Cementoenamel Junction
Pronunciation: se-MEN-toh-eh-NAM-el
Also written as: CEJ — Cementoenamel Junction
The anatomical boundary on a tooth where the enamel of the crown meets the cementum of the root, used as a fixed reference point in periodontal measurements.
Full Definition
The cementoenamel junction (CEJ) is a critical anatomical landmark in periodontal and restorative dentistry, marking the transition between the enamel-covered crown and the cementum-covered root. It serves as the standard reference point from which periodontal probing depths, recession measurements, and bone loss are calculated on radiographs and in clinical notes. Editors must ensure the abbreviation CEJ is expanded on first use in clinical documents. The junction is sometimes inconsistently referred to as the 'amelocemental junction' in older literature; current convention strongly favours 'cementoenamel junction'. Correct hyphenation as a compound noun is 'cementoenamel junction', not 'cemento-enamel junction', in most contemporary style guides.
Usage
Usage note: Do not hyphenate as 'cemento-enamel'; modern dental style guides use the closed compound. Always expand CEJ on first use.
In Context
- "Recession was measured from the cementoenamel junction to the free gingival margin using a UNC-15 probe." — Periodontal assessment record
- "The radiograph showed bone levels 4 mm below the CEJ at the distal aspect of UL5." — Radiographic interpretation report