Crown lengthening is a surgical procedure performed by a dentist, or more frequently a periodontist, where more tooth is exposed by removing some of the gingival margin (gum) and supporting bone. Crown lengthening can also be achieved orthodontically (using braces) by extruding the tooth.
Crown lengthening is done for functional and/or esthetic reasons. Functionally, crown lengthening is used to: 1) increase retention and resistance when placing a fabricated dental crown, 2) provide access to subgingival caries, 3) access accidental tooth perforations, and 4) access external root resorption. Esthetically, crown lengthening is used to alter gum and tooth proportions, such as in a gummy smile. There are a number of procedures used to achieve an increase in crown length.