The article explores the understudied pathophysiology of odontogenic sinusitis (ODS) development as a result of oral surgical complications such as oroantral communication (OAC) or fistula (OAF), maxillary sinus bone grafting, and dental implantation. A temporary OAC presents most often after dental extraction, especially with posterior maxillary teeth, though can happen with any oral surgical intervention. Maxillary sinus augmentation can also cause ODS, and while the pathophysiology is incompletely understood, it may be related to OAC/OAF formation or bone graft infection. Dental implants may also lead to ODS either via displacement into the sinus, partial protrusion into the sinus, or peri-implantitis.