Stafne's bone defect with bicortical perforation: a need for modified classification system

Stafne's bone defect (SBD) or salivary gland-related bone defects are asymptomatic bone cavities in the mandible caused by impingement by the salivary glandular tissue. The major salivary glands, particularly the submandibular gland, are in close relation with the mandible and their impingement can produce radiolucent defects on the lingual cortical surface of the mandible. Submandibular gland-related bone defects or depressions are referred as posterior lingual variant of SBD. These are asymptomatic and appear as well-defined radiolucent areas that are incidentally discovered on panoramic radiographs. Three-dimensional imaging may be required to evaluate the extent of cortical involvement and to determine the content of the cavity or defect. Usually, these defects are seen in the lingual cortices and are lined by cortex that causes a smooth radiopaque periphery. The involvement of both the buccal and lingual cortices by the defect is extremely uncommon. Literature has classified cases with buccal cortical expansion but buccal cortical perforation has not been described and classified. This case report describes this uncommon presentation of the salivary gland bone defect and through an in-depth literature review proposes a modification in the existing classification system.