This is a prospective, single-arm, open-label, pilot clinical study to evaluate the efficacy and safety of nighttime occlusive application of 10% high-concentration 35 kDa hyaluronan (HA35) gel in subjects with temporomandibular joint disorder (TMD). Eligible participants will apply HA35 gel to the TMJ area nightly under occlusive conditions for 8-12 hours. The primary objectives are to assess rapid pain relief and muscle over-tension reduction at 60 seconds and 12 hours after application. Safety and local tolerability will be evaluated throughout the study period. This is a minimal-risk, non-pharmacological, non-invasive intervention.

This prospective, single-center, single-arm, open-label pilot clinical study investigates the efficacy and safety of nighttime occlusive topical 10% high-concentration 35 kDa hyaluronan (HA35) gel for relieving pain and muscle over-tension associated with temporomandibular joint disorder (TMD).

Eligible subjects will apply ≥6.5 mL of HA35 gel to the TMJ region before sleep, covered with an occlusive film for 8-12 hours overnight. Pain intensity and muscle over-tension will be assessed using a 0-10 Numeric Rating Scale (NRS) at baseline, 60 seconds after application, and 12 hours after application.

Local skin reactions, adverse events, and overall tolerability will be monitored continuously.

This is a non-invasive, non-pharmacological intervention with minimal risk to participants. All procedures will be conducted in accordance with the Declaration of Helsinki, and written informed consent will be obtained from all subjects prior to enrollment.

Inclusion Criteria:

• Age 18-60 years, male or female
• Clinically diagnosed with TMD with TMJ pain and/or muscle over-tension
• Baseline TMJ pain NRS score ≥3
• History of bruxism or jaw clenching
• Ability to complete NRS assessments independently
• Signed written informed consent

Exclusion Criteria:

• TMJ treatment (medication, physical therapy, injection) within 2 weeks
• Topical analgesic/anti-inflammatory use within 24 hours
• Skin damage, allergy, or infection in the TMJ application area
• Severe systemic disease (cardiovascular, diabetes, autoimmune)
• Known hypersensitivity to hyaluronan or gel components
• Pregnant or lactating women