cephalometric tracings

[ryche22]

hey hey,

how familiar are dental students with ceph tracings? at the ortho office that i work at, i do computerized ceph tracings for each initial start/initial tmj.

at times i have trouble finding the points due to the quality of the xray, and sometimes due to anatomy, and sometimes due to both!

do you have any tips to find basic landmarks? the minor ones and major ones, like the Anterior Nasal Spine, and Point A. half the time i cannot spot the PTM.

And what is Opisthion? I know the general location, but i just guess, and am not precise when plotting the point.

if i can post a lateral ceph, do you think you guys could help point out some stuff?

late
rick

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[organic]

hey hey,

how familiar are dental students with ceph tracings? at the ortho office that i work at, i do computerized ceph tracings for each initial start/initial tmj.

at times i have trouble finding the points due to the quality of the xray, and sometimes due to anatomy, and sometimes due to both!

do you have any tips to find basic landmarks? the minor ones and major ones, like the Anterior Nasal Spine, and Point A. half the time i cannot spot the PTM.

And what is Opisthion? I know the general location, but i just guess, and am not precise when plotting the point.

if i can post a lateral ceph, do you think you guys could help point out some stuff?

late
rick

Hi Rick

I had the same experience as you did, ceph is an X-ray with lots of bones overlapping on one flat film. Due to the symmetrical nature of our face, it can be very confusing and hard to define the exact locations or points of the landmarks. I am NOT an orthodontist, but I do have my own tips to share:
-- I don't think anyone could point out every exact location of the landmarks on a ceph film. As you said, there are many factors affecting the outcome of the film.

-- I also do not think the measurements have absolute value in themselves. 83 degrees or 84 could mean nothing or something. The most important thing is, you need to have calibration with others who are also doing the ceph tracing in your office/ clinic so that you could at least compare among your patients, or follow a certain school that defines what is "A point" "B point" ( like my teaching hospital has its own definition for Go) etc.. Use multiple measurements, so that you can see the big picture, don't take the measurements for their exact face value. sometimes you can even try out all the possible points you think could be a certain landmark or fine the " mean" and see if different points would change your measurement significantly.

--- to answer your question, Opisthion is the posterior border of foramen magnum. (Basion is the anterior border of foramen magnum, so to locate Opisthion just like locating Basion, but at the rear end )

--- I am not an orthodontist, so these are just my personal ideas about ceph tracing. There are many journal articles discussing errors in ceph X-ray tracing. You could search on Medline and see what the experts say

 

[ryche22]

thanks alot man, i just wish i knew what the foramen magnum was!

what year do dental students start analyzing cephs? do they only do it for ortho as well?

just curious,

rick

 

[Yah-E]

Cephs are usually learned in Ortho and Oral Surgery courses. Both of these courses are usually in the 2nd year dental school curriculum. Since I a second year dental student, I've learned about the ceph quite a bit this year! I know the anatomical landmarks (sella-nasion, pogonion, gnathion, point A & B, etc) pretty well, but we weren't required to memorize the normal angles of the tracings. These values are usually given.

A second year dental student should know the ceph pretty well. What and where the anatomical landmarks are and what anatomical landmarks forms what angle. Also analysing the ceph both in pre-op and post-op and pre-ortho and post-ortho were all taught and learned.

 

[organic]

thanks alot man, i just wish i knew what the foramen magnum was!

what year do dental students start analyzing cephs? do they only do it for ortho as well?

just curious,

rick

Hi Rick
Foramen Magnum is at cranial base, it is the biggest hole, through which the spinal cord enter the skull. the hole is right above the vertebrae, so it can be easily identified.

Opisthion isn't a landmark that is used very often( at least, I don't use it ). The author who identified it was T.M Garber, you should check Medline and see if you can find his published article on the correct method of identifying this landmark.

 

[straightsmile4u]

Yikes! SOunds like you are over your head with this ceph tracing! I am a (graduating) ortho resident, and I've traced a zillion cephs and I can't even sometimes find the point.

We didn't trace cephs in dental school....

 

[Yah-E]

Dr. Straight Smile 4 Me:

Welcome to SDN, congrats on finishing your Ortho residency soon. Please stick around as many of SDNers are interested in applying to Ortho. Perhaps your experience and guidance can help many! Back 2-3 years ago, there were just about ZERO Post-doctoral residents on SDN, but now we have 4-5 OMFS residents, 1-2 Ortho residents, couple of current practicing specialists, and probably others.

Great to have you and please feel free to advice!

 

[oms fan]

We traced cephs in Ortho during second year also. Our orthodontist was pretty hard core and made us do all of the analyses. We had to learn (memorize then forget ) all of the normal angle measurments and their changes with age and deviations. We had to do full diagnosis on the cephs we traced. We never talked about an "ophisthion"...of course I never read the book either!

 

[marshall]

I am no where near an ortho residency but I learned all of these cranial landmarks (and about a hundred others including post-cranial) in forensic anthropology. If you are stuck, there are a ton of great books and most osteology or physical anthropology texts have great figures.

Cheers,
Marshall