Editing Temporomandibular joint dysfunction (section)

==Classification==

{| class="wikitable" style="float:right; width:230px;"
|+ Classification:<ref name="Neville 2001" /> 
|-
|
::::   '''''Muscular:'''''
* Hyperactivity, spasm, and [[trismus]]
* Inflammation ([[myositis]])
* Trauma
* Myofascial pain and fibromyalgia
* [[Atrophy]] or [[hypertrophy]]

:::  '''''Arthrogenic:'''''

* Disc displacement (internal derangement)
* Hypomobility of the disc (adhesions or scars)
* [[dislocation of jaw|Dislocation]] and subluxation
* Arthritis
* Infections
* Metabolic disease ([[gout]], [[chondrocalcinosis]])
* [[Capsulitis]], [[synovitis]]
* [[Ankylosis]] (fibrous or bony)
* [[Mandibular fracture|Fracture]]
* Absent, large, or small [[condyloid process]]
* Neoplasia
|}
TMD is considered by some to be one of the 4 major symptom complexes in chronic orofacial pain, along with [[burning mouth syndrome]], [[atypical facial pain]] and [[atypical odontalgia]].<ref name="Aggarwal 2011">{{cite journal | vauthors = Aggarwal VR, Lovell K, Peters S, Javidi H, Joughin A, Goldthorpe J | s2cid = 34127162 | editor1-first = Vishal R | editor1-last = Aggarwal | title = Psychosocial interventions for the management of chronic orofacial pain | journal = The Cochrane Database of Systematic Reviews | issue = 11 | pages = CD008456 | date = November 2011 | pmid = 22071849 | doi = 10.1002/14651858.CD008456.pub2 }} {{Retracted|doi=10.1002/14651858.CD008456.pub3|pmid=26678041|http://retractionwatch.com/2010/09/20/progressive-how-the-cochrane-library-handles-updates-in-progress/ ''Retraction Watch''|intentional=yes}}</ref> TMD has been considered as a type of [[musculoskeletal]],<ref name="Fernandez 2009" /> [[Neuromuscular disease|neuromuscular]],<ref name="AADR policy statement">{{cite web|title=Temporomandibular Disorders (TMD) Policy Statement|url=http://www.aadronline.org/i4a/pages/index.cfm?pageid=3465#TMD|publisher=American Association for Dental Research|access-date=6 June 2013}}</ref> or [[rheumatological]] disorder.<ref name="Fernandez 2009" /> It has also been called a [[functional disorder|functional]] pain syndrome,<ref name="Cairns 2010" /> and a [[psychogenic pain|psychogenic]] disorder.<ref name="Luther 2010" /><ref name="Kindler 2011">{{cite journal | vauthors = Kindler LL, Bennett RM, Jones KD | title = Central sensitivity syndromes: mounting pathophysiologic evidence to link fibromyalgia with other common chronic pain disorders | journal = Pain Management Nursing | volume = 12 | issue = 1 | pages = 15–24 | date = March 2011 | pmid = 21349445 | pmc = 3052797 | doi = 10.1016/j.pmn.2009.10.003 }}</ref> It is hypothesized that there is a great deal of similarity between TMD and other pain syndromes like [[fibromyalgia]], [[irritable bowel syndrome]], [[interstitial cystitis]], headache, chronic lower [[back pain]] and chronic [[neck pain]].

===Definitions and terminology===
Frequently, TMD has been treated as a single [[syndrome]], but the prevailing modern view is that TMD is a cluster of related disorders with many common features.<ref name="Fernandez 2009" /> Indeed, some have suggested that, in the future, the term 'TMD' may be discarded as the different causes are fully identified and separated into different conditions.<ref name="Luther 2010" /> Sometimes, "temporomandibular joint dysfunction" is described as the most common form of temporomandibular disorder,<ref name="Al-Ani 2004">{{cite journal |vauthors = Al-Ani MZ, Davies SJ, Gray RJ, Sloan P, Glenny AM |s2cid = 28416906 |editor1-first = M Ziad |editor1-last = Al-Ani |title = Stabilisation splint therapy for temporomandibular pain dysfunction syndrome |journal = The Cochrane Database of Systematic Reviews |issue = 1 |pages = CD002778 |year = 2004 |pmid=14973990 |doi=10.1002/14651858.CD002778.pub2}} {{Retracted|doi=10.1002/14651858.CD002778.pub3|pmid=26727210|http://retractionwatch.com/2010/09/20/progressive-how-the-cochrane-library-handles-updates-in-progress/ ''Retraction Watch''|intentional=yes}}</ref> whereas many other sources use the term 'temporomandibular disorder' synonymously, or instead of the term 'temporomandibular joint dysfunction'. In turn, the term 'temporomandibular disorder' is defined as "musculoskeletal disorders affecting the temporomandibular joints and their associated musculature. It is a collective term which represents a diverse group of pathologies involving the temporomandibular joint, the muscles of mastication, or both".<ref name="Mujakperuo 2010">{{cite journal |vauthors = Mujakperuo HR, Watson M, Morrison R, Macfarlane TV |title = Pharmacological interventions for pain in patients with temporomandibular disorders |journal = The Cochrane Database of Systematic Reviews |issue = 10 |pages = CD004715 |date = October 2010 |pmid = 20927737 |doi = 10.1002/14651858.CD004715.pub2 }}</ref> Another definition of temporomandibular disorders is "a group of conditions with similar signs and symptoms that affect the temporomandibular joints, the muscles of mastication, or both."<ref name="Wassell 2008">{{cite book |vauthors=Wassell R, Naru A, Steele J, Nohl F |title=Applied occlusion |year=2008 |publisher=Quintessence |location=London |isbn=978-1-85097-098-9 |pages=73–84}}</ref> 'Temporomandibular disorder' is a term that creates confusion since it refers to a group of similarly symptomatic conditions, whilst many sources use the term temporomandibular disorders as a vague description, rather than a specific syndrome, and refer to any condition which may affect the temporomandibular joints (see table). The temporomandibular joint is susceptible to a huge range of diseases, some rarer than others, and there is no implication that all of these will cause any symptoms or limitation in function at all.{{citation needed|date=December 2020}}

The preferred terms in medical publications is to an extent influenced by geographic location. For example, in the [[United Kingdom]], the term 'pain dysfunction syndrome' is in common use.<ref name="Al-Ani 2004" /> In the United States, the term 'temporomandibular disorder' is generally favored. The American Academy of Orofacial Pain uses 'temporomandibular disorder', whilst the [[National Institute of Dental and Craniofacial Research]] uses 'temporomandibular joint disorder'.<ref name="Medscape reference" /> A more complete list of synonyms for this topic is extensive, with some being more commonly used than others. In addition to those already mentioned, examples include 'temporomandibular joint pain dysfunction syndrome', 'temporomandibular pain dysfunction syndrome', 'temporomandibular joint syndrome', 'temporomandibular dysfunction syndrome', 'temporomandibular dysfunction', 'temporomandibular disorder', 'temporomandibular syndrome', 'facial arthromyalgia', 'myofacial pain dysfunction syndrome', 'craniomandibular dysfunction' (CMD), 'myofacial pain dysfunction', 'masticatory myalgia', 'mandibular dysfunction', and 'Costen's syndrome'.

The lack of standardization in terms is not restricted to medical papers. Notable internationally recognized sources vary in both their preferred term, and their offered definition. For example:

{{blockquote|"Temporomandibular Pain and Dysfunction Syndrome – Aching in the muscles of mastication, sometimes with an occasional brief severe pain on chewing, often associated with restricted jaw movement and clicking or popping sounds." (Classification of Chronic Pain, [[International Association for the Study of Pain]]).<ref name="Classification of Chronic Pain">{{cite web |title=Classification of Chronic Pain, Part II, B. Relatively Localized Syndromes of the Head and Neck; Group III: Craniofacial pain of musculoskeletal origin |url=http://www.iasp-pain.org/AM/Template.cfm?Section=Classification_of_Chronic_Pain&Template=/CM/ContentDisplay.cfm&ContentID=16276 |publisher=IASP |access-date=7 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20121219110805/http://www.iasp-pain.org/AM/Template.cfm?Section=Classification_of_Chronic_Pain&Template=%2FCM%2FContentDisplay.cfm&ContentID=16276 |archive-date=19 December 2012}}</ref>}}
{{blockquote|"Headache or facial pain attributed to temporomandibular joint disorder." ([[International Classification of Headache Disorders]] 2nd edition (ICHD-2), [[International Headache Society]]).<ref name="ICHD-2">{{cite web |title=2nd Edition International Classification of Headache Disorders (ICHD-2) |url=http://ihs-classification.org/en/02_klassifikation/03_teil2/11.07.00_cranial.html |publisher=International Headache Society |access-date=7 May 2013 |archive-date=15 September 2013 |archive-url=https://web.archive.org/web/20130915060152/http://ihs-classification.org/en/02_klassifikation/03_teil2/11.07.00_cranial.html |url-status=dead}}</ref>}}
{{blockquote|"Temporomandibular joint-pain-dysfunction syndrome" listed in turn under "Temporomandibular joint disorders" ([[ICD-10|International Classification of Diseases 10th revision]], [[World Health Organization]]).<ref>{{cite web |title=International Statistical Classification of Diseases and Related Health Problems 10th Revision |url=http://apps.who.int/classifications/icd10/browse/2010/en#/K07.6 |publisher=World Health Organization |access-date=22 May 2013}}</ref>}}

===By cause and symptoms===
It has been suggested that TMD may develop following physical trauma, particularly [[Whiplash (medicine)|whiplash]] injury, although the evidence for this is not conclusive. This type of TMD is sometimes termed "posttraumatic TMD" (pTMD) to distinguish it from TMD of unknown cause, sometimes termed "[[idiopathic]] TMD" (iTMD).<ref name="Fernandez 2009" /> Sometimes muscle-related (myogenous) TMD (also termed myogenous TMD, or TMD secondary to myofascial pain and dysfunction) is distinguished from joint-related TMD (also termed arthogenous TMD, or TMD secondary to true articular disease), based upon whether the muscles of mastication or the TMJs themselves are predominantly involved. This classification, which effectively divides TMD into 2 syndromes, is followed by the American Academy of Orofacial Pain.<ref name="Medscape reference" /> However, since most people with TMD could be placed into both of these groups, which makes a single diagnosis difficult when this classification is used. The Research Diagnostic Criteria (RDC/TMD) allows for multiple diagnoses in an attempt to overcome the problems with other classifications. RDC/TMD considers temporomandibular disorders in 2 axes; axis I is the physical aspects, and axis II involves assessment of psychological status, mandibular function and TMD-related psychosocial disability.<ref name="Medscape reference" /> Axis I is further divided into 3 general groups. Group I are muscle disorders, group II are disc displacements and group III are joint disorders,<ref name="Manfredini 2011" /> although it is common for people with TMD to fit into more than one of these groups.

===By duration===
Sometimes distinction is made between acute TMD, where symptoms last for less than 3 months, and chronic TMD, where symptoms last for more than 3 months.<ref name="Mujakperuo 2010" /> Not much is known about acute TMD since these individuals do not typically attend in [[secondary care]] (hospital).<ref name="Mujakperuo 2010" />