Autotransplantation in dentistry refers to transplanting an extracted tooth to a different tooth socket. It is a technique that finds its roots in the 16th century but has refined in recent years owing to the advances in material science and immunology.

Who introduced autotransplantation?

In 1594, Ambroise Pare documented a case of teeth transplant in the royal families. It was in 1772, when the first clinical procedure was performed by John Hunter. However, compatibility to immunity or the risk of a disease or infection was never considered then. The procedures performed were allotransplants, i.e., donor tooth or teeth were transplanted to another individual's oral cavity.

Autotransplantation became more prominent in 1950s. It gained prominence when wisdom tooth that were unerupted or partially erupted were removed and moved in the region of a lost molar.

When is autotransplantation done?

Autotransplantation is done when teeth are lost due to caries, impaction, periodontal disease, trauma, tumors, etc. Autotransplanted teeth can also be used as alternatives to dental implants, space maintainers and during jaw reconstructions.

How is autotransplantation done?

The first step of autotransplantation is to choose the ideal tooth that can be replaced in place of the missing tooth. A third molar is normally used to replace the first or second molars. In many cases, an upper third molar is capable of replacing the position of power molars. A premolar or canine is used for missing teeth in the anterior upper jaw. The main goal is to choose a tooth that is morphologically similar and also retains the functional aspect. Moreover, the tooth chosen for autotransplantation must have at least 3/4th of its root developed.

The treatment begins by removing the tooth careful in the most minimally invasive method possible. This can help in preservation of cells and fibres that are necessary to maintain the tooth's viability. The tooth is then preserved in a physiologic solution like milk, saline, HBSS, saliva, coconut water, etc. The amount of time the tooth removes dry outside the oral cavity must be as minimal as possible.

It is recommended that the tooth to be autotransplanted must have a completely formed apex, i.e., a mature tooth. In case the chosen tooth is immature, then closure of root apex is unpredictable in its new transplanted position.

Before transplantation of the tooth, the tooth's shape, especially the roots are modified according to the socket in which it is placed. Ideally, the tooth should be placed slightly below the normal bite or occlusion. For the next four weeks, the autotransplanted tooth is splinted in its position.

Which adjunctive treatments are needed for autotransplantation?

The pulp tissue present in the core of the tooth houses the blood vessels and nerves and is responsible for the normal functioning of the tooth. If the pulp is able to revive itself in case of an immature tooth or if the pulp remains vital in cases of a mature tooth, only then can an orthodontic treatment be initiated to better the position on the tooth in the oral cavity.

Composite bone-tooth grafting or other grafting procedures may be needed when adequate bone support is not available after autotransplantation.

What are the advantages and disadvantages of autotransplantation?

Autotransplantation has many advantages apart from retention of aesthetics and function. The autotransplanted tooth maintains the bone height and thus maintains the underlying alveolar bone height. It is cost-effective and serves as a better alternative to fixed prosthesis. In case the tooth is to be moved orthodontically, then the autotransplanted tooth will allow the needed movement as well.

Autotransplantation has its disadvantages as well. If the root resorbs due to poor reattachment, then the tooth might fall out again. Maintenance of poor oral hygiene can lead to attachment loss and eventual failure. In case the bone of the region where the tooth is to be transplanted is infected, then autotransplanted cannot be a treatment option. After autotransplantation, root canal treatment maybe warranted for in case the autotransplanted tooth fails to heal.
One of the most common complications of autotransplantation is ankylosis. When the roots of the autotransplanted tooth fuse wit the underlying socket, it is known as ankylosis.

Given its limitations autotransplantation is a promising treatment approach. The transfer of a tooth from one site to another is thus a recommended treatment modality that restores the integral function and aesthetics of oral cavity.