Masticatory Muscle Disorders and Treatment

Question 1

Musculoskeletal Disorders
(5)

Answer 1

1. Myofascial Pain Syndrome (MFPS)- Centrally Maintained
   Pain
2. Myalgia
3. Fibromyalgia- Centrally Maintained Pain
4. Spasm
5. Myositis

Question 2

Mechanisms that produce Pain for
Masticatory skeletal muscles (1)
(3)
Masticatory Muscle
Pain

Answer 2

Overuse or
Ischemia (i.e.
bruxism)
Endogenous
substances (2) can
sensitize nociceptive
nerve endings
Psychological or
emotional states
can alter muscle
tone (i.e. anxiety)

Question 3

Myofascial Pain Syndrome (MFPS) classified by
International Association for the Study of Pain
 Characterized by the presence of

Answer 3

Trigger Points (TPs) in any voluntary
muscle which cause referred pain and referred tenderness and may
be active or latent. (3)
 TPs evoke referred pain which usually originates from a distant site
rather than the site of the pain complaint.

Question 4

Muscle Palpation Examination
(2)

Answer 4

 Remember that the pain location MAY not be the source of pain
 Palpate the Masseter and Temporalis muscles with mouth open

Question 4

 ACTIVE TPs:

Answer 4

are painful to palpation or spontaneously produce local
pain OR refer pain and autonomic symptoms (i.e. erythema) to
remote areas in reproducible patterns characteristic of each muscle.

Question 4

 LATENT TPs:

Answer 4

exhibit local tenderness but do not currently cause
spontaneous clinical pain or symptoms.

Question 4

Myofascial Pain Syndrome (MFPS)
(3)

Answer 4

 May be found in any voluntary muscle
 Is a Centrally Mediated Pain. Fields (4) described a means where the CNS may switch
on Nociception by stimulating the “on” cells which causes activation of the Trigeminal
Nucleus nociceptors.
 Is chronic, continuous muscle pain (myalgia) that is aggravated by function and refers
pain beyond the boundary of the masticatory muscle being palpated (5).

Question 4

Myofascial Trigger Point
 DEFINITION:

Answer 4

 An irritable locus within a taut band of skeletal muscle or fascia which when stimulated
elicits referred pain & tenderness (“secondary hyperalgesia- increased sensitivity to
normally painful stimuli outside & surrounding a zone of primary hyperalgesia”). (1)
 Referred pain from myofascial trigger points is dull and aching, usually deep, and can range
from discomfort to incapacitating pain

Question 5

 Nociception:

Answer 5

“stimulation of specialized nerve endings designed to transmit
information to the central nervous system concerning potential or actual tissue
damage (5).

Question 6

 Nociceptor:

Answer 6

“a specialized nerve ending that senses painful or harmful sensations”
(i.e. a primary afferent nerve) (5)

Question 7

Myofascial Pain
 The most elusive and difficult to diagnose since it

Answer 7

refers
pain to other locations in the mouth and in the face and
head & does Not always follow Cranial Nerve Distributions-
(CN XI with active SCM trigger point refers to CN V in face
and head)

Question 8

Myofascial Pain
 Diagnostic Criteria: (must be present)
(3)

Answer 8

 Regional dull, aching pain aggravated by mandibular function when muscles
of mastication are involved.
 Trigger points have a characteristic pattern of pain referral & alters the pain
complaint on palpation or spontaneously.
 > 50% pain reduction occurs with vapocoolant spray or local anesthetic
injection (trigger point injection) using 1% Procaine without vasoconstrictor.

Question 9

skipped
Myofascial Pain
 May be accompanied by:
(6)

Answer 9

 Muscle stiffness
 Sensation of acute malocclusion not verified clinically.
 Ear Symptoms, tinnitus, vertigo, toothache, tension-type headache.
 Decreased mouth opening (if masticatory muscles involved).
 Hyperalgesia in region of referred pain.

Question 10

Hyperalgesia:

Answer 10

“an increased response to a stimulus that is normally painful”

Question 11

Pathophysiology of Masticatory Myofascial
Pain
 Not fully understood
1. Suspect — pain thresholds in these individuals
2. — may cause increased nociception
which causes pain sensitivity
3. — in CNS & upregulation of nociceptive processing (decreased
inhibition of pain)

Answer 11

lower
Estrogen and nerve growth factor (NGF)
Hyperexcitability

Question 12

Nociception-

Answer 12

Stimulation of specialized nerve endings designed to
transmit information to the CNS concerning potential or actual tissue damage.

Question 13

Windup-

Answer 13

repetitive nerve stimulation leading to exuberant response in the CNS

Question 14

Thalamus_

Answer 14

relays sensory impulses to the cerebral cortex (i.e. pain, temperature, & touch.

Question 15

Locus ceruleus-

Answer 15

part of a major NE route of CNS

Question 16

skipped
Calcitonin Gene Related Peptide-

Answer 16

contributes to pain transmission & inflammation in migraine & neurogenic inflammation & is released
from the primary terminals of primary sensory neurons. Cell bodies of these neurons in the dorsal root and trigeminal ganglia give origin
to unmyelinated and myelinated fibers conducting in the slow C or A- alpha range respectively.

Question 17

Glutamate-

Answer 17

major mediator of excitatory signals in CNS. Glutamate receptors are contained in most of the nerve cells & glial cells.
NMDA receptor is a subtype of glutamate receptors

Question 18

Pain Referral Patterns
TMJ & Ear Pain:
 Referred by:
(5)

Answer 18

 MASSETER (deep)
 LATERAL PTERYGOID
 MEDIAL PTERYGOID
 STERNOCLEIDOMASTOID (clavicular)

Question 19

Toothache:
 Referred by:
(3)

Answer 19

 TEMPORALIS
 MASSETER (superficial)
 DIGASTRIC (anterior)

Question 20

Myofascial Pain
 May be
 Avoid

Answer 20

transient and self-limiting, resolving without serious long-term
effects.
irreversible treatments (i.e. occlusal adjustments)

Question 21

Myalgia  Diagnostic Criteria: (must be present) (3)  May be present: (1)

Answer 21

1. Muscle pain reported by patient in the jaw, temple, ear or pre-auricular area in the last 30 days 2. Pain is aggravated by jaw movement or parafunction (i.e. bruxism) 3. Muscle palpation exam causes report of localized muscle pain at palpation site 1. Limited range of mouth opening MAY be present

Question 22

Myalgia Secondary to: (6)

Answer 22

 Ischemia  Bruxism  Fatigue  Metabolic alterations  Delayed onset muscle soreness from overuse  Protective splinting

Question 23

Myositis  Diagnostic Criteria must be present: (5) (2) May be present: (4)

Answer 23

1. Local muscle pain following injury (non-infective) or infection (infective) 2. Edema, erythema, &/or increased temperature over the muscle 1. Serologic tests may reveal elevated enzyme levels (i.e. creatine kinase), markers of inflammation & the presence of an autoimmune disease. 2. Diffuse tenderness over the entire muscle. 3. Increased pain with jaw use if masticatory muscles involved. 4. Limited range of motion of unassisted mandibular movements secondary to pain

Question 24

Myospasm  Diagnostic criteria Must be present(5) (4) contralateral unaffected muscle. 5. MAY be present: (1)

Answer 24

1. Acute onset of pain at rest & with function. 2. Immediate report of limited range of jaw motion <40mm for vertical opening 3. Continuous involuntary muscle contraction 4. EMG will Confirm elevated electromyographic activity compared to the 6. Acute Malocclusion

Question 25

Myospasm  Also known as  Occurs relatively infrequently in orofacial pain population & typically is caused by ---.  Difficult to differentiate between

Answer 25

“trismus” or “cramp”. trauma disc displacement without reduction clinically when limited unassisted vertical range of mouth opening is <40mm.

Question 26

Contracture  What is it?  Usually not painful unless muscle is ---  History of ... is often present

Answer 26

Shortening of a muscle due to fibrosis of tendons, ligaments, or muscle fibers overextended radiation therapy, trauma, or infection

Question 27

Contracture  Diagnostic Criteria MUST be present: (1)

Answer 27

1. Progressive loss of range of motion with unassisted and assisted opening < 40mm causing a “hard end feel”

Question 28

Fibromyalgia Pathophysiology  is poorly understood but believed to involve a ---  little evidence of --- abnormalities  may involve dysfunction of ---

Answer 28

central sensitivity syndrome peripheral tissue autonomic nervous system

Question 29

Fibromyalgia ssociated Co-morbid Medical Disorders: (5)

Answer 29

 TMD (10% of population)  Inflammatory & neuroendocrine disorders  IBS, functional chest pain from esophageal origin  Chronic pelvic pain  Headaches especially Migraines

Question 30

Fibromyalgia (FM) DIAGNOSIS:  Widespread pain with...  Associated with exaggerated tenderness in at least --- specified anatomic sites.  Commonly shows up as ---.  May be associated with ...  Refer to a --- for evaluation & treatment

Answer 30

bilateral diffuse musculoskeletal aches & stiffness both above & below the waist for > 3 months. 11 of 18 masticatory muscle pain sleep deprivation & depression. rheumatologist

Question 31

FM symptoms

Answer 31

Tingling, numbness, tightness, stiffness & swelling may affect the jaw. Dizziness is common. Toothache & gingival pain occur commonly in fibromyalgia patients.

Question 32

FIBROMYALGIA  Diagnostic Criteria MUST be present: (3)

Answer 32

1. Tenderness on palpation of at least 11 of 18 specified sites 2. Presence of wide-spread pain with concurrent masticatory muscle pain 3. Pain is bilateral and present above & below the waist

Question 33

Fibromyalgia Medications Effective: (3) Minimally Effective: (3)

Answer 33

 Lyrica  Antidepressants (i.e. amitriptyline)  Savelle (SNRI)  NSAIDs  Opioids  Benzodiazepines

Question 34

Fibromyalgia Conservative Treatment (4)

Answer 34

1. Sleep hygiene- keep bedtime & awakening time the same each day; only sleep while in bed- no TV or computers; rule out obstructive sleep apnea 2. Cognitive behavioral therapy to cope with pain 3. Light impact aerobic activity (i.e. swimming, beginner’s aerobic class) 4. Strength training with light weights Avoid electronic devices in bed Low impact exercises are recommended

Question 35

MOVEMENT DISORDERS: OROFACIAL DYSKINESIA  INVOLVES ---MOVEMENTS  MAY involve the (3)  MAY cause traumatic injury to the (2)  More common with (4)  Patient must provide a history of --- involving the orofacial region, history and examination is positive for myalgia and arthralgia that worsens with episodes of ---  Cranial nerve examination is positive for ...  Intramuscular --- confirms the dystonia diagnosis

Answer 35

INVOLUNTARY, CHOREATIC face, lips, and/or the jaw. tongue or oral mucosa advancing age, use of neuroleptic medications and/or traumatic brain injury, psychiatric or certain neurologic disorders dyskinesia dyskinesia sensory &/or motor nerve conduction deficit (i.e. Trigeminal nerve) EMG

Question 36

Treatment of Masticatory Muscle Pain  Goals of Treatment: (4)

Answer 36

1. Decrease pain 2. Increase range of motion 3. Resumption of normal daily activities (i.e. talking, eating a normal diet) 4. Onabotulinum A injections for Oromandibular Dyskenesia and Dystonias

Question 37

MANAGEMENT MASTICATORY MUSCLE PAIN (8)

Answer 37

REST (soft/liquid diet x 2 wks) HEAT/ICE THERAPY (10 min. 2x/day) ELIMINATE PARAFUNCTIONAL HABITS TRIGGER POINT INJECTION MUSCLE RELAXANTS NSAID’s PHYSICAL THERAPY SPLINT THERAPY

Question 38

MUSCLE Pain Treatment (4)

Answer 38

1. Physical therapy (i.e. stretching exercises, ultrasound, topical steroids with iontophoresis, deep tissue release, vapocoolant) 2. Stabilization splint 3. Medications (i.e. NSAIDs, Medrol dose pack, muscle relaxants, sleep medications, TCAs, local anesthetic injections) 4. Behavioral modification (i.e. stress management, cognitive therapy, elimination of parafunctional habits)

Question 39

Trigger point injection using --- without vasoconstrictor - may require repeat injections --- x to inactivate trigger points

Answer 39

1% Lidocaine 2-3

Question 40

H2 Blocker

Answer 40

 Prescribe an H2 blocker with the NSAIDs if use will exceed 2 weeks or if GI symptoms develop. This will inhibit gastric secretion and serve to protect from GI side effects.  Examples:  Prilosec (20mg) 1 tab q d- OTC  Nexium (40 mg) 1 tab qd

Question 41

skipped Muscle Relaxant Adverse Effects

Answer 41

 Dizziness  Drowsiness  Lightheadedness  Paradoxical stimulation  Abdominal pain  Nausea  Vomiting  Headaches  Nervousness  Uticaria  Hypotension  Blurred vision  Fatigue  Dry mouth  Constipation

Question 42

Steroids (3)

Answer 42

 Medrol dose pack (4mg)- as directed  Methyl prednisone 30-40mg qd for 3-4 days then taper by 10mg q 3-4 days until discontinued  Prescribe for patients with moderate to severe pain and no resolution of pain occurred with NSAIDs

Question 43

Topical Analgesics:

Answer 43

less likely than systemic analgesics to produce side effects & can treat a variety of painful disorders

Question 44

Used for muscle or TMJ pain (i.e. arthritis)  NSAIDS: Compounded (4)

Answer 44

 10% or 20% Indomethacin  10% or 20% Ibuprofen  10%, 15% or 20% Ketoprofen  3%, 5%, or 10% Diclofenac

Question 45

 Used for musculoskeletal pains (3)

Answer 45

 NSAID with muscle relaxants  1% flexeril with10% ketoprofen/10% ibuprofen  1% diclofenac sodium gel(Voltaren) Rx or OTC

Question 46

PHYSICAL THERAPY for Muscle Pain (4)

Answer 46

 Ultrasound  Electrical stimulation  Stretching exercises  Stabilization exercises

Question 47

Treatment of Musculoskeletal Pain (3)

Answer 47

 Physical therapy or Massage  Biofeedback/relaxation training or psychotherapy  Acupuncture

Question 48

Stabilization Appliances for Myalgia or Myofascial Pain (5)

Answer 48

1. Provide joint stabilization 2. Relax the elevator (closing) muscles 3. Provide stable occlusion 4. Increases awareness of jaw habits 5. Alters rest position of jaw to a more relaxed, open position

Question 49

Onabotulinum toxin type A (Botox) (4)

Answer 49

 Potent neurotoxin that inhibits acetylcholine (ACh) on both afferent & efferent motor nerves  Weakens painful muscles & inhibits muscle contractions  Interrupts pain cycle & may block peripheral neurotransmitters (i.e. Substance P, glutamate, & calcitonin gene-related peptide (CGRP)  Therapeutic injections have an average duration of 12 weeks before re-injection is necessary

Question 50

skipped Oromandibular Motor Disorders & Facial spasms treated by onabotulinum A Injections:

Answer 50

 Severe bruxism  Hypertrophy of masseter/temporalis  Secondary muscle spasm (i.e. radiation, multiple sclerosis, amyotrophic sclerosis, scleroderma)  Hemimasticatory spasm  Dystonia  Tongue hyperactivity  Motor tics  Palatal myoclonus which may cause tinnitus  Sialorrhea (i.e. ALS)  Hemifacial spasm- CN VII (synkinesis

Question 51

Psychotherapy (3)

Answer 51

 Biofeedback (EMG, thermal)  Relaxation techniques (imagery, muscle contraction/relaxation, deep breathing)  Cognitive therapy (decrease life stressors, caffeine, alcohol; & coping techniques)