Jaw Joint Pain
Temporomandibular dysfunction (TMD) is common in adults and can reduce quality of life. It is more prevalent in women. Causes are multifactorial.
Table of contents
This article is based on an original article in Swedish which can be found here
BACKGROUND
Several studies have shown that orofacial pain and jaw dysfunction are not only unpleasant sensory experiences, but that these conditions also lead to a diminished quality of life for the affected individual. In addition to individual suffering and reduced quality of life, this is a societal problem with multiple healthcare visits, frequent use of pain-relieving medications, and high absenteeism from work.
Epidemiology
Jaw dysfunction (temporomandibular dysfunction, TMD) is common in the adult population. In a recent study, as many as 16% of the population reported jaw joint pain (arthralgia) in the past month, while earlier studies have shown that approximately 6-12% of the population is affected by chronic jaw joint pain (lasting 6 months or longer).
However, the prevalence of jaw joint noise in the form of clickings is about 3 times higher, with a prevalence of around 30%, while the occurrence of crepitations (grating noise is estimated to be about 4-7%.
Similar to other orofacial pain conditions, the majority of those affected are women. After puberty and until menopause, the prevalence is approximately twice as high in women as in men.
Causes
The underlying causal factors for TMD are not yet fully understood, but the etiology is considered to be multifactorial. After reviewing existing literature, a number of risk factors for jaw joint pain and dysfunction have emerged. The risk factors believed to provoke, trigger, and maintain these conditions include overload, emotional stress, trauma, systemic diseases, and the female gender.
Overload refers to parafunctions such as teeth grinding, teeth clenching, nail, lip, and pen biting, thumb sucking, frequent chewing of gum, stabilizing objects with the chin such as violins and telephones, as well as static tasks such as playing certain wind instruments and holding the mouthpiece of a snorkel/oxygen tank.
Emotional stress refers to both positive stress (from winning a lottery, a vacation trip, a promotion) and negative stress (from job loss, divorce, financial difficulties). Stress is defined as the nonspecific bodily response to any situation that arises. Circumstances and experiences that cause a stress reaction are called stressors.
Trauma refers to both macrotrauma, which can be a direct strong blow to the jaw, or microtrauma, which involves recurring minor forces against the orofacial structures.
Systemic diseases refer to systemic inflammatory diseases such as rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis (childhood rheumatism).
The female gender refers to female sex hormones, which likely, along with genetic factors, influence an individual's pain sensitivity and may also explain the female predominance.
An non-physiological occlusion (unstable bite) was previously considered a significant risk factor for jaw joint pain, but newer studies provide no support for this, rather suggesting that changes in occlusion may be a consequence of TMD. However, it appears that individuals who have previously had TMD are at greater risk of redeveloping TMD if interferences are built into the bite during, for example, prosthetic constructions, and studies suggest that these individuals have a poorer ability to adapt than previously healthy individuals from a dental physiological perspective.
