Impacted canine tooth
WHAT ARE IMPACTED CANINES?
A impacted canine is tooth that is fully formed, but due to various anomalies, it could not erupt and fix in place.
As a rule, such a problem arises precisely with the "wisdom teeth", but there are cases when the canine (second lower premolar) also undergoes retention.
UPPER IMPACTED CANINES: SOME FACTS
After the third molars (wisdom teeth), the upper canines are the teeth that are most frequently impacted . They affect 1 to 2% of the population.
They are more often included than those at the bottom and palatal inclusions (on the palate side) are more frequent (85%) than those on the outer side (15%).
Most impacted canines affect only one side of the mouth, but in 10% of cases both sides will be affected.
When a canine is impacted, there is a good chance that other dental abnormalities are also present in the mouth.
The incidence of impacted canines on the palate is twice as common in women than in men.
There is a familial tendency to have impacted canines ( heredity ).
POSSIBLE CONSEQUENCES OF AN IMPACTED CANINE
Aesthetics: If a canine doesn't come out, there will either be a smaller temporary tooth (which can fall out one day) or a large gap.
Function: In the absence of well-placed canines in the arch, function will be affected and may cause premature wear of other teeth.
Pathologies: Any impacted tooth can develop pathologies or lesions that can cause damage to neighboring structures (cysts, tumors, wear, resorption of the roots of adjacent teeth, displacement of teeth, etc.).
PREVENTION AND INTERCEPTION
When an impacted canine is tilted forward and the primary canine is still in the mouth,
the extraction of the primary canine normalize the direction of eruption after 6 to 12 months in 3 cases out of 4 (78%);
the chances of a successful intervention decrease the more the canine is poorly positioned (tilted forward);
if there is no improvement after a year, the chances of self-correction are slim. (Ericson et al, 1988);
The upper canines normally erupt around the dental age of 11 years , but it is advisable to radiologically investigate their position and course of eruption one to two years earlier.
Incidence: marked family tendency ( heredity ); if a family member has an impacted canine, 40% of their family members also have (Todd, 2008).
The upper canine needs the lateral incisor in its normal eruption process. It uses the root of this tooth as a “ guide ” to move towards its final destination in the arch.
If the lateral incisor is missing, misshapen, misplaced, or resorbs abnormally (root), it can affect the rash of the canines and cause an ectopic rash.
If the primary canine does not resorb normally, it will cause mechanical obstruction that can affect or prevent eruption of the permanent canine.
In normal eruption , the canines descend along the roots of the lateral incisors and will bring the incisors together moving them towards the center. They can thus close a diastema (space) present between the central incisors (see illustration opposite). Most of the time, an ectopic canine (this applies to other teeth as well) is a sign of a significant lack of space in the affected arch.
RESORPTION OF TEMPORARY ROOTS; A NORMAL PHENOMENON
During the eruption process, permanent canines must reabsorb (wear out) the roots of their temporary predecessors. The canines in the palace did not subside the roots of deciduous canines, while the latter may remain in place and be "solid" for a long time, until adulthood.
When the patient described above (21-year-old young woman) began her orthodontic treatment, the temporary canines were extracted. Their root showed very little resorption (indicated by the arrows in the photo).
When a canine grows with a significant malposition, it can cause the same kind of damage to the permanent lateral incisors , which, unlike temporary canines, is undesirable and can compromise the survival of the affected teeth.
THE “ICEBERG SYNDROME”!
We use this term to describe the phenomenon where people see only one aspect (aesthetic) of the problem, a single misaligned (canine) tooth that they find unsightly.
In reality, the (invisible) cause is much more important, just like the iceberg which shows only a point on the surface of the water, but which hides an enormous mass under the surface. People would like to have only “one crooked tooth” aligned , but very often this is not possible because you have to look at the whole problem.
An ectopic canine is often indicative of a much larger underlying space problem than it first appears at first glance.
TREATMENT OF IMPACTED CANINES
CREATE THE NECESSARY SPACE - WHEN?
The treatment of impacted canines requires creating space in the dental arch (extraction, orthodontic displacement of the other teeth), releasing the impacted tooth in order to place an orthodontic traction attachment and exert traction on it using with a light force to “lower” the tooth into place to seat it in the dental arch . The following diagrams illustrate these different steps.
The higher the position of an impacted canine is horizontal and behind the lateral incisor, the more difficult it will be to correct.
The success rate decreases with the age of the patient, hence the importance of early intervention . There are different philosophies in orthodontics about when to create space for the exposure and traction of an impacted palatal canine.
The “classic” or traditional approach is to first create the space necessary to house the canine in the dental arch and then direct the patient to a practitioner who will disengage the tooth and place an orthodontic traction clip on it. The main disadvantage of this technique is that the treatment can take longer.
A more recent approach, supported by Kokich 1 and others, consists in clearing the impacted canine as early as possible , at the start of treatment and sometimes even before the installation of the fixed multi-band devices (“pins”), particularly in adolescent patients where treatment of impacted canines is much more predictable and has an excellent success rate. The idea behind this approach is that it gives the impacted tooth more time to come out or partially erupt on its own without the need for vertical traction. It must still be placed in the arch afterwards.
Each method has its advantages and disadvantages and can be effective if well planned and executed.
HOW LONG DOES THE TRACTION OF AN IMPACTED CANINE LAST?
The traction of an impacted canine can be very, very variable, from a few months only for the simplest cases to more than a year for the more complex cases.
Some factors that can influence the duration of the traction are the position of the canine (the higher and horizontal it is, the longer and more complex the traction will be), the malocclusion (it is rare that a canine is the only problem to be corrected), the mechanics used, the technique used to make it clear, the age of the patient and… his cooperation.
CLEAR A SEVERELY IMPACTED CANINE
Who does the intervention? Most orthodontists do not perform the procedure to free a severely impacted canine. Instead, they will seek help from a specialist more familiar with this procedure such as a periodontist . Some general dentists can do the periodontal procedure to clear a canine if it is not too complex but it is up to the practitioner to decide if it is beyond their capabilities or not.
This surgical procedure is done under local anesthesia ; the gum covering part of the crown of the canine is excised using a scalpel (sometimes a little alveolar bone must also be removed to gain access to the canine) and an orthodontic clip with chain is glued to the tooth. Stitches are placed, and after a few days of healing, light orthodontic traction can already be applied. In some cases, traction may not be started until much later.
When the impacted canine is not very far into the bone and is only below the gum tissue, the canine release can be done with the help of a soft tissue laser in a few minutes at hardly under local anesthesia applied with a topical gel (no puncture). Many orthodontists do this procedure themselves.
IS THE TRACTION OF AN IMPACTED CANINE “GUARANTEED”?
NO . As with any dental or orthodontic procedure, the orthodontist cannot promise or “guarantee” any result when pulling an impacted or ectopic canine. He can only ensure that he takes the means and uses proven and recognized techniques to achieve the treatment goals that he has set with the patient and / or his parents.
An impacted canine is a particular challenge in orthodontics and several factors will influence the success of the treatment, such as the severity of the inclusion, the age of the patient, their cooperation during the treatment, etc.
UP TO WHAT AGE CAN AN IMPACTED CANINE BE TREATED?
In theory, there is no age limit for attempting to free and descend a canine, but in practice, the longer a canine remains impacted, the poorer the prognosis for successfully moving it by traction.
Over the years, it is more likely that an impacted canine will become stiff (fused to the bone) and not move, affect the roots of adjacent teeth (wear, resorption) and have other problems. The use of new three-dimensional imaging techniques greatly facilitates the location of impacted teeth and the detection of the damage they can cause to surrounding structures.
Despite the increased risk of complications associated with the treatment of impacted canines in adults, it is often worth the effort and effort to attempt to accommodate these teeth in the dental arch.
EXTRACTIONS DO NOT CORRECT ANYTHING!
Often, patients or their parents ask the dentist or orthodontist if it is possible to do an extraction to “make room for the other teeth”. This is especially common with canines that pierce out of the arch because, as previously described, these teeth are the last to come out and are often in an unsightly position.
One thing is certain, we prefer to avoid extracting a canine… almost at all costs, even if there are rare exceptions! The alternative might be the extraction of one of the premolars that is just behind the canine, but this rarely solves the problem on its own.
When such an extraction is considered, it is still advisable to preserve the space using orthodontic appliances to guide the eruption of the teeth and prevent unwanted dental movements that will cause other problems.
THE IMPORTANCE OF THE CANINES IN THE NORMAL CLOSURE OF A DIASTEMA
It is normal for a diastema or inter-dental space to be present between one or more upper anterior teeth during some stage of dental development and tooth eruption.
If the upper canines are properly placed and have enough space, their direction of eruption will allow them to follow the roots of the lateral incisors and move the incisors towards the center of the dental arch, thus allowing closure of the diastema (see l 'example below).
However, in “modern” dentition, it is common to see eruption problems and significant lack of space that does not allow this “ideal” situation to occur naturally.
The presence of a muscle attachment called a “ labial frenulum ” between the incisors is often blamed as being responsible for the space between the teeth and many recommend cutting or excising this frenum (frenectomy) at an early age in the hope that the diastema closes by itself. This is contraindicated as long as the canines have not emerged.
CAN WE ONLY CORRECT AN IMPACTED CANINE?
The presence of an impacted or ectopic canine usually indicates that there is a significant lack of space in the dental arch. To accommodate an impacted canine, it is first necessary to find the space and this implies having to move several other teeth of the arch to then pull the impacted tooth.
Moving teeth to the arch where an impacted canine is located (more common in the upper arch but also possible in the lower arch) will change the relationship of the teeth to the opposite arch. Therefore, not only is it not possible to adequately treat an impacted canine by treating only this tooth but it is also, most of the time, to consider more global corrections which will also require corrections to the opposite arch in order to to keep a harmonious and functional relationship throughout the dentition. The treatment of an impacted canine is never a very simple orthodontic treatment!