Smile Arc
The curvature created by the incisal edges of the maxillary anterior teeth, assessed in relation to the curvature of the lower lip on smiling, used as a key aesthetic endpoint in orthodontic treatment planning.
Full Definition
The smile arc describes the relationship between the imaginary curve formed by the incisal edges and cusp tips of the upper anterior teeth and the inner curvature of the relaxed lower lip during a posed smile. A 'consonant' smile arc exists when the upper dental curve is parallel to (follows) the lower lip curve, and is generally regarded as aesthetically pleasing. A 'flat' or 'reversed' smile arc, where the dental curve is flatter or curves upward, is considered less attractive and can result from certain orthodontic mechanics. Editors encounter this term in aesthetic assessment notes, treatment rationale letters, and research publications.
Usage
Usage note: Write as two unhyphenated words. Distinguish clearly from 'buccal corridor,' which refers to lateral dark spaces rather than the antero-posterior curvature of the dental arch.
In Context
- "Treatment planning prioritised preservation of the patient's consonant smile arc to avoid the flattening effect associated with extraction mechanics." — Treatment planning report
- "The aesthetic outcome section references 'smile arc' three times; confirm the term is used consistently and not conflated with 'buccal corridor.'" — Research paper review