In the first article in this series, we went through a letter I received from a new dental patient I was about to see — a young woman who recounted her history with jaw pain and the various treatments she had tried. We looked at the possible reasons for her condition and for why previous treatments did not bring her the relief she was seeking. In this concluding article, I will describe the process I went through when she arrived at the office, specifically the process of diagnosis and presenting treatment options.

New Dental Patient Exam and Diagnosis

The first step in providing the patient with answers and options is to diagnose the condition of the TM joints by conducting an exam. The exam consists of obtaining a history, assessing the occlusion and the face, load testing, measuring range of motion, muscle palpation, and listening to the jaw joints. We have already assessed the case history, and it appeared that this patient would fall into the category of “structurally altered TM joint at the lateral and medial pole.” This would be the high-risk category since structural alterations at the lateral pole and medial pole increase the risk for pain due to the lack of soft tissue coverage during joint loading. These structural alterations also increase the risk of malocclusion from a loss of dimension at the joint level or a failure to achieve normal joint dimension due to incomplete growth. (Figure 4)

TM joint condition categories.
Figure 4: TM joint condition categories.

In addition to what we know from the patient’s history, joint loading was positive on light loading in the left joint, which indicates a potential complete disk displacement. The range of motion was slightly decreased. The muscles presented with moderate tenderness to palpation. The Doppler exhibited crepitus during rotational movement, which also increases the risk of complete disk displacement.

After putting all the pieces of the exam together, our challenge is to determine a tentative joint diagnosis so we can offer the patient the appropriate options. If our tentative diagnosis is a normal joint or a partially herniated disk at the lateral pole, we will assume the TM joints are stable until the patient proves otherwise. These patients do not require any special diagnostic imaging to assess the condition of the TM joints.

If, however, our tentative joint diagnosis is a structurally altered joint at the lateral and medial pole, it is in the patient’s best interest for us to obtain imaging of the TM joint to assess the changes in the soft tissue and hard tissue. In this case, the MRI reveals completely displaced disks in the right and left TM joints (Figure 5). (It is an interesting clinical observation that often, while a patient may report pain in just one joint, both joints have structural alterations.) The CBCT shows bony changes in the left condyle (Figure 6).

MRI showing displaced disks in TM joints.
Figure 5: MRI showing displaced disks in TM joints.
CBCT showing bony changes in left condyle.
Figure 6: CBCT showing bony changes in left condyle.

Treatment Options and Outcome

After evaluating the clinical findings from the exam and the imaging, it is possible to offer patients treatment options that are based on anatomic findings. Understanding anatomy allows the patient to better understand the prognosis of the treatment.

In terms of treatment options, there are two different pathways to consider. The more common pathway is to treat the structural changes in the jaw joint indirectly. This is typically referred to as Phase 1 therapy. This type of treatment does not address the anatomic changes in the jaw joints but attempts to decrease the loading forces on the injured jaw joint in the hope that the joint will adapt. Fortunately, this type of treatment works well in many types of injured jaw joint cases.

While Phase 1 therapy can be highly effective for some jaw joints, it is important to understand that treatment success usually depends on the condition of the soft tissue (disk) and the hard tissue (condyle). If the jaw joint presents with significant anatomic alterations in either the soft tissue or the hard tissue, it may be necessary to consider direct treatment options (Phase 2) at the joint level.

Once the jaw joints have been stabilized through either indirect or direct treatment, Phase 3 treatment may be necessary at the tooth level to create a bite that fits with the jaw joints.

The figure below outlines Phase 1, Phase 2, and Phase 3 treatment options. Patients who have stable jaw joints may proceed immediately to Phase 3 treatment. Patients with injured jaw joints may begin Phase 1 treatment and move to Phase 3 treatment, if necessary, after the jaw joints stabilize. Patients with more advanced structural changes in the jaw joint may require Phase 2 therapy.

 

 

My patient in this case started with Phase 1 therapy with occlusal appliance therapy. The occlusal appliance offered some pain relief, but after using it for 12 months, she asked what other options were available. We discussed replacing the disk with abdominal fat. This is a procedure that has been used for many years to help decrease the chance of heterotopic bone formation when using total joint replacements.

After reviewing her options, the patient decided to have the disk replaced. The disk was removed (Figure 7), and abdominal fat was placed in the joint as a substitute material1,2 (Figure 8).

Removed disk.
Figure 7: Removed disk.
Figure 8: Abdominal fat
Figure 8: Abdominal fat

It is important to understand that fat is different from having a normal disk; therefore, this procedure will always have a guarded prognosis. However, if there is adequate condylar volume and the occlusion can be managed post-operatively, disk replacements can be a predictable treatment option for many patients if Phase 1 treatment does not provide adequate results.

In this case, the patient had orthodontic treatment to align the teeth after the disk replacement procedure (Figure 9).

Figure 9: Post-procedure orthodontics
Figure 9: Post-procedure orthodontics

Today, the disk replacement is 11 years old, and the patient remains mostly pain-free, with a good range of motion and ability to chew (Figures 10 and 11).

Figure 10: 8-year follow-up (closed)
Figure 10: 8-year follow-up (closed)
Figure 11: 8-year follow-up (open)
Figure 11: 8-year follow-up (open)

This case is a good example of how predictable treatment can be achieved even in new dental patients with structurally altered TM joints if we can develop a complete diagnosis from our exam and diagnostic records.

 

Jim McKee, D.D.S., is a member of Spear Resident Faculty.

 

References

  1. Younis, M., Shah, A., & Ahmed, I. (2021). Viability and volumetric analysis of free autogenous dermis fat graft as interpositional material in TMJ ankylosis: a long-term MRI study. Journal of Maxillofacial and Oral Surgery20, 304-309.
  2. Rahman, S. A., Rahman, T., Hashmi, G. S., Ahmed, S. S., Ansari, M. K., & Sami, A. (2020). A clinical and radiological investigation of the use of dermal fat graft as an interpositional material in temporomandibular joint ankylosis surgery. Craniomaxillofacial Trauma & Reconstruction13(1), 53-58.


Comments

Commenter's Profile Image David G.
August 22nd, 2023
Great article and nicely broken down. Particularly like that "listening" to the patients story revealed so much information. Still scared to tx "joints" but hey :)