Crowding
The discrepancy between available arch length and the combined mesiodistal widths of the teeth, resulting in irregular tooth alignment.
Full Definition
Crowding arises when the arch perimeter is insufficient to accommodate all teeth in ideal alignment, causing rotation, displacement, or impaction. In orthodontic records it is quantified in millimetres and classified as mild (0–4 mm), moderate (4–8 mm), or severe (>8 mm). Editors must ensure that the unit of measurement is stated and that classification terminology is used consistently throughout a document. The term 'crowding' is the accepted British clinical noun; 'crowded' is the adjectival form. It should not be confused with 'spacing', which represents the opposite condition. The distinction between arch-length discrepancy and tooth-size discrepancy should be preserved when present in source text.
Usage
Usage note: Always state the quantified discrepancy in millimetres alongside the severity classification in clinical reports.
In Context
- "Moderate lower arch crowding of 6 mm was identified during space analysis." — Space analysis report
- "First premolar extractions were planned to relieve severe upper and lower crowding." — Treatment plan document