TMJ Pain and Neuropathic Painin Patients with

Temporomandibular Joint Disorders

Dr. Gaetano Meli

Symptoms and signs of TMJ disorders

• Lateral deviation of the jaw during the mandibular range of motion

• Bruxism• Presence of sounds or clicks during the jaw

movement • TMJ pain• Neuropathic pain (facial numbness and

dysesthesia, headache, toothache and earache)• Reduction of the mandibular opening• Sleep and Psychological disorders• Spine disorders

Okeson JP, Management of Temporomandibular Disorders and Occlusion, 2006

Different types of Pain

TMJ PAIN• When pain is located in the proximity of the

temporomandibular joint

NEUROPATHIC PAIN• Involving greater portion of the orofacial region

and it is associated with the onset of sensory deficits of the head (facial paresthesia,headaches, toothache, and ear sounds)

Okeson JP, Management of Temporomandibular Disorders and Occlusion, 2006

Neuropathic pain prevalence

Dupont JS, Cranio, 2003

Bell classification OF TMDMasticatory muscle

disordersTemporomandibular joint

disordersChronic mandibular

hypomobilityGrowth disorders

Protective co-contraction Disc displacement with or

without reduction Ankylosis Congenital or

developmental bone disorders

Local muscle soreness

Structural incompatibility of the articular surfaces

Muscle contracture Congenital or developmental

muscle disorders

Myofascial pain Inflammatory conditions

Coronoid impedance

Myospasm

Centrally mediated myalgia

Okeson- Bell; American academy of orofacial pain, 1996

Relationship among pain and MRI findings

Emshoff, 2001-2003

“Not all patients have the same reaction to a given

stimulus.They exhibit a differing

grade of individual physiological tolerance

(Okeson)

Temporomandibular joint disorders

Click

Temporomandibular joint disorders

Lock

Temporomandibular joint disorders

Osteoarthrosis Subchondral Cyst

Which are the causes of the onset of neuropathic pain?

The first mention of a possible clinical relationship among atypical trigeminalgia and temporomandibular disorders was proposed by Costen and dates back to 1934.

He hypothesized that in those patients the disc and/or condyle may directly damage the mandibular nerve and/or its branches by exerting intermittent compression, traction or friction during the jaw opening

AnatomyMRINetter plates

Prospective case-control analysis

Study Group A

Control Group B

Control Group C

16 TMJs with TMJ-D and neuropathic pain

16 TMJs with TMJ-D without neuropathic pain

16 healthy TMJs

Selection criteria

No significant sex or age differences among the three groups

Clinical diagnosis of TMJ-D achieved by “Clinical diagnostic criteria for TMD” (Truelove)

Presence of neuropathic pain assesed bythe “neuropathic pain diagnostic questionnaire” (Bouhassira)

DN4 Neuropathic Pain Diagnostic Questionnaire. Interview of the patient Question 1 : Does the pain have one or more of the following characteristics? 1.Burning yes no 2.Painful cold yes no 3.Electric shocks yes no Question 2: Is the pain associated with one or more of the following symptoms in the same area? 4.Tingling yes no 5.Pins and needles yes no 6.Numbness yes no 7. Itching yes no Examination of the patient

Question 3: Is the pain located in an area where the physical examination may reveal one or more of the following characteristics ?

8.Hypoesthesia to touch yes no 9.Hypoesthesia to prick yes no

Question 4: In the painful area, can the pain be caused or increased by? 10.Brushing yes no

Disc – mandibular nerve distance

ControlCase

Pedullà, Meli, Garufi et al ; AJNR Am J Neuroradiol. Aug. 2009

Healthy subjects Patients with TMJ-D without neuropathic pain

Pedullà, Meli, Garufi et al ; AJNR Am J Neuroradiol. Aug. 2009

Distance of the TMJ disc to the mandibular nerve at the maximum jaw opening in the study group A and in the two control groups B and C

TMJ Study Group A Control Group B Control Group C

1 10 10 102 6 8 113 4 9 124 9 10 95 8 9 86 5 9 107 9 10 108 3 5 119 7 7 810 6 9 711 7 6 712 5 7 813 5 11 1314 4 9 1115 5 5 816 7 7 8

Mean Value 6,25 8,18 9,43Standard Deviation

2,01 1,83 1,82

•TMJ PAIN could be correlated to the presence of internal derangement, effusion, osteoarthrosis, and bone marrow edema within the TMJ

• TMJ NEUROPATHIC PAIN could be associated to the presence of a mechanical impingement of the TMJ disc on the mandibular nerve fibers

Conclusion

Thanks for your time