Odontogenic maxillary sinusitis is often ignored by otolaryngologists, dentists, and imageological diagnosis doctors. Traditional treatments are often frustrating for refractory maxillary sinusitis and odontogenic maxillary sinusitis. In the last few years, new progress has been made in the diagnosis, pathophysiology, and treatment of odontogenic maxillary sinusitis. Periodontitis, polyposis, and iatrogenesis are regarded as causes of odontogenic maxillary sinusitis. Dental implant dislocation into the maxillary sinus and augmentation are the main cause of iatrogenesis compared to root canal full material. The symptoms are too similar to distinguish odontogenic maxillary sinusitis from chronic rhinosinusitis. Computed tomography is the gold standard for diagnosis, while it is difficult to rule out odontogenic maxillary sinusitis by conventional panoramic radiographs. Cone-beam computed tomography (CBCT) is currently the most broadly used to make diagnosis and differential diagnosis for maxillary sinus disease. The imaging diagnosis, clinical diagnosis, and pathological diagnosis are often not completely in accordance. Most researchers believe that odontogenic maxillary sinus infection results from the spread of apical pathogenic microbial infections: either through the local vascular system, lymphatic system, or the Haval system of the alveolar bone itself. DNA and RNA sequencing of mucosal tissues of maxillary sinus disease confirmed that the mechanisms of odontogenic maxillary sinusitis and nonodontogenic maxillary sinusitis are different. Microbial RNA sequencing of the maxillary sinus also verifies this conclusion. Clinical serum testing of chemical factors has not been widely exploited. It is unknown whether the thickening of the maxillary sinus membrane is the result of pathogen infection or inflammatory mediators. Many doctors have recommended a consensus on multidisciplinary cooperation management, but a global consensus has not yet been reached. Diagnosis methods for odontogenic maxillary sinus disease are diversified. Tissue DNA and RNA sequencing, chemical factor determination, and microbiological DNA and RNA sequencing have appeared, and the misdiagnosis rate has gradually decreased. The pathophysiology of odontogenic maxillary sinusitis and chronic rhinosinusitis is different. The molecular mechanism of the thickening of the Schneider membrane in odontogenic sinus is unknown.