Unilocular
Pronunciation: yoo-ni-LOK-yuh-ler
Describing a radiographic lesion that appears as a single, undivided radiolucent cavity without internal bony septa.
Full Definition
In dental radiology reporting, 'unilocular' is used to characterise the internal architecture of cystic or cyst-like radiolucent lesions. A unilocular lesion presents as one continuous radiolucent space, in contrast to a multilocular lesion which is divided by radiographic bony septa into multiple compartments. The distinction is of direct diagnostic importance, as certain jaw pathologies (e.g., ameloblastoma, odontogenic keratocyst) may present as either unilocular or multilocular forms. Editors must ensure the correct term is applied and that it is not confused with 'well-defined' (referring to cortication) or 'radiolucent' (referring to density). Standardised hyphenation is not used; 'unilocular' is a single closed-compound word.
Usage
Usage note: Refers specifically to the internal architecture of a lesion (absence of septa), not to its border definition or density.
In Context
- "The lesion associated with the unerupted lower-left third molar was unilocular with a well-corticated border." — CBCT radiology report
- "Editors must not substitute 'well-defined' for 'unilocular', as these descriptors refer to different radiographic features." — Radiology editorial guide