Mesial Drift
The natural tendency of teeth to migrate in a forward direction (towards the midline) over time, which can close spaces left by extracted teeth.
Full Definition
Mesial drift is the physiological forward movement of teeth along the dental arch toward the midline, driven by occlusal forces and the mesially inclined axial orientation of most teeth. It is clinically significant because the loss of a posterior tooth, if not replaced, can result in neighbouring teeth drifting into the extraction space, causing arch-length discrepancy and occlusal changes. Editors working on extraction consent forms and treatment planning documents should ensure the term is not hyphenated; 'mesial-drift' as a hyphenated form is incorrect outside its use as a compound modifier. Distinguish from 'tipping', which is angular movement, and 'bodily movement', which is translation without axial change.
Usage
Usage note: Unhyphenated as a noun phrase; hyphenate only when used as a compound modifier before a noun: 'mesial-drift tendency'.
In Context
- "Mesial drift of the lower-left second molar was noted following extraction of the lower-left first molar two years prior." — Orthodontic assessment record
- "The treatment plan outlined the risk of mesial drift and subsequent space loss if the missing UL4 was not replaced." — Treatment plan document