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I'd like to show this example of silent sinus syndrome.

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It really has all the elements that you want for

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a good example of this entity. What we see on the

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coronal scan is depression of the floor of the left

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orbit, as well as retraction inward of the lateral and

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medial borders of this somewhat smaller and opacified

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maxillary sinus.

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Not only that, but you have this unusual

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curve to the uncinate process as it becomes

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somewhat opposed towards the orbital wall.

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So this deviation laterally of the uncinate process

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from its normal position is another feature of

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this classic example of silent sinus syndrome.

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You notice that the

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globe, although this is a little bit of an

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oblique section, is a little bit

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lower in location than on the right side.

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And on the axial scan, we can actually

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see and demonstrate here that there

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is a little bit of enophthalmos.

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The globe is a little bit inward

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compared to the contralateral globe.

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On the axial scans, we see that

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characteristic feature of the

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inward buckling of the lateral wall of the maxillary

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sinus associated with proliferation of the fat.

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So notice the volume of fat behind the maxillary antrum

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on the affected left side compared to the right side.

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And then you have the opacified

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left maxillary sinus.

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Now, it happens that this patient

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has aspirated secretions.

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So again, this entity is thought to be due to

1:49

a chronic decrease in the pressure in the sinus,

1:54

leading to the inward drawing in of the sinus

1:59

roof, which is also the orbital floor, as well

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as the lateral, medial, and posterior walls.

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The maxillary sinus is associated with hypoglobus, which

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is a lower appearing globe, as well as enophthalmos,

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which is the inward retraction of the globe, as well as

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the sinus opacification and obstruction at the osteum.

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These patients, strangely, may be asymptomatic.

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But nonetheless, they have a characteristic feature.

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I just wanna make one more comment and say,

2:32

why is this not just maxillary sinus hypoplasia?

2:37

So with maxillary sinus hypoplasia, you usually

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do not have hypoglobus or enophthalmos.

2:43

You usually do not have depression of the orbital

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floor, and you usually have thickening of the

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walls of the maxillary sinus, and you don't

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have this inward deviation of the uncinate process.

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So those are some of the

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features which will distinguish

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maxillary sinus hypoplasia, something that occurs

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congenitally, from silent sinus syndrome, or

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the other term that people use, which is atelectatic

3:06

maxillary sinus, a developmental disorder.