Evaluation of keratocystic odontogenic tumors using cone beam computed tomography

An Insight Into the Effect of Odontogenic Keratocysts on Surrounding Structures: Cone-Beam Computed Tomography-Based Analysis of Cases

Introduction  An odontogenic keratocyst (OKC) is a benign intraosseous lesion with potential to demonstrate aggressive and invasive behavior. The aim of this retrospective study was to analyze the imaging features of the OKC using cone-beam computed tomography (CBCT) and to evaluate the association between the internal structure of the lesion and the effect of the lesion on surrounding structures. Methods Overall, 32 CBCT scans of histopathologically diagnosed cases of OKC were analyzed retrospectively. The following variables were analyzed: anatomic location of the lesions (mandible body (right/left), ramus (right/left), mandible body+ramus (right/left), maxilla (right/left), and both jaws), the internal structure of the lesion (unilocular/multilocular), and the effect of the lesion on the surrounding anatomical structures (involvement of the inferior alveolar nerve canal (IANC), displacement of the IANC, cortical expansion, displacement of the tooth, resorption of the root, associated impacted tooth, associated missing tooth). We also looked for the association between the internal structure and the effect of the lesion on anatomic structures. Results Out of 32 cases, 29 (90.6%) cases involved the mandible alone. Statistically significant association (p-value 0.005) was present between the internal structure and mean age of presentation as well as between the internal structure and impacted tooth (p-value 0.027). The association between the internal structure and other variables was statistically not significant. Conclusions The radiographic features of OKCs can be variable, and these lesions have a considerable effect on the tooth, IANC, and cortical bone. Significant association was found between the internal structure, age, and impacted tooth. Since OKCs have a high recurrence rate, CBCT is advised for evaluating the extent and location of any cortical perforations.

Unilocular Radiolucent Lesions of the Jaws: a Retrospective Panoramic and Cone Beam Computed Tomography Evaluation

Background/Aim: The aim of this study was to evaluate and compare the imaging characteristics of common, radiolucent, unilocular, intraosseous lesions of the jaws using both panoramic radiography and cone beam computed tomography (CBCT); also, to evaluate sufficiency of panoramic radiography in determining characteristic features of jaw lesions.

Material and Methods: Retrospectively selected images of 57 patients with histopathology results were evaluated by two oral radiologists. The lesions were assessed based on shape, location, borders, relationship with the mandibular canal, presence of destruction of cortical bone, and expansion of cortical bone, and presence of an unerupted tooth related to the lesion. In addition, the widest areas of the lesions were measured. A total of 9 (15.8%) odontogenic keratocysts, 9 (15.8%) apical granulomas, 24 (42.1%) radicular cysts, 12 (21.0%) dentigerous cysts and 3 (5.2%) central giant cell granulomas in 57 patients (20 women, 37 men) with a mean age of 36.93 ± 17.96 years were included. Fifty-seven CBCT and 56 panoramic images of these patients were evaluated.

Results: Twenty-nine (50.8%) lesions were in the mandible and 28 (49.2%) in the maxilla. A statistically significant difference was determined for the areas in CBCT images (p=0.007).

Conclusions: Panoramic radiography is not as successful as CBCT in demonstrating some characteristics of the lesions, such as expansion and destruction. The area measurements may be beneficial in establishing the differential diagnosis of the lesion.

Odontogenic keratocyst and ameloblastoma: radiographic evaluation

OBJECTIVES

To describe the radiographic features of odontogenic keratocysts (OKCs) and ameloblastomas and to compare the radiographic findings between these 2 lesions.

METHODS

Radiographs of OKCs and ameloblastomas were retrospectively reviewed. Location, border, shape, association with impacted tooth, tooth displacement, root resorption, and bone expansion were evaluated. Chi-squared or Fisher's exact tests were used for statistical analysis. A p value < 0.05 was considered to indicate statistical significance.

RESULTS

One hundred OKCs and 101 ameloblastomas were reviewed. The ratios of maxilla to mandible were 1:1.4 and 1:9.1 in OKCs and ameloblastomas, respectively. All evaluated features significantly differed between OKCs and ameloblastomas (p ≤ 0.001). Most OKCs showed smooth border (60%) and unilocular shape (82%), while most ameloblastomas showed scalloped border (77.2%) and multilocular shape (68.3%). Association with impacted tooth was found in 47% of OKCs and 18.8% of ameloblastomas. Adjacent tooth displacement was found in 33.7% of OKCs and 55.8% of ameloblastomas. Root resorption was more common in ameloblastomas (66.7%) than in OKCs (7%). Bone expansion was also more common in ameloblastomas (96.3%) than in OKCs (63.6%).

CONCLUSION

A unilocular radiolucent lesion with smooth border, no adjacent tooth displacement, no root resorption and causing mild or no bone expansion is suggestive of an OKC rather than an ameloblastoma.