Teeth are lost by many factors such as cavities, gum diseases, congenital problems, some surgeries, etc.
Depending on the space left by these lost teeth, and depending on whether or not there are teeth adjancent to such spaces, treatment can be proposed for restoring such areas, such as bridges or dental implants. It is important to replace lost tooth, as they all have a specific function.
If these teeth are not replace, the remaining teeth will be compromised by heavier loads.