Initial situation

A 58-year-old healthy female patient with an unremarkable medical history presented at our clinic. The clinical examination showed a reduced number of teeth in both jaws, periodontal disease and hopeless dentition, with a cyst in #12 and a horizontal pattern bone defect atrophy in both arches, and maxillary sinuses with no evident pathology clinically or radiologically (Figs. 1-3). All teeth were mobile and presented with poor masticatory function, and an unsatisfactory esthetic appearance was also observed. The patient reported a decreased quality of life due to these issues.

Treatment planning

Considering the patient’s remaining terminal dentition with a horizontal bone atrophy defect in both arches, and after a careful clinical and radiographic assessment, a full-arch rehabilitation with four Straumann® Zygomatic Implants in the maxilla, and four Straumann® BLT Implants with the Pro Arch concept in the mandible was planned. For the maxilla, an extra-sinus or intra-sinus technique was not chosen, as the aim was to insert the implant through the knife-edge residual ridge and the zygomatic bone. The goal was to preserve the buccal bone located at the implant platform since it provided immediate mechanical stability and periodontal durability, avoiding vestibular dehiscence. In the mandible, the posterior implants were tilted to protect both mental foramina. Furthermore, an immediate implant placement and provisionalization was chosen in order to deliver the immediacy concept and esthetic appearance on the day of surgery with a provisional acrylic-metal-reinforced prosthesis.

Surgical and prosthetic procedures

The whole procedure was performed with local anesthesia and oral sedation with midazolam 7.5 mg.

In the maxilla, the teeth were extracted and the cyst in #12 was resected. A crestal, medial, distal incision was made and a mucoperiosteal flap was elevated to expose and protect the palatal and buccal bone, nasal fossa, infraorbital nerves, zygomatic bones and orbital rims.

Alveoloplasty of the maxilla was performed, and a small bony window was prepared at the upper distal part of the anterior sinus wall to visualize the lower aspect of the zygomatic bone. Implant osteotomies were performed with the recommended sequence drilling, and a gauge was used to ascertain the implant size.

In the left zygomatic bone, we selected one Straumann® Zygomatic Implant, ZAGA™ Round 4.3 x 52.5 mm for the anterior implant in position #23, and one Straumann® Zygomatic Implant, ZAGA™ Round 4.3 x 40 mm for the posterior implant in position #26 (Fig. 4).

For the right zygomatic bone, we selected one Straumann® Zygomatic Implant, ZAGA™ Round 4.3 x 50 mm for the anterior implant in position #13, and one Straumann® Zygomatic Implant, ZAGA™ Round 4.3 x 40 mm for the posterior implant in position #15 (Fig. 5).

All four Straumann® Zygomatic Implants, ZAGA™ Round were inserted with optimal torque values of at least 60 Ncm, thereby enabling predictable, immediate prosthetic loading.

For this purpose, we adapted four Straumann® Zygomatic Implant, ZAGA™ Screw-Retained Abutments (SRA), diameter 4.6 mm, GH 4.5 mm, and their correspondent healing caps (Fig. 6). The flaps were closed with tension-free 4-0 black silk sutures.

In the mandible, the teeth were extracted, a crestal incision was made and a mucoperiosteal flap was elevated to expose the lingual and buccal bone, protecting both mental foramina. Alveoloplasty and implant osteotomies were performed with a tilt orientation of 30º for posterior implants in positions #35 & #45, avoiding the mental foramina.. Two axial implant osteotomies were performed in positions #32 & #42. We selected two Straumann® BLT 3.3 x 14 mm Roxolid® posterior tilted implants and two Straumann® BLT 3.3 x 12 mm Roxolid® anterior axial implants (Fig. 7).

All the Straumann® BLT implants were inserted with optimal torque values of at least 45 Ncm, thereby enabling predictable, immediate prosthetic loading.

We adapted two straight screw-retained abutments, diameter 4.6 mm, GH 3.5 mm, for the anterior implants and two screw-retained abutments 30º, diameter 4.6 mm, GH 4.5 mm, for the posterior implants. The flap was closed with tension-free sutures.

A postoperative panoramic radiograph and CBCT were recorded before continuing with the prosthetic steps for the fabrication of the immediate-loading prostheses (Figs. 8-11).

Following the loading of the provisional prosthesis, a panoramic radiograph was taken and a correct stabilization and fit of the prosthesis was ensured. Pictures were also taken of the clinical prostheses (Fig. 12).

Treatment outcomes

The rehabilitation of the atrophic maxilla with the quadruple zygoma approach is supported by extensive evidence in the scientific literature, with excellent long-term results offering patients a predictable graftless solution to treat this type of challenging maxillary atrophy. This reconstructive zygomatic implant-based protocol orients towards an immediate-loading fixed rehabilitation, with less morbidity and invasiveness compared to large bone grafting reconstructions and shorter treatment times.

An outstanding functional and esthetic result was achieved on the same day of surgery using the immediacy concept with the Straumann® Zygomatic Implant System. The OPG and CBCT tomography showed an optimal distribution of the implants.

The splinting cross-arch stabilization with the prosthesis, for optimization of the biomechanics in this kind of treatment is mandatory.

The patient was very happy to receive an immediate fixed restoration that allowed her to regain function and esthetics and, more importantly, her quality of life. She also received oral hygiene instructions and was involved in a maintenance program with regular check-ups.

Testimonial by Dr. Vladimir García Lozada

“The new Straumann® Zygomatic Implant System design is a great development for adapting the implant to the patient anatomy, optimizing the surgical protocol to achieve outstanding long-term outcomes.

A reduced apical body of the implant allowed us to perform a minimal osteotomy while obtaining an optimal primary stability with high torque values. The medial implant body, with its smooth and machined surface, leads to better soft tissue behavior, and a 55º angled implant head improves the prosthetic insertion axis.

The versatility of the Straumann® Zygomatic Implant System ZAGA™ Round and Flat, provides a competitive advantage, depending on the case anatomy to be applied.

I recently performed cases with the Straumann® Zygomatic Implant System. The overall outcomes were very satisfactory.”