Table 1. Maxillary sinus pathology according to root canal treatment status and the presence of an apical lesion.

Group 1: non-endodontically treated teeth without an apical lesion, group 2: non-endodontically treated teeth with an apical lesion, group 3: endodontically treated teeth without an apical lesion, group 4: endodontically treated teeth with an apical lesion