0:01

I previously mentioned the entity of Ludwig's angina and

0:05

mentioned that quite often this is associated

0:08

with dental caries and dental infections.

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When you are reading head and neck imaging

0:14

in the emergency department,

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you'd be surprised how often you are distracted,

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if you will, by dental caries, cavities of teeth,

0:23

effectively.

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And I just want to go through briefly about dental

0:28

caries because it is a very common incidental finding in

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head and neck CT scans in the emergency room and

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occasionally will be the source of the infection in

0:39

the head and neck. So this is the anatomy of a tooth.

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You notice the E for enamel, the D for dentin,

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and this is the pulp chamber.

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And we have some of the cementum

0:50

and then the periodontal ligament.

0:54

You notice that I've drawn in here an area which shows

0:58

the junction between the enamel and the dentin.

1:01

This is where most dental caries occur.

1:04

And then occasionally, you will get the infection that

1:07

goes along the gingiva or along the edge of the tooth

1:11

to cause some of the inflammatory

1:13

process in the periodontal region.

1:16

I don't expect you to remember this,

1:18

but this is just a nice demonstration of the

1:21

different locations where one can have dental caries

1:25

or cavities. I usually refer to the cavities as occlusal,

1:30

that is

1:30

on the surface of the teeth where you occlude the mouth.

1:34

So the occlusal surface of the teeth versus

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the proximal surface of the teeth,

1:40

which is the junction between the teeth,

1:43

side to side.

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You notice that as the classes go up in number,

1:49

you get closer and closer to the involvement of different

1:52

incisive teeth versus the posterior teeth,

1:55

the molar teeth.

1:56

And you can see that where these different

1:59

dental caries are described.

2:01

And you may hear your dentist talking about

2:03

the caries in terms of this classification.

2:06

But I usually use the term occlusal or occlusal

2:10

surface or the proximal surfaces of the teeth.

2:14

Here's one, number five,

2:15

where it's actually the neck of the tooth as you

2:18

get from the enamel into the pulp chamber.

2:22

Dental caries obviously are seen very

2:24

frequently on our CT scans. It's amazing.

2:27

You probably would be surprised how in American

2:30

teeth, how often there is such bad dental hygiene.

2:34

This is a case of a proximal class two dental caries.

2:40

And here you see dental caries, class two.

2:44

And I think I have class five down here where you see

2:49

it coming down a little bit lower into the

2:51

neck of the tooth and eroding the

2:56

occlusal surface of the enamel on this

3:00

individual here. You can see the diagram of that cavity,

3:03

as opposed to one on the sides.

3:06

This one's taking out the top of the tooth,

3:08

if you will,

3:09

as well as the side of the tooth on the class two.

3:13

So what do we say about dental caries?

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If it is indeed just an incidental finding on a

3:20

patient who you're evaluating for the larynx

3:23

or for a palatine tonsillitis, PTA case,

3:26

then you might just use the term,

3:27

"There are scattered dental caries in the teeth."

3:30

If, on the other hand,

3:31

you start to see erosions around the teeth,

3:34

then you want to use the terms "endodontal" or

3:38

"periodontal erosions." Endodontal erosions are,

3:41

in general, at the tips of the roots of the teeth,

3:45

whereas periodontal disease is on this side.

3:48

So here you have a primary endodontal lesion coming out

3:53

of the pulp chamber and out of the root of the tooth, and

3:56

then secondary spread into the periodontal region.

4:01

Here you have a patient who has primary periodontal

4:03

disease, probably a dental caries right here.

4:06

And then, the infection arises in the periodontal

4:10

space and then goes to the endodontal region.

4:13

Here you have one that is,

4:15

as you can see by the arrows,

4:16

is going both from the root of the tooth,

4:20

maybe requiring root canal,

4:21

as well as coming down from gingival infection at the

4:26

edge of the tooth. And these different characteristics,

4:30

we really actually don't see the arrows,

4:32

so we might just call it endodontal disease

4:35

as well as periodontal disease.

4:37

But I think that a lot of times people,

4:39

even at the tips of the roots when there's

4:41

just a lucency around there,

4:43

are calling it periodontal disease.

4:45

No, that's really endodontal disease.

4:48

It's the involvement on the lateral aspect of the

4:51

tooth that we would call it periodontal disease.

4:55

So, here we have some lucency around the tooth and it's

5:00

coming between the teeth in the periodontal region,

5:04

and that's what periodontal disease refers to.

5:06

Bacterial accumulating at the tooth gingival gum

5:10

interface and then going down along the side

5:13

of the tooth in the periodontal space,

5:15

which can lead to an erosion at the endodontal

5:20

portion of the tooth. Periapical disease,

5:23

again,

5:24

sometimes we just see the lucency at the periapical

5:28

region. Sometimes you will see a cyst.

5:31

We call that either a radicular

5:34

cyst or a periapical cyst.

5:36

And that is something that is relatively painful and

5:40

oftentimes requires removal of the tooth.

5:44

In these periapical cyst or radicular cysts,

5:47

if you have a persistent cyst after removal

5:50

of the tooth, we call that a residual cyst.

5:53

So it's probably more more than you want to know

5:55

about dental caries and nomenclature for dental

6:00

caries. More important for us, besides recommending

6:04

oral cavity evaluation or dental evaluation, or oral

6:07

surgeon evaluation, is whether or not they're

6:09

spread to the deep spaces of the neck.

6:12

And those include sublingual

6:13

or submandibular spaces,

6:15

the parapharyngeal space, sometimes even going

6:19

into the vascular sheath. Again,

6:20

if you have thrombophlebitis of the jugular vein,

6:23

you may call that lemierre's disease with possibility

6:27

of septic emboli to the lung.

6:30

Rarely, you'll have spread of the

6:31

dental infection to the orbit.

6:32

More commonly we see just the sinusitis

6:36

that may be odontogenic.

6:38

And rarely, you will have spread into the

6:40

pterygopalatine fossa and the nerves of the

6:44

second division of the fifth cranial nerve.

6:46

So here, again, spread of dental infection.

6:50

In this case, you can see that there is a low

6:52

density area in the floor of the mouth.

6:56

This may be termed the Ludwig's angina,

6:59

particularly when you have the spread

7:01

to the venous structures.

7:03

Here's the carier's tooth with the low density around

7:08

the root of the tooth, the periapical spread.

7:12

Here you have spread into the muscles of mastication.

7:16

So this is the pterygoid musculature, lateral pterygoid

7:21

medial pterygoid muscle with inflammation from dental

7:25

infection extending into the masticator space.

7:28

Here you have bad tooth over here and on the post

7:32

gadolinium, floor of mouth view, you have an

7:37

inflammatory collection that's located

7:40

in the floor of the mouth.

7:41

This one again could possibly perforate down into

7:45

the submandibular space and be termed Ludwig's

7:47

angina for an abscess in that location.

7:51

And one more time.

7:52

Here we have spread of infection

7:54

to the lower orbit.

7:56

This is very uncommon associated with

7:59

a dental infection but can occur.

8:02

You notice that there's some tenting backwards of this

8:05

globe into a more of a oblong shaped, rather

8:10

than the normal spherical shape.

8:13

This is an inflammatory staphyloma associated with

8:17

the infection that arose from maxillary molar

8:22

dental infection.