Remember the patients should be told ALL the treatment options including doing nothing. They also have a right to know how long the treatment is likely to take and what is involved. I have particular concerns over rushing patients into joint surgical clinics. The problem is that surgeons recommend surgery. You need to go through all the options first Here are some factors to consider: -
Is keeping the deciduous canine an option. If it is not it makes the decision to extract it easier.
Are other teeth of poor prognosis? (look at the lateral incisor)
Check the mobility of the other teeth.
Can the canine be brought down and how long would it take?
If the Unerupted canine were to be extracted would it be possible to close the space? If so how long would it take?
Extraction of deciduous canines. The extraction of deciduous canines is often suggested as away of encouraging the eruption of the permanent teeth but remember: -
This means you loose the option of retaining the deciduous teeth long term so check that the patient is prepared to have surgery to bring down the canine etc.
The condition of the deciduous tooth is a good clue, if it has lost most of the root and is a bit mobile then it would be a poor candidate to last a lifetime and so you could extract it. If it looks good and has a long root then it might well last 40 years.
Extraction is not enough you must also open the space to 9.5 mm to improve the chances of the canine erupting. Sometimes this means increasing the overjet as a temporary measure.
It is only those cases where the crypt of the canine touches the root of the c where you can expect a beneficial effect from extraction of the deciduous teeth.
Leaving un-erupted teeth in situ. What is the danger of leaving the unerupted teeth where they are? Do they resorb the roots of the other permanent teeth? Do cysts develop? How often should you take radiographs? I can only give you my views: -
I have never seen a case where there was no root resorption before the age of 14 and it subsequently developed. It seems to be the phase of active eruption that is associated with resorption.
I have only seen two cases where cysts formed associated with canines and they seem to be very slow growing.
I have seen cases where teeth were damaged during the surgical removal of canines.
There is no “no risk“ solution.
I conclude after the age of 16 a radiograph every 5 years is sufficient.
The exciting possibility of cone beam CT pictures of unerupted teeth should clarify the situation considerably and might show root resorption in cases which with our present radiographs seem to be resorption free.
Space opening. I like to use a two screw URA EOT can be added if needed but if the patient refuses I am happy to let the overjet increase. I do not like to extract premolars until the canines are through into the mouth. Extract the deciduous canines when the patient is making reasonable progress.
Which is better expose or bond chain?
It is impossible to say. Some units are good at bonding chain they never come off , the surgeon knows to stick the chain on the right place (as near the tip as possible) and threads the chain through a hole in the flap to give a direct line of pull. In this unit I would always go for bonding chain. In another unit the chains fall off they are stuck near the gingival margin of the canines and instead of going through a hole in the flap they go in a loop right under the flap. In this unit you will be better to go for open exposure providing they can expose the tip of the canine and leave it in a shallow bowl shaped depression rather than down the bottom of a deep hole.
Exposing canines. For exposure and packing it is important that the tip is exposed. Generally gold chain is best for palatal teeth unless they are very superficial. For buccal canines I use an apically repositioned flap. It is said to be important that you preserve the attached gingiva BUT twice I have seen cases where the exposure just went through the non attached mucous membrane and in both cases a normal gingival margin developed [perhaps I was just lucky]
Making Gold chains.
At Burton we buy jewellers safety chains and ligate them to TP mesh pads It is better and cheaper than the ready made ones. For incisors you can fold over the mesh and stick the gold chain right on the incisor edge.
It is better if you NiTi wire piggybacked to a rigid base wire.
Ballista and modified ballista
Sectional arch from molars.
To move the tooth across the arch I favour cement on upper 6/6 a button on the palatal surface of the canine and a base arch with offsets distal to the lateral and mesial to the first premolar. Then elastomeric chain can be used to catapult the canine across the arch.
Root resorption I have seen canines resorb the roots of laterals and then go on to damage both centrals so sometimes you need to take action, but it can de difficult do you extract the canine or the lateral. It takes a lot of guts to write the patient up for the extraction of a lateral incisor. When I have done this I have always asked for photographs of the lateral just to show how short the root is. It is worth remembering that teeth with quite short roots often survive a long time.
Buccal root torque After you have pulled down the canine check the need for buccal root torque.
Extraction of canines and space closing More predictable but remember that space closure can be slow typically I say 3 years to bring down a difficult palatal canine and two years if you take the canine out and space close. However it would take less time if there was significant crowding.
A letter to the BDJ was published
Canines Crowding and Consent.
Although I agree with Dr Hassan and Dr Nute that hospital advice is needed for patients with impacted canines, I am concerned that practitioners reading the introduction to their paper might decide to extract the deciduous canines without asking for such advice. I feel some of the papers need explanation. The authors quote Eriksson and Kurol who showed that 78% of permanent canines erupted following the extraction of deciduous canines. It is important to understand that there was no control group in this investigation so that it is possible that the same number of teeth would have erupted without the extractions. Indeed in a randomised controlled trial published in a refereed journal in 2004 by Leonardi et al there was no significant difference between the extraction group and the non extraction control group. However there was a difference between these two groups and a third group where the deciduous canines were extracted and headgear was used. The significantly improved success rate in this group throws into doubt the suggestion by Hassan and Nute that crowding is not a factor. For this the authors quote a paper by Power et al, again this paper has no control group so that it compares extractions of deciduous canines in cases with and without crowding and finds no difference between the groups. Of course if the findings of Leonardi et al are true and there is no benefit from the extraction of deciduous canines then there would be no difference between the two groups.
A problem here may be the definition of crowding. From the erupting canines point of view this would be a space between the lateral incisor and the first premolar that is too small for the canine. In a typical 11 year old this could occur in a patient with no overall crowding because the deciduous second molar is much bigger than the second premolar tooth.
Practitioners should remember that even if some patients do benefit from the extraction of deciduous canine teeth, some are worse off, because the option of retaining the deciduous tooth into adult life is lost. It is important that when a deciduous canine with a good crown and no root resorption is extracted a proper consent is obtained explaining to the patient that they will require complex orthodontics if the permanent canine fails to erupt.