Assessing Time Gap between Alveolar Cleft Repair and Dental Implant Placement: A Systematic Review

Introduction: Orthodontic treatment is commonly undertaken in cleft patients for space closure in cleft region. However, it is only able to achieve 50%-75% closure, resorting to use of dental prosthesis in form of removable or fixed partial dentures. Dental implant-based rehabilitation provides a suitable solution however their success depends on the quality and quantity of the residual bone. Resorption of bone graft is a known scientific fact and thus, it is important to know the minimum time after which the implant can be placed so that the grafted bone is minimally lost. However, this time gap between final bone grafting and implant placement in cleft patients has not been well established. Aim: To determine whether the clinical and/or radiological success of dental implant-based rehabilitation depends on the time elapsed between the last grafting procedure and dental implant placement in cleft region with missing permanent teeth in a unilateral or bilateral alveolar cleft patient. Materials and Methods: The systematic review was registered in PROSPERO (International Prospective Register of Systematic Reviews) via registration number CRD42020187709. Systematic review was done at GSR Institute of Craniomaxillofacial and Facial Plastic Surgery, Hyderabad, Telangana, India, between March 2020 to July 2020 wherein articles in electronic databases (PubMed, ScienceDirect, Web of Science, (Literatura Latino Americana de Ciencias da Saude), Cochrane Library and Google scholar, published between January 2011 to February 2020 were searched. Combination of Medical Subject Headings (MeSH) terms used included "cleft palate", "cleft lip", "alveolar bone grafting", and "survival" as some of the key terms. Additional information was sought by contacting the corresponding authors. Search items included were cleft, alveolar bone grafting and dental implants. Only studies with details of time gap between last grating procedure and implant placement were included. Data extraction was done independently by two authors using pre-defined fields. Results: Total of 12 studies were included wherein 255 dental implants were placed in 180 patients. In patients undergoing tertiary grafting, a time of 0 to 26 months was given prior to implant placement while in patients where tertiary grafting was not done, a time of 24 to 144 months was seen between two procedures. A high implant success of 95%-100% was seen irrespective of the grafted bone. The JBI (Joanna Briggs Institute) tool of risk of bias assessment was used. Low level of evidence was presented by case reports and case series. Conclusion: In case of tertiary grafting, a healing period of 3-6 months was seen to be sufficient for successful implant treatment however, a need for more comprehensive studies was recognised due to lack of mutual assessment parameters and shared information in the currently reviewed literature.