Should I Image Before Making an Occlusal Appliance?

I was talking with a young Spear dentist recently about a patient she was treating who suffered from pain in their jaw joints. The dentist had watched a video from an esthetic teaching center that discussed making occlusal appliances for patients with painful jaw joints. Her question was, “Should I image the temporomandibular joints before making the occlusal appliance?”

This question is common among dentists. In this article, I will attempt to provide some guidelines to address this widespread concern.

If we look at this issue from a global perspective, it’s crucial to ask what an occlusal appliance accomplishes. In the most basic sense, an occlusal appliance changes how masticatory muscle forces are applied to the jaw joints and teeth. From a tooth perspective, we can use an occlusal appliance to change the load applied to loose or worn teeth.

STUDY CLUB MODULE: In his latest Study Club module, Dr. McKee explains options for patients with injured temporomandibular joints and how TMJ imaging with MRI and CBCT impacts the treatment planning process. 

It has been well established that changing the load in these types of situations can be beneficial for patients. We are confident when making an occlusal appliance for tooth-related issues because we can directly visualize the teeth and make a diagnosis of the condition. The ability to make an accurate diagnosis helps us explain the pros and cons of an occlusal appliance to the patient.

As an example, if a patient presented with tooth mobility and the clinical exam using indirect visualization revealed generalized 10-mm pockets, the next step in the diagnostic process would be to directly visualize the tooth using a radiograph to assess the tooth anatomy. If the radiograph revealed 80% bone loss in several areas of the mouth, we would explain the guarded prognosis to the patient. We could try the occlusal appliance to help stabilize the teeth and help decrease tooth mobility, but the patient would understand the risk factors are high and the likelihood for successful treatment is low.

The concept is similar when discussing occlusal appliances from a joint perspective. The initial clinical exam using indirect visualization will give us an indication of the amount of structural damage that may be present in the TMJ. The equivalent presentation of a 10-mm pocket at the tooth level at the joint level may include the following items:

• Pain higher than a 5/10
• Interior tooth uncoupling greater than 2 mm (the thickness of the disk maintaining TMJ vertical dimension at the medial pole) in a fully seated condylar position
• History of Class II orthodontic treatment (headgear, maxillary first premolar extraction, functional appliances)
• Multiple occlusal appliances
• Multiple equilibrations
• Orthognathic surgery

If the history and the clinical exam reveals the items listed above, it may be wise to use direct visualization (similar to the tooth example) to assess joint anatomy before beginning occlusal appliance therapy.

The Piper Classifications is a great guideline to use to understand when it may be helpful to image TMJ. The Piper staging is:

• Piper Stage 1: Structurally intact joint
• Piper Stage 2: Beginning lateral pole laxity
• Piper Stage 3A: Lateral pole click with reduction
• Piper Stage 3B: Lateral pole click without reduction
• Piper Stage 4A: Medial pole click with reduction
• Piper Stage 4B: Medial pole click without reduction
• Piper Stage 5A: Perforation-acute
• Piper Stage 5B: Perforation-chronic

When dealing with Piper 1, 2, 3A and 3B joints, the medial pole of the condyle is protected by the disk and there is a low likelihood of pain or bite changes. The items listed above (pain higher than a 5/10, anterior tooth uncoupling greater than 2 mm in a fully seated condylar position, history of Class II orthodontic treatment, multiple occlusal appliances, multiple equilibrations, orthognathic surgery) typically occur in Piper Stage 4A, 4B, 5A and 5B joints.

The history and the clinical exam will help drive the decision whether it is prudent to image before fabricating an occlusal appliance. If the clinical exam and history points to a Piper 1, 2, 3A or 3B joint, it may be acceptable to fabricate an occlusal appliance without imaging. If the clinical exam and history points to a Piper 4A, 4B, 5A or 5B joint, it may be best to image the joints to assess the anatomy before making an occlusal appliance that will change the load distribution on a damaged joint.

References

1. Piper, DMD MD, Mark. “Temporomandibular Joint Imaging.” Handbook of Research on Clinical Applications of Computerized Occlusal Analysis in Dental Medicine. IGI Global, 2020. 582-697. Web. 24 Oct. 2019. doi:10.4018/978-1-5225-9254-9.ch009

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