Immediate Rehabilitation of the Severely Atrophic Maxilla Using Trans-Sinus Nasal Protocol and Extended Length Subcrestal Angulated Implants. Case Series With 1-Year Follow-Up
Immediate fixed full-arch rehabilitation of the severely atrophic maxilla eliminates use of a tissue-supported prosthesis during the healing phase and maximizes patient comfort and quality of life. The surgical treatment options available for immediate rehabilitation of the severely atrophic maxilla are dependent on the location and availability of the residual alveolar ridge. When bone is only available in the intercanine region, a graftless approach using tilted distal implants may not provide adequate distance between implants for favorable biomechanics. Subsequently, zygomatic implants are the alternative to provide adequate posterior occlusal support. Use of extended length subcrestal angulated implants offers an additional implant option for the clinician to restore the severely atrophic maxilla immediately. The treatment protocol involves anchorage of the implant fixture to the lateral wall of the nasal bone. The distally tilted implant transverses an augmented sinus cavity and extends to the site of the first permanent molar. The novel implant subcrestal angulation and use of a multi-unit abutment promotes passivity of fit of a full-arch fixed immediate prosthesis. Five clinical case reports from private practice are presented that outline the clinical value of the novel implant design in the rehabilitation of the severely atrophic maxilla. In each case, the use of zygomatic implants would be the only alternative to provide an immediate fixed prosthesis due to the absence of residual alveolar bone in the maxilla premolar and molar regions. The use of extended-length subcrestal angulated (ELSA) implants with straight or angulated multiunit abutments have successfully restored the maxillary arch immediately.
Figure 1. Diagrammatic representation of extended length subcrestal implant and trans-sinus-nasal protocol.
Figure 2. Extended length subcrestal angulated implant specifications.
Figure 3. Lateral antrostomy window.
Figure 4. Copious saline irrigation is required at the medial wall of the sinus cavity during development of the osteotomy.
Figure 5. Placement of extended length subcrestal angulated implant in the prepared osteotomy and transversing the sinus cavity.
Figure 6. After placement of the implants, sinus cavity augmentation is completed with a particulate bone graft. A resorbable collagen membrane is then placed over the lateral window.
Figure 7. Preoperative osteoprotegerin (OPG) of severely atrophic maxilla.
Figure 8. Postoperative OPG of reconstructed maxilla using extended-length subcrestal angulated implants.
Figure 9. Postoperative occlusal image of all-ceramic full-arch prosthesis.
Figure 10. Preoperative osteoprotegerin (OPG) of terminal maxillary dentition and bilateral sinus pneumatization.
Figure 11. Extended length subcrestal angulated 26 mm × 4-mm diameter × 24° implant placement with a straight multiunit abutment. Sinus augmented using a xenograft particulate (Bio-Oss, Geistlich).
Figure 12. Postoperative osteoprotegerin (OPG) showing immediate rehabilitation of maxillary arch.
Figure 13. Postoperative occlusal view of immediate fixed prosthesis.
Figure 14. Preoperative osteoprotegerin (OPG) of terminal dentition and severely atrophic maxilla.
Figure 15. Postoperative OPG of rehabilitated maxillary arch with bilateral sinus augmentation and bilateral extended length subcrestal angulated implant placement.
Figure 16. Postoperative occlusal view of immediate provisional fixed prosthesis.
Figure 17. Preoperative osteoprotegerin (OPG) of terminal dentition and severely atrophic maxilla.
Figure 18. Postoperative OPG of rehabilitated maxillary arch with 6 implants, bilateral sinus augmentation, and bilateral extended length subcrestal implant placement.
Figure 19. Diagrammatic representation of angulated subcrestal angulated implant fixture versus straight implant fixture in relation to posterior alveolar ridge.
Figure 20. Postoperative OPG of rehabilitated maxillary arch with bilateral sinus augmentation and bilateral extended length subcrestal angled implant placement.
Preoperative osteoprotegerin (OPG) of severely atrophic edentulous maxilla.
Contributor Notes