Orofacial muscle pain Muscle Pain Characteristcs by liaoqinmei

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									                                                           Outline

                                       •    Muscle pain
     Orofacial muscle pain             •    Muscle pain disorders
                                       •    Possible pathophysiology
                                       •    Treatment

                Mun-H Center
                Dec 03, 2009

                Malin Ernberg
                 DDS, PhD




   International Association for the       International Association for the
         Study of Pain (IASP)                    Study of Pain (IASP)
  Pain is                              Pain is
  ‒ “an unpleasant sensory and         ‒ “an unpleasant sensory and
    emotional experience associated      emotional experience associated
    with actual or potential tissue      with actual or potential tissue
    damage, or described in terms of     damage, or described in terms of
    such damage.”                        such damage.”




            Muscle Pain                           Characteristcs
                                       •    Diffuse and difficult to localize
Temporal pattern                       •    Dull, aching
• Acute                                •    Referred to distant areas
• Chronic                              •    Tenderness (allodynia / hyperalgesia)
Spatial pattern                        •    Associated symptoms frequent
                                            – Neurological, gastrointestinal,
• Localized                                   musculoskeletal
• Generalized




                                                                                    1
           IASP, definitions                              Palpatory tenderness
Allodynia                                              Triggerpoints (TrP)
•    Pain due to a stimulus that does                  • Allodynia/Hyperalgesia
     not normally provoke pain                         • Referred pain

Hyperalgesia
                                                       Tenderpoints (TeP)
•    An increased response to a                        • Allodynia/Hyperalgesia
     stimulus that is normally painful                 • ”Latent TrP”




             Time course                                     Epidemiology TrP
• Phase 1                          Acute stage         • 50% 1 TeP
    – Constant pain
                                                       • 12.5% referred
• Phase 2                                                pain
    – Pain at movement and
      effort
    – Pain-free intervals
• Phase 3                                              • Majority latent
                                  Chronic stage
    – Tenderness, stiffness                              tenderpoints
      and reduced mobility
                                   Simons et al 1999           Sola et al 1955




    Etiology orofacial myalgia                                 Anatomic factors

May be factors              Can be                     • TMJ anatomy- steep mandibular
that                                                     fossa
• Predispose            •     Anatomic                 • Joint laxiety
• Initiates             •     Neuromuscular            • Malocclusion
• Perpetuate            •     Psychosocial
                        •     Systemic disease




                                                                                         2
                 Neuromuscular                 Psychosocial

 • Trauma                        •   Stress
    – Micro                      •   Depression
    – Macro                      •   Somatization
 • Ischemia                      •   Catastrophizing
                                 •   Sleep
 • Overload due to bruxism and
                                     disturbance
   parafunctions




            Systemic disease     Muscle pain in orofacial region

                                 Localized              Generalized
E.g.
                                 •   Myofascial pain    • Rheumatic diseases
• Rheumatic diseases                                        –   Fibromyalgia
   – RA                          •   Myositis               –   Polymyalgia Rheumatica
   – SLE                                                    –   Polymyosits
                                 •   Myospasm               –   Dermatomyositis
   – Polymyositis
• Neurologic dieseases           •   Myocontracture     • WAD
   – MS                          •   Neoplasms          • Infection (viruses, bacteria)
   – Dystonias                                          • Hypothyroidism




                                              Symptoms
                                 • Pain or ache in the craniofacial
         Myofascial pain           area
                                 • Pain upon palpation in masticatory
                                                                    y
                                   muscles
                                     – Trigger points
                                     – Tender points
                                 • Referred pain
                                 • Hyperalgesia in the zone of
                                   referred pain




                                                                                          3
                 Symptoms (2)                                                    Referred pain
    • Sensation of muscle stiffness /                        Masseter
      weakness                                                Superficial
    • Sensation of malocclusion                                   Upper and
                                                                  lower molars
    • Ear symptoms
    • Reduced jaw opening capacity                                 Deep
      (jaw opening increased by stretch)                          Ear/TMJ

                                                                Simons et al 1999




Temporalis                                                   Pterygoideus
                                                             Lateralis
 Upper teeth
                                                                  Ear/TMJ



                                                                Pterygoideus
                                                                Medialis
                                                                  Ear/TMJ


 Simons et al 1999                                               Simons et al 1999




                     Epidemiology                                               Risk factors (OR)
    • 40% of patients with chronic myalgia have             •    Grinding 6            •   Tooth clenching 5     •   Bruxism 7
      craniofacial pain (Schiffman et al. 1989)             •    Sleep disturb. 5      •   Women 4               •   Anxiety 5
    • 12% pain in TMJ or masticatory muscles                •    Headache 3            •   Somatizsation 4       •   Tooth clenching 3
      during the last 6 months (von Korff et al 1988)       •    Pain other parts of
                                                                                       •   Extraction wisdom     •   Women 3
                                                                 the body 3
    • 7% have chronic orofacial pain (Lipton et al 1993;                                   tooth 3               •   Trauma 2
                                                            •    Psychologic
      Mcfarlane et al 2004)
                                                                 distress 3
    Adults                         Adoloscents              •    Facial trauma 3
                                                            •    Chewing gum/biting
    • Prevalence ~ 10%             • Prevalence ~ 4.2%           nails (ns)
    • Incidence 2-4%               • Incidence 2.9%
    • Treatment need ~ 5%                                                                                            MyofascialTMD
                                                             pat = 131, ctr = 196          pat = 97, ctr = 195       pat = 83, ctr = 100
      Drangsholt et al 1999            Nilsson 2007
                                                           Macfarlane et al. 2001          Huang et al. 2002         Velly et al. 2003




                                                                                                                                           4
         Muscle hyperactivity                                          Depression/somatization
                                                                 Depression related to
    • Bruxism
                                                                 • Muscle pain
        – Clenching                                                  – Pat with high degree of depression have more painful
        – Grinding                                                     muscles upon palpation

    • Parafunctions                                              Somatization related to
        –   Tongue thrusting                                     • Muscle pain
        –   Chewing gum                                              – Pat with high degree of somatization have more more
                                                                       painful muscles upon palpation
        –   Nail biting                                          • Limitation of jaw function (jaw disability)
        –   Cheek biting                                             – Pat high degree of somatization have more limitations in
                                                                       jaw function

                                                                                                                         Yap et al 2004




                  Catastrophizing                                          Occlusal risk factors

    Catastrophizing related to                                   • Occlusal factors in females explained
    •   Reduced jaw opening                                        4.8% to 27.1% likelihood
    •   Palpatory pain                                           • Extreme ranges of occlusal
                                                                   measurements OR >2
    •   Pain limitation (GCPS)
    •   Limited jaw function (jaw disability)                  Occlusal factors may be a cofactor in the
    •   Number of visits to dentist                            identification of patients with TMD, but
                                                               their role should not be overestimated
                                                                                                     Pullinger and Seligman 2000
                                                Turner et al
                                                2005




                     Etiology?
                     Etiology?
•   Ischemia
•   Microtrauma                                                                     Myositis
•   DOMS (delayed onset muscle soreness)
•   Protective splinting
•   Metabolic alterations




                                                                                                                                          5
             Myositis                                   Myositis

• Localized continous pain following    • Fever
  injury or infection                   • Reddness
• Diffuse tenderness over the entire    • Swelling
  muscle                                • I      d ki
                                          Increasd skin
                                          temperature
• Increased pain upon movement
                                        • Palpatory pain
• Limited range of motion               • Increased CRP and
                                          ESR
Trismus after inferior alveolar nerve   • Reduced jaw
          myositis?
injection myositis?                       opening




                                                       Myospasm

                                        • Acute ”cramping”
           Myospasm                       in involved
                                          muscle
                                        • Involve major
                                          part of or whole
                                          muscle
                                        • Rare




        Diagnostic criteria                 Genera
                                            Generalized myalgias
• Acute onset of pain at rest and       • Rheumatic diseases
  movement                                   – Fibromyalgia
• Continous muscle contraction               – Polymyalgia Rheumatica
• Limitation in jaw function, often          – Polymyosits/dermatomyositis
  with malocclusion                     •   Whiplash associated disorders
• Increased EMG activity                •   Infection (viruses, bacteria)
                                        •   Hypothyroidism
                                        •   Deficiencies




                                                                             6
                                                      Muscle symptoms

                                               • Pain
       Fibromyalgia                            • Stiffness
                                               • Abnormal fatigue




        Epidemiology                                 Diagnostic criteria
• Prevalence: 1-2%
                                                                    ACR
• Females/males: 9/1
                                                          ?
• >40 yrs                                                           •   Widespread pain
                         Cathey et al 1986
                                                                    •   Pain upon
• 30% of patients with widespread                                       palpation in 11 of
  pain                                                                  18 specified points
                          Lindell et al 2000                                Wolfe et al 1990




    Diagnostic criteria                             Fibromyalgi and TMD
                                                 39 TMD, 60 FM
                 ACR
        ?                                                 p
                                                   • 75% patients with FM satisfied
                 •   Widespread pain
                                                     the criteria for myofascial TMD
                 •   Pain upon
                                                   • 18% patients with TMD also
                     palpation in 11 of
                                                     have FM
                     18 specified points
                                                                           Pleash et al 1996
                         Wolfe et al 1990




                                                                                               7
              Fibromyalgia                                               Facial pain FM
    Symptom (%)              Presence Daily
    n = 191                                                 •   Neck 93%
    Headache                    92.6       27.9             •   TMJ 62%
    Facial pain                 77.9       28.4             •   Temple 56%
    Jaw fatigue                 73.1        30              •   Forehead 60%
                                                            •   Cheek 35%
    Joint souds                 53.7       19.5

    Chewing difficulties        44.5       10.5

                           Hedenberg-Magnusson et al 1999                           Hedenberg-Magnusson et al 1999




                                                                        Muscle symptoms

                                                                • Symmetric pain
Polymyalgia rheumatica                                            and stiffness in
                                                                  proximal muscles
                                                                • Pain and stiffness
                                                                  in jaw muscles
                                                                • Morning stiffness
                                                                • Fatigue




        Associated symptoms
                                                                            Epidemiology

•   Weight loss                                                 • >50 yrs (peak 70-79 yrs)
•   Apathy                                                      • Men/women 1:1
•   No hunger                                                   • Often co exists or precedes giant
                                                                         co-exists
                                                                  cell artheritis (temporal artheritis)
•   Fever                                                         – 40% with giant cell artheritis also
                                                                    have polymyalgia rheumatica
                                                                  – 16% med PMR have giant cell
                                                                    artheritis




                                                                                                                     8
                Diagnostic criteria                                                        PMR and TA

    Has to be present                                                     Temporal
    • Pain and stiffness in proximal musculature                             artheritis
                                                                          • New severe                g
                                                                                                   Tongue necrosis
      At least two of the following                                         headache (65%)
       • Quick debut       • Depression                                   • Scalp tenderness
       • ESR > 40          • Weight loss                                  • Jaw claudicatio
       • Morning stiffness • Bilateral                                      (50%)
         >1 tim.             tenderness arms                              • Loss of vision
       • Age > 65 yrs




                                                                                           Mechanisms
                                                                   Peripherally- initate      Centrally- modulate and maintain?
                                                                   and modulate?
                                                                                                              Abnormal pain
                Patophysiology                                                                                transmission
                                                                                                               – Central sensitization
                                                                                                               – Disturbed pain
                                                                                                                 modulation

                                                                  Chronic activation &
                                                                  sensitization                                   Enhanced pain & pain
                                                                   – Chemically
                                                                                                                  spread/referral
                                                                   – Mechanically
                                                                                                                   –   Wind up
                                                                                                                   –   Gamma-activity
                                                                   – Temporal summation
                                                                                                                   –   Motor reflexes
                                                                                                                   –   Convergence
                                                                                                                   –   Latent synapses




                    Patophysiology

Pain                              Activation & sensitization of
Allodynia                         nociceptors
Hyperalgesia                      Central sensitization
                                           Temporal summation              Pain, allodynia & hyperalgesia
                                           Wind up
                                           Wind-up
                                  Disturbed pain modulation
                                  Motor reflexes
Referred pain                     Convergence
Spead of pain                     Latent synapses
Stiffness                         Increased -activity

Limited movements                 Pain adaptation theory
Weakness




                                                                                                                                         9
                                                                                           Activation/sensitization of
               Viscious cycle?
                                                                                                  nociceptors
No evience!                                         A. Lesion
                                                                                   Microtrauma
                                                                                   Ischemia
            ATP drop                               Release of                                                                                                              Pain
                                                   vasoactive                      Oedema                             Activation
                                                   substances                                                         /sensitization of
                                                                                    Release of pain                   nociceptors
                              Local                                                   mediators
Calcium pump                                                         Oedema
                            ischemia                                                   –   Neuropeptides
    failure
                                                                                       –   EAA (glutamate)
                                                    Vaso-
                                                    Vaso-                              –   Serotonin (5-HT)
                                                  constriction                         –   Bradykinin
            Contracture                                                                                              Activation of
                                                                                       –   Adenosine
                                                                                                                     NMDA
                           B. Increased                                                                              receptors
                                                           Mense 1993
                           muscle tonus




                       Clinically                                                                      Experimentally
   Increased level of
                                                                                                                                            50

                                                                                       Intramuscular                                        40                            5-HT
                                                                                                                                                                          NaCl
                                                                 5-HT level
   • 5-HT                                     4                                          injection                                          30




                                                                                                                            VAS diff
                                                                 associated to                                                              20

     – FM/TMD                                                    pain, allodynia       • Activation and                                     10
                                        vel




     – Work-related trapezius
         o e a ed ape us                                         and
                                                                                         sensitization                                       0
                                 5-HT lev




       myalgia                                                   hyperalgesia                                                               -10

                                                                                             – Serotonin                                          B 0   2   4   6 8 10 15 20 25

     – Trapezius trigger                      2                                                                                                             Time (min)

       points                                                                                – Bradykinin                                   20


     – Whiplash associated                                                                   – Serotonin +                                  10
                                                                                                                             PPT diff (%)


       disorders                                                                               Bradykinin                                    0



   • Glutamate                                                                               – Glutamate                                    -10
                                              0                                                                                             -20
     – Myofascial TMD                               FM   LM      C                           – NGF
                                                                                                                                            -30
     – Trapezius myalgia                                                                                                                          B 0   2 4     6   8 10 15 20 25
                                                                                                                                                            Time (min)
     – ”Jumpers knee”                                 Ernberg et al 1999
                                                                                                                                                  Ernberg et al 2000




                     Glutamate                                                                    Temporal summation

                                                                                       Repeated stimulation
                                                                                                              Pain
                                                                                                                 n
                                                                                                              Pain




                                                  Svensson et al. 2002




                                                                                                                                                                                    10
           Temporal summation FM                                                              Temporal summation TMD

                           100                                           HI                                   70                 TMD
                                                                                                                                 HI
                                                                         FM                                   60
                           80
                                                                                                              50




                                                                                                NRS (0-100)
                      0)
             NRS (0-100




                           60                                                                                 40

                                                                                                              30
                           40
                                                                                                              20

                           20                                                                                 10

                                                                                                              0
                            0                                                                                      1   2     3    4    5    6     7   8   9 10
                                  Pulse 1   Pulse 10    AS 15 s   AS 120 s
                                                                                                                                       Trials
                                                       Staud & Rodriguez 2006                                                              Maixner et al 1998




                    Central sensitization                                                     Impaired pain inhibition

                                                                                   • 5-HT deficiency
                                                 Touch causes                             – Reduced opioids (endorphins,
                                       II       pain (allodynia)                            enkelphalins)
                                                                                                 p      )
  Touch                                                                                   – Increased SP

                             IV
                                                                                   • Inhibitory interneurons
5-HT                                                   WDR
                                                                                          – GABA
Bradykinin
Glutamate
                                                         Excitability
                                                       (hyperalgesia)




                                                                                                                                                                             NRM

                                                                                   Muscle                                               CNS                                   5HT
                                   Tryptofan                                                                                                                             +
                                                                                 Tissue damage
                                                                                  Inflammation

             5-hydroxytryptofan                              Kynureninsyra                                                                                       +

                  (5-HTP)
     Tryptofan
                                                                                                                                      Spinal horn
     hydrolas
                                                                                                                                      B i stem
                                                                                                                                      Brain t
                                                                                       5HT1                            SP
             5-hydroxytryptamin                              Quinolinsyra        SP
                                                                                                                       Glu
                                                                                 Glu
                   (5-HT)                                                                                                                   SP
     Monoamin                                                                                                                           +   Glu
     oxidas                                                                        5HT3                                                                   SP
                                                                  NMDA agonist                                                         Opioids, GABA       +
          5-hydroxyindolacetylsyra                                                     5HT2                                                       -
                 (5-HIAA)
                                                                                                                                                                     +




                                                                                                                                                                                    11
                                GABA                                                                           Chronic myalgia

                                                                                         Reduced level
                                                                                         • Tryptophan in plasma and CSF
                         II
                                                                                           (FM)
      Touch                                                   Pre synaptic
                                                               inhibition                • 5-HT in serum (FM, TMD)
                                IN                                                       • 5-HIAA in CSF (FM)
                                                    WDR
                                                                                         Increased level
                                                   Post-synaptic                         • Substance P in CSF, blood (FM)
                                                     inhibition




                          Hyperalgesia                                                     Impaired pain inhibition FM

                 LM                                                                                      100
                                                                        FM                                                                HI-F
                                                                                                                                          FM
                                                    700                                                  80
      25                                                                                                                                  HI-M
                                                    600
                                                                                                   00)




      20
                                                                                           NRS (0-10




                                                    500                                                  60
                                      PPTL (kPa)




      15                                            400
                                                                                                         40
TPI




      10                                            300
                                                    200                                                  20
       5
                                                    100
       0                                                                                                  0
                                                      0                                                        Baseline   DNIC    DNIC + distr
           0    100     200     300                       0       100     200      300
               S-5-HT (ng/ml)                                    S-5-HT (ng/ml)                                                  Staud et al 2003




                      Pain inhibition TMD                                                                      Referred pain

           • SBP correlated to pain tolerance in HI-                                     • Convergence
             M
                                                                                         • Activation of latent synapses
           • Beta-endorphin correlated to pain
                                                                                           (central divergence)
             tolerance in HI-F
           • No correlations in TMD-F                                                    • Convergence-facilitation
                                                                                           – Probably does not occur (Kosek and
                                                                                                    Hansson, 2003)
           • Indication of disturbed pain inhibition in
             TMD
                                                              Bragdon et al 2002




                                                                                                                                                    12
                 onvergence
                Convergence                            Latent synapses (1)

                                                        IV

                                                                     WDR

                V1


                V3                                       IV

                                                                     WDR
                     C2




          Latent synapses (1)                         Latenta synapser (2)

           IV

                          WDR




           IV

                          WDR


                                                                                Mense 1994




            Motor reflexes                               Postural activity

 Increased muscle                               Clinically
   activity?
                          • Postural activity   • Few early studies showed slightly
                          • St ti activity
                            Static ti it                                    EMG activity
                                                  increased postural EMG-activity in
   Pain
                          • Dynamic activity      TMD patients compared to healthy
                                                  controls (Møller et al 1980)
                                                • When controlled for bruxism- no
Increased muscle
     activity
                                                  difference




                                                                                             13
                     Experimentally                                         Static activity

     • Intra-articular inj of pain mediators into             • TMD-patients reduced
                                                                bite force (Helkimo et al
       TMJ in animals increases EMG-activity                    1975).                                     6000
                                                                                                                        **
       in jaw muscles (Hu et al. 1993, Yu et al 1994, 1995)   • Reduced EMG-activity                       5000   **




                                                                                            EMG RMS (V)
                                                                   jaw-closing
                                                                in jaw closing muscles                     4000




                                                                                                    (
     • Intra-muscular inj of pain mediators into                during clenching after                     3000
                                                                                                                             **
       jaw muscles causes a small increase of                   experimentally induced                     2000                    **
                                                                muscle pain                                1000
       EMG activitety (splinting) in humans                     (Svensson et al 1996,
                                                                1998).
                                                                                                             0
        (Svensson et al 1998, 2004)                                                                               Masseter   Digastrius
                                                              • Reduced EMG-activity
     • Without clinical relevance                               in jaw-closing and jaw-
                                                                opening muscles during                Ernberg et al 2006
                                                                clenching after third
                                                                molar extraction




                    Dynamic activity

     • Reduced activity in jaw-closing
       muscles and jaw-opening muscles                                      Spred of pain
       during jaw-closing
             gj          g                                                   Stiffness
     • Incerased activity in jaw-closing
       muscles but reduced/unchanged
       activity in jaw-opening muscles
       during jaw-opening




                    Increased -activity


                           Descending pathways
                                                                         Limited movements
             Joint receptors                                              Muscle weakness
                                          II
Muscle receptors III, IV

                           Ia                    Muscle
                    II
   Muscle spindle                                spindle

                 Primary              Secondary
                  Muscle                Muscle




                                                                                                                                          14
       Pain adaptation theory                         Pain adaptation theory

• Pain leads to reduced activity in              Explains
  agonists but increased activity in
                                                 • Reduced jaw
  antagonists during static and dynamic
                                                   opening
  function (
  f                t ti )
      ti (co-contraction)
                                                 • Reduced bite
• Excitatory and inhibitory interneurons
                                                   force
• Leads to reduced mobility and strength
• Protection of the injured body part


                               Lund et al 1992
                                                                                     Lund et al. 1991




                                                                     pain-
                                                             Chronic pain-
       Treatment strategies
                                                            Treatment stair
•   Information
•   Reduce pain                                                   Irreversible
                                                                       g y
                                                                    Surgery
•   Improve function                                              Occlusal ther
•   Improve occlusion                                             Reversible
    and articulation                                              Pharmacology
                                                                 Physiologic
                                                             Psychologic treatment




     Information (psychologic)
                 (psychologic)                           Reduce pain
• Patient education                              • Physiotherapy
• Advise about home care                         • Unloading
• CBT                                            • Drugs
    – Patient education
                                                   – Oral administration
    – Cognitive techniques (catastrofizing)
                                                   – Intramuscular injections
    – Relaxation
    – Coping




                                                                                                        15
                               Improve occlusion
  Improve function              and articulation
• Jaw exercise          • Bite splint
  – Isotonic            • Occusal
  –IIsometric
          ti              adjustment
                        • Prosthetic
• Physiotherapy
                          treatment
                        • Orthdontic
                          treatment




           Thank you!




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