Simple Bone Cyst

A simple bone cyst (SBC) is a bone cyst without lining epithelium, first reported by Lucas in 1929. There are different names for traumatic bone cyst, solitary bone cyst, hemorrhagic bone cyst, exosmotic bone cyst, idiopathic bone cyst, idiopathic bone cavity and progressive bone cavity. The diversity of naming reflects the uncertainty of pathogenesis. SBC is common in long bones but rare in jaws. Its incidence accounts for about 1% of bone cysts, mostly in young people, and 75% of patients are between 10 and 20 years old, mostly in men. The most common part of the maxillofacial region is the body of the mandible, mainly involving bicuspids and molars, and the maxilla is extremely rare [1–6]. Most cysts are single and can also occur on both sides of the jaw. Clinically, most of the simple bone cyst is asymptomatic, and it are often found by chance during X-ray examination. Sometimes, the patient may suffer from jaw swelling and pain [6–11]. The teeth adjacent to the lesion part are vital teeth that may cause sensory abnormalities when invading the inferior alveolar nerve. X-ray shows a clear-cut single-locular transmission zone and a thin edge hardening zone. Root resorption and tooth displacement are rare, and the periodontal membrane and lamina dura in the lesion area are intact [12–20].