Differential Recovery Patterns of the Maxillofacial bone and muscles after eliminating nasal obstruction in growing rats

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10198
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57070:Developmental dentistry-related
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: Yonemitsu Ikuo 東京医科歯科大学, 大学院医歯学総合研究科, 助教 (00431940)
• Co-Investigator(Kenkyū-buntansha): 清水 康広 東京医科歯科大学, 歯学部, 非常勤講師 (60631968)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 鼻呼吸障害 / 上顎骨 / 下顎骨 / 咀嚼筋 / 顎顔面成長 / 回復

Outline of Final Research Achievements

Nasal obstruction during growth has a suppressive effect on maxillofacial growth, however, there are no previous studies that have clarified whether it is possible to recover to the normal growth volume by improving nasal obstruction and the optimal timing of its treatment. In this study, we clarified these issues using a rat model for restoring nasal obstruction.
Forty-two 4-week-old male Wistar rats were randomly divided into six groups (C, W1, W3, W5, W7 and W9) according to the timing of recovery(n=7). The left nostril was sutured and removed to reproduced unilateral nasal obstruction and its recovery. Morphological growth recovery of the maxillary and mandibular bones and masticatory muscles were observed when the nasal breathing disorder was recovered, suggesting that the optimal timing for each area.

Free Research Field

矯正歯科

Academic Significance and Societal Importance of the Research Achievements

鼻閉は口呼吸を誘発し、全身に様々な悪影響を与えることが報告されている。鼻閉モデルを用いた基礎研究において、咀嚼筋の成長阻害を介した下顎骨・下顎頭成長の抑制が明らかにされてきた。しかし、鼻呼吸障害に対する介入による顎顔面への影響や、その成長回復が何歳まで期待できるかという臨界期を明らかにした研究は存在しない。
本研究において、成長期ラット鼻呼吸障害モデルを用いて、鼻閉塞解除後に顎顔面形態が正常な成長を遂げるかを明らかにし、形態学的および組織学観点から最適な介入時期を明らかにしたことは、小児の顎顔面成長を明らかにする上で、大変重要な意義を与えるものと考える。