A small randomized controlled trial found that pencil-electrode TENS applied to the masseter muscle reduced tinnitus severity and jaw discomfort in people with bruxism-related tinnitus and normal hearing, with improvements in quality of life and anxiety measures . The mechanism appears to involve somatosensory neuromodulation, though the study is too small to establish this as a standard treatment.
Chronic tinnitus affects roughly 15% of adults, but not all cases originate from hearing loss. This study focused on a specific subpopulation: people with normal hearing thresholds who experience tinnitus linked to bruxism, the involuntary grinding or clenching of teeth. The researchers hypothesized that stimulating the masseter muscle, the primary muscle responsible for jaw clenching, could modulate tinnitus perception through somatosensory pathways in the brainstem and cortex.
The trial enrolled 31 participants with normal hearing and chronic subjective tinnitus related to bruxism. The TENS group (18 people) received pencil-electrode stimulation applied to the masseter muscle four times per week for 5 weeks. The control group (13 people) received no active treatment. The researchers measured changes in tinnitus severity using the Tinnitus Handicap Inventory and Visual Analog Scale, along with secondary measures including jaw discomfort, anxiety, bruxism-related behaviors, jaw range of motion, and quality of life.
The TENS group showed statistically significant improvements across multiple domains. Tinnitus Handicap Inventory scores dropped substantially, and participants reported reduced tinnitus severity on the Visual Analog Scale. Jaw discomfort related to bruxism also decreased significantly. Beyond the primary outcome, the TENS group demonstrated lower anxiety scores on the Generalized Anxiety Disorder-7 scale, fewer oral parafunctional behaviors on the Oral Behavior Checklist, improved mandibular range of motion, and better scores on quality of life measures, particularly in pain and general health domains. The control group showed no significant changes across any measure. No adverse events were reported.
The authors propose that pencil-electrode TENS works through somatosensory neuromodulation, potentially activating inhibitory pathways that suppress the hyperexcitability thought to underlie subjective tinnitus in this population. The masseter muscle has rich somatosensory innervation, and stimulation may modulate activity in the trigeminal nucleus and connected brainstem structures involved in tinnitus perception. However, the mechanism remains speculative based on this study alone, and the findings are limited to a specific phenotype: people with normal audiometric hearing thresholds whose tinnitus is associated with bruxism.
This research points to a non-invasive treatment option worth discussing with an otolaryngologist or audiologist if you have tinnitus associated with teeth grinding or jaw clenching and normal hearing thresholds. TENS applied to the masseter appears well tolerated, with no reported side effects in this trial.
However, several caveats apply. First, this is a small trial (18 participants in the active group) published in a single institution, so results should not be over-generalized. Second, the study included only people with normal hearing and bruxism-related tinnitus, so findings may not apply to tinnitus from noise exposure, age-related hearing loss, or other causes. Third, there was no sham-treatment control group, only a no-treatment control, meaning some improvement could theoretically reflect placebo effects or natural variation, though the magnitude of change and specificity to the TENS group argues against this.
If you experience bruxism-associated tinnitus, addressing the underlying teeth grinding remains foundational. This can involve stress management practices like box breathing, journaling, and social connection; avoiding stimulants like caffeine late in the day; and consulting a dentist about occlusal appliances. TENS therapy could complement rather than replace these approaches.
| Characteristic | Details |
|---|---|
| Study type | Randomized controlled trial |
| Sample size | 31 participants (18 TENS, 13 control) |
| Mean age | 41.4 years (TENS), 36.9 years (control) |
| Treatment | Pencil-electrode TENS to masseter muscle, 4 times per week for 5 weeks |
| Primary outcome | Tinnitus Handicap Inventory score |
| Secondary outcomes | Tinnitus severity (VAS), jaw discomfort (VAS), anxiety (GAD-7), bruxism behaviors (OBC), mandibular ROM, quality of life (SF-36) |
| Results | Significant improvements in all measures in TENS group; no changes in control group |
| Journal | Brain and Behavior |
| PubMed ID | 42050847 |
Targeting Tinnitus via Masseter Muscle Stimulation: Innovative Pencil-Electrode TENS Therapy for Bruxism-Associated Tinnitus. *Brain and Behavior*. PubMed: 42050847
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