Following tooth extractions (tooth loss), several areas characterized by the absence of dental units will form in the mouth. These are called edentulous spaces. If they are not restored in time through dental work, irreversible changes with a negative effect on oral health will occur around these spaces.

The following changes can occur following a tooth extraction:

• The antagonist or opposing teeth will migrate vertically toward the extraction site. This migration continues until the tooth reaches the opposing gum or another obstacle in its path.
• The neighboring teeth will tilt toward the edentulous space or, depending on the case, migrate as a whole, considerably narrowing this gap.

These changes lead to serious impairment of the functions of the dental apparatus: chewing, aesthetics and speech. Moreover, teeth that have migrated may develop periodontal conditions or cervical caries. The space needed to make the dental restoration may shrink or disappear entirely. Any prosthetic restoration (including implant-supported work) needs sufficient space so that the artificial teeth can be properly shaped.

After a certain period of time, situations may arise that require complicated (and often extremely expensive) preliminary treatments, or the making of compromise dental restorations with uncertain chewing and aesthetic qualities. There are many cases in which dental restorations can no longer be made due to lack of space.

Once the edentulous gap is restored through a dental restoration, the migration of the teeth stops.