Radiographic findings and prognosis of simple bone cysts of the jaws

Abstract

Objective: The aim was to evaluate the possibility of radiographic prediction of the prognosis of simple bone cysts (SBCs) of the jaws.

Methods: The relationship between the radiographic findings and treatment outcome (healing or recurrence) was investigated in 31 cases treated in the authors' hospital and 108 published cases.

Results: In 17 of our 31 cases, the lesions had radiographic findings of a preserved lamina dura adjacent to the lesion, with a smooth margin, and no or smooth bone expansion, and all of them healed after surgery. In the other 14 cases, there was resorption of the lamina dura, a scalloped margin, nodular bone expansion, root resorption, a sclerotic mass or multiple cavities, and nine cases of recurrence. Although there was incomplete information in the published case studies, similar results were noted.

Conclusions: It was concluded that there was a relationship between the radiographic features of the lesions and prognosis. Radiographic examination should be used not only for discovering and diagnosing the lesions, but also for predicting possible prognosis.

Figure 1

(a) Simple bone cyst cavity with a smooth margin. (b) Radiographic finding of an intact lamina dura. The lamina dura adjacent to the lesion is fairly well preserved. (c) Occlusal radiograph revealing smooth bone expansion. (d) 4 years and 3 months after surgery, healing of the lesion is confirmed by the formation of new bone trabecula

Figure 2

Simple bone cyst with an absent lamina dura. Most of the lamina dura has been resorbed

Figure 3

Simple bone cyst with root resorption of the first molar tooth. Septum-like radiopaque lines are also seen (arrows). This lesion recurred after surgery

Figure 5

Simple bone cyst with a radiopaque mass in the cavity (long arrow). Root resorption is suspected at the medial root of the first molar (short arrow). The lesion recurred twice after surgery

Figure 4

(a) Simple bone cyst accompanied by florid cemento-osseous dysplasia (FCOD). Cavities with a scalloped margin are observed in the right molar and anterior teeth regions. No sclerotic mass is apparent, but one was confirmed in periapical radiographs of the incisor region. (b) Characteristic finding of nodular expansion. Protuberant bone expansion with an irregular surface is noted. (c) Seven months after surgery, bone formation is confirmed in the cavity. (d) 4 years and 10 months after surgery; in addition to recurrence of the lesion, formation of a sclerotic mass of FCOD is confirmed (arrow)