Following dental extractions, one or more toothless spaces will appear on the dental arches. These spaces are called toothless gaps, breaches or edentulous spaces.

toothless gap or edentulous space

Physiological changes following teeth extractions

After a tooth extraction, the seat remaining after tooth removal will produce a series of changes. These processes occur slowly over more months (6 to 8).

First, inside the alveolar socket (where the tooth was formerly held) bone tissue begins to deposit. Over the toothless gap, the gums slowly close the extraction wound. The bone width and height gradually diminishes.

The anatomical structure that appears after the end of the healing process is called edentulous ridge.

edentulous space : the toothless space
edentulous ridge : the anatomical structured located in the edentulous space

Gradually, around edentulous spaces, serious irreversible changes take place. Untreated, these conditions will have important repercussions over the health and functionality of the entire dental system.

Teeth migration

1. Migration of opposing teeth towards edentulous spaces

   Opposing teeth begin to move towards the toothless gaps. This is a vertical migration until teeth reach the opposite edentulous ridge or another obstacle located on the path.

   
   

   

   vertical migration of a tooth
   towards the opposite toothless gap

   
   

   The vertical migration can occur in two distinct ways :

   • The tooth can migrate toward the opposite space along with the surrounding bone.

   • The tooth can move vertically without its surrounding bone. Basically, the tooth "gets out of its alveolar socket" (image above).

   
   

2. Migration of adjacent teeth towards the breaches

   Neighbouring teeth start migrating horizontally in an attempt "to close the gap". This migration can also occur in two different ways :

   • The adjacent teeth are bending towards the breach. This means that only the crown of the tooth is moving while root position remains unchanged. See picture bellow.

     
     

     

     
     

   • The adjacent teeth are moving towards the space with both the root and the crown. This means that, after a period of time, teeth will change their place inside the mouth cavity.

The type of movement that occurs depends on several internal factors.

!!!Dental migrations take place only as long as the edentulous space exists. If a dental prosthesis is manufactured, teeth migration stops.

Teeth migration consequences

Shrinkage of the edentulous space

Once the toothless gap is reduced (as a result of adjacent or opposite teeth migration), a dental restoration will be very difficult to design. Artificial teeth cannot be adequately shaped because there is too little room.

excessive shrinkage of the toothless gap
because of vertical teeth migration

Complex procedures may be required to create an adequate space for the dental bridge. Obviously, these have a high cost and a long period of execution.

There are situations when even such operations cannot improve the clinical situation.

Dental processes are severely affected

First, aesthetics will seriously suffer especially if migrated teeth or toothless gaps are located in visible areas.

Even if teeth are located in the back of the mouth, they will not be able to perform their main function properly: chewing. The chewing process is already diminished because the number of teeth units has decreased after the dental extractions.

Moreover, teeth can migrate in totally inappropriate positions leading to severe occlusal disorders. Pronunciation will also suffer because, as we know, teeth play a major role in speech.

Migrated teeth can suffer from periodontal diseases or cavities

Because of teeth movements, the gum can retract from the teeth leaving the root naked. This area is covered by a thin layer of dental cementum, which is very sensitive to decay.

Moreover, the tooth can change its position inside the alveolar socket. As a result, the periodontal ligaments (a group of specialized fibres that attach the tooth to the bone) may be damaged leading to tooth mobility.

The gum around the bending teeth may create some spaces where food particles and germs can stagnate. These areas will increase, causing the formation of periodontal pockets.

In later stages, because of the continuous pressure of the leaning tooth against the alveolar bone, the bone tissue will suffer a process of resorptionBone resorption is a process that results in the loss of bone around teeth , increasing tooth mobility.