[Methods aimed at lengthening the clinical crown: a review].

This review deals with the different methods of lengthening the clinical crown and discusses the advantages and/or disadvantages of each method. Different flap procedures, including ostectomy and osteoplasty, reduce the height of the alveolar crest aiming at a distance of about 3 mm to a future reconstruction margin. Root planing may avoid reattachment of surgically separated fibers. Other methods like gingivectomy, electrosurgery, intra-alveolar transplantation, and forced eruption might contain considerable biological disadvantages. However, if the extrusion is combined with regular fiberotomy, this method becomes the most conservative with respect to the periodontal tissues of neighboring teeth. On the other hand, not all situations which require lengthening of the clinical crown can be solved by orthodontic extrusion and fiberotomy. Therefore, depending on the clinical problem, either the surgical lengthening of the clinical crown or the orthodontic extrusion with separation of the fibers are the recommended procedures.