Magnetic Resonance Imaging of the Jaw Joint
Magnetic Resonance Tomography (MRT) is a high-definition imaging procedure. It is based on the use of a strong magnetic field rather than on X-rays. In the 20 years since MRT was introduced, there have been no known adverse side effects, so it is seen as a very safe diagnostic technique. Unlike X-rays, MRT makes it possible to see not only the bones but also soft tissue such as muscles, joint capsules, discs, tendons and ligaments.
When MRT was introduced 20 years ago, there were high hopes within orthopaedics that it would at last be possible to diagnose with extreme accuracy the structures that cause pain, for example in the back. It was also hoped that MRT results would make it possible for treatment to accurately target the diseased structures. Unfortunately, these hopes have been largely disappointed, because there are patients with severe structural damage who are pain-free, just as there are patients who, in spite of exhibiting no such damage, still suffer severe pain. So it seems that damage to soft tissue and pain are definitely not so closely connected, which means that the impressive results of MRT only make it possible to develop a specific treatment in a small number of cases.
It has become very fashionable in recent years amongst some dentists and orthodontists to have an MRT of the jaw joint done prior to any routine treatment. The justification for this is that they have to know exactly what the jaw joint looks like and that any variations that are found that diverge from the norm can be dealt with before any dental or orthodontic treatment is carried out. It is actually quite common for an MRT of the jaw to reveal some structural things that do not correspond to the textbook ideal. These are usually not significant and neither require any special treatment nor show any prognostic importance.
So an MRT of the jaw joint is usually a completely pointless diagnostic measure that just worries the patient and costs them a lot of money. Yet, although it runs counter to current scientific knowledge, it is often prescribed so that the doctor can pretend to be some kind of expert and sell special kinds of elaborate treatment based on harmless structural variations.
The correct indicators for an MRT are severe pain which persists for several months and which does not respond to normal treatment, and to provide clarification before any planned surgical procedure on the jaw – both of which are extremely rare!
Tip
If either you or your child is prescribed an MRT before dental or orthodontic treatment even if you have no symptoms, then you can refuse it with a clear conscience! Not even a clicking jaw is a good enough reason to have an MRT because in almost 100% of cases, this just has to do with the protrusion of the disc. This is a harmless thing that requires no further diagnosis or treatment.