| Field | Value |
|---|---|
| ID | OA-0201 |
| Type | component |
| Category | component |
| Fixed/removable | component in removable appliance |
| Primary function | buccal tipping of lingually displaced posterior teeth |
| Malocclusion target | posterior crossbite (single tooth) |
| Uses TADs | no |
The T-spring is similar to the finger spring but the free end is bent into a T shape, spreading the contact area across a broader surface of the tooth. Used for palatal crossbite on posterior teeth in removable appliance therapy. The T-contact reduces the chance of the spring slipping gingivally off the tooth. Application is primarily for mild single-tooth posterior crossbites in the mixed dentition. Typically 0.5–0.6 mm SS wire.
The T-spring is a single-arm spring bent into a T-shape at its active end, providing a broader contact surface than a simple finger spring and reducing the tendency to slip off a tooth during function. The T-shaped tip contacts the palatal or lingual surface of the tooth and delivers a tipping force in the labial, buccal, or distal direction depending on the spring's orientation and angulation.
T-springs are used for the same indications as finger springs — tipping individual teeth in removable appliance therapy — but are preferred when the tooth surface is small, the spring needs to be stabilized against displacement, or when multiple springs in a confined space require a compact design. They appear frequently in twin-block-style functional appliances for detailing tooth positions, and in upper removable expanders where simultaneous tooth tipping and expansion are planned.
0.5 mm SS wire for light force applications; 0.6 mm for heavier engagement. The T-tip width should match the mesio-distal width of the tooth contact zone to avoid point loading. Guard wire or acrylic boxing prevents displacement by the tongue.
T-springs are limited to tipping movements and require patient compliance. The T-tip can become embedded in the mucosa if the spring is over-extended and the patient fails to wear the appliance — the tip migrates gingivally during non-wear periods. Clinicians should confirm adequate clearance between the spring tip and gingival tissue at delivery.
Lab-bent; embedded in acrylic baseplate.
Appliances that incorporate this component. ★ = fabricated by Clear Fusion Lab.
Acrylic plate retainer
appliance
appliance
delivers labial force on narrow incisor
prevent soft tissue catch
labio-palatal depth to cross
specifically for a single tooth in crossbite
laterals); Z preferred for canines and premolars
EJO](https://academic.oup.com/ejo)