Oral and Maxillofacial surgery

Oral and Maxillofacial surgery (2)

When a tooth is unable to fully enter the mouth, it is said to be “impacted”.  Wisdom teeth, also known as third molars, are the last teeth to develop in the mouth, and are the most commonly impacted teeth.  Studies have shown that removing impacted wisdom teeth earlier in life results in fewer complications and easier healing.

 

Symptoms of Impacted Wisdom Teeth 

Wisdom teeth typically erupt between16-20 years of age.  While some may erupt properly through the gum or bone, many people have insufficient space for them to come completely through.  In these cases, a flap of gum tissue known as an operculum covers the tooth, making it difficult to clean properly.  If food or bacteria collects in these areas, a chronic inflammatory reaction can occur, and sometimes infection as well.  Many people will develop swelling of the gum flap, known as pericoronitis, which can be very painful, and make it difficult to chew.

 

The wisdom teeth are marked with an “x”. The upper wisdom teeth are vertically impacted, while the lower wisdom teeth are horizontally impacted.

Many lower wisdom teeth lie at the wrong angle, and point into the back of the adjacent tooth.  This increases the risk of damage to both teeth in the form of cavities, and also the formation of deep gum pockets that cannot be cleaned.  Upper wisdom teeth can sometimes erupt through the gum tissue, but be pointed toward the cheek (sideways, instead of down).  These can sometimes be the most difficult teeth to clean given how high and how far back they are in the jaw.

In rare cases, cysts or tumours may form around impacted wisdom teeth.  These potentially destructive pathologic lesions can cause damage to adjacent teeth, bone, and other anatomic structures.  Pathologic fracture of the jaw is a risk when these lesions enlarge and eat away at the supporting bone.  If any of these lesions are seen on an x-ray, their removal becomes urgent.

 

The impacted wisdom teeth are shown with an “x”. Notice how they are not at the same level as the adjacent teeth, they are mis-angulated, and are stuck in the bone.
The impacted wisdom tooth on the lower left has a large cyst (arrows) on its back half. Notice how the lower edge of the cyst extends near the bottom of the jaw, leaving only a sliver of healthy bone. There is a high risk of a broken jaw in this area.

 

Wisdom Teeth and Braces

In some cases, wisdom teeth are removed to facilitate braces, or orthodontics.  If there is insufficient space in the jaw, your orthodontist may suggest removing the wisdom teeth to decrease pressure, and to lessen the risk of crowding or shifting of adjacent teeth. 

Some people require removal of their wisdom teeth before starting orthodontic treatment, others need them removed during treatment, while some can wait until braces are finished.  Each situation is different, and depends on factors such as the patient’s age, room available in the jaw, whether any additional teeth need to be removed, and whether the wisdom teeth are causing other problems.

What to do After Wisdom Teeth Have Been Removed

Most people have many questions after their wisdom teeth have been removed.  We have some general instructions for care after wisdom teeth have been removed.

 

Overview

In some cases, teeth do not erupt properly through the jawbone and gum tissue, into the mouth.  Maxillary canines (upper eye teeth) are the most commonly impacted, after wisdom teeth.  Impacted teeth may cause problems including bone loss, root resorption, or formation of cysts or tumours.  Your Orthodontist and Oral & Maxillofacial Surgeon can work together with a combination of braces and minor surgical procedures, including tooth exposure & bonding of an orthodontic bracket, to bring the tooth properly in alignment with the other teeth.  Surgical procedure can be completed while awake, or with a variety of anesthesia options.

What are Impacted Canines and Impacted Teeth? 

An impacted tooth is one that does not properly erupt into the mouth.  The most commonly impacted teeth are wisdom teeth, followed by the maxillary canines (upper eye teeth).  The canines are important teeth as they frame your smile, and are also important for chewing.  However, any tooth could potentially become impacted, for numerous reasons.

Impacted canines occur in 2% of the population, affecting twice as many females as males, and twice as many in the top jaw as the bottom jaw.  This can sometimes occur on both the right and left.  The majority of impacted canines are located on the roof of the mouth.   

There are many reasons that teeth may become impacted.  In some cases there may not be enough room in the jaw for them to fit.  In other cases, they cannot follow the normal track along adjacent teeth to erupt into proper position.  Other theories suggest a genetic component may be a contributing factor in impacted teeth, and may be associated with other dental abnormalities.

 

Diagnosis of Impacted Canines and Teeth

How do we find out if a canine or other tooth is impacted?  And how do we find out where it is?

The first method is easy – observation and palpation.  Adult teeth should erupt at certain ages; if they’re missing, then there may be a problem.  In addition, the angulations and positions of adjacent teeth may give a clue as to the position of the missing tooth.  Careful examination of the area, along with feeling along the gum tissue, may give a hint as to the missing tooth’s position.

X-rays are typically the next step in gathering information.  There are several types of x-rays that are typically taken including panorex, periapicals and occlusals.  Multiple x-rays are commonly required, and are important for determining if a tooth is impacted, the tooth’s position in relation to the jaw and adjacent teeth, the effect on adjacent teeth and structures, and for planning purposes.

In some cases, a CT scan may be ordered and will provide detailed 3-dimensional information about the impacted tooth’s position.

Problems from Impacted Canines and Teeth

Impacted canines and teeth that are left in place may go throughout the patient’s lifetime with no untoward effects.  However, close monitoring and at regular dental care intervals is recommended.  On the other hand, these impacted teeth may have several untoward effects and consequences.

The simplest problem is that a tooth will be missing from the smile.  Although sometimes a baby tooth will be retained in that position, it will never have the proper shape and size that an adult tooth will have.  In the worst-case scenario, there will be a gap that is visible beside the rest of the teeth.

Impacted teeth may also cause damage to adjacent teeth, known as resorption.  In resorption, the impacted tooth “eats away” at the a portion of the healthy tooth.  Many times this is unrestorable, and in rare cases may actually cause loss of the tooth.  If resorption does not occur, adjacent teeth may be pushed out of their normal positions from pressure of the impacted tooth, causing mal-alignment.

Pathology can sometimes develop around an impacted tooth.  Pathology usually represents an abnormal growth of tissue around the tooth, typically in the form of a cyst or tumour.   While there are many different variations and types of cysts and tumours, treatment at a minimum would require removal of the lesion and possibly removal of the impacted tooth.  Worst case scenarios would result in loss of adjacent teeth, and possibly need for further surgical treatment to ensure that the lesion does not recur.

Treatment of Impacted Canines and Teeth, including Exposure and Orthodontic Bonding 

Treatment for impacted canines can vary.

In some cases, removing the baby canine can create enough space for the adult tooth to drop into position.  This would usually be done around 10-13 years of age.  However, this does not guarantee correction or elimination of the problem.  The tooth should be monitored and, if not corrected or improved after a year, additional treatment should be undertaken.

Surgical treatments exist to help bring an impacted canine or tooth into proper position.  Selection of the type of procedure depends on which tooth is impacted, the degree of impaction, and the position of the tooth within the jaw bone.

  • Gingivectomy (Open Exposure) can be used, where overlying gum tissue is simply removed to allow the tooth to erupt naturally, or to allow the orthodontist to bond an attachment to it directly.
  • Apically positioned flaps are used to expose the tooth through the gum tissue, but also to create a healthy band of gum tissue around the tooth.

Exposure and bonding involves uncovering the impacted tooth and bonding an orthodontic attachment to it, then replacing the gum tissue over the tooth.  The attachment is connected to a gold chain that is used to apply gentle traction to coax the tooth into position.

Extractions are sometimes considered with some impacted teeth.  However, it is seldom a good idea to extract an impacted canine.  Not only are the canines important aesthetically in the smile, but they are also important in a functional bite.  The rare situation where canine extraction might be considered include: ankylosis, where the tooth is “stuck” and will not come into position; it is undergoing resorption which indicates an inflammatory reaction is compromising the tooth; there are pathologic changes like cysts or tumours, as mentioned above; the impaction is severe, and is jeopardizing adjacent teeth; or if the patient does not want to pursue orthodontic treatment.