Temporary anchorage device in orthodontics

Description

Tads in orthodontics
introduction
“Secure Anchorage” is the primary requirement for successful treatment of various malocclusions. Conventionally, anchorage requirement for orthodontic tooth movement was provided by the teeth, extraoral and/or intermaxillary appliances
The introduction of skeletal anchorage in the form of temporary anchorage devices (TADs) or miniscrews has greatly benefited orthodontists in finding a way of anchorage control with minimum patient compliance and without a complicated clinical insertion and removal procedures.
Definition of TAD: A temporary anchorage device (TAD) is a device that is temporarily fixed to bone for the purpose of enhancing orthodontic anchorage either by supporting the teeth of the reactive unit or by obviating the need for the reactive unit altogether, and which is subsequently removed after use.
History
In 1945, Gainsforth and Higley used vitallium screws in ramus of mongrel dogs to create absolute anchorage for distalization of maxillary canines.
Creekmore and Eklund (1983) gave the first clinical report of TAD usage in the anterior nasal spine for intrusion of upper incisors in a patient with severe deep bite.
Shapiro and Kokich (1988) described the possibility of using dental implants for anchorage during orthodontic treatment.

Jae-Hyun Sung. Microimplants in Orthodontics. Department of Orthodontics, School of Dentistry, Kyungpook National University, 2006.
Shapiro PA, Kokich VG. Uses of implants in orthodontics. Dental Clinics of North America. 1988;32:539-550

History
Kanomi (1997) was the first to describe that mini implant of 1.2 mm diameter and 6 mm length can be explicitly used for orthodontic purpose.
Melsen and co-workers (1998) introduced the use of zygomatic ligatures as anchorage in partially edentulous patients.
Abso-Anchor Screw was developed in 1999 by a group of Korean clinicians
Aarhus Mini-Implant was created by a Scandinavian group
An Italian group developed the Spider Screw in 2003
Lately, palatal onplants, mid palatal screws and miniplate implants are being researched and reported
CLASSIFICATION OF orthodontic IMPLANTS
Classification
Based on the Location
• Subperiosteal: Implant body lies over the bony ridge. Eg. Onplant


Transosseous: Implant body penetrates the mandible completely.

• Endosseous: Partially submerged and anchored within the bone-endosseous implants are most commonly used for orthodontic purposes.



classification
Based on the Configuration Design
• Root form implants: These are the screw type endosseous implants and the name has been derived due to their cylindrical structure.

• Blade/plate implants: Flatter and can be used in resorbed and knife-edge ridges.
classification
According to the Composition
• Stainless steel
• Cobalt-chromium-molybdenum (Co-Cr-Mo)
• Titanium
• Ceramic implants
• Miscellaneous, such as vitreous carbon and composites
classification
According to the Surface Structure
Threaded or Nonthreaded
The root form