Objective: To determine the most frequent anatomical variants of the maxillary sinus by evaluation using cone beam computed tomography (CBCT) in a Guatemalan population attending the DISA Radiological Center in the period 2013-2018. Materials and Methods: Descriptive cross-sectional study. 217 CBCT was performed in a total of 434 maxillary sinuses, determining the frequency of anatomical variants, the presence of pneumatization of the maxillary sinus and their classification and sinus septa in association with sex and the dental condition of the patient. Measurements were made by a trained and calibrated researcher, using Carestream CS 3D software. The Chisquare test was used to determine associations among variables (p<0.05). Results: The frequency of pneumatization of the maxillary sinus was 79.2%, with class II being the most prevalent with 53.5%. The distribution and frequency of ...