Temporomandibular disorders (TMDs) are a group of related musculoskeletal conditions affecting the masticatory muscles, the temporomandibular joint (TMJ), and associated structures. They are one of the most common causes of chronic orofacial pain. TMDs share clinical features, such as pain in the TMJ and surrounding structures, limitation of jaw movements, and/or sounds (such as clicking, popping, grating, or crepitus) from the TMJ.
Temporomandibular Joint Dysfunction Syndrome (TMJ) is a common condition affecting a wide variety of people. TMJ is characterized by severe headaches, jaw pain of varying degrees, grinding teeth, and an intermittent ringing in the ears. The symptoms of TMJ are debilitating and can greatly interfere with every day life. Complications of temporomandibular disorders (TMDs) include chronic pain, psychosocial distress, tooth wear and fracture and speech, chewing, and swallowing problems. Early self-management should be encouraged and specialist treatments including TMJ injections and botox injections should be considered if conservative management fails.
TMDs have previously been referred to as TMJ disorders or TMJ dysfunction. The current term of TMDs is more clinically accurate as it encompasses disorders of associated structures as well as the TMJ itself.
Pain-related TMDs may be subdivided into different categories:
TMDs may be also classified according to the duration of symptoms:
The exact prevalence of temporomandibular disorders is difficult to establish, as the majority of people do not seek help from a healthcare professional. Temporomandibular disorder is the second most common musculoskeletal pain condition after chronic low back pain. It affects more than 35 million people in the US. A US review article suggests that only 5% of adults seek treatment for their symptoms. Females may be affected up to twice as much as males in the general population.
The causes of temporomandibular disorders (TMDs) are not fully understood. They are likely to be complex and multifactorial involving the interaction of anatomical, physiological, and psychosocial risk factors.
Pain in and around the temporomandibular joint (TMJ) and/or muscles of mastication, which may radiate to other structures.
Reproducible joint noise of the TMJ (clicking, popping, or crepitus) on any jaw movements, with or without restricted movement or locking of the TMJ.
Headache limited to the temporal region.
Otalgia and/or tinnitus in the absence of ear disease.
Red flags for orofacial pain that may mimic temporomandibular disorders (TMDs) include:
Specialist investigations may be considered for people with significant functional impairment of the temporomandibular joint (TMJ), and/or an intra-articular disorder such as anterior disc displacement or degenerative joint disease.
Arrange referral to oral medicine or oral and maxillofacial surgery for specialist investigations and management, depending on clinical judgement, if a person has:
For all other people with a suspected TMD, encourage early self-management to help control symptoms and limit functional impairment:
Consider whether additional drug treatment may be helpful for adults:
Consider referral to additional specialists if appropriate, such as to:
This should be considered in patients with degenerative disorder of the TMJ. A steroid injection can help reduce pain and swelling in a joint or the surrounding soft tissue. Most people report feeling less pain within the first 24 hours to one week.
The most commonly affected muscles are the temporalis muscle, masseter muscle and lateral pterigoid muscles. The temporalis muscle and masseter muscle are almost always involved and usually manifest as direct muscle pain. Lateral pterygoids involvement usually manifests as buccal pain, lateral jaw deviation or bruxism. We typically use a concentration of 2.5–5.0 units per 0.1 mL of Botox with a starting dose of 10–25 units for each temporalis muscle, 25–50 units to the masseter muscles and 7.5–10 units to the lateral pterygoids. Subsequent doses are individualized and are based on the patients’ response.
Approximately 3-4 weeks after the initial injection, patients are reevaluated for any adverse effects and/or suboptimal responses. Some patients may require a booster injection at that time. Additional BoNT injections are directed by the patients’ history and clinical examination, and pain diaries are a useful guide to help in patient directed therapy. It may take several weeks before patients experience the maximum pain relief from BoNT. Although the typical duration of efficacy is 12 weeks, we have noted tremendous variability among patients with respect to optimal dosing frequency. Some patients experience relief well beyond the predicted pharmacokinetic duration of the drug supporting the possibility that BoNT does not strictly act at the periphery and may be involved in neuromodulation at the level of the central nervous system. It is important to note that an individual patient’s response to toxin may change over time, which further supports the importance of patient-directed dosing.