Orthodontic mini implants, also called temporary anchorage devices (TADs), are small titanium screws placed in bone to provide fixed anchorage during treatment. They let a clinician retract or intrude teeth and move molars without relying on patient cooperation. Safe use depends on anatomy, placement site and force direction.
What a mini implant is
A mini implant is a small screw, commonly 1.2 to 2.0 mm in diameter and roughly 6 to 12 mm in length depending on the site. Unlike a dental implant it is not meant to osseointegrate and it is removed when the orthodontic movement is complete.
Material and design
Most mini implants are made from titanium alloy. Designs differ in thread pattern, in whether they are self-drilling or require a pilot hole, and in the head, which carries a hole, slot or bracket like feature for attaching a spring or elastic.
Anatomy and clinical protocol: choosing the location
Common sites are between the roots on the buccal side of the upper and lower arches, the palate, the infrazygomatic crest and the mandibular buccal shelf. Hazards include root proximity, the maxillary sinus and nasal floor, the mental foramen and the inferior alveolar canal. Use radiographs, and a CBCT when the anatomy is unclear, and plan the angle of insertion for the site.
What mini implants are used for
- Anchorage during extraction space closure
- Intrusion of anterior or posterior teeth
- Molar distalisation and uprighting
- Correction of a midline or canted occlusal plane
- Assistance in open bite correction
Biomechanics and consent
Where the line of force passes relative to the centre of resistance of the tooth decides whether it tips, translates or intrudes, so the height of the hook and the position of the screw are part of the plan. Use light, continuous forces. Explain the possible complications to the patient, such as loosening, soft tissue irritation, root contact and infection, and record the consent. See the biomechanics guide for the underlying principles.
Key takeaways
- Mini implants provide anchorage that does not depend on patient compliance.
- Site selection and anatomy decide safety.
- Force direction relative to the centre of resistance decides the movement.
Frequently asked questions
Are orthodontic mini implants safe?
They are widely used and, when placed in suitable sites with a sound technique, are a reliable anchorage method. Failures and complications do occur, which is why training, site planning and informed consent matter.
Do mini implants need a CBCT?
Not always. A CBCT helps when the relationship of roots, sinus or other structures to the planned site is unclear. Many sites can be planned from an OPG and periapical films with careful technique.