Large J-shaped lesions are often associated with vertical root fractures. This tooth was asymptomatic to percussion, non responsive to thermal testing and surprisingly normal to probing. Diagnosis: necrotic pulp and asymptomatic apical periodontitis. It was was determined to be an endodontic problem.
The large radiolucency extends up the distal root into the furcation. Microscopic examination during endodontic therapy revealed no root fracture. In this case, the assumption of a root fracture, based on radiographs alone, would have been incorrect.
Without proper diagnosis, this tooth might easily be labeled a fractured root and extracted. A new crown is indicated to prevent coronal leakage.