This image shows a typical apical transportation that occurs when the merging is located in the more apical part or the canals, so shaping from two different directions will create a drop-shaped foramen and parallel walls. Early diagnosis can be done by different methods in different steps of an endodontic treatment. With traditional intra-oral Rx there is no possibility of understanding the anatomical configuration of a tooth. Sometimes patients listed for endodontic treatment might already have a CB-CT scan available (for previous treatments such as implant positioning or wisdom tooth extraction). In these cases clinicians have the possibility to visualize the anatomy prior to performing the treatment.
It is very important to understand the anatomy and to respect the root canal configuration in order not to transport the foramen, not to strip and weaken the root, and not to fracture an endodontic instrument.
Early diagnosis is the solution to face this kind of situations in a safe, predictable way.
Weine FS, Healey HJ, Gerstein H, Evanson L. Canal configuration in the mesiobuccal root of the maxillary first molar and its endodontic significance.Oral Surg Oral Med Oral Pathol. 1969 Sep;28(3):419-25.
Weine FS.Initiating endodontic therapy in posterior teeth. Part II. Maxillary molars. Compend Contin Educ Dent. 1982 Nov-Dec;3(6):455-64.
Berutti E.Respecting apical foramina in the endodontic treatment of confluent canals. G Endodonzia. 1990;4(1):6-21.
Hess W, Zürcher E. The anatomy of the root canals of the teeth of the permanent and deciduous dentitions, New York: William Wood & Co, 1925.
Burns RC, Buchanan LS. Tooth Morphology and Access Openings. In Cohen S, Burns RC, editors: Pathways of the Pulp, 6th ed., Mosby Yearbook Co., 1994.
Ruddle CJ.The Mesial-Buccal Root of the Maxillary First Molar: Treatment Considerations, The Endodontic Report, Fall/Winter, 1986.
Ruddle JC.Endodontic Canal Preparation : Breakthrough cleaning and shaping strategies , Dentistry Today, February 1994