Placebo Modulation of Orthodontic Pain

Placebo Modulation of Orthodontic Pain: a Single-blind Functional MRI Study

How placebo modulates orthodontic pain remains largely unknown. The present study aimed to investigate the placebo modulation of brain activity associated with orthodontic pain using fMRI.

Study Overview

• Status: Completed
• Conditions: Pain
• Intervention / Treatment: Other: placebo; Device: orthodontic elastic separators

Detailed Description

How placebo modulates orthodontic pain remains largely unknown. The present study aimed to investigate the placebo modulation of brain activity associated with orthodontic pain using fMRI. 23 voluneers were recruited in a longitudinal fMRI experiment. At both the baseline and the one-month follow-up, orthodontic separators were placed between right lower molars 24 hours before MRI scans. At baseline, the subjects were scanned without placebo while all subjects took placebos half an hour before the scan at follow-up. Scans include a bite/non-bite task fMRI and a followed resting state fMRI. A generalized linear model was used to identify pain-regulating network from task fMRI, and functional connectivity analysis of pain related brain regions was performed to study the possible modulation of placebo on connectivity of pain-regulating networks using resting-state fMRI.

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 25 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Female, 20-25 years old;
• Right handed;
• Understand the Visual Analog Scale;
• No history of serious illness, surgery, psychiatric disorders or neurological;
• No history of drug or alcohol abuse;
• No Maxillofacial diseases, agomphiasis, caries, metal filling material or crown;
• Individual normal occlusion with no orthodontic treatment history.

Exclusion Criteria:

• claustrophobic or experienced obvious adverse reactions including fear, nausea, vomiting
• discomfort during the scan process or during menstruation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: placebo arm; Orthodontic pain was introduced by placement of orthodontic elastic separators to the mesial and distal sides of the right mandibular first molar. Participants took placebos (pills made by starch) that were told to be an effective analgesic	Other: placebo; participants took placebos (pills made by starch) that were told to be an effective analgesic.; Device: orthodontic elastic separators; Orthodontic pain was introduced by placement of orthodontic elastic separators to the mesial and distal sides of the right mandibular first molar.
Sham Comparator: sham arm; Orthodontic pain was introduced by placement of orthodontic elastic separators to the mesial and distal sides of the right mandibular first molar. But participants do not take placebos	Device: orthodontic elastic separators; Orthodontic pain was introduced by placement of orthodontic elastic separators to the mesial and distal sides of the right mandibular first molar.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
fMRI data change during MRI scan	The fMRI data were collected with a Siemens 3.0T MRI system at West China Hospital. Scans include a bite/non-bite task fMRI and a followed resting state fMRI. Through MRI data we can investigate the modulation of brain activity associated with orthodontic pain using fMRI.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The chronological changes of anxiety level	Secondary outcomes concerning chronological changes of anxiety were assessed before and after orthodontic treatments through state-trait anxiety inventory (ST-AI). A higher score indicates higher anxiety level.	Day 1

Collaborators and Investigators

• Sponsor: West China Hospital
• Investigators: Study Director: Wenli Lai, Prof, West China Hospital of Stomatology

Study record dates

Study Major Dates

• Study Start (Actual): August 7, 2014
• Primary Completion (Actual): July 8, 2016
• Study Completion (Actual): December 7, 2016

Study Registration Dates

• First Submitted: September 25, 2018
• First Submitted That Met QC Criteria: September 27, 2018
• First Posted (Actual): September 28, 2018

Study Record Updates

• Last Update Posted (Actual): September 28, 2018
• Last Update Submitted That Met QC Criteria: September 27, 2018
• Last Verified: September 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: WCHSIRB-D-2014-048

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No