Anatomy of the Alveolar Mucosa
HIDEInteractive Transcript
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Hello everyone, it's Sidney Levy here, continuing
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our discussion of the oral cavity anatomy and in
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particular its subsites as a prelude to the diagnosis
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and staging of squamous cell malignancy in this region.
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So previously we've spoken about the buccal mucosa.
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Today, in this vignette, I'd like
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to talk about the alveolar mucosa.
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Once again, I have our pre-contrast fat
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suppressed T1-weighted imaging in three planes.
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Before I go any further, I will quickly point out
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that this particular patient has an oral tongue
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malignancy, which we're not going to discuss any
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further, but in case you are wondering why there
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is some distortion of the appearance of the tongue
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on the coronal projection, that is the reason.
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I'm going to draw its boundaries for you.
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So firstly, on the axial projection,
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you can consider it two lines.
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So we have the
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gingivobuccal sulcus
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on the right and the left, where the alveolar
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mucosa medially meets the buccal mucosa laterally.
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Posteriorly, the buccal mucosa and the
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alveolar mucosa join posterior to the molars,
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at the level of the retromolar trigone,
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which is this triangular-shaped region here.
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It's also important to remember that the alveolar
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mucosa is present on the medial side of the teeth.
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So here, we also have a line of alveolar mucosa, which
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heads all the way back to the retromolar trigone.
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And at the junction of the alveolar
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mucosa medially, we have two subsites.
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In the inferior portion of the oral
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cavity, it is the floor of mouth.
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And that is easier to demonstrate
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on the sagittal projection.
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So the alveolar mucosa is here, and it meets
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the floor of mouth, which is this area here.
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So in the inferior portion of the oral
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cavity, we have the floor of mouth. In
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the superior portion of the oral cavity,
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it's a similar concept, but this
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time we have the hard palate.
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So we've got some alveolar mucosa here,
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and the hard palate commences here.
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Now to complete our diagram, we have the
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alveolar mucosa contacting the oral cavity.
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Buccal mucosa at the
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gingivobuccal sulci
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anteriorly on the sagittal projection.
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And then on the coronal projection, we can
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see the gingivobuccal sulci more easily.
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And the alveolar mucosa is really this portion here.
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We can also see where it meets the
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hard palate and the floor of mouth.
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But as you're beginning to appreciate, it is
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easiest to appreciate it on the axial projection.
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Buccal mucosa here, floor of mouth here, hard palate.
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So in summary, I have drawn the boundaries and
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described some of the relations of the alveolar mucosa,
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otherwise known as the upper and lower alveolar ridges.
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You can consider it the mucosa overlying the
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alveolar processes of the maxilla and mandible.
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And its boundaries are the lines of attachment
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of the alveolar mucosa in the upper and
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lower gingivobuccal sulci, the lines of
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attachment of mucosa in the upper and lower
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gingivobuccal sulci,
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where it meets the buccal mucosa, as well
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as the lateral borders of the floor of mouth
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inferiorly and the hard palate superiorly.
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And lastly, posteriorly.
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The mucosa of the retromolar trigone, where the buccal
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and alveolar mucosa join posterior to the molars.
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Thank you.
Sidney Levy, PhD, MBBS
Radiologist and Nuclear Medicine Specialist
I-MED
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