Stafne's bone cyst revisited and renamed: the benign mandibular concavity

Objective: Stafne's bone cyst (SBC) is an asymptomatic, round or oval-shaped, well-defined, uniform radiolucent lesion, usually incidentally observed in the posterior aspects of the mandible. Radiographical appearance may be confusing though. This study aimed to review the literature on SBCs and to map the SBC as shown in their respective papers. Methods: A Pubmed (R) search (1/9/2018 till 31/5/2019), mentioning SBC, was carried out. Included papers had to contain: patient's age, gender and radiographs. Results: In total, 114 papers were found, but only 64 papers were retained, which contained 109 cases (95 males, 14 females). The patients' ages ranged between 14 and 89 years old (mean age being 52 years). Male patients' ages (N = 95) ranged from 14 to 89 years (mean age 52.3 years), whereas the females (N = 14) ages ranged between 22 and 68 (mean age 50.2 years). 28 combinations of locations of SBC were recorded. Only three lesions were located at the symphysis, six were bilateral, 55 appeared on the left hand side and 45 on the right hand side of the mandible.The literature mentioned that these cavities could contain salivary gland tissue, muscular tissue, lymphoid tissue, blood vessels, fat tissue or connective tissue. Discussion/Conclusion: This study illustrates the wide variation of SBC locations across the mandible and leads us to conclude that the differential diagnosis of every asymptomatic, oval or round, well-defined, uniform radiolucent lesion on two-dimensional radiographs of the mandible should include "a benign mandibular concavity", formerly known as SBC.