Imaging approach for jaw and maxillofacial bone tumors with updates from the 2022 World Health Organization classification

Table 1 Imaging characteristics for distinguishing between jaw lesions

Key imaging characteristics	Description and/or spectrum of imaging findings
Radiodensity	Radiodensity is a crucial imaging feature for distinguishing between different jaw and maxillofacial bone lesions and is generally classified into 2 categories: (1) Radiolucent; and (2) Radio-opaque
	Radiolucent lesions include cysts and radiolucent neoplasms. They can be classified based on margin definition into 2 categories: (1) Well-defined margins; and (2) Ill-defined margins
	Radiopaque lesions can be classified into 3 types: (1) Densely sclerotic; (2) Ground-glass; and (3) Mixed lytic-sclerotic patterns. Most densely sclerotic lesions are benign, including conditions such as odontoma and cementoblastoma
Marginal definition	Assessing the margins of lesions indicates their aggressiveness and is crucial for differentiating between slow-growing benign tumors and more aggressive neoplasms
	Well-defined margins are typically seen in benign, slow-growing lesions like dentigerous cysts, whereas aggressive, rapidly growing lesions, such as odontogenic carcinomas, often exhibit ill-defined margins
Loculation pattern	Loculation patterns apply primarily to radiolucent lesions and are classified into two types: (1) Unilocular; and (2) Multilocular
	For unilocular lesions with well-defined margins, the lesion’s location relative to a tooth can help differentiate diagnoses. For example, radicular cysts are found at the tooth apex, while dentigerous cysts are typically located around the crown of unerupted teeth
	Evaluating multilocular lesions on imaging can be challenging due to overlapping features among various pathologies. Accurate diagnosis often requires tissue sampling and histopathologic correlation. Ameloblastoma is a common odontogenic lesion that exhibits a multilocular pattern
Relationship to adjacent teeth, erosion of the teeth or bone	The relationship of lesions to adjacent teeth is another important imaging clue, particularly when lesions are closely associated with or near teeth. Lesions closely related to a tooth or located above the inferior alveolar canal are more likely to be odontogenic in origin. Conversely, lesions centered below the inferior alveolar canal are likely non-odontogenic, while those within the canal may be vascular or neurogenic in origin
	In lesions closely related to teeth, the specific location within tooth structures (i.e., root or crown) and their association with erupted or unerupted teeth can provide valuable diagnostic clues. For example, a dentigerous cyst typically attaches to the cemento-enamel junction of the crown of an unerupted tooth. In contrast, an odontogenic keratocyst generally attaches apically to the cemento-enamel junction of the crown
	The impact of lesions on surrounding structures, such as tooth displacement, tilting, or resorption, as well as bone erosion and destruction, may help distinguish between cystic and neoplastic lesions. Cystic lesions generally cause minimal tooth destruction and may tilt adjacent teeth, while neoplastic lesions often lead to resorption, destruction, and bodily movement of adjacent teeth
Internal matrix appearance	Internal matrix patterns may help differentiate jaw lesions. Slowly growing tumors may deposit bone, creating a trabecular pattern, while some lesions, such as ameloblastomas, may display a “soap bubble” appearance. The presence of an internal chondroid matrix with a ring-and-arc pattern can suggest chondroid tumors, such as chondrosarcomas
Patterns of osseous expansion	Odontogenic keratocysts typically extend along the mandibular axis (the long axis of the mandible), while ameloblastomas tend to expand along the buccolingual axis (the short axis of the mandible)
Soft tissue component	The presence of an enhancing soft tissue component on contrast-enhanced computed tomography or magnetic resonance imaging indicates a higher likelihood of a true neoplasm rather than a cyst