Crown lengthening is a surgical procedure performed by a periodontist to expose a greater amount of tooth structure for the purpose of subsequently restoring the tooth with a crown. This is done by incising the gingival tissue around a tooth and, after temporarily displacing the soft tissue, predictably removing a given height of alveolar bone from the circumference of the tooth or teeth being operated on. This is a very predictable procedure that has been performed for more than 50 years to keep teeth.