Background: Misdiagnosis on radiographic examination is a significant risk for dentists and medical practitioners. This review focuses on an anatomical variation of the maxillary sinus that can mimic a radicular (periapical) cyst. Knowledge of morphological variations, their prevalence, and the radiographic criteria distinguishing these variations from true lesions is essential to ensure accurate diagnosis and appropriate treatment and to prevent unnecessary or potentially harmful interventions.

Objective: The aim of this study was to perform a systematic literature search of published cases and to present a clinical case illustrating a specific maxillary sinus variant, an enlarged sinus with a prominent alveolar recess that can mimic a periapical cyst on radiographs.

Methods: After defining specific MeSH terms, a systematic literature search was conducted across three databases: Web of Science, PubMed, and Embase. Relevant articles reporting on enlarged maxillary sinuses with alveolar recesses resembling radicular cysts were identified and analyzed. Results: Four articles describing the presence of an enlarged maxillary sinus with an alveolar recess resembling a periapical cyst were extracted from the literature.

Conclusion: Knowledge gaps regarding the alveolar recess of the maxillary sinus remain in the literature and should be addressed to avoid misdiagnosis. The findings also underscore the importance of three-dimensional imaging, such as CT or CBCT, for accurate detection of this anatomical variant.