TMJ Pain and Neuropathic Pain in Patients with Temporomandibular Joint Disorders

1. TMJ Pain and Neuropathic Painin Patients with Temporomandibular Joint Disorders Dr. Gaetano Meli

2. Symptoms and signs of TMJ disorders • Lateraldeviation of the jaw during the mandibular range of motion • Bruxism • Presence of sounds or clicksduring 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

3. Differenttypes 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

4. Neuropathic pain prevalence Dupont JS, Cranio, 2003

5. Bell classification OF TMD Okeson- Bell; American academy of orofacial pain, 1996

6. Relationshipamong pain and MRI findings Emshoff, 2001-2003

7. “Notallpatientshave the samereactionto a givenstimulus. Theyexhibit a differinggradeofindividualphysiologicaltolerance(Okeson)

8. Temporomandibular joint disorders Click

9. Temporomandibular joint disorders Lock

10. Temporomandibular joint disorders Osteoarthrosis Subchondral Cyst

12. Which are the causesof 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

14. Anatomy Netter plates MRI

15. Prospective case-control analysis 16 TMJs with TMJ-D and neuropathic pain Study Group A 16 TMJs with TMJ-D without neuropathic pain Control Group B Control Group C 16 healthy TMJs

16. 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 by the “neuropathic pain diagnostic questionnaire” (Bouhassira)

17. 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 physicalexaminationmay 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

18. Disc – mandibular nerve distance Case Control Pedullà, Meli, Garufi et al ; AJNR Am J Neuroradiol. Aug. 2009

19. Patients with TMJ-D without neuropathic pain Healthy subjects Pedullà, Meli, Garufi et al ; AJNR Am J Neuroradiol. Aug. 2009

21. Conclusion • TMJ pain could be correlated to the presence of internal derangement, effusion, osteoarthrosis, and bone marrow edema within the TMJ • TMJ neuropathic paincould be associated to the presence of a mechanical impingement of the TMJ disc on the mandibular nerve fibers

26. Thanks for your time