Tooth elongation is also known as crown lengthening. It is also sometimes referred to as a "gum lift". Teeth can need elongation for different reasons. Many times your dentist will recommend crown lengthening of a single tooth when a filling or crown is needed and the tooth is too short to hold it properly. The case below demonstrates a patient who desired to show more tooth when smiling. A gum lift is performed, followed by new restorations that dramatically change the patient's appearance.
You can read more about crown elongation on the AAP website.
“It has been estimated that 69% of Americans age 35 to 44 have at least one missing tooth, and one in four over the age of 74 have lost ALL their natural teeth.” — Dental Implants