I’m not sure of the exact percentage of patients that have a “pop” or “click”, but joint noise is a common finding. When working with a patient that has joint noise my primary concern is to assess the stability of the joint. If the situation is unstable or the patient is symptomatic relative to the joint, then together we determine the appropriate treatment to try to establish an asymptomatic, stable condition. Other patients who come to see me with joint sounds are asymptomatic, and from my examination have a stable joint. The next question I ask myself, especially if they have restorative concerns, is “what is the risk of altering that stability”?
Checking for Palpable Sounds
Regardless of whether I am trying to answer the question of stability, or determine a course of treatment, one question must be answered, where is the disc? A more accurate way to ask the question is really, “Where is the disc off?” There are only two choices, medial pole or lateral pole, but knowing the answer is a key piece of information. Taking a thorough history is an important piece of understanding the health and stability of the joint, and begins to point us towards our answer. The definitive answer comes from analyzing the joint sounds and determining whether they occur in rotation or translation. When the temporomandibular joint is seated the load from the muscles is delivered through the medial aspect of the head of the condyle and disc. This load remains on the medial aspect during rotation and begins to move laterally as the joint opens further and begins to translate. Rotation occurs during approximately the first 1/2 inch (12mm) of opening, after that the joint is translating until it reaches maximum opening, and then the process reverses. During lateral excursions, the working joint (right lateral the right joint) is rotating and the non-working or balancing side is translating.
Doppler Auscultation
With this ability to differentiate when rotation is occurring versus translation, all we have to do is record during which movement the noise occurs. If the pop, click or crepitus occurs during rotation, the disc is displaced on the medial. If the noises occur after translation has begun, the displacement is at the lateral aspect. Pops and clicks can often be detected with joint palpation and this is always part of my exam, but in order to not miss crepitus or noise that isn’t palpable I auscultate. the doppler will pick up noise and let me easily differentiate when it is occurring rotation (medial) or translation ( lateral), it also allows the patient to hear the noises and get curious about what it means.
Another great posting. Thanks Lee. I just had a patient last week who presented with bilateral TMJ pain for over 6 months. Muscle palpation was WNL, lateral pole palpation was positive. Load test with lucia jig deprogramming was positive and doppler was positive for crepitus on rotation. Range of motion was WNL. Because of the chronicity, I sent for an MRI which confirmed my assessment of a Piper 4a, medial disc displacement. I dont send for alot of MRIs, but when I do they have always confirmed my doppler exam findings.
Dr.Brady , Thanks for the great article !
My question is how to utilize this information and how does it impact the treatment approach ?
Same thing goes for the muscle exam , how is the information gathered utilized to tailor a personalized treatment plan for the patient ?
Thank you .
We are looking for health or stability when it comes to joints and muscles. We are also looking for evidence of parafunction and system overload, and lastly predictable positioning of the mandible to the maxilla for bite relationship. If patients have joint inflammation we need to resolve that first, the same is true for muscle inflammation, both are signs of breakdown and instability of the occlusal position. I also want to understand the person’s functional risk so we can manage it or be aware of it. There is no one thing these findings add to a treatment plan, but appliance therapy before or after treatment is one that often becomes part of my thought process.
Hi Leann!
I have personally made a full arch appliance for myself in CR with no excursive mvmt interferences to successfully resolve myofascial pain and muscles stiffness due to nighttime clenching (and possibly bruxing).
3 yrs later, I am now noticing new, L side crepitus on translating that is fortunately asymptomatic, but certainly of concern to me. I do have my second molars functioning as the first point of contact on this side of my mouth. My muscles still feel great, I dont have any dental symptoms, but just wondering if you had any guidance with this type of case before I consider doing anything irreversible like an occlusal adjustment? Any thoughts on how I should adjust or remake my nighttime device? During the day I am hypervigilant about avoiding parafunctional habits and can ensure that I am not clenching/bruxing while awake for at least a decade. Thanks!