Bone structures involved in planning for implant retained prosthesis
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| Bone Present for Implants |
Posterior Surgical Approach |
| Zone 1, 2, 3 |
Traditional implants |
| Zone 1, 2 |
Inclined implants, posterior implants |
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Traditional anterior implants |
| Zone 1 only |
Zygomatic implants or sinus-inlay
grafting followed by implants |
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Traditional anterior implants |
| Insufficient bone in any zone |
4 zygomatic implants or Brånemark
horseshoe graft followed by
traditional implants |
From an implant placement perspective, there is growing recognition that a large number of people with fully edentulous maxillae are able to be given a stable foundation to support a fixed restoration with fewer implants and fewer bone grafts.15,18,25,26 Advances in computer-guided surgery allow placement of implants in the fully edentulous maxilla in a minimally invasive manner with increased precision to support the fixed prosthetic outcome. Demonstrated viability of immediate function18 and minimally invasive protocols 38 for fixed full-arch restorations may further increase demand and acceptance of this treatment by the public.
Definitive preoperative prosthodontic work-up for an implant-supported fixed maxillary prosthesis is a multifactor process. Steps of this process include surgical, medical, and laboratory consultations, transference of facial and occlusal records for analysis, radiographic
templates, scanning procedures and subsequent interpretation, and development of a written comprehensive plan including potential complications and treatment alternatives. Completion of these preoperative steps requires significant commitments of time, resources, and ultimately patient investment. Results of these findings will indicate but still not assure that a postoperative outcome is in accord with patient expectations identified in the preoperative subjective symptom interview.
Two prosthodontic diagnostic criteria have been coupled with 3 variations of implant-supported fixed maxillary prostheses to form a table. Each prosthesis alternative represents a potential restorative solution appropriate for the 4 possible combinations of these 2 diagnostic criteria.
The third preoperative diagnostic criterion divides a panoramic radiograph into 3 zones that have potential for implant placement. Due to a range of resorption, there are 4 potential zone combinations on each side of the maxilla that would allow for implant placement or suggest consideration of bone grafting. From a structural support perspective, there are no differences
in implant requirements to support any of the 3 implant-supported fixed maxillary prosthesis variations given. Furthermore the clinical success rates for the various implant approaches are similar. It should be noted however that for the metal-ceramic variation, the ridge position of the implants ideally corresponds with mesial-distal cervical tooth position; for the Marius bridge and profile prosthesis variations, implant alignment coincident to cervical tooth anatomy is not a factor. This second table suggests implant or grafting strategies for the posterior maxilla appropriate for different resorptive patterns.
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