Vertical root fractures are difficult to diagnose using routine radiographic techniques like periapical radiography or by using panoramic radiographs. Such non- displaced fractures present a difficulty to be located and detected on intraoral radiographs. Long standing vertical root fractures usually show changes in the surrounding structures in the form of a radiolucent J-shaped lesion involving the culprit root, visualized on periapical radiographs. However, a recent root fracture not showing involvement of the adjacent bone or periodontium is difficult to identify using periapical radiographs due to superimposition of the cortical plates and projection geometry issues. In such cases showing presence of clinical signs similar to pulpal pathosis, a CBCT can be recommended to rule out or detect possible root fracture/s.
CBCT imaging shows increased sensitivity in detecting vertical and horizontal root fractures, with or without involvement of the adjacent structures. The dedicated design of CBCT imaging is able to reproduce undistorted information of dental and maxillofacial skeletal tissues. For the above mentioned scenario, a small Field of View (FOV) is recommended to include the tooth requiring investigation. The recommended voxel size is of 0.2mm or less, which is similar to endodontic investigations as it clearly visualizes the fine anatomical details. (2)
An important consideration during evaluation of teeth with suspected fracture is presence of metallic artifacts, which are caused by metal restorations and/ or implants. Endodontically treated teeth contain root fillings, endodontic posts (metallic) which cause artifacts. Such artifacts can obscure the detection of small/ partial fractures. (1)
Cross sectional image showing vertical fracture line with the mesial portion of the crown of 26 from the occlusal aspect involving dentin and pulp space extending to the mesial furcation dentin.
Sagittal image showing the partial fracture line extending along mesial aspect of palatal root and widening of PDL space along the mesial socket wall. Apical loss of lamina dura is noted.
Dentoalveolar fracture : Cross sectional and coronal images showing localized discontinuity with the labial socket wall of 21 at apical level. Conical root is noted with apical fracture involving radicular dentin. Widening of periodontal ligament space is noted along with apical hypodensity and localized loss of lamina dura. Incisal defect involving enamel noted i.r.t crown with 21. Widening of periodontal ligament space is noted along with periapical hypodensity i.r.t 11. Partially visualized fracture line is noted extending into the distal interdental bone i.r.t 22 in the coronal image.
Horizontal crown- root fracture : Axial images showing horizontal fracture line involving the coronal and radicular portion i.r.t 47 extending superio-inferiorly from the mesial to the distal aspect. The fracture line extends horizontally from the mesial aspect to the distal aspect of the crown involving pulp space.
Sagittal images partially demarcating the fracture line involving coronal dentin and pulp space extending into the cervical 3rd region of the distal root. Widening of PDL space and localized loss of lamina dura is noted with the distal socket wall. Apical osteolysis is also noted.
Horizontal root fracture : Sagittal image showing horizontal fracture (displaced) with the distobuccal root of 28. Localized osteolysis is noted with the roots showing approximation with the left maxillary sinus floor. Distal bone loss is noted extending till midtoot level corresponding to the fracture site.
Fractures in endodontically treated teeth :
Periradicular osteolysis is noted involving socket walls and cortices i.r.t endodontically treated 21. A partially demarcated, linear radiolucency is noted involving the distal root wall in the apical 3rd region, which could be suggestive of a partial fracture line. The osteolytic lesion extends into the periapical bone and shows erosion of the nasopalatine canal. It extends into the distal interdental bone i.r.t 21.
Axial and sagittal images showing distal root of 36 and related osteolytic lesion. Partial fracture line is noted with the lingual wall i.r.t distal root visualized in the axial and sagittal image.
Cross sectional images showing localized osteolytic lesion is noted extending from the lingual crestal bone till the periapical bone i.r.t distal root of 37. Localized discontinuity is noted with the lingual plate at apical level of the distal root.
Sagittal images showing the lesion extending into the distal interdental bone at apical level. The lesion shows contact with the apices of the mesial root of 37. Potential localized loss of lamina dura is noted with the apical area i.r.t mesial root of 37.
Guidelines by AAE/AAOMR :
Recent guidelines published by “AAE/AAOMR Joint Position Statement 2015/2016 Update” recommends that limited FOV CBCT should be the imaging modality of choice when evaluating the non-healing of previous endodontic treatment to help determine the need for further treatment, such as nonsurgical, surgical or extraction. Moreover, limited FOV CBCT was suggested for nonsurgical retreatment to assess endodontic treatment complications, such as overextended root canal obturation material, separated endodontic instruments, and localization of perforations.(2)
References :
1. Yilmaz F, Sönmez G, Kamburoğlu K, Koç C, Ocak M, Çelik HH. Accuracy of CBCT images in the volumetric assessment of residual root canal filling material: Effect of voxel size. Niger J Clin Pract 2019;22:1091-8.
2. American Association of Endodontists. AAE/AAOMR Joint Position Statement – Use of Cone Beam Computed Tomography in Endodontics‑2015/2016. Visit : https://www.aae.org/specialty/clinical-resources/guidelines-position-statements/
