THE EDITOR'S CORNER

How many times have you extracted a well-positioned upper first bicuspid in order to provide space to move a distant, deeply impacted cuspid into the arch? Why did you do it?

I can only think of two good reasons to do this. One is that the first bicuspid is in poor condition. The other is that the disparity between the widths of the cuspid and first bicuspid would be likely to cause spacing of the upper anterior teeth.

Many a complicated orthodontic case has been created by a fetish of the cuspid. Suppose you had a case in which you had two closed, well-formed arches, with a satisfactory anterior relationship, with a perfect Class II posterior relationship, and with the cuspids completely blocked out of the arch. Would you extract the cuspids and have done with it? Or would you extract the upper first bicuspids, expose the crowns of the cuspids, wait for their eruption, bring them down orthodontically if they do not erupt, utilizing a full-banded upper appliance plus headgear for a period of six months to two years? There are men who come close to doing this routinely. Apart from anything else, I wonder if they are never haunted by the spectre of cuspids that won't come down after the first bicuspids have been extracted. They may say that this almost never happens. Correct. But you will only have to have it happen to you once to remember it for the rest of your days.

I think that all of us have been deluded by some early education which taught the inviolability of the cuspid. To preserve the cuspid, we may subject the patient, the teeth, and the parents' bank account to traumas that may not be necessary. We do this because the cuspid is supposed to be a unique tooth, better able to hold up the corner of the arch and to function as that area was intended in grasping, holding, and tearing food. That concept may have had some bearing in primitive times.

There is an opinion that the cuspid has a functional role of providing guidance in lateral excursions. Possibly so, but bicuspid guidance might be a satisfactory substitute especially in light of the modern diet and when measured against the amount of treatment avoided.

In all fairness, most impacted cuspids do erupt after the crown has been surgically exposed and/or with orthodontic means. In all fairness, placing a lateral next to a bicuspid doesn't always satisfy, and the cuspid-less upper arch will rarely occlude perfectly with the lower arch. Upper cuspids average a half a millimeter more in width than upper first bicuspids.

I believe that the decision on the question should be made after throwing all the available evidence on the scale, keeping in mind that this is a case in which upper extractions have been decided upon.

First, rule out any pathology of cuspid or bicuspid that could swing the balance.

Second, how much treatment would be needed if the cuspid is retained and the first bicuspid extracted, as against the case if the cuspid is extracted and the first bicuspid retained?

Third, what is the position of the impacted cuspid and what are the possibilities of bringing it into the arch in a reasonable period of time? What are the possibilities of damage to neighboring teeth in the process? What is the possibility that it might not respond?

Fourth, what are the possibilities of an alternative diagnosis and trying for distal movement with or without second molar extraction?

Fifth, what can we learn from a Bolton analysis and from a diagnostic set-up regarding the final occlusion to be expected if cuspids or bicuspids are removed? If only one cuspid is involved, will you get a midline shift if it is extracted and the first bicuspid retained?

Sixth, what has been your own individual, personal experience in bringing down impacted cuspids in terms of success, time, and trauma to teeth and tissue.

Throw it all on the scale. I would think the balance would have to markedly favor the cuspid before extracting a well-placed first bicuspid for a badly impacted cuspid. At the very least, whenever possible, both teeth should be retained to see that the cuspid will erupt before extracting the first bicuspid.