Sometimes permanent canines lie retained (do not erupt) and displaced in the jawbone. The result is a gap in the dental arch when the deciduous canine tooth is lost. In this case, the surgical technique of tooth transposition (synonym: tooth transplantation) can be applied. In this case, an autogenous (originated from the body itself) (synonym: autologous = transplantation: donor and recipient are the same/patient’s own) tooth is transplanted (grafted) in the place of a tooth that was extracted (removed) shortly before.If the tooth has not yet completed root growth, is still developing and has not yet erupted into the oral cavity, i.e. a tooth germ, it is accordingly a tooth germ transposition (synonym: tooth germ transplantation). This surgical technique can also be used in rare cases for displaced and retained canines.
Indications (areas of application)
The consequences of canine displacement are either a deciduous canine standing in the 2nd dentition (permanent dentition) or a gap after extraction (removal) of a tooth not worth preserving. Both situations are disadvantageous for esthetics as well as for function.
In principle, transposition surgery of impacted and/or displaced teeth that have already completed their root growth is rarely indicated: for example, to temporarily bridge an upper canine gap when the displaced tooth cannot be orthodontically adjusted into the dental arch and the patient is still too young for a prosthetic or implant restoration. Ideally, healing occurs with restoration of esthetics and function.
Before surgery
Clinical findings include measuring the gap that will accommodate the tooth to be grafted. Radiographic findings (OPG, dental film, bite record) supplement the clinical findings.In addition to the general risks of tooth removal (tooth extraction), the possible loss of the transplanted tooth and possible infection of the graft bed must be pointed out in advance.
The surgical procedure
- Operative exposure of the impacted and/or displaced canine tooth.
- If root growth is complete: root canal filling and apicoectomy of the tooth to be transposed.
- Intermediate storage in patient serum
- Removal of the canine tooth of the 1st dentition (milk canine), which is not worthy of preservation, or creation of a sufficiently large receptacle for the tooth to be transposed in the jawbone.
- Insertion of the tooth into the graft bed.
- Subsequent stabilization of the canine tooth by splinting to the adjacent teeth for the healing phase.
Prognosis
The success of the operation depends on the extent to which the tooth or tooth germ can be placed in a vascularized soft tissue bed and whether the periodontium of the tooth to be transplanted remains largely uninjured during its previous surgical removal. Furthermore, the transposed tooth must not be loaded during the healing phase. Postoperative infection may also contribute to a worsening prognosis.
