The use of a topical medication was compared to placebo to be applied over the symptomatic temporomandibular joint in women with the diagnosis of osteoarthritis of the temporomandibular joint(s).

The hypothesis is to investigate whether the use of a topical anti-inflammatory medication when compared to the placebo would decrease the pain of the affected joint and/or increased mouth opening.

The purpose of this study is to measure the efficacy of topical diclofenac to topical placebo in the symptomatic relief of degenerative temporomandibular joint disease in a female population between the ages of 18-45 years of age.

Primary Objectives:

• To compare the efficacy of placebo and diclofenac topical PLO gel in terms of functional pain intensity of symptomatic temporomandibular degenerative joint disease in participants by comparing baseline measures obtained prior to commencement of the study, with the measurements obtained at 30, 60 and 90 days during the treatment intervention through the use of a Visual Analogue Scale (VAS).

Secondary Objectives:

• To compare the efficacy of placebo and diclofenac topical in PLO gel in terms of measurement of the range of motion of voluntary and assisted vertical jaw opening of symptomatic temporomandibular degenerative joint disease (TMDJD) in participants by comparing baseline measures obtained prior to commencement of the study, Time 0, through the use of a 100 mm ruler to measures obtained at 30, 60 and 90 days during the treatment intervention.
• To compare the efficacy of placebo and diclofenac in terms of effect on quality of life of symptomatic TMDJD in participants by comparing baseline measures obtained prior to commencement of the study, Time 0, to measures obtained after 90 consecutive days of treatment, utilizing a subsection of The Brief Pain Inventory Scale (BPI) which relates to quality of life.
• To compare the efficacy of placebo and diclofenac in terms of effect on pain intensity of symptomatic TMDJD in participants by comparing baseline measures obtained prior to commencement of the study, Time 0, to measures obtained after 90 consecutive days of treatment, utilizing a subsection of The Brief Pain Inventory Scale (BPI) (Cleeland & Ryan, 1994) which relates to pain intensity.
• To compare the efficacy of placebo and diclofenac topical PLO gel in terms of effect on disability on specific activities of daily living of TMDJD participants by comparing baseline measures obtained prior to the commencement of the study, Time 0, to that obtained after 90 consecutive day of treatment, utilizing The Pain Disability Index (PDI) (Bush & Harkin, 1995).

Tertiary Objectives

• To compare the adverse effects documented by the topical diclofenac group to those documented by the topical placebo group.
• To compare the amount of breakthrough medication used by the topical diclofenac group versus the placebo group in order to assess if the use of topical diclofenac reduces the amount of oral medication.
• To compare reasons for withdrawal from the study between topical placebo and topical diclofenac groups.

The null hypothesis is that there is no difference between the efficacy of topical diclofenac and topical placebo in the treatment of degenerative temporomandibular joint disease.

Inclusion Criteria:

• A baseline score of ≥ 3.0 cm on a 10 cm measured VAS (Visual Analogue Scale) according to the criteria established by Collins et al. (Collins, Moore, & Mcquay, 1997) (for moderate and severe pain) required for participants prior to use of analgesics, in order to provide adequate sensitivity.
• Females from the ages of 18 to 45 years of age inclusive.
• Primary degenerative joint disease as diagnosed through radiographs utilizing volumetric cone beam computed tomographic images reformatted in axial, coronal, and sagittal views that will be assessed by an independent radiologist.

Exclusion Criteria:

• Nursing or expectant females or females planning on becoming pregnant.
• Participants not clearly diagnosed as having symptomatic degenerative joint disease.
• Participants having DJD secondarily to trauma, previous infection or general joint/muscle disease.
• Participants who have experienced adverse reactions to any of the components of the formulation used in the study.
• Participants who have evidence of periodontal disease, dental caries, oral pathology or infections of the oral cavity.
• Participants with a history of neuropathic pain in the orofacial region.
• Participants scheduled for surgery in the near future.
• Participants currently undergoing orthodontic treatment.
• Participants with a history of epilepsy, cardiovascular disease, renal disease/disorder, hepatic disease/disorder, glaucoma, bowel obstruction, urinary retention, diabetes, hypertension or orthostatic hypotension.
• Participants with a malignancy.
• Participants who are currently using topical preparations for palliative relief for their DJD.
• Participants with a baseline intensity of ≤ 3/10 on the VAS.
• Inability to understand English.
• Participants who have been wearing an occlusal splint ≤ 3 months.