Crown Lengthening Liverpool, NY Dentist Crown lengthening treatment removes excess gum tissue from around one or more of your teeth, exposing additional tooth structure above your gumline. This may be recommended if you have a “gummy” smile or to provide better access to correct issues with decayed or broken teeth or infected gums. During treatment, your gums are moved away from your tooth and jawbone. The bone will be smoothed, if needed, prior to reattaching the gums lower on the teeth. With more tooth structure showing above the gumline, your teeth now appear longer and your gums less prominent.