What is a common indication for "crown lengthening" surgery?

Crown lengthening surgery is commonly performed to expose more tooth structure for both restorative and aesthetic purposes. This procedure is particularly beneficial when a tooth is subgingival (below the gum line) and inadequate tooth structure is available for proper restorative treatment. By surgically removing a portion of the gum tissue and possibly some underlying bone, clinicians can gain access to the tooth structure that needs to be restored, allowing for better placement of crowns or other restorations.

This procedure can also enhance the smile by correcting a "gummy" appearance where excess gum tissue covers a significant portion of the tooth, improving the visual harmony of the smile. In contrast, the other choices do not accurately reflect the purpose of crown lengthening surgery; extracting a tooth, removing decay, or reshaping the jawbone do not address the restorative or aesthetic needs that crown lengthening specifically aims to fulfill.