A Permanent Answer to Four Missing Front Teeth

The Patient's Journey

This patient was missing four upper front teeth: the lateral incisor, central incisor, lateral incisor and canine on one side of the midline, numbers seven, nine, ten and eleven. He had been managing with a removable partial denture, a flipper, and had tolerated the arrangement long enough to be thoroughly tired of it. What he asked for was something permanent.

He also presented with severe bone loss across the edentulous span, and that finding, rather than the absent teeth themselves, determined how long this reconstruction would take.

Alveolar bone exists to support teeth, and it is maintained by the occlusal load they transmit into it. Extract the tooth and the stimulus disappears with it, so the ridge resorbs. Resorption is most rapid during the first year following an extraction and continues at a diminishing rate indefinitely afterwards, which means an edentulous anterior ridge that has carried no teeth for years is both narrower and lower than it was, sometimes markedly so.

A removable partial denture does not prevent this. The appliance rests on the mucosa and transfers its load to the soft tissue rather than into the underlying bone, so resorption continues beneath it undisturbed. The prosthesis is subsequently relined to the new contour, which is the reason a flipper that fitted accurately at delivery becomes loose within a year or two.

Implants cannot be placed into bone that is not there. Where the ridge has resorbed below the volume an implant requires for primary stability, the bone is reconstructed first and allowed to consolidate before any implant is placed, and that sequence is the reason this case ran seven months rather than three.

Implants cannot be placed into bone that is not there. Where the ridge has resorbed below the volume an implant requires, the bone is rebuilt first and allowed to consolidate, and only then is the implant placed. That sequence is the reason this case ran seven months rather than three.

Whitening came first, for the same reason it comes first in every case carrying restorations at the front of the mouth. Ceramic does not respond to peroxide, so a shade recorded before the natural dentition has been lightened produces restorations that are wrong the moment the whitening is finished, and the only available remedy is to remake them.

The ridge was grafted and left to consolidate. Three implants were subsequently placed into the reconstructed bone, at teeth seven, nine and eleven. Four teeth were missing and three implants replaced them, because tooth ten is carried as a pontic on a bridge spanning nine to eleven. A pontic is a replacement tooth suspended between two supporting units rather than standing on an implant of its own.

That distribution is deliberate rather than economical. Adjacent implants in the anterior maxilla compete for the limited interproximal bone between them, and the interdental papilla, the triangle of gingival tissue occupying the space between two teeth, is notoriously difficult to maintain between two implants placed side by side. Spanning the space with a pontic gives the soft tissue a considerably better chance of reading as gum between teeth rather than as a flat shelf beneath them.

That distribution is deliberate rather than economical. Adjacent implants in the anterior maxilla compete for the same limited bone between them, and the papilla, the small triangle of gum that fills the space between two teeth, is difficult to maintain between two implants placed side by side. Spanning the gap with a pontic gives the soft tissue a better chance of looking like gum between teeth rather than a flat shelf.

Five units now span teeth seven to eleven: an implant crown, a porcelain veneer, and a three-unit bridge. The flipper is gone, and he occludes on restorations anchored in bone rather than on an appliance resting against his palate.

The grafted bone now carries occlusal load again, which is what preserves it. Bone loaded through an osseointegrated implant is maintained in a way that bone beneath a removable prosthesis is not, so the ridge reconstructed for this restoration is also being maintained by it.

Five units span teeth seven to eleven: an implant crown, a veneer, and a three-unit bridge. The flipper is gone. He bites on teeth that are attached to his jaw rather than resting on his palate.

The grafted bone now carries load again, which is what keeps it. Bone that is loaded through an implant is maintained in a way that bone under a denture is not, so the ridge that was rebuilt for this reconstruction is also being preserved by it.