From Rachael Gordon, A neuron who reads TMJ’s. Great points!
Phil,
I have seen the pterygoid atrophy. Mostly in patients with head and neck CA
who have had XRT. This is better seen on axial images, which can be worth
adding, especially if the patient has trismus.
I have seen the disc tear like this with posterior horn stuck back, but not
often at all.
RG, neuro rad who reads the TMJs!
—–Original Message—–
From: Phillip Tirman MD <ptirmanmd@gmail.com>
Sent: Oct 11, 2021 12:00 PM
To: OCAD <ocad-msk@googlegroups.com>, Neuro-OCAD <n-ocad@googlegroups.com>
Subject: [N-OCAD] 80 yoF right TMJ pain MRI. No trauma reported.
I am sending this to N-OCAD (Neuro) and OCAD (MSK) because the TMJ is a
joint that falls into the neuroradiologists domain in many places, probably
the majority. I was told by a few of my neuroradiology partners that they
are glad an msk person wants to read them, they cringe. Not all of course.
It is a joint that I think is a lot like a half knee: 1 meniscus,
ligaments, cartilage, bone and muscles. I’ve been looking at them for a
long time and have never seen what I saw today. Or, more likely, have never
recognized it. Surely it has seen me.
The mandible is an L shaped bone. The lateral pterygoid inserts onto the
anterior condyle and contraction of the muscle pulls the upper part of the
“L” and thus opens the mouth.
[image: Lat Pterygoid action labeled.jpg]
I think this patient has extensive partial tearing of the right lateral
pterygoid tendon associated with muscle belly fatty atrophy and focal
scarring of the remaining tendon along with chronic enthesopathy at the
tendon insertion on the mandibular condyle resulting in remodeling.
[image: Slide2.jpg]
[image: Slide3.JPG]
[image: Slide4.JPG]
The poor patient has been dealing with chronic instability of the joint and
has medial tearing of the meniscus resulting in separation of the anterior
and posterior bands as well as anterior subluxation of the intact meniscus.
[image: Slide5.JPG]
Here is the left to compare. She also has disc displacement on the left
associated with lateral pterygoid scarring as well as an anvil appearance
of the mandibular condyle because of the remodeling of degenerative
arthrosis.
[image: Slide6.JPG]
Do you agree? Feel free not to and we can all learn.
Phillip Tirman
