Fig. 1

Preapical radiographs of tooth #44. a The lower third of the root canal of the first right premolar had branches; b Working length radiographs of four root canals of the tooth were measured; c Four root canals were filled; d The missing mesiobuccal root canal was found and measured; e Radiograph showing obturation of all five canals; f Recall observation X-ray 6 months later; g Recall observation X-ray 48 months later