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 bea challenge for the restorative dentistry. Crown-lengthening procedures can help address thosechallenges and can also be useful to improve the results of orthodontic and pre-prosthetictreatment. Clinical crown lengthening should be based on the adequacy of a biological width of2.04 mm in order to obtain healthy periodontal tissue. Purpose: To review crown lengthening procedures used for post-orthodontic and pre-prosthetictreatment, and explain the importance of biological width and its role in dental reconstruction andmaintaining healthy periodontal tissue. Case Report: Case #1 is a crown lengthening procedure performed with gingivectomy alonewithout bone reduction in the region of 22 in a post-orthodontic treated patient with asymmetricclinical 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 bonereduction were both required to obtain adequate crown length. Discussion: Bone reduction may be required as part of a crown lengthening procedure in order toobtain adequate biological width. To determine the need for bone reduction, the anatomicalrelationship 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 formand function need to be reestablished. The key to success for this therapy is proper planning andan adequate amount of attached keratinized gingiva.