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CATEGORY LINICAL

TMJ Surgery – what’s it all about?

By Dr George Dimitroulis , Oral & Maxillofacial Surgeon, Epworth Freemasons Hospital, East Melbourne.

Introduction While

Category 1 – TMJ Arthralgia is category describes a painful but otherwise structurally normal joint (Fig. 1). Clinically, there are no joint sounds and smooth function of the TMJ although the range of mandibular motion may be limited due to pain. e pain is speci c to the TMJ and may be acute and caused by contusion resulting from a traumatic incident following a fall, assault, whiplash, or sporting incident. Radiological scans demonstrate no obvious structural joint damage. Alternatively, the arthralgia may be chronic as part of a wider spectrum of bromyalgia or myofascial pain that may be associated with underlying stress, anxiety, or depression. Chronic joint pain may also arise from neuralgia or neuropathic

conditions, chronic ear disorders, or psychosomatic disorders that are referred to the joint 2 . In acute conditions, TMJ arthrocentesis may be e ective in resolving acute pain by reducing joint in ammation such as synovitis, as well as improving joint range of motion. Chronic conditions are treated non-surgically however, TMJ arthrocentesis may be used as a diagnostic tool to eliminate the possibility of anchored disc phenomenon in patients with limited joint mobility. Category 2 – Reducing Disc-Displacement e most common joint disorder in this category is TMJ reducing disc displacement which may also include acute or recurrent TMJ dislocation. While joint clicking is the obvious clinical presentation in this category, it may also be accompanied by pain and intermittent locking. In severely symptomatic cases that don’t resolve with conservative TMD measures, TMJ arthrocentesis or arthroscopic lavage and lysis may be used to lubricate the disc, help reduce joint pain and locking, and promote smoother joint function. Forthiscategory, themostcommondisorder is TMJ non-reducing disc displacement whereby the disc is structurally normal and intact but permanently displaced from its normal position above the head of the mandibular condyle (Fig. 2). e usual clinical presentation is painful locking as the patient tries to open their mouth but Category 3 – Non-Reducing Disc Displacement

non-surgical still make up about 90% of all treatment for Temporomandibular Disorders (TMD), there are still 5-10% of TMD cases where the Temporomandibular Joint (TMJ) is the primary cause of painful mandibular dysfunction that may require surgical intervention 1 . Unfortunately, many surgical techniques of the Temporomandibular joint (TMJ) have been devised with scant referencetoanactual radiologicaldiagnosis. So how is it possible to compare treatment outcomes when a radiological diagnosis of actual joint pathology is lacking? e aim of this article is to review the rationale for surgical interventions of the TMJ with the aid of a TMJ speci c surgical classi cation that was originally devised and previously published in international peer-reviewed literature 2 by the author. Tmj surgical classification e TMJ surgical classi cation 2 was essentially conceived to match the diagnosis (i.e.. degree of joint pathology) to the surgical treatment and is used in this article as a means of explaining the rationale for TMJ surgery for general dentists. e TMJ Surgical Classi cation is divided into 5 categories of escalating joint speci c pathology [Table 1]. measures

Figure 1 Illustration of a Category 1 TMJ – normal structure

TABLE 1: A TMJ Surgical classification*

Category Clinical Presentation

Radiological Image

Treatment

1

Joint pain

Structurally Normal Joint

Conservative TMD TMJ Arthrocentesis Conservative TMD TMJ Arthrocentesis

Limited mouth opening

2

Joint clicking

TMJ reducing disc

Intermittent joint pain Intermittent locking

displacement

TMJ Arthroscopy – Level 1

3

Painful Chronic closed

TMJ Non-reducing disc

Conservative TMD

lock

displacement TMJ Arthroscopic discopexy Disc exhibits normal contour Arthroplasty disc repositioning

4

Severe Joint Pain Limited chewing

TMJ disc degeneration/ deformity/perforation Early condylar changes

TMJ Discectomy

+/- interpositional graft

Reduced mouth opening

5

Crepitus, constant low to moderate joint pain

TMJ destructive/

TMJ Resection +/-

catastrophic degeneration Reconstruction

Limited chewing, intermittent locking

of disc and condyle

Total Joint Replacement

Figure 2 Illustration of a Category 3 TMJ – Disc displacement without reduction

* Dimitroulis G. A new surgical classi cation for temporomandibular joint disorders. Int J Oral Maxillofac Surg. 2013;42:218-22. doi: 10.1016/j.ijom.2012.11.004.

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