where it bifurcates into small wings (23) that will minimize rocking. The stone model bearing the design, together with the bite registration and instructions for the height of the bar above the crest, are sent to the laboratory.

The pterygoid extension implant is cast and inserted as quickly as is possible to protect the bladevents. The fabricated implant is checked for structural flaws and accurate fit on the stone model upon delivery from the laboratory. The tissues are then re-incised and reflected, and the implant is tried in position. The posterior pterygoid portions (24) and the anterior copings (25) should fit accurately. Any adjustments needed to improve the fit are done. It may be necessary to modify the copings to make the soft tissues more comfortable. Once the implant fits properly, the bladevent posts and copings are dried. Hard cement is put in the copings (26) and the pterygoid implant is fitted into position. It is held firmly in place with evenly-distributed manual pressure until the cement hardens.

The excess cement is removed, and the tissues are closed over the subperiosteal portions of the pterygoid extension implant, under the bar that will bear the restoration.

The denture is once again relieved and fitted to prevent the palatal tissue from dropping. Today, I do not use any part of the hard palate as the palatal tissues do not seem to accept anything beneath them! The denture must be carefully adjusted to retain its original occlusion against whatever serves in the lower arch. The patient is dismissed until his tissues heal, when impressions can be made for the final palateless, removable prosthesis with internal clips or a fixed prosthesis.

The Partially Edentulous Maxilla:

The Unilateral Pterygoid Extension Implant

The ideal anterior support for the unilateral pterygoid extension implant is at least six natural teeth. The minimal support required is two strong cuspid teeth with bladevents used between them for added retention and balance, or just the cuspids them-selves, if their roots are long enough and their bone support excellent. Preferably, the abutment bordering the posterior edentulous site is a firm, natural tooth.

The anterior situation is restored first, with a smooth-surfaced pontic cantilevered from the most distal anterior abutment. This cantilevered pontic will incorporate an anchorage or retention mechanism for the posterior restoration, and should be generous

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