Radiology

There may be initially nothing to see on the radiographs if the injury is small and affects buccal or palatal sites. In order to improve visualization, two strategies are available: either obtain two views with different horizontal projections, or remove the canal obturation and leave the canal empty.

There may be simple local widening of the periodontal ligament space, or a type of "lateral canal” with limited lateroradicular bone destruction simulating a lateroradicular lesion by necrosis of the pulp of a lateral canal, when it affects the proximal sides. It can also affect two sides. Sometimes, after removing the canal filling, VRF can be seen radiolog-ically or clinically. In this case and because of the fracture line twisted from middle third, where the sinus tracks were located, to mesial inter-proximal area, it could not be seen with a gum retractor.

There may be lateroradicular osseous destruction that communicates the radicular surface affected by the fracture to the bone crest; this will create two different radiological patterns:

• A "pear-shaped halo" appearance is a combination of periapical and lateroradicular lesions and represents the projection of extensive damage to the cortical bone plate. It is the most frequent finding.
• A "periodontal" appearance is of angular resorption of the crestal bone along the root on one or both sides without involving the periapical area, like radiolucencies also found in periodontal disease or perforation accidents.

The fracture itself can be seen clearly only when separation of the fragments has occurred and the incidence angle of the rays coincides maximally with the fracture plane. There is also a correlation between direction of fracture, amount of bone destruction, radiographic appearance, and time.

Other radiological explorations - like axial computed tomography, flat panel volume detector (cone beam computed tomography; CBCT) and tuned aperture - can help in detection of early widening of the periodontal ligament area or small bone resorption.