Fall 2006 - College of Dental Medicine - Columbia University

meeting of Oral and Maxillofacial Surgeons.Researchers exploring the pathogenesis of TMDover the past decade had already identified somekey immunological regulators. But, by using whatthey believed to be more appropriate controls,Drs. Chang and Israel were seeking to demonstratea clearer distinction between disease andhealth in the temporomandibular joint than hadbeen shown previously.Twenty TMD patients with “severe pain and limitationof mandibular movement that had failed toimprove with at least three months of a full courseof nonsurgical therapy” and 13 members of a controlgroup were examined arthroscopically forsigns of osteoarthritis, synovitis, internal derangement,disc perforation, or adhesions. Next, theresearchers analyzed the level of three specificinflammatory mediators in lavage samples fromthe temporomandibular joint synovial fluid of bothpatient and control groups. Their work revealedthat degenerative conditions found in the TMJs ofsymptomatic subjects were “almost always”accompanied by significantly elevated levels of synovialinflammation, which can cause destruction tothe joint tissues by stimulating inflammatory activitythat has the potential to damage the articulardisc surface. Earlier research had tended to sidestepbiochemical and tissue changes that may precedecartilage destruction in the joint space.Not only did their results help to clarify the pathogenicmechanisms of TMDs in patients with severesymptoms, but the authors also point out that themethodology used in the study could lead to beneficialresults for TMD patients. They concludedthat, “Lavage of the joint space via arthrocentesisassists in the removal of inflammatory mediatorsand antigenic sources. Arthroscopic surgery alsoprovides lavage of the joint space while enablingdirect visualization and treatment of inflamed synovialtissues, osteoarthritic cartilaginous tissues, thephysical removal of adhesions and mobilization ofthe articular disc. The end result of a successfularthroscopic surgery is a joint with reduced inflammatorymediators and a reduction of cartilagebreakdown products in the synovial fluid. Thisleads to a decrease in antigen load and a decreasein inflammation, which ultimately results inimproved maximum opening distance and reducedjoint pain.”Dr. Chang has also explored pharmacologicaltreatment for TMD. Writing in the December2005 issue of Dentistry Today, she discusses botulismtoxin (BTX) use for this purpose. A blocker ofneuromuscular transmission, BTX received FDAapproval in the 1980s for use in cases of focal dystonias.Subsequently, BTX has found medical applicationin many areas, including subcategories ofTMD, like bruxism, clenching, masseteric hypertrophy,recurrent dislocation, oromandibular dystonia,and myofacial pain. Dr. Chang summarizes studiesthat show a growing body of evidence for successin treating these TMJ problems with BTX, althoughshe adds that there have been some reports of difficultyin swallowing, which could lead to moreserious problems. In closing, she points out thatthe effects of the treatment are reversible and itsadministration is minimally invasive.Whether through elucidating the causes of TMD atthe cellular level, or determining the best course oftreatment to give them relief, Dr. Chang’s focus ison helping her patients. Her attitude is made clearin the New York Times article, which quotes her assaying, “...if someone comes to you with pain, theyhave pain. I don’t give patients the runaround andsay it is imaginary.”Dr. Chang in her office in the Division of Oraland Maxillofacial Surgery at CDM.14primus2006