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Hello everyone.

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My name's Dr. Sidney Levy,

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and today I'm going to be commencing

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a series of vignettes on the oral cavity as part

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of our larger series on head and neck malignancy.

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So specifically, I'll be speaking about the

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anatomy of the oral cavity and then moving on to

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examples of squamous cell carcinoma within the

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oral cavity and how we diagnose it and stage it.

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So firstly, I'd like to begin with the anatomy.

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I've prepared a, uh, an example case of a patient

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who happens to have a left oral tongue malignancy,

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but we're not going to talk about that just yet.

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And you'll notice that I've brought up axial,

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coronal, and sagittal T1-weighted images without fat

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suppression and without contrast because I want to

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use them to take you on a tour of the oral cavity

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19 00:00:59,916 --> 00:01:02,840 so that you're comfortable with its boundaries,

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its subsites, and its anatomical relations.

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So, let's begin.

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I'm going to start off with the axial projection, and

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I'm going to start drawing at the line of contact of the

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opposing mucosal lips, which is the anterior boundary.

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So now I'm tracing along where the buccal mucosa laterally meets

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the alveolar mucosa medially, in the gingivobuccal sulcus.

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When I reach the posterior boundary, I have the retromolar trigone,

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where the buccal and alveolar mucosa meet.

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And then, I have the anterior tonsillar pillar,

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which is the posterior boundary of the oral

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cavity, with the palatine tonsil behind it.

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I'm then moving across

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at the junction of the anterior two-thirds

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and posterior third of the tongue, which is again

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a posterior boundary of the oral cavity.

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I've then got the retromolar trigone

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of the contralateral side.

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And once again, I'm now tracing the

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gingivobuccal sulcus, where the alveolar mucosa

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medially meets the buccal mucosa laterally.

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The other thing to mention is that,

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uh, here we have alveolar mucosa,

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which meets floor of the mouth and tongue structures, which are here.

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So that's the axial projection.

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Now I'm going to show you the coronal projection.

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I'm going to start off at the midline of the hard palate.

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So we have the hard palate, which reaches

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the alveolar mucosa superiorly, I'm just

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going around the teeth, the maxillary teeth.

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Now I've got the alveolar mucosa and the buccal

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mucosa within the right gingivobuccal sulcus.

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So now we head to the mandibular alveolar

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and buccal mucosa, and down here we have the

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floor of the mouth where it meets the oral tongue.

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So I'm going around the oral tongue, heading back towards the

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junction of the floor of the mouth and the alveolar mucosa of

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the contralateral side, going around the mandibular teeth.

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Once again in the gingivobuccal sulcus and

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the alveolar mucosa on the left-hand side.

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Back to the hard palate.

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So that is the, uh, outline of the

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oral cavity in the coronal projection.

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Lastly, I'd like to show you the sagittal projection.

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I'm going to start at the posterior margin of the hard

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palate, at its junction with the soft palate posteriorly.

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I'm heading forward.

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Some alveolar mucosa here, of maxillary teeth, a little

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bit of gingivobuccal sulcus, the line of contact of

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the opposing mucosal lips, now the mandibular teeth,

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alveolar mucosa, meeting floor of the mouth, which then

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reaches over to the oral tongue, up to the junction of

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the anterior two-thirds of oral tongue, and posterior

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third of tongue, which is the part of the oropharynx,

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the tongue base, and then we head back to where we started.

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So, in summary, I've drawn the boundaries of the

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oral cavity for you in three projections, and in our

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next vignette, we're going to discuss the subsites

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of the oral cavity and their anatomical relations.

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Thank you.