Mechanism underlying orthodontic force-induced pain focusing on nociceptin

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K19300
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57070:Developmental dentistry-related
• Research Institution: Kyushu Dental College
• Principal Investigator: Sago Misa 九州歯科大学, 歯学部, 助教 (40815825)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 歯科矯正 / 疼痛

Outline of Final Research Achievements

Many orthodontic patients complain of pain and tooth discomfort, which peak at 1 day after applying orthodontic force and gradually resolve within 5-7 days. Nickel titanium coil springs are designed to produce light continuous forces. However, few studies examined mechanism underlying the later disappearance of orthodontic force-induced pain. In the present study, we examined relationship between endogenous opioids and orthodontic force-induced pain using experimental tooth movement（ETM) model rats. The behavioral signs of orofacial nociception, facial rubbing and wiping, increased　to a peak on day 1 and gradually diminished to the control level on day 5. The enhanced nociceptive behaviors on day 1 were suppressed by the administration of TRPA1 antagonist. Systemic administration of the morphine receptor antagonist naloxone did not show any changes in mouth rubbing behavior in ETM model rats on day 5. The later disappearance of nociception was independent of endogenous opioids.

Free Research Field

歯科矯正学

Academic Significance and Societal Importance of the Research Achievements

本研究結果は、矯正治療時の疼痛発症機序の解明にとどまらず、口腔顔面領域で生じる疼痛や不快感などの病態解明や治療法、治療薬開発へ貢献すると期待される。痛みのために治療を断念していた患者をなくし、さらに患者のQOLや治療に対するモチベーションも大いに向上することが期待され、社会にも大きな影響を与える。