Lea Alhilali, MD Profile picture
Jun 8, 2022 14 tweets 7 min read Read on X
1/Mike Tyson once said, “Everyone has a plan until they get punched.”
In honor of all the great hooks and crosses—here is a #tweetorial about mandibular fxs! #FOAMed #medtwitter #Meded #neurorad #HNrad #FOAMrad #Medstudenttwitter @MedTweetorials Image
2/A key concept in these fxs is dental occlusion. The jaw is meant to chew. To crush food, teeth need to come as close together as possible—occlusion. Each tooth needs to meet up with its counterpart that fits with it, so no room is left for food—and food will be crushed. Image
3/Occlusion can be lost w/a fx. The importance of dental occlusion makes mandibular fxs different from other fxs. Usually, we want to fix a bone so that it lines up again. But for the mandible, we want to fix it so the TEETH line up again—so chewing will work. Image
4/Another important concept is multiplicity. It used to be taught that the mandible was a ring w/the skullbase—& you can’t break a ring in one place, so every mandible fx had to have a 2nd one. But this is only true ~50% of time—but it is still worth it to look for the 2nd fx. Image
5/Because of the shape of the mandible and the typical forces applied to it, mandibular fractures usually occur at the same few locations. But the names of these fxs are not always intuitive—at least not without a tweetorial to help explain them! 😉 Image
6/Well, perhaps I lied a little. The most common fx does have an intuitive name. An angle fx starts at…wait for it…the angle and extends into socket of the 3rd molar. If you can’t remember an angle fx starts at the mandibular angle, then not even this tweetorial can help you! Image
7/A subcondylar fracture starts from the notch between the condyle and coronoid process, called the sigmoid notch and extends into the posterior ramus. Don’t call this a ramus fx bc a ramus fx goes straight horizontally through the ramus! Image
8/Here are examples of subcondylar fxs. A key finding in subcondylar fxs is that it separates the condyle from the rest of the mandible. It can be difficult to see the fx running through the sigmoid notch & ramus on 2D images—3D images can be helpful to see the fx anatomy. Image
9/I remember subcondylar fxs bc they separate the condyle from the rest of the mandible. If you isolate someone, you make them feel SUBpar—so SUBcondylar fxs make the condyle feel subpar bc they separate it from the rest of the mandible! Image
10/Condylar head/neck fxs are easy to remember—they are through, well, the condylar head or neck. These are fx/dislocations. Pterygoid muscles attach to the head & pull medially. So when the head is no longer attached to the mandible, pterygoids are unopposed & pull it medially. Image
11/So if you ever see a condylar head displaced medially, you know it is a condylar head or neck fracture bc this is where the pterygoids are unopposed and pull medially! Image
12/Body fxs are through the body of the mandible and are named for the tooth socket that they involve. So you would say “A mandibular body fx through the FILL IN THE BLANK TOOTH socket.” Image
13/Body fxs through the canine are given the special name “parasymphaseal” or “mental” fx bc they are near the mental foramen where the inferior alveolar nerve exits. Menton means “chin” in French, so if they are a body fx anteriorly near the chin, they are “mental” fxs Image
14/So now you know your mandibular fractures & you have a plan even when the patient gets punched! Image

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Lea Alhilali, MD

Lea Alhilali, MD Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @teachplaygrub

Dec 5
1/They say form follows function!

Brain MRI anatomy is best understood in terms of both form & function.

Here’s a short thread to help you to remember important functional brain anatomy--so you truly can clinically correlate! Image
2/Let’s start at the top. At the vertex is the superior frontal gyrus. This is easy to remember, bc it’s at the top—and being at the top is superior. It’s like the superior king at the top of the vertex. Image
3/It is also easy to recognize on imaging. It looks like a big thumb pointing straight up out of the brain. I always look for that thumbs up when I am looking for the superior frontal gyrus (SFG) Image
Read 12 tweets
Dec 1
1/To call it or not to call it? That is the question!

Do you feel a bit wacky & wobbly when it comes to calling normal pressure hydrocephalus on imaging?

You don’t want to overcall it, but you don’t want to miss it either!

Let me help you out w/a thread about imaging in NPH! Image
2/First, you must understand the pathophysiology of “idiopathic” or iNPH.

It was first described in 1965—but, of the original six in the 1965 cohort, 4 were found to have underlying causes for hydrocephalus.

This begs the question—when do you stop looking & call it idiopathic? Image
3/Thus, some don’t believe true idiopathic NPH exists.

After all, it’s a syndrome defined essentially only by response to a treatment w/o ever a placebo-controlled trial.

However, most believe iNPH does exist--but its underlying etiology is controversial. Several theories exist Image
Read 19 tweets
Nov 21
1/Time to go with the flow!

Hoping no one notices you don’t know the anatomy of internal carotid (ICA)?

Do you say “carotid siphon” & hope no one asks for more detail?

Here’s a thread to help you siphon off some information about ICA anatomy! Image
2/ICA is like a staircase—winding up through important anatomic regions like a staircase winding up to each floor Lobby is the neck.

First floor is skullbase/carotid canal. Next it stops at the cavernous sinus, before finally reaching the rooftop balcony of the intradural space.Image
3/ICA is divided into numbered segments based on landmarks that denote transitions on its way up the floors.

C1 is in the lobby or neck.

You can remember this b/c the number 1 looks elongated & straight like a neck. Image
Read 10 tweets
Nov 4
1/The 90s called & wants its carotid imaging back!

It’s been 30 years--are you still on NASCET?

Feeling vulnerable about plaque vulnerability?

This month’s @theAJNR SCANtastic has what you need to know about carotid plaque

ajnr.org/content/46/10/…Image
2/Everyone knows the NASCET criteria:

If the patient is symptomatic & the greatest stenosis from the plaque is >70% of the diameter of normal distal lumen, patient will likely benefit from carotid endarterectomy

But that doesn’t mean the remaining patients are just fine! Image
3/Yes, carotid plaques resulting in high-grade stenosis are high risk

But assuming that stenosis is the only mechanism by which a carotid plaque is high risk is like assuming that the only way to kill someone is by strangulation. Image
Read 13 tweets
Oct 24
1/Having trouble remembering how to differentiate dementias on imaging?

Is looking at dementia PET scans one of your PET peeves?

Here’s a thread to show you how to remember the imaging findings in dementia & never forget! Image
2/The most common functional imaging used in dementia is FDG PET. And the most common dementia is Alzheimer’s disease (AD).

On PET, AD demonstrates a typical Nike swoosh pattern—with decreased metabolism in the parietal & temporal regions Image
3/The swoosh rapidly tapers anteriorly—& so does hypometabolism in AD in the temporal lobe. It usually spares the anterior temporal poles.

So in AD look for a rapidly tapering Nike swoosh, w/hypometabolism in the parietal/temporal regions—sparing the anterior temporal pole Image
Read 16 tweets
Oct 17
1/My hardest thread yet! Are you up for the challenge?

How stroke perfusion imaging works!

Ever wonder why it’s Tmax & not Tmin?

Do you not question & let RAPID read the perfusion for you? Not anymore! Image
2/Perfusion imaging is based on one principle: When you inject CT or MR intravenous contrast, the contrast flows w/blood & so contrast can be a surrogate marker for blood.

This is key, b/c we can track contrast—it changes CT density or MR signal so we can see where it goes. Image
3/So if we can track how contrast gets to the tissue (by changes in CT density or MR signal), then we can approximate how BLOOD is getting to the tissue.

And how much blood is getting to the tissue is what perfusion imaging is all about. Image
Read 18 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(