temporomandibular joint syndrome

Last edited 11/2019 and last reviewed 04/2021

According to the American Association of Orofacial Pain (AAOP) definition, a temporomandibular disorder (TMD) is:
 “a collective term embracing a number of clinical problems that involve the masticatory musculature, the Temporomandibular joint and associated structures, or both.” (1)

Several terms have been used in the past to describe TMD which include Costen’s syndrome, temporomandibular joint dysfunction syndrome, temporomandibular joint disorders, and craniomandibular syndrome (1). 

Around 60-70% of the general population has at least one sign of a temporomandibular disorder (2)  

  • only 5% of patients with symptoms will seek treatment
  • most common in early adulthood (2) and in women than in men.
  • discomfort from these conditions is occasional and temporary
  • often they occur in cycles
  • the pain finally disappears with little or no treatment
  • some develop significant, long-term symptoms (3).

TMD are a class of degenerative musculoskeletal conditions associated with morphological and functional deformities

  • TMD include abnormalities of the intra-articular discal position and/or structure as well as dysfunction of the associated musculature

The conditions fall into three main categories (4):

  • myofascial pain
    • this is the most common temporomandibular disorder
    • it involves discomfort or pain in the muscles that control jaw function.
  • internal derangement of the joint
    • this involves a displaced disc, dislocated jaw, or injury to the condyle.
  • arthritis
    • this refers to a group of degenerative/inflammatory joint disorders affects the joint. 

Symptoms and signs include painful joint sounds, restricted or deviating range of motion, and cranial and/or muscular pain known as orofacial pain (5)

TMD is a symptom complex (i.e. a group of symptoms occurring together and characterizing a particular disease)

  • aetiological factors for TMJ disorders include:

    • likely to be multifactorial

    • capsule inflammation or damage and muscle pain or spasm may be caused by:
          • parafunctional habits (e.g., bruxism [teeth grinding], teeth clenching, lip biting)
          • stress, anxiety
          • abnormalities of the intra-articular disk
        • parafunctional habits may play a role in initiating or perpetuating symptoms in some patients
          • the cause-and-effect relationship remains uncertain
        • some evidence to suggest that anxiety, stress, and other emotional disturbances may exacerbate TMJ disorders, especially in patients who experience chronic pain
          • interest in occlusal factors as a causative factor in TMD was especially widespread in the past, and the theory has since fallen out of favour and become controversial due to lack of evidence - a systematic review concluded that " seems to lack ground to further hypothesise a role for dental occlusion in the pathophysiology of TMD.." (6)

Short term treatment consists of a very soft diet and simple analgesia, and may be sufficient for mild symptoms.

Long term treatment may involve dental correction or stress relaxation. Referral to a specialist clinic may be needed.

Notes:

  • temporomandibular articulation is composed of bilateral, diarthrodial, temporomandibular joints (TMJs)
    • each joint is formed by a mandibular condyle and its corresponding temporal cavity (glenoid fossa and articular eminence)
      • TMJ and its associated structures play an essential role in
        • guiding mandibular motion
        • distributing stresses produced by everyday tasks, such as chewing, swallowing, and speaking

Reference:

Related pages:

aetiology

clinical features

examination

differential diagnosis

management