TMJ Flashcards
What are the three cardinal features of temporomandibular dysfunction (TMD)?
Orofacial pain, restricted jaw movement, and joint noise.
Why is the TMJ important in a head and neck examination?
The TMJ is one of the most frequently used joints in the body, essential for talking and eating, but often overlooked.
What bones are involved in the TMJ?
Temporal bone, mastoid process, mandible, mandibular fossa, articular tubercle, and head/condyle of the mandible.
What is unique about the articular surfaces of the TMJ compared to most other joints?
The surfaces are covered with dense collagen instead of hyaline cartilage, making them more pliable.
What structures contribute to the stability of the TMJ?
Joint capsule, lateral ligament, and the articular disc.
What muscles are involved in TMJ function?
Temporalis, masseter, lateral pterygoid, medial pterygoid, suprahyoids, and infrahyoids.
What type of joint is the TMJ?
A synovial hinge joint.
What is the resting position of the TMJ?
Mouth slightly open, lips together, teeth not in contact, and tongue resting gently behind the front teeth or on the roof of the mouth.
What is the close-packed position of the TMJ?
Teeth tightly clenched.
What is the capsular pattern of the TMJ?
Limitation of mouth opening.
Where is the articular disc located in the TMJ?
Between the head of the mandible and the temporal bone (primarily the articular tubercle).
What is the function of the TMJ articular disc?
Maintains congruency between the mandible and temporal bone, prevents excessive anterior translation, and assists with posterior movement of the disc during compression.
How does the thickness of the TMJ articular disc vary?
The disc is thicker posteriorly than anteriorly, and the middle is the thinnest but most dense region.
Why is the middle of the TMJ disc unique?
It is avascular and aneural, meaning it lacks blood supply and nerve endings.
Where is the TMJ disc highly innervated?
Along the edges.
What is the anterior attachment of the TMJ disc?
It attaches to the joint capsule, with fibers from the superior head of the lateral pterygoid inserting onto the anterior edge.
How does the TMJ disc attach medially and laterally?
It connects to the lateral edges of the condyle via the collateral ligaments.
How does the TMJ disc attach posteriorly?
It connects to the posterior joint capsule via the retrodiscal pad.
What is the function of the retrodiscal pad?
It acts like a rubber band, pulling the disc back to check excessive anterior translation during mandibular depression.
What is the significance of the retrodiscal pad’s structure?
It is highly vascularized and innervated, making it pain-sensitive.
What are the two primary movements involved in mandibular depression?
Rotation (beginning to midrange) and translation (midrange to end range).
Where does the rotation of the mandible occur during depression?
In the mandibular fossa.
Where does the translation of the mandible occur during depression?
From the mandibular fossa onto the articular tubercle.
What is the role of the articular disc during depression of the mandible?
It is pulled anteriorly by the superior head of the lateral pterygoid to maintain joint congruency.
Why is both rotation and translation of the mandible essential?
They are required for full elevation and depression of the mandible.
What muscles are activated during mandibular depression?
Suprahyoids, inferior head of the lateral pterygoid (pulls the mandible anteriorly), and superior head of the lateral pterygoid (pulls the disc anteriorly).
What movements occur during mandibular elevation?
Translation (mandibular head moves from the articular tubercle to the fossa) followed by rotation (mandibular head rotates within the fossa).
How is the articular disc repositioned during mandibular elevation?
The retrodiscal pad pulls the disc back into position.
What prevents the articular disc from snapping back into place too quickly during elevation?
Eccentric contraction of the superior head of the lateral pterygoid controls the posterior translation of the disc.
What muscles are activated during mandibular elevation?
Masseter, medial pterygoid, temporalis, and the superior head of the lateral pterygoid.
What is Temporomandibular Dysfunction (TMD)?
Unilateral or bilateral pain around the ear, TMJ, teeth, head, or other associated structures.
How can TMD pain present?
As tension and/or pain in the jaw, face, head, neck, and/or ear, ranging from mild, intermittent ache to chronic and debilitating pain.
What are common symptoms of TMD?
• Clicking, popping, or grinding/crepitus with opening and closing the mouth.
• A feeling of fullness in the ear, tinnitus, and/or earaches.
• Possible locking of the TMJ with opening or closing movements.
Does every patient with TMD experience all symptoms?
No, patients may experience many or only a few of these symptoms.
What causes clicking in the TMJ?
The disc is displaced anteriorly; as the mouth opens, the mandibular head slips onto the disc (click), and when the mouth closes, the mandibular head slips back off the disc (click) into the fossa.
What causes locking in the TMJ?
The disc is displaced anteriorly, preventing the mandibular head from slipping onto the disc, making it impossible to open the mouth.
What is the reverse scenario of TMJ locking?
The disc is jammed behind the mandibular head, causing the joint to be locked in an open position.
What are the biomechanics of mandibular depression (opening the mouth)?
• Beginning to midrange: Rotation of the head of the mandible in the mandibular fossa.
• Midrange to end range: Translation of the head of the mandible from the fossa onto the articular tubercle.
• The articular disc is pulled anteriorly by the superior head of the lateral pterygoid to maintain joint surface congruency.
• Both rotation and translation are essential for elevation and depression of the mandible.
What muscles are activated during depression (opening) of the mandible?
• Suprahyoids
• Inferior head of lateral pterygoid (pulls the mandible anteriorly)
• Superior head of lateral pterygoid (pulls the disc anteriorly)
What are the biomechanics of mandibular elevation (closing the mouth)?
• Translation of the mandibular head from the articular tubercle to the fossa.
• Followed by rotation of the mandibular head in the fossa (reverse of depression).
• The disc is pulled back into position by the elastic retrodiscal pad fibers.
• Eccentric contraction of the superior head of lateral pterygoid prevents the disc from snapping back into place.
What muscles are activated during elevation (closing) of the mandible?
• Masseter
• Medial pterygoid
• Temporalis
• Superior head of lateral pterygoid
What is Temporomandibular Dysfunction (TMD)?
Unilateral or bilateral pain around the ear, TMJ, teeth, head, or other associated structures.
What are common symptoms of TMD?
• Tension/pain in the jaw, face, head, neck, and/or ear.
• Clicking, popping, grinding/crepitus with opening and closing.
• Feeling of fullness in the ear, tinnitus, and/or earaches.
• Possible locking of the TMJ with opening or closing.
• Symptoms may range from mild and intermittent to chronic and debilitating.
What is happening in the TMJ when clicking occurs?
• The disc is displaced anteriorly.
• The mandibular head slips onto the disc when opening (click).
• The mandibular head slips back off the disc into the fossa when closing (click).
What is happening in the TMJ when locking occurs?
• The disc is displaced anteriorly, preventing the mandibular head from slipping onto the disc and opening.
• Alternatively, the disc can become jammed behind the mandibular head, locking the joint in an open position.
What are the three main causes of TMJ pain?
- Muscles: High resting tone, active trigger points, or muscle spasms.
• Head forward carriage (HFC) places passive tension on the hyoids, altering the mandible’s resting position (posteriorly and inferiorly).
• Muscles work harder for talking and chewing. - Joints: Degeneration (OA, RA) can lead to pain, stiffness, and disc displacement.
- Nerves: Irritation or compression of the greater occipital nerve (C1-C2) and trigeminal nerve (CN5) can cause head and face pain.
How can TMJ structures become injured?
• Falls
• Whiplash
• Contact sports collisions
• Dental work/surgery
What patient presentations may indicate the need for TMJ treatment?
• Stress
• Depression/anxiety
• COPD (pink puffers)
• Chronic sinus problems
• Mouth breathers
• History of whiplash
• Scoliosis
• Malocclusion, dental work, or dentures
What does the knuckle test assess?
• Patient should be able to fit at least two knuckles between their front teeth.
• More than three knuckles suggests hypermobility.
What does pain with opening the mouth suggest?
A muscle problem.
What does pain with biting suggest?
A joint/disc issue.
What can cause limited ROM in the TMJ?
• An anteriorly displaced disc (likely with popping/clicking).
• Tightness or spasm of masseter, temporalis, or medial pterygoid.
What do different jaw movement patterns indicate?
• C-curve: Joint restriction on the side the mandible swings toward.
• S-curve: Muscle imbalances.
What are the typical treatment goals for TMJ dysfunction?
• Manage pain.
• Normalize ROM.
• Normalize muscle tone.
• Correct posture.
• Relieve nerve compression.
• Address stress levels.
What treatment techniques are commonly used for TMJ dysfunction?
• Myofascial techniques
• Swedish techniques
• Joint play of TMJ, C-spine, T-spine
• Hydrotherapy (warm towels on the face)
What are important positioning considerations during TMJ treatment?
Prone may not be tolerated if facial pressure provokes symptoms.
What precautions should be taken for intra-oral treatment?
• Check in with the patient before starting.
• Set up a communication system.
• Have towels and tissues ready.
• Wash gloves and keep them on a clean surface.
What self-care strategies help with TMJ dysfunction?
• Relaxation and proprioceptive TMJ exercises
• Wine bottle cork stretch.
• Diaphragmatic breathing and relaxation techniques.
• Self-mobilization (distraction) using a cotton dental roll.
What habits may need to be addressed to prevent recurrence of TMD?
• Bruxism (teeth grinding).
• Clenching teeth (stress response).
• Improper chewing habits, nail-biting, gum chewing, • smoking.
• Mouth breathing and snoring.
• Poor posture.
• Leaning on one hand.
• Prolonged phone use.
• Mouth guard use.
What other healthcare professionals may be involved in TMJ treatment?
• Dentist:
- Bite plates for grinding.
- Denture refitting.
- Malocclusion correction.
• Physiotherapy.
• Psychotherapy.
Where does pain from a masseter trigger point refer?
• Over the eyebrow, maxilla, mandible, and molars (upper and lower).
• Molars may be sensitive to pressure and temperature.
• Can refer to the ear and cause unilateral tinnitus.
Where does pain from a lateral pterygoid trigger point refer?
• Maxilla and TMJ region.
• Pain with chewing.
• Occasional ringing in the ear.
Where does pain from a medial pterygoid trigger point refer?
• Throat pain.
• Deep ear pain.
• Difficulty swallowing.
Where does pain from a temporalis trigger point refer?
• Temporal headache.
• Maxillary toothache.
• Pain and sensitivity of the upper teeth.
How do you palpate the masseter extraorally?
• Locate inferior to the zygomatic arch on the external surface of the mandible.
• Confirm by having the patient lightly clench their teeth.
How do you palpate the masseter intraorally?
• Use a pincer palpation technique (between the index finger and thumb).
• Follow the medial surface of the cheek until reaching the ramus of the mandible.
• Move laterally from the mandible to contact the masseter.
• Confirm by applying light mandibular elevation against resistance.
How do you palpate the temporalis extraorally?
• Locate above the zygomatic arch.
• Feel the muscle fibers fanning out over the temporal fossa.
• Confirm activation by having the patient gently clench their teeth.
How do you palpate the temporalis intraorally?
• Locate its attachment to the coronoid process.
• Follow the medial surface of the cheek until reaching the ramus of the mandible.
• With the mouth slightly open, the coronoid process becomes accessible.
• Follow the ramus superiorly until finding the coronoid.
• Confirm with gentle mandibular elevation against resistance.
How do you palpate the lateral pterygoid extraorally?
• Have the patient voluntarily open their mouth to relax the masseter.
• Palpate through the masseter, between the mandibular notch and the zygomatic arch.
• If a soft spot is felt, you are in the correct place.
• Palpate for tenderness at the muscle’s attachment site.
How do you palpate the lateral pterygoid intraorally?
• Follow the outside of the upper teeth to the uppermost rear corner of the cheek (posterolaterally).
• Have the patient deviate their jaw to the ipsilateral side to increase space.
• Move a little more posteriorly and superiorly.
• Palpate medially toward the pterygoid plate.
• Confirm by resisting contralateral deviation of the mandible.
How do you palpate the medial pterygoid extraorally?
• Have the patient laterally flex their neck/head to soften the tissues.
• Use a gentle hooking technique underneath the angle of the mandible.
• Confirm palpation by having the patient perform contralateral deviation or clench their teeth.
How do you palpate the medial pterygoid intraorally?
• Follow along the inside of the bottom molars with the index finger.
• Stay in contact with the teeth and move slowly to avoid triggering the gag reflex.
• From the back molars, aim further posteriorly and inferiorly toward the angle of the mandible.
• Confirm palpation by resisting contralateral deviation.
