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Hello everyone, Sidney Levy here,

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continuing our discussion of the diagnosis

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of oral cavity squamous cell malignancy.

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I wanted to introduce our next area, which is the buccal

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mucosa by, uh, reminding people of relevant anatomy in

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this region and discussing one or two important techniques

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that may help in diagnosing these often subtle lesions.

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So I have an example case here with a buccal mucosal

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squamous cell malignancy on the left, outlined as such.

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But I'd like to focus on the anatomy on the right

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to help show the normal appearance to assist you

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in deciding whether a lesion is present or not.

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The right gingivobuccal sulcus is a line,

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hypointense line, right on the lateral

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margin of the maxillary or mandibular teeth.

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Then on the pre-contrast T1 weighted imaging, there

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is a buccal fat plane, which is very important because

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if this plane is infiltrated by hypointense tissue,

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that is an early feature of buccal mucosal malignancy.

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And then the next structure that's important

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to be aware of is the buccinator muscle,

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which is external to the buccal fat.

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And that's important for staging purposes.

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These are components of the so

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called buccal deep neck space.

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So as you can quickly appreciate, uh, the lesion on the

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contralateral left-hand side has obliterated these layers.

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Now, it's easy enough in this case, but in a subtle

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early T1 or T2 stage lesion, that infiltration

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of the buccal fat is very important to look for.

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This will be a prelude to a more formal

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discussion of the diagnosis of this tumor.

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One last thing.

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An important technique to keep in mind is the puffed cheek

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method for CT and MR imaging, but particularly CT imaging.

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And this can help to elucidate whether a lesion is

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arising from the buccal mucosa or the alveolar mucosa.

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So let me demonstrate that for you because in the

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natural state, the gingivobuccal sulcus is collapsed.

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You can't really distinguish clearly

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a difference between where the buccal

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mucosa ends and the alveolar mucosa begins.

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The alveolar mucosa being the mucosa lining

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the gums, and the buccal mucosa lining

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the cheeks and the side of the mouth.

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So the puffed cheek method consists of a closed

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Valsalva maneuver, which I'll demonstrate for you now.

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And this helps to create air, hypointense air, between

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the buccal and the alveolar mucosa, which can be

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very helpful in localizing a lesion in this region.

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With MR, it is more difficult because people

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need to stay still during the acquisition.

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So some have tried to insert hypointense gauze packing

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between the alveolar mucosa of the gums and the buccal

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mucosa of the lining of the cheeks with some success.

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So that's an alternative method.

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We will go on in our next vignette to formally discuss

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the diagnosis and staging of this tumor.

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Thank you.