Occlusal Equilibration vs. Sham Therapies for TMDs: Post-Trial Follow-up (OEST) (OEST)

March 2, 2026 updated by: Urbano Santana Penin

OEST Protocol: Physiologically Oriented Occlusal Equilibration Versus Sham Therapy for Chronic Temporomandibular Disorders (TMDs): 10 Years Post-trial Follow-up

Chronic temporomandibular disorders (TMDs) affect the masticatory muscles, the temporomandibular joints (TMJs), and associated structures. Except in cases of trauma, their etiology remains uncertain, debated, and multifactorial. Conservative therapies-including no active intervention-often alleviate symptoms; however, approximately 3% of the population develops persistent forms associated with substantial individual suffering and significant social and economic burden.

At the Unit of Occlusion and Prosthodontics of the University of Santiago de Compostela (USC), Physiologically Oriented Occlusal Equilibration (POOE) has been used for chronic painful TMDs since 1985. POOE aims to correct unilateral mastication patterns and to establish appropriate non-working side contacts in order to protect the temporomandibular joints from mechanical overload. Singh (Cochrane, 2024) emphasized that occlusal interventions should be evaluated with long-term follow-up of at least 3-5 years.

This is a single-blind study: the evaluator remains blinded to treatment allocation during outcome assessment. The aim of this observational study is to assess the long-term effectiveness of POOE treatments for chronic TMDs from 1985 to the present. Treatment effectiveness will be confirmed if the reduction in pain achieved with POOE is statistically significant and clinically meaningful (≥1.5/10 on a 0-10 visual analog scale) compared with sham therapy at ≥3 years post-intervention relative to baseline. Additionally, effectiveness will be supported if the proportion of individuals meeting criteria for chronic TMD ("affected") is lower in the POOE-treated group than in those receiving alternative therapies.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Chronic TMDs constitute a complex syndrome that is currently understood as comprising more than 30 distinct nosological entities. The underlying cause of their pathophysiology has not been fully elucidated. Consequently, treatments are typically empirical and applied simultaneously, including pharmacotherapy, counseling, physiotherapy, occlusal splints (perhaps the most widely used), physical modalities, and other minimally invasive procedures such as arthrocentesis or arthroscopy, extending even to total TMJ replacement. None of these interventions has demonstrated superior efficacy compared with placebo or no treatment. Globally, these patients often consult multiple specialists and undergo numerous treatment modalities, with an unpredictable prognosis.

Physiologically oriented occlusal equilibration (POOE) was shown to be more effective than placebo at 6 months post-treatment. The 2024 Cochrane review indicated that assessing the efficacy of occlusal therapies requires evaluation at least 3 to 5 years after treatment. The treatments performed at USC since 1985 for chronic TMDs represent a valuable source of long-term clinical experience that may clarify whether POOE remains effective many years after treatment (from 1985 to the present), rather than only at 6 months.

Scientific Objectives To evaluate the effect of occlusal adjustment on pain intensity in patients with chronic TMDs during long-term follow-up over several years.

To disseminate the findings-whether positive, negative, or inconclusive-in peer-reviewed scientific journals.

Methods This is an observational study, as no intervention will be applied to participants. It will be open-label or single-blind (outcome assessors will be blinded to the treatment previously received, but participants will not be). The study is cross-sectional, as it will be conducted at a single time point and in a single visit. The study will consist of diagnosing any current TMDs potentially affecting individuals who were previously treated at USC for chronic TMDs. All participating individuals are familiar with the diagnostic procedures, which include extra- and intraoral examination, dynamic recording of mandibular and condylar movements, and the tests recommended in the DC/TMD criteria.

If the participant provides authorization, clinically relevant information from their medical record regarding TMD history will be used to determine the degree of improvement or deterioration relative to the pretreatment baseline.

Study Type

Observational

Enrollment (Estimated)

110

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Marcos Almeida Cerreda, Officer
  • Phone Number: +34 881 811 000
  • Email: dpd@usc.es

Study Locations

  • Spain
    • A Coruña
      • Santiago de Compostela, A Coruña, Spain, 15782
        • Recruiting
        • Universidad de Santiago de Compostela
        • Contact:
      • Santiago de Compostela, A Coruña, Spain, 15782
        • Enrolling by invitation
        • Urbano Santana Penín

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

All individuals previously treated with occlusal equilibration therapy at the University of Santiago de Compostela for chronic TMD pain who consent to undergo a follow-up diagnostic assessment will be eligible for inclusion. The subgroup that participated in the MAP clinical trial will be analyzed separately.

Description

Inclusion Criteria:

  • Previous occlusal equilibration for TMD pain at the University of Santiago.
  • Be diagnosed with joint and/or muscle TMD pain according to DC/TMD.
  • Be aged 18-85 years.
  • Be completely dentate with normal or adequately restored occlusion (fixed crowns/bridges allowed).
  • Report pretreatment significant TMD pain (VAS/NRS 4-9 on a 0-10 scale).
  • Have actively sought treatment and been referred to the University/Hospital service.
  • Have undergone ≥6 months of prior conservative therapy.

Exclusion Criteria:

  • Psychosis, major depression, substance abuse, or cognitive impairment.
  • Opioid (morphine-derivative) addiction.
  • Ongoing litigation or disability claims related to chronic pain.
  • Dental professional background.
  • Orthodontic treatment within the last 2 years.
  • Severe tooth mobility (grade 3).
  • Other pain conditions indistinguishable from or more severe than TMD pain.
  • Additionally, patients will be excluded if minimally invasive occlusal adjustment cannot achieve equilibration, defined by: 2 mm discrepancy between maximal intercuspation and centric occlusion, and/or 4 mm total interarch discrepancy (≥2 mm on one side) in defined premolar/molars reference points, measured intraorally using a Boley gauge.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Physilogically Oriented Occlusal Equilibration (POOE) Therapy
Occlusal equilibration to recover physiological jaw closure and alternate chewing function
Sham therapy
Simulation (placebo) of occlusal equilibration therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Group differences in change in pain intensity at 10 years follow-up in respect pretreatment scores.
Time Frame: Pretreatment, and 10 years follow-up
Differences between POOE and sham terapy groups in mean change in pain intensity at 10 years folloow-up, in respect pretreatment scores using VAS scale 0(no pain) to 10 (worst possible pain) . Greater differences indicate a better outcome.
Pretreatment, and 10 years follow-up
Odds of "success" in pain reduction of POOE compared with sham therapy
Time Frame: Pretreatmen, 10 years follow-up

"Success" was defined as a decrease in pain scores ≥ 2 points while decreases <2 points, as well as unmodified or increased pain scores were labeled as "failure". We also carried out an additional analysis in which we focused on strong effects of the treatment. In this additional analysis, we redefined success as a decrease in pain ≥ 4 points, and any other effect as "failure".

It will be adjusted for third covariables in order to remove any confounding bias.
Pretreatmen, 10 years follow-up
Group differences in the change in maximum unassisted mouth opening
Time Frame: pretreatment, 10 years follow-up
Distance between incissors during jaw opening using 0 to 60 mm TheraBite® range of motion scale™
pretreatment, 10 years follow-up

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Psychological distress (GSI from SCL-90-R test)
Time Frame: Pretreatment, 10 years follow-up
SCL-90-R. Higher scores indicate greater psychological distress. The Global Severity Index (GSI) of the SCL-90-R ranges from 0 to 4. This index represents the mean score of all 90 items, each rated on a 0-4 Likert scale (0 = not at all, 4 = extremely). Thus, GSI values can vary between 0, indicating no symptoms, and 4, indicating maximum symptom severity.
Pretreatment, 10 years follow-up
Change in condylar path angles
Time Frame: Pretreatment, 10 years follow-up
Condylar path angles are meassured between the Franckfort horizontal plane and the condylar path recprdings
Pretreatment, 10 years follow-up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Urbano Santana Penin

Investigators

  • Principal Investigator: José López-Cedrún, Dr., Complejo Hospitalario Universitario de A Coruña

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

February 16, 2026

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

August 30, 2026

Study Registration Dates

First Submitted

February 17, 2026

First Submitted That Met QC Criteria

February 26, 2026

First Posted (Actual)

March 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 4, 2026

Last Update Submitted That Met QC Criteria

March 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • USC 124/2025 (Other Identifier: University of Santiago de Compostela)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Temporomandibular Disorders (TMD)

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Paraguay

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe