TEMPOROMANDIBULAR JOINT DYSFUNCTION Steve Churchill, MPT, LATC, CSCS AIM Physical Therapy Clinic, LLC

Objectives Discuss the basic anatomy and joint function of the craniomandibular system. Describe joint motion and associated muscle function of the temporomandibular joint. Describe the importance of postural positioning and its relationship to TMJ functioning. Explain the effects of TMJ hypermobility and its impact on jaw function.

Introduction TMJ pain first identified as source of facial pain in 1934 (COSTEN). 1960-1970’s TMJ pain thought to be mostly a dental problem not a joint problem. 1980’s TMJ pain thought to be rooted in muscle dysfunction (Myogenic). 1990’s TMJ pain thought to be both muscular and dental related with a psychological component.

Today TMJ pain is classified as Temporomandibular Dysfunction (TMD) and continues to be a controversial diagnosis. The treatment emphasizes function while minimizing pain and promoting self-management. Conservative management or minimally invasive treatments exhausted prior to the use invasive procedures.

Introduction Prevalence as high as 12% of population have signs of TMD but many are asymptomatic. 2:1 female to male. Mean age of onset 30 years of age. 30-40% report joint clicking. Usually insidious onset but often can find some history of trauma. Usually parafunction noted. (microtrauma) Tension headaches seen in 50% cases.

Treatment Physical Therapy Dentistry Pharmacologic Surgical Psychological

Temporomandibular Joint Complex synovial joint with two convex surfaces articulating during movement. Articular disc allows for a more congruent and stable joint. Formed by the condyle of the mandible and fossa-eminence on the temporal bone. Joint divided into two compartments the inferior and superior compartments.

The Joint

Inferior Compartment Composed of the mandibular condyle and synovium attached to the distal aspect of the disc. Joint capsule is taut in the inferior compartment to allow for pure rotation of the condyle in the fossa. Initial motion of jaw opening occurs in the inferior compartment as pure rotation.

Superior Compartment Composed of the temporal fossa/eminence and the superior synovium attached to the disc. Joint capsule is loose in the superior compartment to allow for translation. Translation of the condyle on the eminence occurs after rotation.

Compartments

Ligamentous Structures Posterior ligament limits extreme opening and provides protection for blood and nerve supply. Anterior capsule provides stability by attaching to anterior aspect of disc. Medial and lateral ligaments including the collaterals attach the disc to the condyle while the temporomandibular ligament protects the superior joint structures and assists in condylar translation while protecting at maximum opening. Stylomandibular and sphenomandibular limit at extreme opening.

Muscles of Mastication Temporalis guides biting motion to close the jaw and laterally deviates jaw. Lateral pterygoid depresses and protrudes the mandible and guides disc movement by pulling the condyle and disc forward. Medial pterygoid elevates or closes jaw. Masseter initiates elevation of mandible and is considered the strongest elevator of the jaw. Digastric muscles pull or depress the mandible inferiorly. Hyoids initiate jaw opening.

Craniomandibular System Components include the cranio-cervical joints and craniomandibular joints. Neck and jaw position need to be evaluated together when considering facial pain. Cervical spine positioning and muscle tightness effect jaw mechanics and vice versa. Most important area of examination in the cervical spine is the suboccipital region including C2. Neck pain experienced in up to 70% of TMD cases reported.

Mechanical Entrapment Neuropathy Created by posterior rotation of cranium and loss of cervical lordosis. Creates muscle tension and tissue entrapment. Less than 20 mm of space noted between occiput and C2 (2 fingers in width). Changes jaw positioning by causing mandibular retraction and distal occlusion. This creates muscle overuse and tension, thereby changing jaw mechanics.

TMJ Osteokinematics Depression(opening) Lateral excursion Protrusion There is a 4:1:1 relationship between opening, lateral excursion, and protrusion. Norms for opening approximate 40mm with lateral excursion and protrusion 10mm but this varies depending on the source. Quick reference is 3 fingers width to the PIP.

Joint Arthrokinematics The first half of opening occurs primarily as rotation (roll-glide). 10-20mm The condyle glides anterior as the disc moves posterior relative to the joint. As the temporomandibular ligament tightens rotation ends and translation begins. The condyle and disc move forward together on the eminence to create translation from 20mm of opening and beyond.

Jaw Parafunction Clenching Grinding Nail biting Excessive tension Repetitive overuse Jaw compression

TMJ Hypermobility Thought to result from excessive or premature translation of condyle. Parafunction causes microtrauma to the disc and ligamentous tissue. Mouth breathing leads to an increase in muscle activity and changes jaw positioning. Hypermobility creates anterior disc migration and possible synovium trauma. Ultimately a vicious cycle is created. Almost 80% of those with TMJ hypermobility and parafunction will develop problems versus only 16% for those that have hypermobility alone.

Signs and Symptoms Jaw clicking Headaches Facial pain Jaw locking Ear pressure Ear pain Ear ringing Tooth sensitivity Muscle tension Malocclusion Jaw deviation Neck pain Suboccipital tenderness

Disc Displacement (Internal Derangement) Phase 1 involves no joint clicking or significant pain, but may find disc slightly anterior on eminence. Phase 2 involves joint clicking at ten to twenty mm of opening. Phase 3 involves joint clicking at twenty to thirty mm of opening. Phase 4 involves a loss of 50% of normal opening with the absence of joint clicking.

Moffett’s Classification Stage I Disc displacement with reduction. Joint noise with open & close. Stage II Disc displacement without reduction. No joint noise. Stage III Disc displacement with osteoarthritis. Crepitus present.

Pain Map #1 Anterior - inferior synovium #2 Anterior - superior synovium #3 Lateral collateral ligament #4 Temporomandibular ligament #5 Posterior - inferior synovium #6 Posterior - superior synovium #7 Bilaminar zone #8 Retrodisc zone

Pain Map

Pain Map Findings Map findings guide the exam and treatment. Pain #1 usually occurs early in dysfunction. Pain #4 usually due to malocclusion. Pain #5 indicates start of disc displacement. Pain #7 start of degenerative process. Pain #8 posterior joint compression.

Evaluation Facial symmetry Lip position (upper covers 3/4 upper teeth) Bite position (contact anterior vs posterior) Profile with head and jaw position Craniovertebral position Neck ROM Jaw ROM and mechanics (quality vs. quantity) Deviation or Deflection Muscle palpation TMJ palpation and pain map

Treatment Education Proprioceptive training Postural correction Manual therapy Relaxation training Stabilization exercises Flexibility and ROM Modality management

Proprioceptive Training Rest positioning – The tip of the tongue resting gently against the roof of the mouth at rest. Controlled opening – Proprioceptive feedback from the tongue to stabilize for pure rotation in the joint.

Manual Therapy Soft tissue mobilization. Joint glides. Long axis distraction. Manual stabilization training. Cervical spine mobilization and postural correction.

Modalities Ultrasound Phonophoresis Iontophoresis Electrical Stimulation (TENS) Low-Level Laser Biofeedback Hot and Cold Therapy

In Summary… Consider the head and neck position. Palpation of the joint and related musculature. Headaches. Joint noise. Ear pressure or pain. Hypermobility. Hypomobility.

Questions?