Crown lengthening procedures: A literature review

Dentists are often faced with clinical conditions requiring (1) exposure of subgingivally located deep restorative margins, extensive caries or fractures, (2) increase of supragingival tooth dimension of short crowns, and (3) correction of excessive gingival display and/or discrepant gingival margins. This therapeutic goal can be achieved surgically, orthodontically, or by a combination of both. Clinical crown lengthening is defined as a surgical procedure that aims at exposing sound tooth structure for restorative purposes via apical repositioning of the gingival tissue with or without removal of alveolar bone (AAP Glossary of Terms 2001). This definition applies to what has been categorized as "restorative" or "functional" crown lengthening while "esthetic" crown lengthening refers to indications in the context of esthetic surgery in the anterior sextants. This literature review will highlight the biologic basis for crown lengthening procedure (CLP), the variants of surgical crown lengthening with their indications and contraindications, and the orthodontic contribution to crown lengthening in the multidisciplinary approach.