Partially Guided Remote Anchorage With a Full-Arch Digital Workflow

Zygomatic and pterygoid implants can provide immediate life-changing results for patients with severe maxillary atrophy

Chris Barrett, DDS | Nate Farley, DDS, MS | Kent Howell, DMD, MS

Patients with severe maxillary atrophy have limited treatment options to restore form and function. Fortunately, the use of zygomatic and pterygoid implants can provide immediate life-changing results.

Patients who have worn complete dentures for years often experience alveolar resorption that leaves them with insufficient bone for traditional full-mouth implant reconstruction. Traditionally, these patients are treatment planned for significant bone grafting procedures, such as ridge and sinus augmentation. When extensive grafting is required, if there aren't any complications, the healing period can be anywhere from 6 to 9 months. Once the graft sites have healed, then implants can be placed with additional healing times of 4 to 6 months. After the implants have integrated, they can be loaded with a fixed hybrid solution. The total treatment time for traditional grafting, implant placement, and restoration in a severely atrophic maxilla can be anywhere from 12 to 18 months.

An alternative treatment option for patients with severe maxillary atrophy is remote anchorage with the use of zygomatic and pterygoid implants. This option can expedite the treatment timeline without the additional time and expense of ridge and sinus augmentation. Instead of waiting 12 to 18 months before receiving a fixed restoration, with remote anchorage, patients can have a hybrid prosthesis placed the same day or next day and do not have to go without a prosthesis at any point during the treatment timeline.

This case report demonstrates a partially guided approach to rehabilitate a patient with a functional and esthetic outcome. The patient presented with an ill-fitting and severely worn maxillary denture opposing a terminal mandibular dentition. After discussing different treatment options, the patient was treatment planned for a double-arch, fixed hybrid implant solution with remote anchorage in the maxilla.

A digital workflow was utilized to treatment plan the case by combining DICOM data from a cone-beam computed tomography scan, intraoral scan data, and facial photographs. Next, Farley fabricated a series of stackable guides for both aches, which would enable fully guided placement of the implants in the mandible and the maxillary anterior but only pilot osteotomies for the zygomatic and pterygoid implants. The combination of these technologies allowed for a restoratively driven surgical plan.

On the day of the procedure, the mandibular surgery was completed by Farley, and in the maxilla, Barrett raised a full-thickness mucoperiosteal flap and fixated the base guide. The base guide supported each separate part of the guided surgery but also served as a fiducial marker that allowed the postoperative (surgical) data to be aligned with the preoperative data. This was key because the preoperative data was used by the laboratory to begin designing the prosthesis before the surgery, and only the implant positions were needed to finish out the design and 3D print it on the day of surgery.

Root form, zygomatic, and pterygoid implants were placed according to the surgical plan, which resulted in an optimal anterior-posterior spread for the fixed hybrid prosthesis. Next, the multi-unit abutments were placed, and photogrammetry was performed to record the 3-dimensional implant positions. Before the guide was removed, it was scanned intraorally, and comfort caps were placed on the multi-unit abutments. Finally, the buccal fat pad was advanced to cover the partial exposure of the zygomatic implants, and the soft tissue was approximated and closed passively. With the data from the photogrammetry and intraoral scans, the laboratory had all of the information that was needed to fabricate the provisional restorations, which were then 3D printed and inserted.

The case was fully executed as planned, and the patient received life-changing treatment in one day instead of over the course of 12 to 18 months. For patients with severe maxillary atrophy, remote anchorage solutions can help achieve treatment goals in a more efficient and cost-effective way and should be considered during the treatment planning process.