Martins JNR, et al. - Using cone beam computed tomography (CBCT), researchers conducted a systematic review of anatomical studies to evaluate the impact of demographic factors (age, gender and geographic region) on the prevalence of C-shaped canal anatomy in maxillary molars, mandibular premolars and molars. Using Joanna Briggs Institute Critical Appraisal tool, the selected studies were submitted to full text analysis and critical appraisal by two evaluators. Data on 25,445 teeth of 13,142 patients were reported. According to findings, gender and geographic region may be a confounding factor in the prevalence of C-shaped anatomy in mandibular second molars, whereas age has not affected the prevalence of C-shaped configurations in this tooth group. Knowing these preoperative factors in clinics would help in anticipating complex morphologies.