Burning Mouth Syndrome: Effects of Occlusal Splint Therapy

The Effects of Essix Splint Therapy on Burning Mouth Syndrome. A Prospective N-of-1 Study.

Burning Mouth Syndrome (BMS) causes chronic oral pain and significantly affects quality of life. Effective treatments are limited and often provide only temporary relief.

This prospective N-of-1 study evaluates the effect of an intraoral Essix appliance on pain intensity and salivary secretion in patients with BMS.

Saliva samples are collected and analysed for volume and composition.

Study Overview

• Status: Not yet recruiting
• Conditions: Mouth Dryness; Orofacial Pain; Burning Mouth Syndrome
• Intervention / Treatment: Device: Essix splint

Detailed Description

Burning Mouth Syndrome often causes substantial suffering, both due to persistent oral pain and its long-term impact on quality of life, daily activities, and psychological well-being (including depression, anxiety, and stress). Effective treatment options for BMS remain limited, and existing interventions generally demonstrate only modest and temporary benefits.

This study aims to investigate the effect of an Essix appliance on pain relief and salivary secretion in patients with Burning Mouth Syndrome (BMS) using an N-of-1 design, in which each participant serves as their own control.

This is a prospective N-of-1 study designed to assess the treatment effect of an intraorally applied Essix splint compared with periods without splint use. Each participant will use the Essix appliance and have a no-appliance period in randomized order, each lasting one week, separated by a one-week washout period. During the active weeks, saliva samples (both unstimulated and chewing-stimulated) will be collected at home. Additionally, saliva will be collected twice at the Faculty of Odontology in randomized order.

Saliva samples will be analyzed for total protein concentration, with specific focus on lubricating glycoproteins (mucins) using antibody-based methods. Further analyses will employ lectins recognizing specific carbohydrate structures to characterize the glycosylation patterns of salivary glycoproteins and salivary markers.

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Aurelia Ilgunas, Doctor; Phone Number: 0406657000; Email: aurelia.ilgunas@mau.se
• Study Contact Backup: Name: Thomas List, Professor; Phone Number: 0406657000; Email: thomas.list@mau.se

Study Locations

• Sweden
  • Malmo, Sweden
    • Malmö University
    • Contact: Department for the orofacial pain and jaw function; Phone Number: 0406657000; Email: osk@mau.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• patients with oral mucosal pain from participants in the previous BMS validation study.
• greater than 30% pain relief during prior use of an Essix appliance.
• chronic intraoral pain lasting more than 3 months.
• age between 18 and 80 years.

Exclusion Criteria:

• fibromyalgia
• ongoing dental treatment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Essix splint; The treatment (intraorally applied Essix splint) effect on pain and saliva. Each participant will use the Essix appliance and collect saliva together with a clinical examination and saliva collection at the clinic. A questionary will also be completed.	Device: Essix splint; The treatment effect of an intraorally applied Essix splint compared with periods without splint use. Each participant will use the Essix appliance and have a no-appliance period in randomized order
No Intervention: No Essix splint; Effect on pain and saliva while not using the splint: collection of saliva together with a clinical examination and saliva collection at the clinic. A questionary will also be completed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective change in pain perception	Subjective perception of the change of pain in percent when wearing the splint and not wearing the splint	two weeks for wearing the splint and two weeks not wearing the splint. The time point for the measurement is during the two clinical appointments - directly after the period with the splint and directly after the period without the splint.
Saliva volume	Saliva volume (rest saliva and stimulated saliva) in milliliters; 10 minutes collection for the rest saliva and 5 minutes collection for the stimulated saliva.	Twice during the clinical appointments:one directly after the period of 2 weeks after using the splint and the another period directly after 2 weeks when not using the splint; and 8 times collection at home. Saliva collection in the morning hours.
Concentration of glycoproteins in rest saliva	Glycoproteins from the rest saliva measured in mg/mL	Two occasions -directly after the period of using the splint and after the period of not using the splint. The saliva is collected and then put into the freezer immediately. Analysis starts when whole saliva collection of all participants is finished.
Concentration of proteins in stimulated saliva	Saliva proteins e.g., inflammation-, stress-, or metabolism-related biomarkers from the stimulated saliva, measured in ng/mL.	Stimulated saliva is collected in two occasions - periods with and without the splint. After the collection saliva is centrifuged immediately and then put into the freezer. Analysis starts when the whole collection is done.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global impression of change	Subjective change of the condition using Patient Global Impression of Change Scale which scores the global perception of change: the scale is composed of expressions for change, starting with "Very much improved" and ending with "Very much worsened". The first one indicate a positive change and the later indicates a negativ change.	Twice: after the time period with the splint (two weeks) and after the time period without the splint (two weeks). The score is taken during the clinical appointments - directly after the period with and without the splint.
Subjective perception of mouth dryness	Subjective description of the perceived mouth dryness using a numeric scale 0-10 where 0 indicates very dry and 10 indicates no dryness.	The score is taken twice: immediatle after the period with the splint (two weeks) and after the period without the splint (two weeks) - during the clinical appointments.

Collaborators and Investigators

• Sponsor: Malmö University

Study record dates

Study Major Dates

• Study Start (Estimated): January 15, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2027

Study Registration Dates

• First Submitted: November 26, 2025
• First Submitted That Met QC Criteria: January 8, 2026
• First Posted (Actual): January 15, 2026

Study Record Updates

• Last Update Posted (Actual): January 15, 2026
• Last Update Submitted That Met QC Criteria: January 8, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Mouth Diseases; Stomatognathic Diseases; Salivary Gland Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Xerostomia; Facial Pain; Burning Mouth Syndrome
• Other Study ID Numbers: 2025-04647-02

Drug and device information, study documents

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