Temporomandibular Disorder (TMD): Disc Displacement, Click Classification and Rocabado 6x6 Rehab
In short
Jaw clicking, locking, and temple headaches point to temporomandibular joint dysfunction. Learn disc displacement mechanics, click timing, and Rocabado's 6x6 exercise protocol.

In this guide (5 sections)
Anatomy and Kinematics of the Temporomandibular Joint (TMJ)
The Temporomandibular Joint (TMJ) is a ginglymoarthrodial joint linking the mandibular condyle to the temporal mandibular fossa, divided into upper and lower joint cavities by a fibrocartilaginous biconcave articular disc.
Jaw kinematics involve a delicate two-stage opening sequence: the first 20 to 25 mm of jaw opening consists of pure rotational hinge movement in the lower joint cavity, followed by anterior translation (sliding) of the disc and condyle complex down the articular eminence in the upper joint cavity for maximal opening (40 to 50 mm).
Temporomandibular Disorders (TMD) encompass a spectrum of conditions involving the masticatory muscles (masseter, temporalis, lateral pterygoid) and intra-articular disc disruptions.
Internal Derangement: Disc Displacement With vs Without Reduction
The articular disc is held posteriorly by the highly elastic, innervated retrodiscal tissue (bilaminar zone). Excessive lateral pterygoid hyperactivity or jaw clenching (bruxism) pulls the disc anteromedially.
Internal derangement is classified into two distinct diagnostic stages.
| Diagnostic Feature | Disc Displacement WITH Reduction | Disc Displacement WITHOUT Reduction (Closed Lock) | Clinical Urgency | |
|---|---|---|---|---|
| 1. Jaw Clicking Phenomenon | Reciprocal clicking: click on opening, second click on closing | Zero clicking; previous clicking history suddenly stopped | Loss of click indicates disc is permanently jammed anteriorly. | |
| 2. Maximal Mouth Opening | Normal or near-normal maximal mouth opening (>= 40 mm) | Severe restriction in mouth opening (typically < 25-30 mm) | Severe closed lock; patient cannot bite an apple. | |
| 3. Jaw Opening Deviation | Transient 'S-shaped' jaw deviation; centers at full opening | Persistent 'C-shaped' deflection TOWARD the affected side | Condyle cannot slide past the obstructed anterior disc. | |
| 4. Primary Management | Rocabado 6x6 coordination exercises; oral splinting | Manual jaw joint distraction manipulation; dental review | Urgent mobilization before chronic disc adhesion develops. |
The Rocabado 6x6 Jaw Rehabilitation Protocol
Developed by Chilean physiotherapist Mariano Rocabado, the 6x6 exercise protocol restores harmonious craniomandibular and cervical biomechanics through 6 fundamental exercises performed 6 times each, 6 times daily.
- 1. Tongue Cluck and Resting Posture: Make a 'clucking' sound with the tongue, then rest the tip of the tongue gently on the roof of the mouth directly behind the front teeth, keeping teeth slightly apart and lips together.
- 2. Controlled TMJ Rotation: Maintain the tongue on the roof of the mouth and open the jaw slowly until the tongue begins to pull away. This enforces pure condylar rotation without anterior disc translation.
- 3. Rhythmic Jaw Stabilization: Place the tongue on the palate; apply gentle isometric manual resistance to the chin in opening, closing, and lateral movement without allowing the jaw to move.
- 4. Axial Cervical Extension (Chin Tucks): Perform a gentle craniocervical flexion nodding motion to realign the upper cervical spine, reducing forward head posture torque on the mandible.
- 5. Shoulder Retraction and Depression: Pull shoulder blades backward and downward, countering slumped desk posture.
- 6. Masseter and Temporalis Myofascial Release: Perform gentle intra-oral or extra-oral ischemic compression of the masseter and temporalis muscle bellies to release trigger points driven by nighttime clenching.
Stress, Bruxism and Indian Daily Realities
High work stress, competitive exam pressures, and prolonged desk typing drive nocturnal teeth grinding (bruxism) and daytime clenching.
Physiotherapists prescribe custom nightguards fabricated by dentists, educate patients on the 'lips together, teeth apart' resting rule, and eliminate chewing gum or hard nuts.
Frequently Asked Questions
Why does my jaw click on opening and click again on closing?
This is a 'reciprocal click'. The first click occurs when the condyle slides forward and pops back underneath the anteriorly displaced disc (reduction). The second click occurs just before complete closure when the condyle slips off the posterior edge of the disc.
Can neck pain cause jaw pain?
Yes. The trigeminocervical nucleus in the upper cervical spinal cord integrates sensory inputs from both the trigeminal nerve (jaw) and upper cervical nerves (C1-C3). Stiff neck joints frequently refer pain directly into the TMJ and temples.
What is the normal measurement for jaw opening?
A normal functional jaw opening is between 40 and 50 mm, which comfortably accommodates the vertical width of the patient own three middle fingers placed between the front incisors.
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The BookPhysio.in editorial team writes and maintains this content, checking it against reliable clinical sources. Content follows our medical review policy: general information only, and no page claims a clinical review until a named registered physiotherapist has signed it off.
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