bone in this area also has less visco-elasticity than anywhere else in both arches along with a poorer blood supply. Thus, this bone could fracture more easily if the bladevent should be tapped too hard. In order to avoid this, the groove must be made extremely deep, constantly changing the 700 XXL bur and using copious amounts of water.

When contemplating crossing the midline with an implant, careful anterior peri-apical radiographic studies are essential, as well as full exposure of the bony ridge.

Sometimes artificial abutments are desirable in the midline area. Perhaps the bone in more distal, and prosthodontically desirable, sites is pinched or flawed. Or, only incisors are missing and the remaining teeth would benefit from some form of artificial anterior support.

Although a few designs fit the site, the open-socket bladevent offers several advantages. The recessed shoulder (1) allows a significant amount of bone to regrow as a shelf (2) over the central part of the implant (3), locking the implant securely in its site. This bonus feature often makes the open-socket design desirable in many situations other than a true open-socket situation. Postoperatively, bone always resorbs away from the crest as it heals, even if only slightly in the most successful implant situations. The bony shelf keeps a good protective barrier covering the recessed shoulder of this particular designed bladevent.

The open-socket blade's double posts also fall on each side of the midline under the central incisors. This is desirable in constructing a natural-looking prosthesis. It also gives more balanced, as well as additional, support than would a single-posted design.

The socket must follow the arch, which necessitates curving it in the majority of cases. Occasionally, the ridge may have undergone extensive resorption which has flattened the sweep of the arch. Extra care must be taken to avoid fracturing or penetrating the labial or lingual plate, particularly at the ends of the socket (4) because of its extreme density. The thumb and finger should be placed (5) on labial and lingual aspect of the alveolous, to sense the bur's location.

The bladevent itself must be curved to follow the groove, and be passively insertable. The posts must be parallel with the natural abutments to be included in the prosthesis.

Sometimes, in order to greatly reduce what could have been a severe overjet, the implant socket is created toward the labial plate and then countersunk lingually (6) in order to properly bury the

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