• Class I: painless clicking, no restricted motion
    • Painless reducing disk
  • Class II: occasional painful clicking, intermittent locking, headache
    • Painful reducing disk
  • Class III: frequent pain, joint tenderness, headaches, locking, restricted motion, and painful chewing
    • Acute or subacute painful nonreducing disc
  • Class IV: chronic pain, headaches, and restricted motion
  • Class V: variable pain, joint crepitus, and painful function
    • Painless nonreducing perforated disk

Class III: recent progression to disc displacement without reduction

Class IV: internal derangement is defined as complete disc displacement with hard tissue degenerative changes and clinical chronicity. Interincisal opening is usually greater than 30mm

 

  • In the Wilkes Classification of internal derangement stage III represents a non-reducing disk displacement that is acute or subacute. Early stage III internal derangements may be reducible with mandibular manipulation. Late stage III internal derangements represent permanent disc displacement.
  • Stage I: painless reducing disc
  • Stage II: painful reducing disc
  • Stage III: acute or subacute painful reducing disc
  • Stage V: painless nonreducing perforated disc
  • Pain and diet are significantly improved 3 years after modified condylotomy for internal derangement. Disc position is improved at least 70% of the time with disc displacement with reduction. Non-reducing disc displacement is unaffected by condylotomy. Late stage internal derangement joints with degenerative joint disease (Wilkes Stage IV, V) have less satisfactory pain relief after modified condylotomy. Although modified condylotomy can be applied simultaneously to the patient with Class III malocclusion and symptomatic internal derangement this is not well documented and a represents a more novel application of condylotomy.