Your appearance is one reason. Another is that the gap left by a missing tooth can mean greater strain is put on the teeth at either side. A gap can also mean your "bite" is affected, because the teeth next to the space can lean into the gap and alter the way the upper and lower teeth bite together. This can then lead to food getting packed into the gap, which causes both decay and gum disease.
How are missing teeth replaced?
This depends on the number of teeth missing and on where they are in the mouth. The condition of the other teeth also affects the decision. There are two main ways to replace the missing teeth. The first is with a removable false tooth or teeth or a partial denture. The second is with a fixed bridge. A bridge is usually used where there are fewer teeth to replace, or when the missing teeth are only on one side of the mouth.
What is a partial denture?
This is a plate with a number of false teeth on it. It may be all plastic or a mixture of metal and plastic. Both types may have clips (clasps), to help keep the denture in place in the mouth. Depending on where they are, some of these clips may show when you smile or open your mouth.
What is the difference between a plastic partial denture and one that contains metal?
Plastic partial dentures are less expensive to make. But unless they are designed very carefully they can damage the teeth they fit against. Metal partial dentures are usually from an alloy of cobalt and chromium and they are much stronger. They are lighter to wear and can be supported by the remaining teeth. Although the base is metal, they have gum-coloured plastic and natural-looking teeth fixed to them. They are more expensive than the plastic ones.
What is the alternative to a partial denture?
The main alternative is a fixed bridge. This is made by putting crowns on the teeth at either side of the space, and then joining these two crowns together by placing a false tooth in the space. This is all made in the laboratory and then the pieces are cemented into place with special adhesives. The bridge can't be removed. Another option is an adhesive bridge. This has wings that are bonded to the back of the supporting teeth with very little drilling involved.