Crown lengthening is a procedure some dentists choose to do for their patients, although many refer patients to a periodontist instead for this process. Crown lengthening involves removing gum tissue and bone around the tooth socket to expose more of the tooth. When there is sufficient tooth and bone structure available, crown lengthening can be an effective way to expose enough of the sound tooth for prosthetic restoration.
However, there are challenges with this procedure. There are often variations in the height of the tooth after removal of tissue and bone, and these variations can affect the success of the procedure. If not enough tooth is exposed, it can lead to a failed crown attachment or pain.
In addition, removing bone for a crown lengthening procedure can damage the bony support of adjacent teeth, and bone removal may prevent using a dental implant in the future, should the crown fail.
An alternative to surgical crown lengthening can be orthodontic forced eruption, or using orthodontics to move the tooth upward so that more surface is exposed (similar to using braces to move teeth into proper position). This procedure is simple and non-invasive, and it doesn’t require the removal of bone. In forced eruption, the tooth is extruded to expose more surfaces by bracketing adjacent teeth and using light force. The procedure is cost effective and typically takes a couple of months. In this case, an orthodontic solution can be preferable to a periodontal one.
And should the eruption procedure not work as hoped, your dentist can still provide other options to correct the problem.
Orthodontic crown lengthening has the same biologic basis as traditional crown lengthening, and that is getting the margin of the restoration 3mm away from the level of the bone. Whereas surgical crown lengthening works well from a functional and biological standpoint, if done in the upper front teeth it can sometimes result in an un-esthetic appearance of the gum tissue.
Orthodontic crown lengthening is a method of achieving the biological crown lengthening required while still maintaining the esthetics that are so important in the front teeth.
Orthodontic crown lengthening takes advantage of dental anatomy and uses it to your advantage. There are fibers, called supra-crestal fibers. These supra-crestal fibers go from the tooth to the top of the bone. Orthodontic brackets (braces) are put on the tooth to be lengthened, as well as on one tooth on each side. With the braces dentists orthodontically erupt the tooth. If the supra-crestal fibers are left intact then as the tooth erupts these fibers will “pull” the bone and gum tissue with it. This would not give you any lengthening of the crown. If, however, the supra-crestal fibers are cut as the tooth is erupted, the tooth will erupt, the bone will stay put, the crown will be lengthened, and the esthetics will have been preserved. Generally it takes 2-3 weeks of active eruption followed by 3 months of stabilization before you can get your final restoration.