Crown Lengthening Procedures after Orthodontic Treatment and before Placement of Prosthetic Crowns

Background: The need to provide aesthetic as well a functional dental restoration continues to be a challenge for the restorative dentistry. Crown-lengthening procedures can help address those challenges and can also be useful to improve the results of orthodontic and pre-prosthetic treatment. Clinical crown lengthening should be based on the adequacy of a biological width of 2.04 mm in order to obtain healthy periodontal tissue.

Purpose: To review crown lengthening procedures used for post-orthodontic and pre-prosthetic treatment, and explain the importance of biological width and its role in dental reconstruction and maintaining healthy periodontal tissue.

Case Report: Case #1 is a crown lengthening procedure performed with gingivectomy alone without bone reduction in the region of 22 in a post-orthodontic treated patient with asymmetric clinical crown and gingiva compared to the region of 12. The procedure resulted in symmetric gingiva and a balanced clinical crown. Case #2 is an example of crown lengthening as a pre-prosthetic treatment prior to crown restoration in the area of 13 and 14. Gingivectomy and bone reduction were both required to obtain adequate crown length.

Discussion: Bone reduction may be required as part of a crown lengthening procedure in order to obtain adequate biological width. To determine the need for bone reduction, the anatomical relationship between alveolar bone and the gingival margin should be assessed prior to treatment.

Conclusion: Clinical crown lengthening can be useful in a variety of clinical situations where form and function need to be reestablished. The key to success for this therapy is proper planning and an adequate amount of attached keratinized gingiva.