title: A systematic review and meta-analysis on the effects of crown lengthening on adjacent and non-adjacent sites.
abstract: OBJECTIVE
  The objective of the study was to assess the impact of periodontal crown lengthening surgery on clinical parameters at adjacent and non-adjacent sites compared to treated sites.
  
  
  METHODS
  An electronic search was carried out on MEDLINE-PubMed, The Cochrane Library, and ISI Web of Science databases between 1978 and 2015. Methodological quality assessment was based on Cochrane recommendations. Meta-analyses were assessed with RevMan 5.0 and heterogeneity between studies by the Higgin test (I2). Clinical attachment level (CAL) and probing depth (PD) were the primary outcome variables. Four case series studies were included and three in the meta-analysis. All studies showed high risk of bias.
  
  
  RESULTS
  The surgery promoted significant changes in treated, adjacent, and non-adjacent sites. There were greater changes in PD (mean difference -0.14, 95 % CI -0.18 to -0.10, p < 0.00001) and CAL (mean difference 0.16, 95 % CI 0.13 to 0.20, p < 0.00001) in treated sites when compared to adjacent and non-adjacent sites for PD (mean difference -0.09, 95 % CI -0.12 to -0.05, p < 0.00001) and CAL (mean difference 0.91, 95 % CI 0.87 to 0.94, p < 0.00001).
  
  
  CONCLUSIONS
  Crown lengthening surgery results in changes of clinical parameters in treated, adjacent, and non-adjacent sites.
  
  
  CONCLUSIONS
  Clinical and esthetic alterations on the adjacent/non-adjacent teeth can lead to clinical and esthetic alterations, which must be considered in surgical planning.
authors: Federal University of Rio Grande do Norte, João Alves Flor St, 983, Candelária, Natal, RN, 59066-120, Brazil.
authors: Cintia Mirela Guimaraes
authors: CM
authors: Nobre
authors: Universidade Federal do Rio Grande do Norte, Senador Salgado Filho Ave., 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil.
authors: Ana Luisa
authors: AL
authors: de Barros Pascoal
authors: São Paulo University, Professor Lineu Prestes Butantã Ave., São Paulo, SP, 05508000, Brazil.
authors: Emmanuel
authors: E
authors: Albuquerque Souza
authors: Univesity of Florida, 1395 Center Drive, PO Box 100434, Gainesville, FL, 32610, USA.
authors: Luciana
authors: L
authors: Machion Shaddox
authors: Universidade Federal do Rio Grande do Norte, Senador Salgado Filho Ave., 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil.
authors: Patricia
authors: P
authors: Dos Santos Calderon
authors: Universidade Federal do Rio Grande do Norte, Senador Salgado Filho Ave., 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil.
authors: Ana Rafaela Luz
authors: AR
authors: de Aquino Martins
authors: Universidade Federal do Rio Grande do Norte, Senador Salgado Filho Ave., 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil. bcgurgel@yahoo.com.br.
authors: Bruno César
authors: BC
authors: de Vasconcelos Gurgel
mesh_terms: D016556:Crown Lengthening; D006801:Humans; D010043:Outcome and Process Assessment, Health Care; D017622:Periodontal Attachment Loss; D010510:Periodontal Diseases / Q000601:surgery*; D010512:Periodontal Index; D010514:Periodontal Pocket
keywords: Crown lengthening; Oral surgery; Periodontal attachment loss; Tooth injuries