CC
A 55-year-old female (degenerative joint disease [DJD] has a higher prevalence with advanced age and in female patients) presents to your office with a 20-year history of temporomandibular joint dysfunction (TMD), complaining, “I’ve been through several TMJ surgeries, and now my right joint is very painful and makes grinding noises.”
HPI
The patient reports several months of anxiety and stress that she relates to the pain centered around her right TMJ; this pain is most pronounced upon mouth opening during mastication and speech. She has a long, progressive history of TMJ problems. In her late teens, she developed bilateral reciprocal TMJ clicking (suggestive of anterior disk displacement [ADD] with reduction), which was confirmed by magnetic resonance imaging (MRI). She also had intermittent right-sided preauricular pain and bilateral myofascial pain. She was managed nonsurgically with occlusal splint therapy and nonsteroidal antiinflammatory drugs (NSAIDs). She reported mild improvement and did not pursue further treatment because she tolerated her discomfort by minimizing masticatory function. In her mid-20s, the right TMJ stopped clicking, and she developed an acute closed lock with severe right-sided pain and restricted left lateral excursive movements of the mandible without clicking. (This is consistent with the progression of ADD with reduction to ADD without reduction of the right TMJ.) She underwent right-sided TMJ arthrocentesis, which provided 8 months of symptomatic resolution. A second arthrocentesis procedure was performed, which provided only brief additional relief. Subsequent MRI studies showed evidence of ADD and DJD of the right TMJ, with a displaced, deformed, nonreducing disk and evidence of perforation of the posterior band of the disk in addition to degenerative bony changes of the TMJ with decreased joint space, flattening of the condylar head, and osteophyte formation in addition to ADD without reduction on the left side with associated degenerative bony changes. Her surgeon elected to perform a right TMJ diskectomy (removal of the disk) without disk replacement, which resulted in an excellent outcome for several years. She now presents with a 2-year history of loud, grinding noises or crepitus (crepitus is a pathognomonic sign of advanced osteoarthrosis) of the right TMJ with increasing levels of debilitating pain localized to the right TMJ.
PMHX/PDHX/medications/allergies/SH/FH
Noncontributory, except for arthritic changes diagnosed in the patient’s cervical spine and the proximal interphalangeal joints of the hands. She has taken NSAIDs as needed for pain over the past several years. Patients with arthritic degeneration of the TMJ frequently have involvement of other joints that precedes involvement of the TMJ. However, it is possible to have DJD of the TMJ with no evidence of arthritis in any other joints.
Examination
General. The patient is a well-developed and well-nourished female in moderate distress because of right-sided TMJ pain.
Maxillofacial. The patient has no facial swelling or asymmetry. The right TMJ is exquisitely tender to palpation (upon both preauricular and endaural palpation). The left TMJ is nontender. She has limited opening (20 mm) because of pain and a loud, bony crepitus of the right TMJ that is easily heard without a stethoscope. Lateral excursive movements are limited (3 mm to the left and 6 mm to the right). She has a class I occlusion without an open bite. (Advanced condylar degeneration and loss of posterior mandibular height can lead to a contralateral posterior open bite or an anterior open bite.) The external auditory canals are clear, and the tympanic membranes appear normal. Her right preauricular surgical scar is well healed, and cranial nerve VII is intact. (Multiple open TMJ procedures increase the risk of cranial nerve VII injury, especially the frontal or temporal branch.)
Imaging
The panoramic radiograph is the initial imaging study of choice for evaluation of the TMJ. It provides a general overview of the bony morphology of the mandible and condyle. MRI scans, in the open- and closed-mouth positions, are considered the standard when evaluating for TMJ internal derangement to view the disk. MRI provides the most detailed information regarding the soft tissue structures (disk morphology) and disk position in the open- and closed-mouth positions. (Some patients may not be able to open sufficiently because of pain, ADD without reduction, or closed lock.) A bony window computed tomography (CT) or cone-beam CT scan is indicated when bony or fibrous ankylosis of the TMJ or other bony pathology is suspected. A CT scan can be used to better delineate the bony anatomy of the TMJ and demonstrate any degenerative changes.
For the current patient, the panoramic radiograph demonstrated evidence of right TMJ osteoarthrosis (small condyle with arthritic remodeling, likely because of joint overloading and prior intra-articular surgical procedures), including flattening of the condylar head, subchondral eburnation (sclerosis), and osteophyte formation. The panoramic radiograph ( Fig. 70.1 ) showed the right condylar head with a loss of normal anatomy, and was significantly smaller than the left side, had sharp edges, and had lost its cortical definition (signs of advanced degeneration). A CT scan showed right-sided bony TMJ degenerative changes when compared with the left TMJ ( Fig. 70.2 ). Sagittal and coronal MRI scans showed moderate degenerative changes. (Whereas TMJ soft tissue anatomy is best seen with T1-weighted images, TMJ inflammation and effusions are best seen with T2-weighted images because they appear with increased signal intensity; Fig. 70.3 .)
Labs
No routine laboratory testing is indicated for the workup of patients with DJD. Clinical suspicion of systemic arthropathies (e.g., rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, and gout) would dictate further laboratory testing. Other laboratory values are obtained based on the medical history, and the results of nonspecific laboratory studies of inflammation (e.g., C-reactive protein and erythrocyte sedimentation rate) may be elevated because of chronic inflammation. Baseline preoperative hemoglobin and hematocrit levels are recommended for patients undergoing an open joint procedure or total joint reconstruction.
Assessment
DJD of the right TMJ with localized pain on the multiply operated right side.
Treatment
The goals of treatment for DJD of the TMJ are to decrease pain and swelling, improve joint function, and limit disease progression. Generally, treatment follows a stepwise sequence, beginning with noninvasive or minimally invasive procedures and progressing to more advanced surgical treatment modalities when indicated.
Nonsurgical therapy includes a jaw rest regimen, occlusal appliances, physical therapy, warm compresses, and NSAIDs. Arthrocentesis is a minimally invasive treatment modality; however, the use of intraarticular adjunctive medications (e.g., corticosteroids, platelet-rich plasma, and hyaluronic acid) is somewhat controversial, with some studies showing benefit of each of these medications. Arthroscopy does not offer additional outcome benefits over arthrocentesis, but it may provide a diagnostic advantage. The majority (about 80%) of patients respond, at least in the short term, to both noninvasive and minimally invasive treatments, perhaps as a result of the joint lavage and clearance of inflammatory mediators.
More invasive surgical modalities include open joint (arthrotomy) procedures, such as arthroplasty with osseous recontouring of the condyle or glenoid fossa and, if necessary, disk removal or repositioning. Diskectomy may be performed in conjunction with placement of an interpositional material (e.g., autogenous fat graft, dermal graft, alloplastic graft, cadaveric graft, temporalis muscle–fascia flap, ear cartilage). With severe degeneration of the TMJ, reconstruction may be necessary using either autogenous options (e.g., free fibula flaps, costochondral or calvarial grafts) or an alloplastic joint prosthesis. Various stock and custom alloplastic total joint implants are available.
In the current patient, right total joint replacement was performed using custom prefabricated condylar head and fossa alloplastic implants ( Fig. 70.4 ). In this surgery, a gap arthroplasty was performed with a condylectomy and coronoidectomy to provide adequate space (2.0- to 2.5-cm minimum distance) for the TMJ implant, fossa, and condylar prosthesis. A minimally invasive endaural or preauricular approach can be used.
