A survey of 156 dental surgeons was conducted on the issues of knowledge of the maxillary sinus anatomy, pre-surgery diagnostic specifics, and possible complications developing in the upper jaw during implantation and subantral augmentation. Objective. To study the causes of the maxillary sinus floor perforation during surgical interventions. Material and methods. A questionnaire was developed for dental surgeons. The questions concerned their work experience, the diagnostics used during planning of implantation and subantral augmentation surgery, the use of templates for implant placement, knowledge of the anatomy of the maxillary sinus, and the use of antibacterial therapy. Results. The survey results showed that most doctors had sufficient work experience from 10 to 20 years, 98 % of surgeons were men. Respondents rated their knowledge of the anatomical and topographic structure of the maxillary sinus as "good" and "excellent", prescribed antibacterial therapy, and took into account the structural features of the sinus mucosa. Conclusion. Despite the dentists’ competence in the anatomy of the maxillary sinuses, the use of CBCT at the stage of diagnostics and planning of implantation and subantral augmentation surgery, the use of templates, and the use of antibacterial therapy, the number of maxillary sinus perforations during surgical interventions does not decrease.