As the name implies, crown lengthening makes the clinical portion of the crown longer. A crown lengthening procedure is most often done when a tooth has a dental cavity that is so extensive that after removal of the cavity only a short portion of clinical crown height is left inadequate for future crown retention. In these situations, crown lengthening procedures will increase the clinical crown height by removing the surrounding gums and bone around the tooth, thereby increasing future crown retention. Crown lengthening is also frequently performed in “altered passive eruption” situation in which excessive amount of gums are covering the teeth (short teeth) due to the underlying bony architecture. Crown lengthening procedure will help establish more favorable bony architecture leading to normal looking teeth.
Gingivectomy refers to the removal of gums to expose more tooth structure below the gum margin. Gingivectomy is often used to remove fibrous enlargement of gum tissues. In addition, it is useful in creating more room on the tooth for the placement of orthodontic brackets. Unlike hard-tissue crown lengthening, gingivectomy is a soft-tissue procedure in that the underlying bony structures are left untouched.