The goal of this clinical trial is to evaluate the efficacy of topical 2.5% hydrocortisone in TMJ arthralgia. The main questions it aims to answer are:

• How does pain reduction compare?
• How does improvement in jaw function limitation compare?
• How do side effects compare? Participants will
• On day 1 be examined and report their pain level and jaw function limitation
• On days 1-21, apply their cream four times a day
• On day 21, report their pain level, jaw function limitation, compliance with instructions, and side effects.

Researchers will compare topical 2.5% hydrocortisone and topical 1% diclofenac to see if efficacy and side effects differ.

• Person 2 will label creams, patient packets (pre-stamped envelope, questionnaire, consent form), and give packets to Person 1 in the order in which they are to be dispensed.
• Person 1 will recruit all eligible patients in the order in which they are seen, enrolling all that consent. Packets and gel will be given to patient, and written and verbal instructions, including that email will be sent saying "Keep it up!" to remind them to continue applying get, as well as "Please send us your questionnaire". Consent forms will be stored in locked drawer.
• Person 1 will remind patient on days 7 and 14 to continue with the study
• Person 1 will remind patient on day 21 to mail back the completed questionnaire
• Person 1 will reach out to all patients from whom the questionnaire is not returned within 1 week of day 21, and do so at weekly intervals a minimum of 3 times.
• Person 1 will enter data in Excel as it comes, reaching out to patients if there are questions. Excel file uses random number ID, not patient name, thereby anonymizing the data
• Persons 1, 2, 3, and 4 will decide which patient's data, if any, should be removed
• Person 1 will send complete anonymized Excel data file (containing all patients) to Person 3
• Person 2 will determine, using random number generator, which group will be referred to as "Group A" during the statistical analysis, and which will be referred to as "Group B"
• Person 2 will tell Dr. Korczeniewska which data will be in Group A, and which will be in Group B
• Person 3 will perform statistical analysis
• Person 2 will reveal which group was Hydrocortisone, and which was Diclofenac

Inclusion Criteria:

• Arthralgia of at least 1 TMJ for at least 3 days

Exclusion Criteria:

• Systemic pain condition
• Past adverse reaction to steroid
• Currently taking steroid
• Taken steroid in the past ___ months
• Muscle relaxants (may start after study is complete)
• New night guard during study, or within 1 month of start of study (may start after study is complete)

Cream containers labeled by randomly-generated numbers, by person not involved in analysis or patient interaction.

Statistical analysis done by person not aware of the treatment received by each group