Somatosensory Training Versus Exercise Therapy in Awake Bruxism

Somatosensory Training Versus Exercise Therapy in Awake Bruxism: A Randomized Controlled Trial

Awake bruxism (daytime teeth clenching or jaw tension) is a common condition that can cause jaw pain, facial pain, muscle fatigue, and reduced quality of life. Although current treatments often focus on the jaw muscles and posture, recent research suggests that changes in the brain's sensory processing may also play an important role in bruxism-related pain.

This randomized controlled trial aims to compare two physiotherapy-based treatment approaches with a wait-list control group in adults with awake bruxism. Participants will be randomly assigned to one of three groups: (1) somatosensory awareness-based training, (2) jaw and posture exercise therapy, or (3) a wait-list control group.

The somatosensory training program focuses on improving body awareness and sensory perception of the face and jaw, while the exercise program includes jaw mobility, postural alignment, and cervical exercises. Both active interventions will be delivered over a 4-week period. Participants will be assessed at baseline, immediately after treatment, and during follow-up to evaluate changes over time.

The main outcome of this study is orofacial pain intensity. Secondary outcomes include jaw function, sensory processing, muscle structure, oral parafunctional behaviors, and oral health-related quality of life. The results of this study may help improve physiotherapy-based treatment strategies for people with awake bruxism by addressing both physical and sensory aspects of the condition.

Awake bruxism is a repetitive jaw muscle activity occurring during wakefulness and is frequently associated with orofacial pain, muscle fatigue, functional limitations, and reduced oral health-related quality of life. Increasing evidence suggests that bruxism-related pain cannot be fully explained by peripheral mechanisms alone and that central nervous system processes, including maladaptive neuroplasticity and somatosensory cortical reorganization, may play a key role in symptom persistence. Distortions in somatosensory processing, such as impaired tactile acuity, altered laterality recognition, and disrupted facial emotion recognition, have been reported in individuals with chronic orofacial pain.

This single-blind, parallel-group, randomized controlled pilot trial aims to investigate whether a somatosensory awareness-based training program leads to greater improvements in pain, function, and somatosensory processing compared with a conventional jaw and posture exercise program and a wait-list control group in individuals with awake bruxism.

The study will be conducted at the Physiotherapy and Rehabilitation Unit and the Faculty of Dentistry of Aydın Adnan Menderes University. Participant recruitment is planned between December 2025 and September 2026. Eligible participants will be adults aged 18-45 years with a diagnosis of awake bruxism confirmed by an expert dentist using the Standardised Tool for the Assessment of Bruxism (STAB) and DC/TMD Axis I criteria. Additional inclusion criteria include self-reported daytime clenching behavior, baseline orofacial pain intensity of at least 5/10, and the presence of at least one measurable somatosensory impairment identified during clinical or digital assessment. Individuals with severe disability (GCPS Grade IV), systemic inflammatory or neurological disorders, recent jaw-related treatments, or conditions that may interfere with participation will be excluded.

Following baseline assessment (T0), participants will be randomly allocated in a 1:1:1 ratio to one of three groups using stratified block randomization based on age and sex. Allocation concealment will be ensured using sequentially numbered, sealed opaque envelopes managed by an independent research assistant. Due to the nature of the interventions, participant and therapist blinding will not be possible; however, all outcome assessments and data analyses will be performed by assessors blinded to group allocation.

Inclusion Criteria:

• Adults aged 18 to 45 years
• Clinical diagnosis of awake bruxism confirmed using standardized diagnostic criteria (STAB and DC/TMD Axis I)
• Presence of at least one measurable somatosensory alteration confirmed at baseline using digital and clinical assessments
• Self-reported daytime jaw clenching or parafunctional activity
• Baseline orofacial pain intensity of ≥5/10 on a Visual Analog Scale (VAS)
• Chronic pain graded as GCPS Grades I-III according to DC/TMD Axis II (Turkish validated version)
• Willingness to comply with the study protocol and attend scheduled treatment sessions
• Ability to understand the study procedures and provide written informed consent

Exclusion Criteria:

• GCPS Grade IV (high disability level)
• Presence of systemic inflammatory, neurological, or rheumatological disorders
• Diagnosis of severe chronic pain conditions unrelated to bruxism
• Use of occlusal splints or participation in jaw, neck, or facial therapy within the past 3 months
• Psychiatric disorders or cognitive impairment that could interfere with study participation
• Pregnancy, due to potential effects on joint laxity and postural parameters