Temporomandibular Disorder: A Bite Size Intro to Management and Classification

Temporomandibular Disorder is defined by the American Dental Association as any pathology that affects the temporomandibular joint, masticatory muscles, or other closely related structures.¹ Local jaw pain, limitations in mastication, clicking/popping when opening the mouth, and mandibular deviations are all signs and symptoms of TMD. TMD prevalence in adults has been reported between 25-52%,² and as high as 16% in children and adolescents.³ However, only 5-10% of the symptomatic populations require or seek treatment for TMD.⁴

Physical therapists are part of the interdisciplinary team that manages and treats TMD. Recently Anne Harrison, PT, Phd adapted the American Academy of Orofacial Pain’s diagnostic classification scheme in the Journal of Orthopedic and Sports Physical Therapy to help manage this population.⁵ Below is a brief overview of this classification system and some basic management ideas for TMD.

Classification

Arthralgia

• Pain in preauricular area
• Pain with end-range movements like jaw opening and lateral excursion
• Pain with joint compression or biting on a tongue depression opposite to the site of compression

Disc displacement with reduction

• Clicking with jaw opening and closing during at least 1 of 3 repetitions, or…
• Clicking during lateral excursion or protrusion during 1 of 3 repetitions

Disc displacement without reduction

• History of jaw locking or catching, but without current joint clicks or crepitus
• Range of motion with opening less than 40mm

Capsular adhesions of a single joint

• Possible limited mouth opening of less than 40mm
• Limited contralateral lateral excursion, protrusion with the jaw deflecting towards the affected joint

Osteoarthritis

• Suspect if arthralgia and crepitus are present

Masticatory Muscle Disorder

• Exhibits pain to palpation of masseter or temporalis
• Pain with mouth opening or biting
• May be limited to less than 40mm or less of mouth opening
• Opening range of motion can be normal as well

Basic Management Principles

Further study by the reader is required to understand and treat this condition. Some basic ideas are useful for any skill level of clinician. Depending on classification, some basic treatment options are available:

• Behavior modification
  • Teeth should only touch when talking or chewing. A good subjective interview will identify bruxism or habitual grinding during the day. Habitual retraining may be necessary to avoid clenching. A good cue is “teeth apart and breath.”
  • Diet modification (start a soft diet)
• Stress management
• Pain education and neuropsychological pain management
• Joint mobilizations increase Temporomandibular Joint Dysfunction (TMJ) motion
• Sleep hygiene

Exercise

Exercise should be prescribed to address the impairments noted during evaluation. It’s important to note that most exercise evidence and trials are low quality and at high risk for bias. Higher quality studies need to be performed to increase certainty that exercise is effective for TMD.⁶

That being said, the most well-known group of TMD exercises are the Rocabado Six.⁷

1. Resting tongue position maintained after making “cluck” sound
2. Scapular retraction
3. Stabilized neck flexion – grasp hands around back of neck and flex neck
4. Axial extension of neck – nod head into OA flexion and retract neck
5. Controlled opening of TMJ – tongue in position one, open jaw slowly with control, palpate in preauricular area with index fingers
6. Rhythmic stabilization of slightly open jaw
   • Tongue in correct position per first exercise
   • Maintain jaw positions with resistance into opening, closing, right, and left

Individualized TMD Treatment Plans

Dr. Harrison and colleagues have adapted this useful classification scheme for identifying and management TMD. Clinicians should be aware of competing diagnoses, such as primary headache, secondary headache, cranial neuralgias, CNS lesions, and central sensitization, to ensure an informed differential diagnosis. Thus, TMD is a more nuanced diagnosis and treatment than previously described in the literature. Behavior change, manual therapy, exercise, and pain science education are all options for individualized TMD treatment plans.