Definitions and Terminology, Prevalence and Demographics
- TMD is an umbrella term covering pain and dysfunction of the muscles of mastication and the temporomandibular joints.
- TMD is not life-threatening but can be detrimental to quality of life.
- The term TMD is taken to mean any disorder that affects the temporomandibular joint.
- There is no single, globally accepted term or definition for TMD.
- TMD often co-occurs with other medical conditions such as headaches, fibromyalgia, back pain, and irritable bowel.
- About 20% to 30% of the adult population are affected by TMD to some degree.
- TMD is more common in females than males.
- TMD is the second most frequent cause of orofacial pain after dental pain.
- TMD is considered one of the 4 major symptom complexes in chronic orofacial pain.
- TMD is considered a musculoskeletal, neuromuscular, or rheumatological disorder.

Causes and Symptoms
- TMD may develop following physical trauma, such as whiplash injury.
- Muscle-related TMD and joint-related TMD are two classifications of TMD.
- The Research Diagnostic Criteria (RDC/TMD) allows for multiple diagnoses.
- TMD can be acute (symptoms last less than 3 months) or chronic (symptoms last more than 3 months).
- Symptoms of TMD can involve various components of the masticatory system.
- Pain aggravated by manipulation or function (chewing, clenching, yawning)
- Dull or aching pain, poorly localised and intermittent
- Unilateral pain (one side) rather than bilateral
- Limited range of mandibular movement, causing difficulty eating or talking
- Noises from the joint during movement (clicking, popping, crepitus)

Treatment Options
- There are many treatments available for TMD, but there is a lack of evidence for their effectiveness.
- Common treatments include occlusal splints, cognitive behavioral therapy, physical therapy, and pain medication.
- Irreversible treatments should not be carried out for TMD.
- There is no widely accepted treatment protocol for TMD.
- Treatment for TMD should be individualised based on the patient's specific symptoms and needs.

Complications and Controversies
- TMD can lead to chronic and difficult-to-manage symptoms.
- The causes and factors associated with TMD are poorly understood.
- There is disagreement about the relative importance of overlapping medical conditions in TMD.
- The terminology and classification of TMD are still debated.
- TMD has been compared to other pain syndromes like fibromyalgia and chronic lower back pain.

Subtopics (Symptoms, Causes, Mechanisms, Joint Noises, Pain Symptoms, Degenerative Joint Disease, Diagnosis)
- Subtopic 1: Symptoms
- Subtopic 2: Causes (Trauma, Occlusal factors, Genetic factors, Hormonal factors, Possible associations)
- Subtopic 3: Mechanisms of TMJ movement
- Subtopic 4: Joint noises
- Subtopic 5: Pain symptoms
- Subtopic 6: Degenerative joint disease
- Subtopic 7: Diagnosis (RDC/TMD criteria)