Pterygoid implants

Indications

In the edentulous upper jaw the placement of implants can be challenging due to limited bone quantity and the presence of the maxillary sinus. Pterygoid implants present an alternative option to use residual bone for implant anchorage and to overcome the need for augmentation procedures. To avoid distal cantilevers the insertion of a pterygoid implant can be indicated in partial and total edentulism. The findings in literature show no clear differences between pterygoid and pterygo-maxillary implants.

Clinical recommendations

The terms "pterygoid implants", "pterygo-maxillary implants" and "tuberosity implants" are used interchangeably in scientific literature (for what is described as implants in the retromolar region). By definition, all "pterygoid implants" encompass the tuberosity region and engage the pterygoid plate but not all "tuberosity implants" necessarily engage the pterygoid plates (they are placed in a more anterior position of the pterygo-maxillary area, parallel to the posterior wall of the sinus).

The success rates for all these different treatment possibilities seem to be similar. Therefor the need for engaging the implants at the level of the pterygoid plate is currently controversially discussed.

Prognosis

The average success rate for pterygoid implants lies at 90.7%. However, there is still insufficient data about implant failures that occur beyond the first year of load, thus making it difficult to draw conclusions about long-term survival rates of these implants. 

Complications

Insertion of implants at the level of the pterygoid plate can be potentially associated with bleedings (from the pterygoid plexus or the a. maxillaris). Nevertheless this can be avoided by inserting the implant just at the level of the tuberosity. Another complication is lack of primary implant stability [Candel 2012] which can be solved through underpreparation drilling protocols and innovative implant designs (NobelActive).