What is the norm for airways?

[Dogmatix]

I recently had a cbct scan made, and one of my interests is to evaluate the volume of my airways. I feel like I have narrow airways, but I'm also a bit hypochondriac and it's hard to know what's normal when it always have been like this. The line marked 2  was the most narrow point I found and it meassure 6.9mm. Is there anyone in here who've suffered from sleap apnea and had surgery done for this purpose, if so, what was the meassurements in your cases?

Any other reference available to give me a better understanding? See below and please give input and thoughts.

[dammit_daniel]

This study provides some figures.

http://www.joomr.org/article.asp?issn=2321-3841;year=2013;volume=1;issue=2;spage=55;epage=60;aulast=Guttal

And the table in the article: https://imgur.com/a/Hf8DhlN\

If I'm reading the diagram correctly I think Pas-min is the measurement of concern. And it states 11.7 for male 9.8 for female. My max fac told me around 12mm aswell for my airways, I'm a guy. I've heard it's better to take measurements off of ceph xrays aswell although I think cone beam xrays would give some indication.

[Dogmatix]

I'm a guy. I've heard it's better to take measurements off of ceph xrays aswell although I think cone beam xrays would give some indication.

Isn't a ceph more inaccurate, as it's only 2 dimensional? In a cbct you can measure the actual volume and view the width at diffenth planes. For instance when I open the cbct I see 3mm width something, but then I can trace to this point.

Anyway, it seems like I'm well below 12mm. Have you had surgery for this.or are you plannig to? What does your airways measure?

[dammit_daniel]

Isn't a ceph more inaccurate, as it's only 2 dimensional? In a cbct you can measure the actual volume and view the width at diffenth planes

Yeah that's true, I'm sure I've seen some airway volume analysis with a cone beam. Someone told me cephs are better and my surgeon used a ceph to take measurements of my airways, I don't know the reasoning behind it.

My cone beam showed around 3mm. https://imgur.com/a/yecWsvJ. Although I put those measurements on myself. My surgeon told me my ceph showed about 2mm of airway width. I have alot of trouble breathing lying down and find I have to arch my neck back to even breath. Can't breath at all lying on my back. I did a sleep study and I didn't meet the criteria for mild apnea, but I have a lot of fatigue and restless sleep. My surgeon recommended bimax to increase airway width. He said he was surprised my study didn't show apneas as he has seen alot of patients with airways larger than mine(but still considered narrow) that had apnea.

[Dogmatix]

I found this study, where the numbers are quite different. Here it seems like OSA patients have an A-P distance of ~5.3mm in mean, while control group have a mean of 6.19mm, which is quite different from 12mm, which noone in the control group had. The biggest was 10.2mm.

How can it differ this much between studies? It seems like it's in completely different regions, am I missing something?

[Dogmatix]

Wops, forgot to post the study
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816775/

[haven]

I saw a doctor recently who did a CT-Scan of my airway and uses a color scale (what they called again?) to visualize my airway. I didn't get to see the measurements on there, but according to him my airway was larger than the average patient he treats for sleep apnea, and no other surgeon has brought my airway up when shown a regular ceph. I have never had a sleep study done. I'm 28 and function fine. I get up at 4:00am and commute three hours a day (FML). Obviously with surgery my airway would just get bigger.

[dammit_daniel]

Wops, forgot to post the study
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816775/

From looking at the study you posted it looks like the anterior-posterior(A-P) length they are talking about is from the narrowest area of the airway of a particular person, the quote is from the study you linked.

...in our study we evaluated the width (lateral) and A-P distance of the smallest axial cross sectional slice

I think the lengths in the study I linked are common landmark of airways anatomy but not necessarily the narrowest of any one person.

So I think you are better of using your study to compare your NARROWEST A-P LENGTH to the 6.19 mm stated in your study of a "normal person". Seeing as your narrowest A-P is 6.9mm you might have a good length? Just my interpretation.

Also I guess the study doesn't capture what happens when a person is lying down?(assuming the scans were of people standing up). I think some peoples airways are more prone to collapse than others when lying down e.g if you have excessive weight around that area

[Dogmatix]

From looking at the study you posted it looks like the anterior-posterior(A-P) length they are talking about is from the narrowest area of the airway of a particular person, the quote is from the study you linked.


I think the lengths in the study I linked are common landmark of airways anatomy but not necessarily the narrowest of any one person.

So I think you are better of using your study to compare your NARROWEST A-P LENGTH to the 6.19 mm stated in your study of a "normal person". Seeing as your narrowest A-P is 6.9mm you might have a good length? Just my interpretation.

Also I guess the study doesn't capture what happens when a person is lying down?(assuming the scans were of people standing up). I think some peoples airways are more prone to collapse than others when lying down e.g if you have excessive weight around that area

If the study is read more accurate, they actually say that A-P is not considered a relevant measurement.

The mean A-P distance was not significantly different between groups.

and also regarding the difference between supine and upright position

OSA subjects have a smaller upper airway compared to controls with the exception of airway length. The lack of a significant difference in the mean A-P distance may indicate that patient position during imaging (upright vs. supine)

So what actually seems relevant is the cross section area, which is meassured as a mean value in this study, the total volume and also the length of the airways. Narrow long airways seems to be a problem factor.

In my meassurements I see a cross section ranging from 130-180mm^2, which seems to be out of the normal range in the control group, and also a length of 57mm, which seems a bit longer. Average airway area for OSA patients range from 159+-74, and non OSA 253+-76. So within one SD the average area should be at least 177mm^2, which I find hard to see that it could be in my cbct with the current view. But what do I know, if you want to find figures saying you have problems, you always will..

In your study I also see that they evaluate using a ceph, while my study evaluate using a cbct, not sure if the meassurements between these 2 can be compared.

[dammit_daniel]

Looks like useful info thanks for sharing that. The area data is quite interesting I haven't seen anything to compare my airways too and doctors I've seen haven't wanted to comment on area. My airway looks to be around 65mmsq and a bit less in others. I think this study helps me to be more confident going ahead with my surgery.

So you're saying you think your airways are a bit on the narrow side according to the study, are you going to pursue further action? 

[Dogmatix]

Looks like useful info thanks for sharing that. The area data is quite interesting I haven't seen anything to compare my airways too and doctors I've seen haven't wanted to comment on area. My airway looks to be around 65mmsq and a bit less in others. I think this study helps me to be more confident going ahead with my surgery.

So you're saying you think your airways are a bit on the narrow side according to the study, are you going to pursue further action?

This is one decision point. For me I have many small issues that build up, a bite that is a bit off, aesthetic concerns, and now airways that seems to be in the range to motivate surgery. To me my 130-180mm^2 seems to be in the range to motivate surgery, but then again, I've seen people having down to <10mm^2. So no, not this alone will make me pursue further action, but it's surely a motivation.

It's so hard to know how big of a problem this is, I do suffer from not feeling well rested after sleep etc, but who knows what the cause is and if surgery is the solution. I also do feel a bit chocked when lying on my back, but more importantly I have some neck problems and forward head posture.

Can't you go ahead with the surgery first and then tell me
Would be interesting to hear from someone on this forum how they experience their breathing in different situations after surgery.