Learning objectives
MR-imaging of the TMJ with surface coils in a closed and open mouth position as well as dynamic MR-series of joint motion is the method of choice and has become an important part of the workup for TMJ disorders.
Radiologists have to be familiar with the anatomy,
biomechanics and pathologies of the TMJ prior to reading.
Therefore knowing where to look and what to look for in TMJ-MRI is crucial for musculoscelettal,
head and neck as well as neuroradiologists.
This poster is focused on teaching...
Background
Pain related to temporomandibular joint (TMJ) is very common and experienced in up to 20 -30% of the population with a female predominance (f:m = 3:1).
Clinical symptoms of TMJ disorder include also decreased mandibular movement and mastication problems.
The most common cause and clinical diagnosis for TMJ-symptoms is internal derangement of the articular disc an joint biomechanics.
Clinical evaluation of the TMJ can be unreliable due to a huge overlap of internal derangement symptoms with myofascial pain dysfunction,
that is often stress related and...
Imaging findings OR Procedure Details
Standard MR-protocols for imaging the TMJ consist of PD and/or T2w sagittal obliqueslices in closedand maximum open mouth position as well ascoronal oblique in closed mouth position(figure 1) for evaluation of the intraarticular structures and disc position.
At least one plane in T1 is necesseray to fully evaluate the bony structures.
T2w with fatsaturation helps in detecting joint effusion and together with T1 in evaluatingbone marrow edema.
Dynamic TMJ-series can be acquired as fast spinecho PD or T2 in cine mode.
Optimal slice orientation is...
Conclusion
For the interpretation of an static and dynamic MRI of the TMJ with a good level of confidence radiologists have to be familiar with the anatomy of the joint,
the dynamic biomechanics and motion of joint-structures as well as the normal and pathologic imaging findings in common and rare TMJ disorders.
The most common cause of TMJ pain is internal derangement,
which we introduced in detail with a step by step instruction for reporting on TMJ-scans in clinical routine.
References
Bag AK,
Gaddikeri S,
Singhal A et al.
Imaging of the temporomandibular joint: an update.
World J Radiol 2014 28 (2014); 6 (8): 567 - 582
Aiken A,
Bouloux G,
Hudgins P et al.
MR Imaging of the Temporomandibular Joint.
Magn Reson Imaging Clin N Am 20 (2012); 397 - 412
Ikeda R,
Ikeda K.
Directional characteristics of incipient temporomandibular joint disc displacements: A magnetic resonance imaging study.
Am J Orthodontics and Dentofacial Orthopedics 149 (2016); 39 - 45