Curve of Spee
Pronunciation: SHPAY
The anteroposterior curvature of the mandibular occlusal plane, following the arc from the incisal edges of the lower incisors to the buccal cusps of the posterior teeth.
Full Definition
The curve of Spee, named after anatomist Ferdinand Graf von Spee, describes the natural curvature of the mandibular dental arch in the sagittal plane. In a normal occlusion, this gentle upward curve corresponds to the arc of a circle approximately 65–70 mm in radius. An exaggerated curve of Spee is associated with deep overbite and requires arch leveling during orthodontic treatment, which consumes arch perimeter and may contribute to apparent crowding. Editors should capitalize 'Spee' as a proper noun and use 'curve of Spee' (lowercase 'curve') in running text. The curve of Spee should not be confused with the curve of Wilson, which describes transverse curvature.
Usage
Usage note: Capitalize 'Spee.' Write as 'curve of Spee' in body text; 'Spee's curve' is acceptable in informal usage but should be standardized per journal style.
In Context
- "Leveling the exaggerated curve of Spee required 2 mm of arch length and was factored into the space analysis." — Orthodontic treatment plan
- "The author wrote 'Spee curve' without the possessive; the editor amended this to the standard 'curve of Spee.'" — Manuscript copyediting