Objectives. The aim of this study was to investigate the number of roots and root canals in the maxillary second premolar in a group of Jordanian population. Materials and Methods. A total of 217 patients, 100 female (46%) and 117 male (54%), received root canal treatment of maxillary second premolar from January 2012 to January 2014. The mean age of the patients was 32.7, ranging from 18 to 60 years. The teeth included in the study were examined clinically and radiographically for the number of roots and root canals using magnifying loupes. Results. Out of the total of 217 maxillary second premolars, 120 teeth had one root (55.3%), 96 teeth had two roots (44.2%), and one tooth had three roots (0.46%). Regarding root canal configuration, 30 teeth (13.8%) had one canal, 54 teeth (24.9%) had two canals shared in one apical foramen, 132 teeth (60.8%) had two canals with two separate apical foramina, and one tooth (0.46%) had three canals with separate apical foramina. Conclusion. The incidence of two canals (either with shared or separate apical foramina) is very high in the maxillary second premolars in Jordanian population; therefore inspection should be done for the presence of second canal whenever endodontic treatment is planned for this tooth.

Objectives: To investigate clinically and radiographically the number of roots and root canals in the maxillary first premolars in a group of Jordanian population using magnifying loupes while carrying out routine endodontic practice. Methods: A total of 176 patients 87 female (49.4%) and 89 male (50.6%) received root canal treatment of maxillary first premolar at King Hussein Medical Centre from January 2012 till January 2015. The age of the patients was ranging from 18 to 60 years. The teeth included in the study were both clinically and radiographically examined for the number of root canals using sharp endodontic explorer and magnifying loupes. Diagnostic preoperative radiographs were taken for evaluation. Two radiographs in two planes (parallel and 20ᵒ-40ᵒ horizontal angle cone shift) were taken during routine endodontic treatment for these teeth. The number of roots and root canals in the maxillary first premolars was recorded. Results: Out of the total of 176 maxillary first premolars 56 teeth had one root (31.8%), 118 teeth had two roots (67.0%) and two teeth had three roots (1.1%). Based on Vertucci's classification of root canal morphology: one tooth (0.6%) had type I canal configuration (one canal), 17 teeth (9.7%) had type II (two canals with shared apical foramen), 156 teeth (88.6%) had type IV (two canals with separate apical foramen) and two teeth (1.1%) had type VIII (three canals with separate apical foramina). The percentage of two canals (type II and IV) is 98.3%. Conclusion: The percentage of two canals (either with shared or separate apical foramina) is very high in the maxillary first premolars in Jordanian population. Inspection should be done for the presence of second canal whenever endodontic treatment is planned for this tooth.