| Field | Value |
|---|---|
| ID | OA-0199 |
| Type | component |
| Category | component |
| Fixed/removable | component in removable appliance |
| Primary function | deliver controlled tipping force to individual teeth |
| Uses TADs | no |
A finger spring is a single cantilever wire spring with one end embedded in the acrylic baseplate and the other end free to contact a tooth. When the appliance is inserted, the spring is lightly activated (pre-loaded by contact with the tooth), applying a gentle tipping force. Finger springs are used in removable appliances to: tip teeth labially or buccally, correct minor rotations, or close small spaces. Activation is incremental — the clinician bends the spring slightly further at each adjustment visit. Common applications: tipping individual incisors labially in mixed dentition, palatal cross-bite correction on single teeth. Typically 0.5–0.6 mm SS wire.
The finger spring is a single-arm cantilever spring embedded in the baseplate of a removable appliance. It deflects away from its passive position when the appliance is inserted, and as it springs back it applies a light, continuous force to the target tooth, tipping it in the desired direction. The point of application is typically the lingual or palatal surface of the crown. Force is controlled by the gauge of the wire (0.5 mm for light force, 0.6 mm for heavier), the length of the active arm, and the amount of activation.
Finger springs are the standard active element in removable orthodontic appliances for tipping individual teeth. Common uses: correcting a single palatally displaced or labially tipped incisor; maintaining or correcting space in the mixed dentition; tipping a canine after extraction closure; producing minor tooth alignment in a Phase I or limited treatment context. Multiple finger springs can be incorporated to tip several teeth simultaneously.
Force should be in the light continuous range — 25–50 g is the biological optimum for tipping. Spring length determines force: a longer arm bends more per unit of deflection, delivering lighter force. The spring must have adequate guide wire or be boxed in by acrylic to prevent displacement under occlusal load. A guard wire (additional wire loop over the spring) prevents the spring from being depressed by the tongue.
Finger springs produce tipping only — they cannot produce bodily tooth movement, which requires fixed appliances. Compliance is essential; the spring delivers force only when the appliance is worn. Appliances with multiple active springs on opposing teeth can create reciprocal unwanted movements if force vectors are not carefully designed. Springs that are over-activated or fabricated in too-stiff a gauge cause pain and discourages wear.
Lab-bent from 0.5–0.6 mm SS wire; coil incorporated for flexibility; embedded in acrylic. Doctor prescription specifies which tooth and direction of movement.
Appliances that incorporate this component. ★ = fabricated by Clear Fusion Lab.
appliance
Acrylic plate retainer
appliance
posterior, arm engaging canine labially; most common finger spring application
teeth labially (for palatally displaced teeth)
Z-shaped activation section for labial tooth movement
for labio-palatal tooth movement
over-activation of finger spring and protect soft tissue
Orthodontics](https://www.oup.com)