Sample test

[Chad Carter (Course Director)]

Joti, Thanks for getting a jump start on the course! (Sorry for the delay I just got discussion access today).

Is your question asking how the molars became lingually inclined – through treatment? Or are you asking the diagnosis of lingually inclined molars?

Keep the questions coming!

[Joti Kaler]

This was the question for the case:

“Describe the concerns associated with mechanotherapy at this point in treatment.”

All the answers were side effects of class II mechanics except for the one I posted. I didn’t understand how the lingual inclination happens.

[Chad Carter (Course Director)]

Excellent! Thanks for the clarification.

So what all comes to mind with Class II elastics?

In this case, we can see that there is some sort of light archwire in place. In addition it appears round and not a large rectangular. So if you imagine a single 3D mandibular molar with a Class II elastic on the facial hook then it will tip the tooth to the lingual, pull it forward and extrude it. Does that description help? Sorry I don’t have a sketch board in front of me right now.

Now you may not see that tipping lingual in your own cases if you are in rectangular wire before starting heavy Class II elastics. Orthodontics is all about dealing with / accepting side effects.

You bring up a great point here –

This is a great exercise in thinking of a group of effects. We know that certain presentations clinically are generally a cluster of items (think all the descriptors for a Class II bracyfacial patient). Thinking through these ahead of time can help during the exam to expedite your diagnosis and treatment.

Keep the great discussion coming!

[Joti Kaler]

Yes, makes total sense. Thank you!!

[Greg Gittleman (Course Director) Gittleman (Course Director)]

Joti – to add on Chad Carter’s great breakdown, I just wanted to add a visual. With the class II elastics, the mandibular molar experiences an extrusive force. When we look at the tooth from the mesial-distal perspective, we can see where the center of rotation would be. Typically in a larger and rectangular wire, this lingual tipping side effect wouldn’t be a big issue, but in the setup they have shown with a light round wire, these side effects are more prominent. I hope that helps!

[Joti Kaler]

Thank you for the visual, it helps!!!

[Joti Kaler]

So I was just reviewing this case and additional answers include mesial rotation of max and mand molars. Mand makes sense with the class II elastic. I see the mesial rotation of the max molar but I would think the comfort tube is too long and pushing it distal not mesial?

[Greg Gittleman (Course Director) Gittleman (Course Director)]

I definitely see where you’re going with this question, however I believe the board went with this answer as they’re viewing comfort tubing as not truly delivering any appreciable force. If this was open-coil spring, I think you’d be spot on.

[Joti Kaler]

Thank you!!!