Extremely thick tissues (1,2) pad some adverse features, including a knife-edge ridge (4) that must be reduced (5) to accept the bladevent used in this old style pterygoid extension implant. As a result of extensive reduction to get a thick enough ridge, the bladevent is set much higher than its companion (6,7). Behind the left bladevent the discontinuous arch shows why no weight must be placed on the bone in the sinus area (8). The marked difference in the height of the bladevent posts is compensated partially in the copings incorporated in the pterygoid extension implant (10-12) and partially in the restoration itself (14,15).

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