Although braces are still one of the most effective methods available to straighten teeth, they do not target the underlying problems causing the teeth to be crooked. Often once braces are removed, the teeth will have a tendency to change their positions, or ‘relapse’ back into their previous positions. This problem can be addressed by using retainers, which are often prescribed for life. In some cases, relapse can be severe enough to warrant further treatment.
Research has now proven that orthodontic movement of teeth with braces and constant force arch wire will cause root shortening (also know as root resorption) in most patients.
Orthodontic movement of teeth with braces, combined with constant-force arch wire, causes root shortening (Orthodontically Induced Inflammatory Root Resorption - OIIRR) in nearly every case. This can lead to the loss of up to 4mm or one third of the tooth's root length. In time this may lead to the loss of one or more teeth. The use of intermittent forces and removable appliances has been proven to cause little or no root shortening.
"The patients treated with fixed-appliances had notable OIIRR (root shortening), but the other group [using removable appliances] had none."
|American Journal of Orthodontics and Dentofacial Orthopedics 2009, Volume 136, Number 1|
The surface of a tooth is made up of tooth enamel - a hard, mineral coating that protects the tooth against decay. Enamel is the hardest tissue in the human body.
When braces are fitted they are bonded to the teeth through a chemical process. The enamel on the surface of the tooth is etched to allow for better bonding strength.
When the braces are removed, there is a chance that the enamel on the surface of the tooth that was etched can be permanently damaged.