Elucidation of pathological mechanism of progressive condylar resorption from the point of view of estrogen and inflammatory cytokine

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K20434
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Pathobiological dentistry/Dental radiology
• Research Institution: Tohoku University
• Principal Investigator: NOGAMI Shinnosuke 東北大学, 歯学研究科, 助教 (70573575)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 進行性下顎頭吸収 / 顎関節 / 下顎後退症 / 炎症性サイトカイン

Outline of Final Research Achievements

We compared condylar resorption between ovariectomized and non-ovariectomized rabbits. These rabbit's TMJs were under mechanical stress. The rabbits were allocated into three groups and were sacrificed at 1 week, 2 weeks, and 4weeks. Scores for the area of bone resorption were higher in the ovariectomized group than in non-ovariectomized group. Moreover, scores for the depth of bone resorption were higher in ovariectomized group than those in non-ovariectomized group. For the depth and area in 2 weeks, the largest amount of bone resorption was observed in the ovariectomized group. There were substantially more cells that were positive for tartrate-resistant acid phosphatase in the ovariectomized group than in non-ovariectomized group. These results suggested that estrogen may be related to condylar resorption and repairing mechanism of bone metabolism in TMJs with ovariectomized rabbits was normal.

Free Research Field

口腔外科

Academic Significance and Societal Importance of the Research Achievements

本研究は、我が国において難治性疾患の一つに挙げられる、進行性下顎頭吸収（ Progrssive Condylar Resorption:PCR）の病態解明を目的としている。実際に臨床で経験したPCR症例は顎関節症の既往があり、さらに低容量ピルの服用をしている女性に多く見られた。顎関節症では復位を伴わない関節円板の前方転位症例がほとんどだった。エストロゲンが下顎頭吸収に関与することは本研究の結果より明らかとなったが、骨代謝の修復機構も働いており、進行性下顎頭吸収の原因は下顎頭に対する過度なメカニカルストレスやエストロゲン以外にも関与していることが示唆された。