphology and masticatory function at the growth period.

Free Research Field

歯科矯正学

Academic Significance and Societal Importance of the Research Achievements

本研究ではボツリヌストキシンを筋注入することで、血液供給を持続させたまま、手術に伴う瘢痕を形成することなく特定の咀嚼筋機能を低下させ、顎骨の形態変化を解析することが可能であった。また、形態データと顎運動・咀嚼筋筋電図の同時記録とを組み合わせることで、同一個体の機能および形態変化を関連付けて検討することができ、その結果機能と形態との相互関連が示唆された。本研究結果は成長期における摂食機能障害、ならびに顎骨の発育不全に起因する不正咬合の早期治療・形態機能回復リハビリテーションの検討に貢献するものであると考える。