Patient History 101 (Lesson 1): Jaw Joints

Editor’s note: “Patient History 101” is a series of four articles from Dr. Jim McKee with advice on how to obtain accurate and helpful patient history.

Patient history plays an important part during a clinical exam and shouldn't be overlooked as an invaluable tool. It provides time to review previous dental experiences and current oral problems so you can offer optimal care.

Although taking a thorough dental history is an opportunity to fortify a relationship with a patient, its main purpose is to lead you in accurately diagnosing and managing their oral issues or discovering problems and areas for concern they never knew they had.

One of the goals of the clinical exam is to assess the condition of the temporomandibular joints. There are three common presentations of jaw joints in clinical practice:

• Low risk
• Low-moderate risk
• Moderate-high risk

A structurally intact jaw joint or a Piper Stage 1 is a normal joint. A Piper Stage 2 is a joint with beginning ligament laxity at the lateral pole. Both these common presentations are considered low-risk joints.

Another common type of joint seen in clinical practice is structurally altered at the lateral pole. This would be a Piper Stage 3A, which is a joint with an intact disk at the medial pole and a torn ligament at the lateral pole. This type of joint clicks at the lateral pole upon opening.

A Piper Stage 3B is a joint with an intact disk at the medial pole and a disk with a torn ligament at the lateral pole. This type does not click at the lateral pole upon opening since the disk has deformed. Stage 3A and 3B are typically considered low-moderate risk joints.

A joint that is structurally altered at the lateral pole and the medial pole is a Piper Stage 4A, which is a joint with a torn ligament at the medial pole and a torn ligament at the lateral pole. This type of joint clicks at the medial pole upon opening.

A Piper Stage 4B is a joint with a torn ligament at the medial pole and a torn ligament at the lateral pole. This type does not click at the medial pole upon opening since the disk has deformed.

The Piper Stages of 4A/4B and 5A/5B joints are typically considered moderate-high risk joints. In these joints, the disk is not covering the medial pole. The medial pole is the load-bearing portion of the TMJ and the disk as the medial pole maintains the vertical dimensions at the level of the TMJ. The Piper 4A/4B, 5A/5B joints have an increased likelihood for pain, bite changes, or both.

Patient history plays a role in the Piper Stage diagnosis

To obtain a tentative Piper Stage diagnosis for the right and left TMJs we use the six indirect visualization testing methods:

• History
• Occlusal/facial analysis
• Load testing
• Listening to the TMJ
• Range of motion
• Muscle palpation

The goal is to recognize the high-risk joint patients (Piper 4A/4B, 5A/5B) before beginning any occlusal, orthodontic, restorative, orthognathic, or airway treatment.

These high-risk patients have an increased risk for bite instability, pain, or both. Understanding the joint condition allows the dentist to have a realistic discussion with the patient about the likelihood of successful treatment.

Each of the six areas of the exam will lead the dentist to a tentative Piper classification. However, asking the patient relevant questions to gain an accurate history and then correlating their answers to the condition of the TMJs is key.

Accurate history can be an invaluable tool for the dentist when developing a tentative Piper classification. Obtaining a history is usually done first during the exam and, in many cases, it is possible to recognize high-risk patients with some confidence based solely upon their history.

What are patients telling us about their jaw joints?

Does your joint click or pop?

If a patient says their joint clicks, it typically means there is a torn ligament attaching the disk to the condyle. The ligament attaching the disk to the lateral pole could be torn (Piper Stage 3A/3B) or the ligament attaching the disk to the medial pole could be torn (Piper 4A/4B/5A/5B). This would be referred to as an anteriorly displaced disk with reduction.

If “yes,” moderate to increased chance of a Piper 4A/4B or 5A/5B joint.

Has either joint clicked or popped in the past?

If a patient says their joint used to click but doesn’t anymore, typically the disk has changed shape and the condyle cannot move under the disk when the condyle moves forward. This would be referred to as an anteriorly displaced disk without reduction. A disk that used to click but does not click currently, typically indicates a long-standing injury to the joints.

If “yes,” increased chance for a Piper 4A/4B or 5A/5B joint.

Does either jaw joint lock when trying to open?

If a patient's jaw is locking when trying to open, the disk is usually anteriorly displaced. In these joints, it is common for the disk to wedge in front of the condyle. As a result of the disk displacement, it is difficult for the condyle to move normally.

If “yes,” increased chance for a Piper 4A/4B or 5A/5B joint.

Has either jaw joint locked in the past?

If a patient's jaw has locked in the past, it is common for the joint to have a long-standing injury that has changed the anatomy of both the soft tissue (disk) and hard tissue (condyle/joint socket).

If “yes,” increased chance for a Piper 4A/4B or 5A/5B joint.

Do you remember having the problem in high school?

The earlier in life a patient notices a jaw joint problem, the greater the chance for advanced structural changes at the soft tissue (disk) and hard tissue (condyle/joint socket).

If “yes,” increased chance for a Piper 4A/4B or 5A/5B joint.

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

References

Piper M. Temporomandibular Joint Imaging. In: Handbook of Research on Clinical Applications of Computerized Occlusal Analysis in Dental Medicine. Hershey, PA: Medical Information Science Reference; 2020:582-697.