Anatomy and Motion Review Summary:

The temporomandibular joint (TMJ) consists of the mandibular fossa of the temporal bone and the head of the mandible.

A fibrocartilaginous articular disc separates these two structures. The articular disc and head of the mandible move anteriorly on the articular surface of the temporal bone when the mouth is opened. The head of the mandible also rotates about a transverse axis on the inferior surface of the articular disc¹¹. During protraction, the head and articular disc slide anteriorly. During retraction, the head and articular disc slide posteriorly. To close the mouth the temporalis, masseter, and medial pterygoid muscles contract. The lateral pterygoid muscle protracts the mandible and the posterior fibres of the temporalis muscle retract the same structure. To open the mouth, gravity with assistance from the lateral pterygoid, suprahyoid and infrahyoid muscles is required.

Restriction of anterior gliding motion of the mandible and articular disc is the most common dysfunction. As the mouth opens in someone with a right sided TMJ restriction, the left side of the mandible and left articular disc glide anteriorly while the right side is restricted. This results in deviation of the chin to the right side (the side of restriction).

Leg length discrepancy has also been associated with TMJ pain, via pelvic torsion and the resultant functional scoliosis that terminates in the cervical spine thereby unbalancing the stomatognathic system¹². Many of the muscles in this region act in a dynamic balancing way with the efficiency of this balancing system contributing to effective function of the mouth, throat, cervical spine and head as well as the thorax and upper extremities. Dysfunction in the TMJ can have a widespread effect on the balance of the entire area⁶, thus manual therapy can be of great help in returning balance to this area.

Classification:

The approach to evaluating dysfunction at the TMJ and its associated structures can be broadly classified into three groups:

1. Dysfunctional Conditions (Most Common)

I. Altered bite malocclusion

II. Muscular imbalance

III. Capsular strain

IV. Excess chewing

V. Teeth grinding

VI. Stress

VII. Bruxism

VIII. Hypomobility

IX. Hypermobility

X. Disc displacement or adhesion

XI. Trauma to the mandible.

 

2 Developmental Abnormalities

I. Hypoplasia

II. Hyperplasia

III.
Bony impingement of the coronoid process

IV. Chondroma

V. Eagles syndrome.

 

3 Intracapsular Diseases

I. Degenerative Arthritis

II. Osteochondritis

III.
Rheumatoid and psoriatic arthritis

IV. Synovial chondromatosis

V. Bacterial and viral infections

VI. Metastatic tumours.

 

Observation, examination and diagnosis

Inspect the face, cervical and thoracic spines and jaw, looking for asymmetry and misalignment of teeth. Assess ill-fitting dentures, poorly filled teeth, raised crowns, missing or removed teeth especially molars which contribute to altered bite malocclusion. An intraoral screening, evaluating for evidence of pathology, such as swelling, cavities, and deflection of the soft palate is also recommended.

Subjectively, patients with TMJ pain generally locate their pain to the masseter muscle, preauricular area, and/or the anterior temporalis muscle regions. The quality of pain is generally an ache, pressure, and/or dull pain and may include a background burning sensation. Episodes of sharp pain may occur, and when the pain is intensified, the primary pain quality may become a throbbing sensation.

Aggravating factors often include stress, clenching and eating, while easing factors include relaxing, applying heat to the painful area, and taking over-the-counter analgesics^1,4,5,10. Be alert for unexplained fever suggestive of disorders that may mimic symptoms (e.g. infection, giant cell arteritis, meningitis) ^2,5. It is also important to assess from the patient if the movements are painful, if they notice a click or clonk on opening or closing their mouth and whether they grind their teeth.

Place your hands on either side of the patients head with your index fingers anterior to the external auditory meatus (area of the TMJ). Instruct the patient, “Open your mouth slowly.” Normal opening should accommodate three of the patient’s fingers inserted between the incisors (minimum of normal is a 40mm opening).

If not, hypo mobility resulting from joint dysfunction or a closed lock as a result of disc displacement should be suspected. If the patient has a restricted opening, the origin can sometimes be determined by stretching the mouth wider. This is performed by placing the index finger over the incisal edges of the mandibular incisors and the thumb over the incisal edges of the maxillary incisors and pressing the teeth apart by moving the fingers in a scissor-type motion². If there is also an audible ‘clonk’ on opening the mouth the lateral pterygoid has become shortened pulling the articular disc into a position of mechanical disadvantage, resulting in the condyle riding over the disc⁹.

If opening beyond three fingers occurs, hyper mobility from ligament laxity (previous trauma) or capsular overstrain is likely⁷. Observe the chin (or midincisural line) for deviation from the midline while palpating the TMJs. Remember that deviation usually occurs to the side of the dysfunctional TMJ, with associated hypertonia of the temporalis, masseter and medial pterygoid muscles, also on the side of dysfunction. The minimum of normal is 7mm to the right and to the left movements, and a 6mm protrusive movement^2,5,15.

Determine if there are changes in tone, texture, and tenderness when palpating the muscles of mastication. Temporalis and masseter can be reached externally while the pterygoid muscles can be reached intraorally. When working intraorally it is important to explain fully to the patient what you are going to do, preferably demonstrating on a plastic skull first and ensuring you have full consent. It is also recommended that the thyroid, carotid arteries, suboccipital and postural musculature be palpated to determine whether they cause or contribute to the complaint^17,18.

If the patient’s pain was not intensified or reproduced on palpation, locate and palpate the myofascial trigger points within the previous structures^19–21. Maps that identify locations responsible for producing referred pain to the different regions of the head and face are beneficial when the true source of the pain has not been identified^19–21. In patients with forehead pain, rule out local structures, e.g. sinuses, when identifying the source of referred pain as the cause of this initial pain.  Then palpate the structures that have been found to commonly refer pain to the forehead.

Placing gloved thumbs over the lower teeth and wrapping the fingers around the mandible externally can assess the accessory motions of the TMJ intraorally. Apply a passive stress in two directions (i) A-P (anteroposterior) glide and (ii) lateral glide. A springing end feel should be felt. Ask the patient to close their teeth quickly and sharply. A broad painfree clicking of teeth should be heard. If pain or only a single strike is heard, a tooth abscess or malocclusion is indicated ¹².

---

Fig. references

 

 

 

 

 

 

 

 

 

 

 

 

---

Treatment approaches

The best theory for TMJ dysfunction appears to best target patients and their contributing factors and correlates treatment strategies with their daily variations in symptoms ^15-16. Those that awake with pain that only last minutes to hours implies that nocturnal factors are the primary contributors to these symptoms^2,3,5,13-14. Those whose symptoms develop later in the day suggest that daytime factors are the primary contributors (e.g., daytime muscle tensing or clenching habits). Patients who report that they awake with TMJ pain that never goes away suggests that both nocturnal and daytime factors are contributing to their symptoms.

Improving sleep positions, wearing occlusal orthotics at night, relaxation prior to sleep and medications that decrease electromyelographic activity have been shown to be beneficial for symptoms that patients awake with. Occlusal orthotics are splints made to cover the occlusal surfaces of mandibular or maxillary teeth and should ideally be worn only at night and possibly for a few hours during the day when the habit of heavy clenching activity has not yet broken.

Relaxation, stress management, orthotics and medications have shown to be beneficial for daytime TMJ symptoms.

NSAIDs and/or steroids, physiotherapy modalities (heat, ice, ultrasound), jaw-stretching, head and neck posture exercises and cervical manual therapies appear beneficial for both awaking and daytime TMJ symptoms.

It is important to decide which therapies have the greatest potential to provide the most cost-effective, long-term symptom relief. It is recommended that the least invasive procedures be used first.

Current best evidence in physiotherapy treatment

The evidence supporting the following is limited however treatments should include

manual techniques (i.e., stretching, mobilisations, and manipulations of the TMJ and cervical spine)

exercise instruction (i.e., self stretching and mobility strategies for the TMJ and cervical spine)

patient education (i.e., postural instruction, relaxation techniques, and parafunctional awareness) and

modalities that improve tissue health.

Postural training, manual therapy and exercise, have all demonstrated significant benefit¹⁷ with a systematic review concluding that “active and passive oral exercises and exercises to improve posture are effective interventions to reduce symptoms associated with TMJ”¹⁷. A second systematic review concluded that active exercise and manual mobilisations may be effective as well as postural training in combination with other interventions¹⁸.

An additional study compared four treatment strategies for TMJ close-lock: medical management (education, counseling, self-help, and NSAIDS); rehabilitation (occlusal orthotic, physical therapy, and cognitive-behavioral therapy); arthroscopy with post-operative rehabilitation; and arthroplasty with post-operative rehabilitation (i.e., physiotherapy). The results demonstrated that “the four treatment strategies did not differ in magnitude or timing of improved function or pain relief ²⁰. Since the four treatment strategies had similar efficacy, the most cost-effective and conservative methods should be explored prior to progression to more costly, invasive procedures.

One study suggested that osteopathic manipulative treatment can induce changes in the stomatognathic dynamics, offering a valid support in the clinical approach to TMJ ¹⁹. The use of a variety of structural osteopathic techniques used to treat TMJ dysfunction is discussed here.

Manipulative techniques to the TMJ:

Soft tissue to temporalis muscle

Procedure:

1)
Ask the patient to lie in a supine position. Ensure the head and neck are supported with a pillow.

2)
The therapist should stand at the head of the table.

3)
Locate the zygomatic arch and place your finger pads 2-3 cm superior to the arch and ask the patient to clench and relax their jaw. The temporalis muscle should be felt to contract.

4)
By continuing this, you should be able to locate the attachment area of the temporalis.

5)
Using re-enforced thumbs, cross-fibre the wide origin of temporalis until you feel the muscles softening and a change in tissue tone.

Soft Tissue to Masseter

 

Procedure:

1)
Ask the patient to lie in a supine position. Ensure the head and neck are supported with a pillow.

2)
The therapist should stand at the head of the table.

3)
Locate the zygomatic arch and angle of the mandible and place your thumbs between them.

4)
Ask the patient to clench and relax their jaw. The masseter muscle should be felt to contract.

5)
Once this muscle has been identified, cross-fibre can be carried out until you feel the muscles softening and a change in tissue tone.

 

Isolytic muscle energy technique:

Muscle energy technique to lateral pterygoids

Procedure:

1)
Ask the patient to lie in a supine position. Ensure the head and neck are supported with a pillow.

2)
The therapist should stand at the side of the table and should support the patients forehead with one hand whilst the other hand is placed palm side against the middle of the patient’s mandible for patient comfort.

3)
Ask the patient to open their mouth. The therapist should resist this action for between three to five seconds. Repeat three times. Care should be taken not to force the mouth shut.

4)
Re assess muscle tone and check for reduction in mandibular deviation.

 

Intra-oral techniques

Soft tissue inhibition to lateral pterygoids and medial pterygoids

Procedure:

1)
Ask the patient to lie in a supine position.

2)
The therapist should stand at the head of the table.

3)
Instruct the patient to open their mouth.

4)
Using a gloved hand, the pterygoids can be palpated intraorally by the index finger following the molars to the back of the mouth and beyond onto the buccal mucosa, to the medial aspect of the TMJ, just proximal to the tonsils.

5)
The lateral pterygoid should be felt more by the tip of the extended index finger. Ask the patient to ‘open wide’. You should feel lateral pterygoid contract. Then turn the index finger 90 degrees and flex the distal interphalangeal joint, which should make contact with the medial pterygoid.

6)
Inhibition to either muscle can be carried out as necessary but ensure patient comfort

 

High-velocity thrust

(low amplitude)

Assume the patient has a right TMJ restriction. The chin deviates to the right as the mouth is opened. Presume soft tissue preparation has been carried out.

Procedure:

1)
Ask the patient to lie in a supine position. Ensure the head and neck are supported with a pillow.

2)
The therapist should stand at the head of the table.

3)
Rotate the cervical spine to end range of left rotation.

4)
Palpate the left TMJ with the finger pads of the index and middle fingers of the left hand. Maintain slight flexion of the cervical spine.

5)
Place the medial border of the right hand along the raised border of the mandible and add slight compression.

6)
Instruct the patient to “open your mouth slowly”.

7)
As movement of the mandible is sensed via proprioception of the left hand, a high-velocity thrust (low amplitude) is delivered by the right hand laterally and obliquely towards the side of the couch.

8)
This will gap the right TMJ restriction.

9) Re-evaluate motion at the TMJ.

 

Conclusion

Symptoms emanating from the TMJ and its associated structures are quite common and are frequently sources of considerable functional disability. It is important to consider the structure and functional inter-relation between the structures of the head, neck, TMJ and the body as a whole. More accurate diagnosis of mechanical, pathological and somatic dysfunctions and the implementation of appropriate treatment and management plan is imperative. It is important to rule out disorders that mimic TMJ symptoms, to identify non-TMJ disorders that may negatively impact the patient’s TMJ symptoms, and to offer therapies that will provide the most cost-effective, long-term symptom relief. Patient education about the source of their problem and tips to prevent future re-occurrence are essential.

Tony Spain M. Sc (Sports Physiotherapy), B.Sc. (Physiotherapy), B.Sc. (Sports and Exercise Science), MISCP, MSOM, CSCS, Lic. Acupuncture

---

Fig. references

 

 

 

 

 

 

---

References

1. American Academy of Orofacial Pain . In: Orofacial Pain: Guidelines for Assessment, Diagnosis and Management, 4th ed. de Leeuw R, editor. Chicago: Quintessence; 2008.

2. Wright EF. Manual of Temporomandibular Disorders. Ames, IA: Blackwell; 2005.

3. Okeson JP. Management of Temporomandibular Disorders and Occlusion, 6th ed. St. Louis, MO: CV Mosby; 2008.

4. Fricton J. Myogenous temporomandibular disorders: Diagnostic and management considerations. Dent Clin North Am. 2007;51:61–83.

5. Murphy E. Managing Orofacial Pain in Practice. Chicago: Quintessence; 2008.

6. Kuchera ML, Kuchera WA. Osteopathic Considerations in Systemic Dysfunction. 2nd ed. Columbus, Ohio: Greyden Press; 1994.

7. Farrar WB, McCarty WL: A clinical outline of the temporomandibular joint: Diagnosis & Treatment, Walter, 1983.

8. Kraus SL: TMJ disorders: Management of the cranio-mandibular complex, Churchill Livingstone, 1987.

9. Wadsworth CT: Manual examination & treatment of the spine and extremities, Williams & Wilkins, 1988.

10. Fricton JR, Schiffman EL. Management of masticatory myalgia and arthralgia. In: Sessle BJ, Lavigne GJ, Lund JP, Dubner R, editors. Orofacial Pain: From Basic Science to Clinical Management. Chicago: Quintessence; 2008.

11. Kapandji IA: The physiology of joints 2nd ed, vol 1, Edinburgh, Churchill Livingstone, 1970.

12. Walther DS: Applied Kinesiology, vol; 2: Head, Neck, Jaw Pain & Dysfunction – The Stomatognathic System, Systems DC, Colorado, 1983.

13. Rossetti LM, Pereira de Araujo Cdos R, Rossetti PH, Conti PC. Association between rhythmic masticatory muscle activity during sleep and masticatory myofascial pain: A polysomnographic study. J Orofac Pain. 2008;22:190–200.

14. Camparis CM, Siqueira JT. Sleep bruxism: Clinical aspects and characteristics in patients with and without chronic orofacial pain. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101:188–193.

15. Orlando B, Manfredini D, Salvetti G, Bosco M. Evaluation of the effectiveness of biobehavioral therapy in the treatment of tem-poromandibular disorders: A literature review. Behav Med. 2007;33:101–118.

16. Chen CY, Palla S, Erni S, Sieber M, Gallo LM. Nonfunctional tooth contact in healthy controls and patients with myogenous facial pain. J Orofac Pain. 2007;21:185–193.

17. McNeely ML, Armijo Olivo S, Magee DJ. A systematic review of the effectiveness of physical therapy interventions for temporomandibular disorders. Phys Ther. 2006;86:710–725.

18. Medlicott MS, Harris SR. A systematic review of the effectiveness of exercise, manual therapy, electrotherapy, relaxation training, and biofeedback in the management of temporomandibular disorder. Phys Ther. 2006;86:955–973.

19. Monaco A, Cozzolino V, Catteneo R, Cutilli T, Spadaro A. Osteopathic manipulative treatment (OMT) effects on mandibular kinetics: Kinesiographic study. Eur J Paediatr Dent. 2008;9:37–42.

Tags: 2018, anatomy, clinical, physical therapy, TMJ