High-density areas within low-density areas in radiographs of dentigerous cysts.

Purpose: This study aimed to analyze radiographs of dentigerous cysts containing high-density areas within low-density areas to identify their characteristic radiographic features. Materials and Methods: This retrospective study included histopathologically confirmed cases of dentigerous cysts in patients who underwent computed tomography (CT). The analyses included demographic data, the position of the low-density area relative to the impacted tooth, and the number, size, and location of the high-density area within the low-density region. Group comparisons were performed for each analytical factor. Results: The patients were classified into 550 cases of dentigerous cysts without high-density areas and 34 cases with high-density areas within the low-density regions. In the group with high-density areas, the low-density regions more frequently extended beyond the cementoenamel junction toward the center of the tooth root. In addition, many lesions exhibited high-density areas with a maximum diameter of less than 3 mm, contact with the tooth crown, and involvement of impacted teeth. Conclusion: Lesions displaying high-density features, such as a maximum diameter <3 mm, contact with the tooth crown, and association with impacted teeth, are likely dentigerous cysts. These findings suggest that dentigerous cysts containing high-density areas differ from other lesions with calcified components. Although such cases are rare, recognizing them is important for understanding the disease spectrum.