Abstract
With the spread of oral implant therapy, serious medical complications related to implant surgery are becoming a social problem. Although the number of complications after implant surgery in the edentulous jaw is decreasing in Japan, maxillary-sinus-related complications (MSRCs) have reached the highest number since 2012. It is essential to identify and eliminate possible predisposing risk factors for MSRCs at an early stage to prevent MSRCs. In this review article, we highlight the causal factors of postoperative complications with or without sinus augmentation for the maxillary molar region to achieve optimal treatment outcomes and reduce complications. In particular, we focus on anatomical variations that can cause the impairment of maxillary sinus drainage. Furthermore, we emphasize that the paradigm for personalized medicine for patients with a maxillary edentulous jaw by ENT specialist and dentist cooperation is shifting from the traditional assessment of maxillary sinus pathologies alone to the new assessment of anatomic variations that can cause the impairment of maxillary sinus drainage in addition to maxillary sinus pathologies.