Lower front teeth that need straightening – this is a class 1 canine case, and there is no occlusal room to just tip the incisors forward.
The problem is that often (in a class 1 or 3) occlusion, there is little space to tip the lower teeth forward, without addressing the upper teeth.
This may mean you need a lot of IPR, or a lower incisor extraction.
Both valid treatment options in the right cases, but here is another which might not be so obvious.
So this lady just wanted the LL2 corrected. The top teeth are fine, its just this one that really bugs her.
As you can see, the bite is slightly deeper than normal, and you will need to take my work that there is almost no room to tip the lower incisors labially.
I just want to apologise for the quality of the photos, I should have taken buccal shots in occlusion, and the lips should be fully retracted. Thankfully the photography gets better!
Ok, so I need space. You might be able to see that the lower arch incisors are overerupted. When you intrude the lower incisors, you can get a little room to tip the teeth forward… Here is a diagram to explain this:
The green dot is the initial point of contact, and the blue dot is the final point.
The arrow marked “1” is how much we can now procline the lower teeth, without IPR! suddenly we have some space without IPR! And with fixed ortho, we do not need a lot of space.
The arrow marked “2” indicates the intrusion needed.
Ok, now the treatment is easy right??
I can’t remember if I did this without IPR (probably, as IPR is rare for me), or if I did a minimal amount.
So now, we are into a 18 NiTi wire (the 2 month review was when I placed the 18 NiTi, so this wire still needs to do its job).
My photos are all taken at the end of the review appointment, so if I did IPR, you would be able to see it.
The teeth are straightening out well. I had to place bite raisers for this lady (upper molars) – So I cannot really judge if the incisors are intruded enough – so its all a little guess work at the moment. The teeth are straightening as I would expect but if I reduce the bite raisers and there is a heavy occlusion on the incisors, then this can cause unwanted movement in the upper front teeth.
Having bite raisers on the upper molars also lets passive eruption of the buccal segments (other than the 6’s) and this helps to reduce the deep bite.
A Little Helping Hand
So to this point, we have just let the wire do its work, as the incisors were over erupted, they levelled up nicely… But I want more!!!
So now I started to use some black magic. Also known as wire bending.
It is a lot easier to bend a stainless steel wire, this is an 18SS wire.
You can see the two bends in the wire, between the lateral and the canine. This puts an intrusive force on the incisors.
Now, there is also an equal and opposite force on the canines/ premolars, but from memory these teeth were in occlusion, so there would be no unwanted extrusion there.
Also remember, the premolars and canines have much larger roots, so you would expect more intrusion of the incisors than extrusion of the others with the same force.
The end result
As you can see, we got a really nice result. It took about 6 months and from memory the IPR was either none, or very minimal (I am writing this from memory, not clinical notes…)
What I would change next time…
Next time, I would place the incisor brackets a little more incisal at the bond up. This will avoid (or reduce) any wire bending and intrusion will start from day 1.
Hopefully this change can trim a month or two from the overall treatment.