Hydrogels with lavender and geranium essential oils for reducing jaw joint pain in patients with temporomandibular joint dysfunction
| ISRCTN | ISRCTN16566765 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN16566765 |
| Secondary identifying numbers | 40541/21.11.2024 (CEU no. 16/09.12.2024) |
- Submission date
- 28/10/2025
- Registration date
- 29/10/2025
- Last edited
- 29/10/2025
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Oral Health
Plain English summary of protocol
Background and study aims
Many people experience pain or discomfort in the jaw joint, known as the temporomandibular joint (TMJ). This can lead to difficulty chewing, talking, or opening the mouth, and can significantly affect daily life. The aim of this study is to test whether a topical hydrogel containing natural essential oils (lavender and geranium) can help reduce TMJ pain and improve jaw function when applied daily on the skin over the joint.
Who can participate?
Adults over 18 years old who have been diagnosed with temporomandibular joint pain or dysfunction can take part in the study. People who have allergies to any of the gel ingredients or are currently using anti-inflammatory medication can’t be included.
What does the study involve?
Participants will apply the study gel once a day over the TMJ area and will be monitored regularly for changes in pain and jaw function. There are four groups in the study: three groups receiving gels with active essential oils and one group receiving a placebo gel without any active ingredients. Pain levels and jaw movement will be evaluated at the beginning of the study and again after 1, 2, and 3 months.
What are the possible benefits and risks of participating?
The study gels may help reduce pain and improve movement of the jaw. The treatment is non-invasive and easy to use at home. Risks are minimal and may include mild skin irritation in rare cases.
Where is the study run from?
The study is being conducted at the Ambulatory Dentistry Clinic of the County Emergency Clinical Hospital in Târgu Mureș, Romania.
When is the study starting and how long is it expected to run for?
November 2025 to May 2026
Who is funding the study?
The study is funded by “Dunărea de Jos” University of Galați, Romania.
Who is the main contact?
Dorin Ioan Cocoș, cdorin1123@gmail.com
Contact information
Public, Scientific, Principal investigator
50 Gheorghe Marinescu Street
Târgu Mureș
540142
Romania
 ORCID ID |
0009-0003-6823-8138 |
|---|---|
| Phone | +40 (0)748649110 |
| cdorin1123@gmail.com |
Study information
| Study design | Randomized double-blind placebo-controlled parallel-group clinical trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised parallel trial |
| Study setting(s) | Hospital, University/medical school/dental school |
| Study type | Efficacy |
| Participant information sheet | Not available in web format, please use the contact details to request a participant information sheet |
| Scientific title | Controlled-release essential oil hydrogels (geranium, lavender and combination) for pain management in temporomandibular joint dysfunction: a randomized, double-blind, placebo-controlled clinical trial |
| Study acronym | GEO-LEO TMJD |
| Study objectives | To evaluate the analgesic efficacy and safety of controlled-release hydrogels containing geranium essential oil (GEO), lavender essential oil (LEO), and their combination (GEO+LEO) compared with placebo in the management of chronic pain associated with temporomandibular joint dysfunction (TMJD). |
| Ethics approval(s) |
Approved 09/12/2024, Ethics Committee of 'Dunărea de Jos' University of Galați (47 Domnească Street, Galați, 800008, Romania; +40 (0)236 460 000; Diana.Gheorghe@ugal.ro), ref: 40541/21.11.2024 (CEU no. 16/09.12.2024) |
| Health condition(s) or problem(s) studied | Temporomandibular joint dysfunction (TMJD) associated with chronic orofacial pain |
| Intervention | Participants were randomly assigned to four groups: a hydrogel containing geranium essential oil (H-GEO), a hydrogel containing lavender essential oil (H-LEO), a combined geranium-lavender hydrogel (H-GEO/LEO), and a placebo hydrogel without active ingredients. The formulations were applied topically once daily to the TMJ region for 3 months. Participants will be randomised in a 1:1:1:1 ratio to four arms (H-GEO/LEO, H-GEO, H-LEO, placebo). The allocation sequence will be computer-generated by an independent statistician using permuted blocks of variable sizes (e.g., 4 and 8), stratified by sex (male/female) and baseline TMJ pain intensity (VAS <5 vs ≥5). Allocation concealment will be ensured via sequentially numbered, opaque, sealed envelopes (SNOSE) prepared off-site by the statistician/pharmacist. After eligibility confirmation and written consent, the investigator enrols the participant; the pharmacist assigns the next code and dispenses identically packaged interventions. The trial will be double-blind (participants, investigators, outcome assessors). The randomisation list will be stored securely and only accessible to the independent pharmacist/statistician. Emergency unblinding will follow a predefined SOP and will occur only when knowledge of the assignment is essential for participant safety. Analyses will follow the intention-to-treat principle. |
| Intervention type | Drug |
| Pharmaceutical study type(s) | Not Applicable |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | H-GEO (hydrogel containing geranium essential oil), H-LEO (hydrogel containing lavender essential oil), H-GEO/LEO (combined geranium-lavender hydrogel), and placebo hydrogel (vehicle only) |
| Primary outcome measure | Pain intensity measured using the Visual Analog Scale (VAS) at baseline (T0), month 1 (T1), month 2 (T2), and month 3 (T3) |
| Secondary outcome measures | Measured at baseline (T0), month 1 (T1), month 2 (T2), and month 3 (T3): 1. Maximum mouth opening (MMO) measured as part of the modified Helkimo Index using a digital Vernier caliper, recorded as the interincisal distance (mm) between the upper and lower central incisors. MMO values were then scored according to the modified Helkimo scale. 2. Muscle tenderness on palpation is assessed by common bilateral palpation of the masseter, temporalis, medial pterygoid, and other TMJ-associated muscles using approximately 1 kg/cm² of pressure, applied with the fingertips. The number of painful sites is then scored according to the modified Helkimo Index severity scale. 3. TMJ sounds (clicking, crepitus) and mandibular deviation are evaluated through direct clinical observation during mouth opening and closing, following the protocol used in the modified Helkimo Index. The presence or absence of deviation/sounds, as well as locking or dislocation, determines the score. 4. Patient-reported quality of life and functional impairment are assessed using a structured questionnaire based on the anamnestic (AnI) component of the modified Helkimo Index, which evaluates jaw-related discomfort, pain during function, stiffness, and the effect of symptoms on daily activities. 5. Adverse events are monitored continuously throughout the study and documented at each follow-up visit. Any unexpected reactions (e.g., skin irritation or discomfort) are recorded and, if necessary, reported to the safety protocol. |
| Overall study start date | 01/01/2024 |
| Completion date | 31/05/2026 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 65 Years |
| Sex | All |
| Target number of participants | 112 |
| Total final enrolment | 112 |
| Key inclusion criteria | 1. Diagnosed temporomandibular joint dysfunction (TMJD) according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) criteria 2. Aged between 18 and 65 years 3. Chronic TMJ-related pain lasting more than 3 months 4. Baseline visual analogue scale (VAS) pain score ≥4/10 5. Ability to comply with treatment and follow-up visits 6. Signed informed consent |
| Key exclusion criteria | 1. Previous TMJ surgery 2. Acute infection or trauma of the TMJ area 3. Systemic rheumatologic or autoimmune disorders in active phase 4. Pregnancy or breastfeeding 5. Known allergy to essential oils or hydrogel components 6. Concurrent use of systemic corticosteroids or NSAIDs during trial period 7. Psychiatric or neurological conditions impairing protocol adherence |
| Date of first enrolment | 10/11/2025 |
| Date of final enrolment | 10/02/2026 |
Locations
Countries of recruitment
- Romania
Study participating centre
50 Gheorghe Marinescu Street
Târgu Mureș
540136
Romania
Sponsor information
University/education
Faculty of Medicine and Pharmacy
47 Domnească Street
Galați
800008
Romania
| Phone | +40 (0)236 460 000 |
|---|---|
| Diana.Gheorghe@ugal.ro | |
| Website | https://www.ugal.ro |
"ROR" |
https://ror.org/052sta926 |
Funders
Funder type
University/education
Government organisation / Universities (academic only)
- Alternative name(s)
- University of Galati, Dunarea De Jos University Of Galati, 'Dunarea de Jos' University of Galati, Univ. Dunarea de Jos Galati, Galati University 'Dunarea de Jos', 加拉茨市 Dunarea de Jos 大学, Университет „Dunărea de Jos' в Галац, Universitatea „Dunărea de Jos' din Galați, UDJG, DJUG
- Location
- Romania
Results and Publications
| Intention to publish date | 01/11/2025 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Not expected to be made available |
| Publication and dissemination plan | The results of this study are intended to be submitted for publication in a peer-reviewed scientific journal in the field of dental medicine, such as The Journal of Contemporary Dental Practice. The findings will also be disseminated through academic conferences and professional meetings. |
| IPD sharing plan | No individual participant data (IPD) will be shared. Only aggregated and anonymised results may be made available upon reasonable request after publication. |
Editorial Notes
29/10/2025: Study's existence confirmed by the Medical Ethics Committee of the County Emergency Clinical Hospital Târgu Mureș, the Mureș County College of Dental Physicians, and the University Ethics Committee of “Dunărea de Jos” University of Galați.
