| Field | Value |
|---|---|
| ID | OA-0097 |
| Type | anchorage |
| Category | anchorage |
| Fixed/removable | fixed (TAD-anchored) |
| Primary function | posterior dental intrusion; anterior open bite correction |
| Malocclusion target | anterior open bite; hyperdivergent cases |
| Uses TADs | yes — 1–4 TADs (palatal or buccal) |
| Period | modern |
| Status | current |
Posterior intrusion with TADs is one of the most significant advances in non-surgical open bite treatment. By intruding the upper and/or lower posterior teeth (molars and premolars), the mandible rotates counterclockwise, bringing the anterior teeth into contact and closing the open bite. A mid-palatal TAD with an intrusion transpalatal arch (TPA) or bilateral buccal TADs with elastic or sectional wire mechanics deliver light, continuous intrusive force to the posterior segment. This achieves a maxillary impaction-like effect orthodontically, without surgery — reducing lower anterior facial height and improving the profile.
TADs placed in the palate (mid-palatal or paramedian) or buccally (between roots of premolars/molars) serve as the intrusion anchor. An intrusion TPA, elastic, or wire segment connects the TAD(s) to the molar brackets, applying approximately 50–100 g intrusive force per side. As the posterior teeth intrude, the mandible rotates counterclockwise (closing rotation), reducing lower anterior facial height and closing the anterior open bite. Simultaneously, a TPA or lingual arch prevents rotation of the intruding molars.
Anterior open bite due to posterior dentoalveolar excess; hyperdivergent facial pattern where surgery is not desired; adolescents or adults with open bite from posterior over-eruption; cases where traditional extrusion of anterior teeth would worsen the facial profile; as an alternative to surgical maxillary impaction.
TAD placement between molar roots requires CBCT to avoid root damage; intrusion of multiple teeth requires careful force calibration; not appropriate if open bite is skeletal (mandibular deficiency or maxillary excess requiring surgery); relapse is possible if myofunctional habits persist.
The intrusion TPA is fabricated by the lab from 0.9–1.0 mm SS or TMA wire, designed to engage the TAD and connect to the palatal sheaths of the molar bands. The TPA must be passive initially, then activated to deliver the prescribed intrusive force. Buccal TAD systems may not require lab fabrication of the intrusion element.
TAD-based deep bite correction
and multiple loops for differential force delivery
posterior segments; simple, adjustable
eruption while TADs retract/intrude simultaneously
(zygoma/infrazygomatic) for high-load posterior intrusion cases; surgical placement required
continuous force via elastic chain from TAD to molar band; common in open-bite management
MDPI](https://www.mdpi.com/2076-3417/13/9/5464)
Update](https://www.dental-update.co.uk/content/orthodontics/molar-intrusion-using-tads-in-the-management-of-an-anterior-open-bite-a-case-report)
APOS](https://apospublications.com/correction-of-open-bite-with-temporary-anchorage-device-supported-intrusion/)
open bite correction, intrusion TPA fabrication.