This case report of a 45-year-old patient at initial presentation shows an illustration of the limitations of periodontal maintenance therapy and subsequent implant prosthetic therapy. In close consultation with the patient, treatment strategies were adopted to maximize the preservation of prognostically questionable teeth. Eight years later, the patient had a highly atrophied maxilla that could be successfully restored with implants. This was achieved with 2 zygoma implants and 2 anterior conventional implants, which were immediately loaded according to the All-on-4 concept and immediately provided with a definitive prosthetic restoration. The case report demonstrates to the general practitioner that using zygoma implants in such constellations may offer a solution to achieve a fixed, rapid, and financially acceptable prosthetic rehabilitation.

The fixed implant prosthetic restoration of the edentulous, highly atrophic maxilla is typically associated with a considerable treatment effort and is surgically demanding. Surgical techniques include bilateral sinus lifts, major bone reconstructions using bone grafts from the iliac crest, and Le Fort I osteotomies.1  These procedures require several additional treatment steps until definitive prosthetic restoration, require time, and are cost-intensive. In contrast, the use of zygoma implants allows for faster treatment. Typically, only a single surgical intervention is required. The treatment time is thus shortened, and due to the bicortical anchorage in the zygomatic bone, immediate loading is possible in some cases, which helps to reduce the overall treatment time and the financial aspect once again. The protocol initially developed by Brånemark in 1998 involved placing zygoma implants through the maxillary sinus without elevating the sinus membrane.2  In addition to the sinus-slot technique described by Stella & Warner,3  placement outside the sinus is also possible.4  Zygoma implants show a long-term survival rate of up to 95.2%.5 

The present case is intended to show how, after a long period of periodontal therapy focused on tooth preservation, a fixed, immediately loaded, and definitive implant restoration in the maxilla could be achieved without extensive surgical pretreatment.

Case presentation

Case History

A patient, 45 years old at the time of initial presentation, was referred to our outpatient clinic by his primary dentist to take over periodontal therapy (Figure 1). At that time, the patient was wearing a removable temporary denture to replace his maxillary anterior teeth #7–10. After thorough patient education, systematic periodontal therapy with regular supportive periodontal therapy (SPT) sessions was performed. To replace teeth #7–11, a wide-span bridge construction was placed 2 years later on the remaining teeth #4–6, #12, and #13 as a metal-supported long-term provisional, veneered with ceramic (Figure 2). Already at the initial presentation, an implant-supported prosthetic restoration in the anterior maxillary segment was suggested to the patient as a treatment alternative, which the patient, however, rejected despite the poor prognosis of his maxillary remaining teeth and favored a metal-supported long-term provisional restoration. Of course, the patient was already informed at this point that the removal of all of his maxillary teeth and an implant solution were an alternative. The maximal tooth-preserving treatment strategy was due to the patient’s anxiety toward dental treatments. Subsequently, closed curettages and supportive periodontal therapies were performed as indicated.

Figure 1.

Panoramic radiograph at initial presentation. The patient is 45 years old and is wearing a provisional partial denture to replace teeth #7–10.

Figure 1.

Panoramic radiograph at initial presentation. The patient is 45 years old and is wearing a provisional partial denture to replace teeth #7–10.

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Figure 2.

Clinical situation 8 years after initial presentation. The patient is now 53 years old. He has been wearing the fixed long-term temporary fixed bridge to replace teeth #7–11 for 6 years.

Figure 2.

Clinical situation 8 years after initial presentation. The patient is now 53 years old. He has been wearing the fixed long-term temporary fixed bridge to replace teeth #7–11 for 6 years.

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After 6 years, the patient was referred once more by his family dentist due to the presence of a canine fossa abscess starting from upper premolar #5. As a result, the patient explicitly expressed the wish for a quickly performed, fixed new restoration of his maxilla with implants. Apart from this finding, the medical history was normal.

Clinical Findings

In the maxilla, the fixed long-term temporary bridge was incorporated (Figure 2). Teeth #3–6 and #11–14 showed a horizontal bone loss of 90%. The maxillary teeth showed probing depths of 6–10 mm. The furcations of the multirooted teeth could all be probed continuously. Meanwhile, in the mandible, the crowns of teeth #24 and #25 were interlocked with composite to the adjacent teeth. The probing depths were between 4 and 9 mm in the lower teeth. The mandibular teeth reacted positively to CO2 snow in the sensitivity test. Periodontal bone loss was 50%–60% in the mandible (Figure 3).

Figure 3.

Radiological situation after many years of periodontal therapy.

Figure 3.

Radiological situation after many years of periodontal therapy.

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Extraoral findings and a functional screening examination were insignificant. Oral hygiene at this time could be described as inadequate.

Consultation and Treatment Planning

In the maxilla, all teeth were classified as nonpreservable. Thus, different treatment options were discussed with the patient for the prosthetic restoration of the severely atrophied maxilla. The patient categorically rejected a complete removable denture because he wanted a fixed construction. Due to the pronounced bone atrophy, different implant-supported prosthetic solutions were discussed with the patient. Since the patient was equally opposed to a time-consuming, multistage treatment with bilateral sinus lift, the treatment alternative of placing zygoma implants in the posterior region was discussed in detail. The various options for removable and fixed denture reconstructions supported by implants were also explained. The informed consent provided included the advantages and disadvantages of the treatment options, treatment procedure, costs, and risks. In addition, the patient was explicitly informed about the necessity of consistent oral hygiene. In addition, the need for renewed periodontal treatment as pretreatment with regularly scheduled supportive periodontal therapy sessions after implant treatment was emphasized.

After another consultation appointment, the patient decided to have a fixed restoration with 2 posterior zygoma implants and 2 anterior conventional implants, which were to be immediately restored and immediately loaded according to the All-on-4 concept.

Cone Beam Computerized Tomography

The 3-dimensional image shows the bone situation with the planned implants (Figure 4).

Figure 4.

3-dimensional implant planning with CBCT.

Figure 4.

3-dimensional implant planning with CBCT.

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Surgical, Periodontal, and Prosthetic Pretreatment

Due to the periodontal conditions of the residual dentition in the maxilla, the oral mucosa appeared to be inflamed. Immediate implant placement in such a case would carry a high risk of recession on the implants. In addition, the risk of bacteria spreading into the maxillary sinus was considered high. Consequently, 2 months before the planned implant placement, all maxillary teeth, as well as teeth #18, #31, and #32, which were impossible to preserve, were removed under local anesthesia. The postoperative radiograph showed pronounced atrophy in the maxillary posterior region.

For the period between tooth removal and implant placement, the patient received a temporary complete denture. At the beginning of this 8-week interval, periodontal treatment was performed in the mandible, and the patient was once again instructed and motivated regarding oral hygiene.

In preparation for the implant prosthetic restoration, an impression with alginate was taken in the mandible and a silicone impression (Imprint 4, 3M, Neuss, Germany) in the maxilla, and a facebow transfer was performed. The bite jig was produced in the in-house dental laboratory and used to determine the arch relation with a bite registration. The esthetic try-in followed this. After minor esthetic corrections in consultation with the patient, an orientation template for implant placement and the bite jig for transferring the bite registration after the surgical procedure were customized.

Implant Procedure

Eight weeks after extraction therapy, the mucosa was stable and free of inflammation. The patient was instructed to start antibiotic therapy for a total of 3 days (3 times daily 750 mg amoxicillin) one day preoperatively. Implantation was performed under general anesthesia. First, the alveolar process was exposed with a ridge incision, and granulation tissue was removed from the remaining extraction sockets. To make the subsequent denture base as even as possible, moderate leveling of the maxillary alveolar bone crest was performed. The mucosa was mobilized to obtain a sufficient overview of the facial sinus wall and the arcus zygomaticus. The access to the lateral maxillary sinus wall and the implant position were then marked with a sterile pencil. The sinus window was prepared on both sides according to a conventional external sinus lift, with the mobilized bone flap slightly displaced medially to protect Schneider’s membrane during implant placement. The zygoma implants in region #4 and #14 (NobelZygoma 0°/40 mm, Nobel Biocare, Gothenburg, Sweden) were placed bicortically in the os zygomaticum with high primary stability of 45 Ncm (Figure 5) and multi-unit abutments (60°/6 mm, Nobel Biocare) were inserted. The conventional implants in regions #7 and #10 were inserted axially into the local bone with a torque of 35 Ncm (NobelActive 4.3 mm/13 mm, Nobel Biocare) and multi-unit abutments (0°/1.5 mm, Nobel Biocare) were placed (Figure 6). Finally, sinus augmentation, placement of healing abutments, and wound closure were performed. After the general anesthesia had worn off, the patient and the accompanying person were informed about the postoperative behavior.

Figure 5.

Operative site after osteoplastic approach and insertion of the zygoma implant and the multi-unit abutment, including the healing cap. The bone flap is moved medially to protect the Schneider membrane.

Figure 5.

Operative site after osteoplastic approach and insertion of the zygoma implant and the multi-unit abutment, including the healing cap. The bone flap is moved medially to protect the Schneider membrane.

Close modal
Figure 6.

Final situation after insertion of the implants in region #’s 4, 7, 10, and 13.

Figure 6.

Final situation after insertion of the implants in region #’s 4, 7, 10, and 13.

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Impression and Definitive Immediate Restoration

The implant impression was taken with multi-unit impression posts at the abutment level. To protect the peri-implant tissue and the wound area, rubber dam flaps were attached to the abutments. The impression posts were splinted with the aid of a stable wire and a flowable composite (Ceramill Gel green, Amann Girrbach, Pforzheim, Germany) to achieve dimensionally accurate reproduction of the implant position and therefore a tension-free fit of the denture framework (Figure 7). The impression (Impregum, Espe, Seefeld, Germany) was taken using an implant impression tray with foil technique (Miratray, Hager & Werken, Duisburg, Germany). The template was milled in the area of the multi-unit abutments and relined with a registration silicone (R-SI-LINE METAL-BITE, R-dental Dentalerzeugnisse GmbH, Hamburg, Germany). A CAD/CAM-milled bar was produced in the external dental laboratory. This was incorporated into the prepared tooth setup as a “Maló bridge” in the clinic’s laboratory. Two days after implant placement, the denture was placed as a definitive immediate restoration on the 2 zygoma implants and the 2 anterior conventional implants (Figures 8 and 9). The screw channels were closed with Teflon tape, a temporary composite (Telio Inlay, Ivoclar Vivadent, Schaan, Liechtenstein), and a covering layer with a restorative composite (Tetric EvoCeram, Ivcoclar Vivadent). A panoramic image was taken for control purposes (Figure 10).

Figure 7.

Isolation with rubber dam flaps and splinting of the impression posts with stable wire and Ceramill gel.

Figure 7.

Isolation with rubber dam flaps and splinting of the impression posts with stable wire and Ceramill gel.

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Figure 8.

Frontal view of the definitive fixed denture before insertion 2 days after insertion of the implants.

Figure 8.

Frontal view of the definitive fixed denture before insertion 2 days after insertion of the implants.

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Figure 9.

Lateral view after insertion of the definitive immediate restoration.

Figure 9.

Lateral view after insertion of the definitive immediate restoration.

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Figure 10.

Control radiograph after insertion of the fixed restoration.

Figure 10.

Control radiograph after insertion of the fixed restoration.

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Follow-up and Progress Control

The checkups took place 1, 2, and 4 weeks after insertion of the denture. The prosthetic follow-up visits after 3 and 6 months were uneventful.

In this case report, the patient was referred late for periodontitis therapy by his general dentist. Therefore, due to the pronounced bone loss in the maxilla that had already occurred, it was too late to replace the maxillary anterior teeth #7–10 with a conventional implant-supported solution with 2 dental implants. With an earlier referral, this standard implant solution for the anterior maxillary segment could possibly have been implemented in conjunction with systematic periodontal therapy. Per the patient’s preference for maximum tooth preservation, it was agreed in the present case that an attempt would be made to preserve the maxillary teeth for as long as possible. However, the anxious patient was already informed then that it would only be possible to retain his upper teeth for a few years and that if the tooth-supported restoration failed, an implant solution would be necessary to provide a fixed restoration for the upper jaw. The patient may have obtained information about implant treatments from social media, although the information available is usually ambiguous and misleading.6  Here, the dental profession is required to provide generally understandable and solid information for patients. This would include presenting all the options for implant therapy and also presenting the available options for pain relief (oral sedation, intubation anesthesia) objectively. Based on this information, the patient might have been open to implant treatment earlier.

The clinical use of zygoma implants is a scientifically validated procedure that can be considered a possible routine for anchoring implant-supported prostheses in cases with highly atrophied maxilla.4,7,8  The requirement is the correct indication, careful planning, surgical routine, and working in a well-coordinated team of prosthodontists, implantologists, and dental technicians. The use of zygoma implants regularly achieves high satisfaction in patients with atrophied maxillae.9  However, a misperception would be to assume the use of zygoma implants as a simple treatment technique that avoids surgically complicated augmentations and would, therefore, be an easy treatment option to perform. On the contrary, just as when conventional implants are used in combination with complex augmentations, surgical, biological, and technical complications are possible.

In the case presented, the decision and consideration made together with the patient in favor of periodontal therapy aimed at preserving the maxillary teeth were followed for many years. Scientifically validated recommendations for case planning and consistent patient counseling would be helpful in making reliable prognostic statements about the expected course of cases with severe periodontitis. Individual consideration of each case is necessary. If therapies with an unfavorable prognosis are used, implant solutions should be included in the explanatory discussion in advance.

Another unique feature of the case shown is the implemented immediate definitive restoration, which requires an easy and readily performed interaction between prosthetics, surgery, and dental technology.

A recent study determined that fixed anchorage of prostheses on zygoma implants in combination with anterior implants regularly provides a high quality of life and achieves high patient satisfaction.10  In another study, visual analog scales on the postoperative pain course determined that the All-on-4 procedure with and without zygoma implants regularly achieves high patient satisfaction and that even the use of zygoma implants shows surprisingly low pain levels in the postoperative course.11  In the case report, the immediate definitive prosthetic restoration corresponded to the patient’s request for rapid prosthetic rehabilitation and could be implemented due to the high primary stability. Consequently, not only the zygoma implant concept but also the immediate definitive restoration saved time and, ultimately, costs for the patient.

As the case report has shown, periodontal therapy has certain limits. Medical education, also regarding the use of zygoma implants, should always be provided, especially when periodontal maintenance therapies are used in special exceptional cases, which, due to the severity of the disease and the patient’s age, are likely to result in a highly atrophied maxilla. In such cases, zygoma implants can offer a solution to achieve a fixed, rapid, and financially acceptable prosthetic rehabilitation despite the unfavorable initial bony situation.

The authors declare that there is no conflict of interest.

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