Horizontal Ridge Augmentation Under a Removable Partial Denture and Implant Placement
Implant planning has moved in recent years to virtual planning with a CBCT scan and fabrication of a surgical guide based on that virtual planning. Unfortunately, positioning based on prosthetics is typically missing from the CBCT scan. Use of a diagnostic guide fabricated in office permits information from ideal prosthetic positioning to improve virtual planning and subsequent fabricated of a corrected surgical guide. This becomes more important when insufficiencies in the ridges horizontal aspects (width) will require ridge augmentation to allow later implant placement. This article discusses a case with insufficient ridge width and determination of where augmentation is required to house implants in ideal prosthetic positions, the subsequent grafting, implant placement and restoration.

Components of the Guide Right guide system: (a) guide posts, (b) guide sleeves, and (c) drills.

Fabrication of the diagnostic guide starts with drilling holes in the cast at ideal prosthetic positions: (a), guide posts and guide sleeves are placed into those holes; (b) light-cure resin is placed over the sleeves retentive element on the lingual and on the lingual and occlusal surfaces of adjacent teeth; (c) and the diagnostic guide is completed and ready for the CBCT scan intraorally (d).

CBCT analysis of the diagnostic guide at site #11 confirms inadequate width of available bone for implant placement at the planned site.

CBCT analysis of the diagnostic guide at site #13 confirms inadequate width of available bone for implant placement at the planned site.

Virtual planning at site #11 of a 3.3-mm implant demonstrates inadequate width of the ridge, necessitating osseous augmentation to prepare the site for implant placement.

Virtual planning at site #13 of a 3.3-mm implant demonstrates inadequate width of the ridge, necessitating osseous augmentation to prepare the site for implant placement.

Virtual planning in the CBCT scan notes adequate height of available bone for implant placement at both sites.

Cast fabricated from an impression after grafting of the arch with current partial denture intraorally with a black mark made at ideal prosthetic position of the implants planned at site numbers 11 and 13 (left); a Vacuform stent was made of the cast (middle) and holes drilled in the stent at the black marks to allow transfer of the ideal positions to a cast of the arch post-grafting.

A cast fabricated of the arch without the partial denture intraorally after graft healing, with holes positioned using the Vacuform stent and drilled with the 3/32-inch drill (left). A new diagnostic guide is fabricated with light-cure resin and guide posts and guide sleeves (middle), yielding a new diagnostic guide ready to analyze the improved arch (right).

Virtual planning of site #11 after graft healing using the new diagnostic guide, indicating adequate width of ridge for implant placement.

Virtual planning based on ideal prosthetic positioning determined a correction of implant position would be necessary on site #11 with a 2.5-mm buccal offset and a 1° angle correction.

Virtual planning in the CBCT cross-section at site #13 determined that a 2.0-mm buccal offset would be necessary and a 1° palatal angle correction to ideally position the implant prosthetically.

Virtual planning based on ideal prosthetic positioning determined a correction of implant position would be necessary on site #13 with a 2.0-mm buccal offset and a 1° angle correction.

Fabrication of the corrected implant surgical guide consisted of placement of guide posts into the cast at the prior drilled holes (a), the upper portion of the modified 2-piece offset guide post was inserted over them (b), guide sleeves were then placed over the 2-piece offset guide posts with the retentive element at the lingual (c), light-cure resin was placed to capture the sleeves retentive element and cover the occlusal/incisal and lingual surfaces of the remaining teeth (d), and the corrected surgical guide was completed (e).

After 6 months of graft healing, an incision was made and a full-thickness flap elevated to expose the underlying titanium mesh and tenting/fixation screws (left) and after removal of the mesh to demonstrate an improved width of ridge to allow implant placement.

Guide Right drills for osteotomy preparation with the surgical guide.

Comparison of site #11 of pretreatment (left), post osseous grafting (middle), and implant placed (right).

Comparison of site #13 of pretreatment (left), post osseous grafting (middle), and implant placed (right).

CBCT cross-sections after implant placement with virtual planning overlaid to demonstrate accuracy between planning, the corrected surgical guide, and achieved implant positions.

Completed prosthesis with the female portion of the attachments for the overdenture bar within the cast partial overdenture (left) and VKS-SG (Bredent) attachments on the terminal ends of the overdenture bar intraorally (right).
Contributor Notes