From the Guidelines
The origin of Temporomandibular Joint (TMJ) pain is primarily from the muscles, with myofascial pain being a common component of Temporomandibular Disorders (TMD) 1.
Key Points
- Temporomandibular joint disorders often involve myofascial pain, where the masticatory muscles (masseter, temporalis, and pterygoid muscles) become painful, tender, and dysfunctional 1.
- These muscles can develop trigger points, experience fatigue from overuse, or become strained from clenching and grinding habits.
- While the disc can also be a source of pain in TMJ disorders, particularly in cases of disc displacement or derangement, muscle-related pain is more common and typically precedes joint internal derangement.
- Muscle pain in TMJ disorders often presents as a dull, aching sensation that worsens with jaw movement and can radiate to the temples, ears, or neck.
Treatment Recommendations
- Treatment typically focuses on relieving muscle tension through physical therapy, muscle relaxants, stress management, and oral appliances to reduce parafunctional habits like bruxism that contribute to muscle overuse and fatigue.
- According to the latest clinical practice guideline, strong recommendations are made in favour of cognitive behavioural therapy (CBT) with or without biofeedback or relaxation therapy, therapist-assisted mobilisation, manual trigger point therapy, supervised postural exercise, supervised jaw exercise and stretching with or without manual trigger point therapy, and usual care 1.
- Conditional recommendations are made in favour of manipulation, supervised jaw exercise with mobilisation, CBT with non-steroidal anti-inflammatory drugs (NSAIDS), manipulation with postural exercise, and acupuncture 1.
From the Research
Temporomandibular Joint (TMJ) Pain Origin
The origin of Temporomandibular Joint (TMJ) pain is a complex issue, with various studies suggesting that it can arise from both muscular and disc-related factors.
- Muscular factors: Studies have shown that the muscles of mastication, particularly the lateral pterygoid, play a key role in TMD, with biological changes associated with the vicious cycle, pain adaptation, and integrated pain adaptation making the muscle a key pain generator associated with TMD 2.
- Disc-related factors: Degenerative changes can disrupt the relationship between the TMJ capsule, articular disc, and muscles of mastication, resulting in disc displacement and pain 2.
- Multifactorial etiology: TMD is recognized as a multifactorial condition, involving genetic, anatomic, and hormonal factors, as well as trauma, habitual activity, psychosocial components, and occlusal variation 2, 3, 4.
- Diagnostic challenges: Distinguishing the precise source of the pain is a significant diagnostic challenge to clinicians, and effective management hinges on establishing a correct diagnosis 5.
Pathoanatomical Characteristics
The pathoanatomical characteristics of TMD involve the relationship between the TMJ capsule, articular disc, and muscles of mastication.
- Degenerative changes: Degenerative changes can disrupt this relationship, resulting in disc displacement and pain 2.
- Articular disc position: The position of the articular disc coincides with three primary classifications of TMD: Type 1 (muscle disorders), Type 2a/b (disc displacement with and without reduction), and Type 3 (any joint pain) 2.
- Lateral pterygoid muscle: The lateral pterygoid muscle, with its superior and inferior heads, plays a key role in TMD, undergoing biological changes associated with the vicious cycle, pain adaptation, and integrated pain adaptation 2.