In case of failure to replace a missing tooth, you could end up loosing all your teeth. Each tooth has two part - Crown and Root. Crown is visible in the mouth whereas the root is embedded in the bone. Molars have two or three roots whereas the front teeth are usually single rooted.

Loosing A Tooth

As shown in the picture extraction of a lower molar has created a space 'X' . Upper tooth 6 is now useless because it no longer has a tooth to chew against. Therefore loosing one tooth can result in the loss of two or more teeth.

Supra-Eruption

Back teeth have a lifetime tendency to ERUPT. Only the presence of a tooth to chew against keeps a back tooth from supra-erupting. In the above case the upper 6 has supra-erupted. The resulting unevenness among the upper back teeth has created areas between the teeth that trap debris. Despite the best efforts to brush and floss it is difficult to keep uneven areas clean. Thus gum infection and tooth decay start in these areas. The lower tooth wedges food in the space created in between the upper teeth. This causes the upper 7 to move backwards. As the space further increases infection increases.

Tilt and Drift

Back teeth have a lifetime tendency to TILT and DRIFT towards the front of the mouth. Thus in the above case the lower 7 is drifting and tilting forward.

Gum Pocket formation and bone loss

A tilted tooth develops a Gum pocket along its front tooth. Gum pockets are narrow abnormal spaces or clefts that develop between the gums and the tooth root. These pockets trap food debris and bacteria. A gum pocket is a problem as it is very difficult to keep it clean, even with the best brushing and flossing. The debris and bacteria that collect in the pocket lead to worsening of the gum infection. This gum infection finally infects the adjacent bone which softens and slowly begins to disappear. Thus the lower is lost due to gum infection and the upper 6 and 7 eventually lost because of tooth decay and infection.

Conclusion

Failure to replace a single molar tooth may start a chain of events : Supra-eruption, Tilt, Gum pockets, Decay, Bone loss. Over the years this can lead to the loss of all your teeth. Inserting a false tooth today will avoid grief and much greater expense tomorrow.