BACKGROUND: Insufficient bone mass in the posterior maxilla region often increases the difficulty of dental implantation. The application of maxillary sinus floor elevation successfully solves this problem. In the surgery bone grafting can be used to obtain sufficient bone mass. However, nonuse of graft materials can shorten the cycle of patient's treatment and reduce trauma and cost. OBJECTIVE: Combining the latest relevant research trends, to review the advances in the study of maxillary sinus floor elevation with and without bone grafting. METHODS: The first author searched PubMed, VIP, WanFang and CNKI databases using computer for relevant articles published from January 1985 to August 2018. The key words were "dental implant, maxillary sinus, bone augmentation, bone substitute" in English and Chinese, respectively. Finally, 78 articles were included in result analysis after screening and summarizing. RESULTS AND CONCLUSION: Ideal results can be achieved in the maxillary sinus floor elevation with or without simultaneous bone grafting In addition, the nonuse of grafting materials have the advantages of simplifying surgical procedures, shortening treatment cycles, reducing trauma and pain, reducing treatment costs, reducing complications and failure rates, thus gaining the favor of doctors and patients. Therefore, the maxillary sinus floor elevation without simultaneous bone grafting will be the primary choice of the doctors engaged in dental implantation in the future.

This review introduces a qualitative methodology called institutional ethnography (IE) to healthcare professionals interested in studying complex social healthcare systems. We provide the historical context in which IE was developed, and explain the principles and terminology in IE for the novice researcher. Through the use of worked examples, the reader will be able to appreciate how IE can be used to approach research questions in the healthcare system that other methods would be unable to answer. We show how IE and qualitative research methods maintain quality and rigour in research findings. We hope to demonstrate to healthcare professionals and researchers that healthcare systems can be analysed as social organisations, and IE may be used to identify and understand how higher-level processes and policies affect day-to-day clinical work. This understanding may allow the formulation and implementation of actionable improvements to solve problems on the ground.