Key points
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Temporomandibular joint (TMJ) arthroscopy is primarily indicated for intra-articular disorders, especially intra-articular pain disorder, in patients unresponsive to conservative therapy.
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Common indications include chronic closed lock, persistent pain, synovitis, adhesions, and degenerative joint disease, while contraindications include extra-articular pain and advanced ankylosis.
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Arthroscopic equipment includes small-diameter arthroscopes, cannulas, visualization systems, and specialized hand and energy-based instruments for diagnosis and treatment.
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TMJ arthroscopy is classified into 3 levels: diagnostic (level I), operative (level II), and advanced operative procedures (level III).
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A systematic 7-zone arthroscopic evaluation of the superior joint space ensures comprehensive assessment and guides surgical management.
Abbreviations
| RFE | radiofrequency energy |
| TMJ | temporomandibular joint |
Indications, patient selection, and decision-making
Temporomandibular joint (TMJ) arthroscopy is indicated for symptomatic intra-articular disease that persists despite appropriate conservative therapy. Selection should be based on symptoms, duration, functional limitation, and imaging findings, with treatment matched to the appropriate arthroscopic level. This pathway defines when to intervene, when to escalate intraoperatively, and when open surgery or reconstruction is more appropriate. The decision process is summarized in Fig. 1 . ,
Preoperative decision algorithm for TMJ arthroscopy. Clinical presentation and imaging are mapped to Wilkes stage and closed-lock duration to select the arthroscopic level; contraindications direct patients to nonarthroscopic management. ADD, anterior disc displacement; ADDwR, anterior disc displacement with reduction; DJD, degenerative joint disease; MIO, maximum interincisal opening.
The main indication is intra-articular pain disorder, particularly anterior disc displacement with or without reduction, typically Wilkes stages II to IV. Arthroscopy permits lavage, lysis of adhesions, anterior release, disc mobilization, posterior scarification, and discopexy when required. ,,, .
Operative arthroscopy is also useful for inflammatory synovial disease of the TMJ. This includes focal or diffuse synovitis and systemic inflammatory arthropathies affecting the joint, such as juvenile idiopathic arthritis, rheumatoid arthritis, and related conditions. In these cases, arthroscopy allows lavage, synovectomy, directed biopsy when needed, and intra-articular medication delivery.
Other indications include adhesions with hypomobility, early fibrous ankylosis, disc perforation, synovial chondromatosis, painful hypermobility or recurrent dislocation, and early-to-moderate degenerative joint disease. Arthroscopy may also be diagnostic when imaging is inconclusive or biopsy is required.
Arthroscopy is not appropriate for primarily extra-articular pain, established bony ankylosis, severe joint destruction, or disease requiring open reconstruction.
Mapping clinical presentation and imaging to arthroscopic level
Clinical presentation, MRI/CT findings, and the Wilkes radiographic stage are correlated with the expected arthroscopic (Bronstein–Merrill) findings to select the procedural level ( Table 1 ). Wilkes stages II to IV represent the principal indications; Wilkes I rarely requires arthroscopy, and Wilkes V frequently requires advanced (Level III) intervention or open surgery. ,,
Table 1
Mapping of clinical presentation, imaging (MRI/CT) findings, and Wilkes stage to arthroscopic procedural level
| Clinical Presentation | Wilkes Stage | MRI/CT Findings | Arthroscopic Findings (Bronstein–Merrill) | Recommended Level |
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| Clicking without pain; disc displacement with reduction | I | MRI: anterior disc displacement with reduction; normal disc form and marrow signal. Computed tomography (CT): normal osseous contours. | Disc roofing over the condyle 80%–100%; normal disc and synovium | Conservative ± Level I diagnostic |
| Clicking with intermittent pain; early limitation | II | MRI: disc displacement with reduction; early posterior-band thickening/mild disc deformity; ± minimal effusion. CT: normal bone. | Disc roofing over the condyle 50%–100%; early synovitis, anterolateral capsular prolapse, adhesions | Level I–II (lysis, lavage, synovectomy) |
| Acute/subacute closed lock <3 mo; ADD without reduction | II–III | MRI: anterior disc displacement without reduction; moderate disc deformity; joint effusion common. CT: normal or minimal osseous change. | Synovitis, reduced lateral recess, adhesions, chondromalacia I–II | Level I–III arthroscopy (lysis, lavage, synovectomy) |
| Chronic closed lock >3 mo; persistent pain/limitation | III–IV | MRI: ADD without reduction; marked disc deformity; reduced joint space. CT: early osseous change—condylar flattening, surface irregularity, small osteophytes. | Marked synovitis, adhesions, chondromalacia II–III | Level II–III (anterior release, disc reduction, posterior scarification) |
| ADD without reduction + early bone change; unstable after reduction | IV | MRI: ADD without reduction; hyalinized/retracted retrodiscal tissue; degenerative disc. CT: osteophytes, subchondral sclerosis, condylar and eminence flattening. | Hyalinized posterior ligament, chondromalacia III–IV | Level II–III (disc reduction + discopexy) |
| Crepitus; advanced DJD; disc perforation | V | MRI: disc perforation; gross disc deformity; adhesions; advanced degenerative change. CT: advanced DJD—osteophytes, erosions, subchondral cysts, sclerosis, loss of joint space. | Retrodiscal hyalinization, disc perforation, gross adhesions, chondromalacia IV | Level II–III debridement/discopexy OR open surgery |
| Recurrent dislocation | __ | MRI: condyle anterior to the eminence crest at maximal opening; capsular laxity. CT: prominent/steep articular eminence. | Hypermobility | Level II–III eminoplasty |
| Hypomobility from intra-articular adhesions | __ | MRI: restricted disc-condyle translation; fibrous bands; reduced recess volume/effusion. CT: usually normal osseous contours. | Fibrous adhesions, decreased recess volume | Level II lysis and lavage |
Abbreviations: ADD, anterior disc displacement; CT, computed tomography; DJD, degenerative joint disease.
Thresholds for intervention
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Failure of ≥4 to 6 weeks of structured conservative therapy (occlusal splint, physiotherapy, pharmacotherapy). ,
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Closed-lock duration: acute (<1 month) and subacute (1–3 months) disc displacement without reduction respond to level I-II arthroscopy; chronic closed lock (>3 months) is preferentially treated by arthroscopy.
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Persistent functional limitation, maximum interincisal opening less than 30 to 35 mm with intra-articular pain on loading. ,
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Confirmed intra-articular pathology on MRI/CT, or inconclusive imaging requiring diagnostic arthroscopy.
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Wilkes II to IV is the principal indication; Wilkes V often requires level III or open management. ,
Contraindications
Absolute. TMJ bony ankylosis (requires open arthroplasty or joint replacement); active cutaneous, otic, or articular infection over or around the joint; and tumor with risk of intra-articular extension or seeding.
Relative. Severe fibrous ankylosis or advanced osseous change (limited, often temporary benefit); severe glenoid fossa destruction or defect (risk of cranial penetration); predominantly extra-articular pain (myofascial or neuropathic); and inability to tolerate general anesthesia. ,
Armamentarium
TMJ arthroscopes typically measure 1.2 to 1.9 mm in diameter and are available with 0° or 30° viewing angles.
Cannulas and trocars
Cannulas (commonly 2.0 mm in diameter) are marked in 5-mm increments to control depth. They are introduced using sharp trocars for penetration and blunt obturators for safe advancement.
Visualization systems
Arthroscopy tower: light source, HD camera, and monitors.
Basic equipment
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22-gauge × 1.5-inch lavage needle
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French #3 myringotomy suction tip
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Intravenous tubing and stopcock
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Lactated Ringer’s solution
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Local anesthetic with vasoconstrictor
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Appropriate sutures
Hand instruments
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Probes: straight or hooked.
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Biopsy forceps
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Curette/Rasps
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Suction cannulas
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Suture-passing devices (eg, Meniscus Mender)
Motorized and energy-based devices
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Motorized shavers (whisker or full-radius
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Radiofrequency energy (RFE) (Coblation)
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Holmium:YAG laser
Arthroscope selection: 0° versus 30° arthroscopes in temporomandibular joint surgery
A zero degree arthroscope provides a direct forward-facing view aligned with the instrument shaft, allowing intuitive visualization and simpler spatial orientation during TMJ arthroscopy ( Fig. 2 ). Many modern 0° systems are disposable arthroscopes , offering advantages including reduced setup time, elimination of sterilization requirements, and increased accessibility. However, visualization is limited to structures directly in front of the scope, which can make the assessment of recesses and areas around anatomic contours more challenging.
Zero degree disposable scope.
In contrast, a 30° arthroscope provides an angled field of view that allows surgeons to visualize around structures and inspect a broader area of the joint by rotating the scope. This expanded visualization is allows for comprehensive evaluation of intra-articular pathology. Choice of arthroscope ultimately depends on surgeon preference, experience, and procedural goals.
Classification and levels of temporomandibular joint arthroscopy
TMJ arthroscopy is conventionally divided into 3 procedural levels based on the number of ports used:
Level I: diagnostic arthroscopy
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Single-puncture technique
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Visualization of the superior joint space
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Diagnostic assessment and lavage can be considered an arthroscopy-guided arthrocentesis with the benefit of a clear understanding of the joint pathology. Arthroscopy has been shown to be superior to arthrocentesis in managing internal derangement, with similar complication rates, with 4% for arthroscopy and 3% for arthrocentesis.
Level II: operative arthroscopy
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Double-puncture technique
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Lysis of adhesions
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Lavage
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Synovectomy
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Disc manipulation
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Anterior disc release and lateral pterygoid myotomy.
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Posterior scarification
Level III: advanced operative arthroscopy
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Disc repositioning (discopexy).
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Advanced meniscal repairs
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Osteoplasty and advanced debridement with shavers
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Meniscectomy
Endoscopic anatomy of the temporomandibular joint
Arthroscopic evaluation is performed within the superior joint compartment, located between the mandibular fossa and the articular disc. A systematic examination ensures complete assessment and minimizes missed pathology.
Standard 7-point arthroscopic examination
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Medial synovial drape
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Appears as a gray-white translucent synovial lining with vertical striations; hyperemia or fibrosis may be present ( Figs. 3 and 4 ).
Fig. 3 The 7 points of interest of the TMJ arthroscopic examination. 1. Medial synovial drape. 2. Pterygoid shadow. 3. Retrodiskal synovium. 4. Posterior slope of the articular eminence and glenoid fossa. 5. Articular disk. 6. Intermediate zone. 7. Anterior recess.
Fig. 4 Medial synovial drape.
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Pterygoid shadow
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A purplish area anterior to the medial synovium corresponding to the lateral pterygoid muscle insertion ( Fig. 5 ).
Fig. 5 Zone 2: Pterygoid shadow.
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Retrodiscal synovium
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Posterior attachment of the disc forming the oblique protuberance during mandibular opening ( Fig. 6 ).
Fig. 6 Zone 3: Retrodiscal synovium.
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Posterior slope of the articular eminence and glenoid fossa
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Covered by thick fibrocartilage and commonly affected in degenerative disease ( Fig. 7 ).
Fig. 7 Zone 4: Posterior slope of the articular eminence and glenoid fossa.
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5.
Articular disc
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Normally white, smooth, and avascular; assessed for mobility, perforation, or deformation ( Fig. 8 ).
Fig. 8 Zone 5: Articular disc.
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6.
Intermediate zone
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Demonstrates a characteristic white-on-white appearance during joint motion ( Fig. 9 ).
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