Case Study: Failing 3-unit Dental Cantilever

 

So, what is a cantilever? According to the Merriam-Webster.com dictionary, a dental cantilever is:

a dental bridge having one end attached to a natural tooth and the other resting unattached in a tooth depression .”

 

The most common utilization of a cantilever is when a person is missing a lateral incisor (one of the teeth next to the 2 front teeth). The canine (eye) tooth is frequently strong enough to support the missing lateral incisor, so only one tooth needs to have a crown to support the missing tooth. With a traditional bridge, both teeth on either side of the missing tooth is crowned for the additional support.

 

I have one patient who presented many years ago with a missing canine. This is a bad situation for a restoring dentist because the canine is a very strong tooth and many times is used to support other missing teeth. In this situation, the lateral incisor is not a good tooth to support the canine, so the restoring dentist made a cantilever with 2 teeth BEHIND the canine space to support the missing tooth. When he presented 8 years ago, all looked fine. When the patient wanted a cosmetic update of his upper teeth, I provided the same prosthesis, namely a 3 unit cantilever for the missing canine.

 

A couple of weeks ago I received a call from this patient letting me know that his cantilever had come out. When I looked at what happened, the posterior (further back) of the 2 teeth of the cantilever was missing to the gum line and can no longer support the needs in this area. Now the choices are to make a new cantilever using the molar behind the tooth that now needs to come out, and make a 4-unit prosthesis. My concern is that the remaining tooth will not be able to handle the forces of chewing and he’ll need to lose that one as well. The best solution from a dental standpoint is to have implants placed to replace the canine (which has been missing for some time) and the second premolar with dental implants. During the healing he will have a flipper to wear replacing the 2 missing teeth until implants can be placed.

 

The lesson to be learned is that cantilevers, even with 2 teeth supporting the missing tooth on one side, will probably not last forever (and this patient is only in his early 40’s). Dental implants have a much better chance of lasting much longer which is always the desired solution for both esthetics and function.