Zygomatic implants

22 June 2021
3 min read
Published:

Cemal Ucer discusses the benefits.

Dental implants are widely regarded as the gold standard for edentulous rehabilitation. However, there are anatomical factors that can prevent implant placement. Most notably, for patients who have severely resorbed, insufficient or poor-quality bone available for conventional implants in the maxilla, additional procedures such as grafts are typically required to facilitate implant anchorage.

While often highly successful, grafting procedures can be costly, time consuming and carry their own risks of complications. Major grafts inherently require at least one additional surgery, with the attendant pain, discomfort, morbidity and inconvenience that entails. The time factor can also be significant – it typically takes around six months for a graft to heal and become ready for implant placement. Typically, implant treatment with staged grafting takes eight to 12 months to complete. During these months, wearing provisional dentures can be quite uncomfortable for patients, particularly for extended periods of time. Many patients might even avoid using their dentures temporarily during this period.

Zygomatic implants (ZI) side-step the challenges and difficulties of grafting procedures, potentially offering a more efficient treatment path with a reduced risk of morbidity. Unlike many procedures requiring grafts, it is entirely possible for a prosthesis to be loaded onto the implants immediately, using the so called “same day teeth” treatment approach.

Zygomatic implants are strongly indicated for rehabilitation of the severely atrophic maxilla or replacement of failing full arch implants or grafts. These implants can also help those who have had ablative tumour surgery in the maxilla, which can leave a patient with substantial anatomical defects. Zygomatic implants have been successfully used to support an obturator and removable dentures in patients who have undergone a maxillectomy, which otherwise can be difficult to adequately secure in instances where few teeth remain.

While once a comparatively underused procedure, in recent years, zygomatic implants have become significantly more accessible, in part thanks to the development of the Zygoma Anatomy-Guided Approach (ZAGA), a technique pioneered by Carlos Aparicio.

ZAGA is a patient-centric and anatomically guided approach. This method allows maximum fixation of a ZI strategically in three key anatomical points – the alveolar ridge, anterior wall of the maxilla and the dense zygomatic bone. Depending on the resorption pattern of the maxilla and concavity of the anterior wall of the sinus cavity, ZI can follow an intra-sinus or extra-sinus trajectory (ZAGA classification 0-4). Where possible ZI are placed using a “channel” through the lateral sinus wall to increase the bone implant contact as much as possible. The ZAGA technique advocates the use of the new Straumann ZAGA implants with reduced profiles. This preserves available bone and helps to maximise the sealing of the underlying sinus cavity.

Under this protocol, the relationship between the zygomatic buttress and the intraoral starting point, based upon the specific anatomy of the patient, determines the trajectory of the implant through the sinus wall. For some patients, this means the implant will be in a completely intra-sinus position (ZAGA tunnel technique), but for the vast majority it is placed either extra-sinus or in the wall of the maxilla (ZAGA channel technique). Anatomically guided ZAGA classifications (0-4) help oral surgeons in selecting the ideal entrance points for drilling. This helps to maximise bone anchorage and enhances sinus cavity “sealing” which has seen a reduction in long-term complications compared to earlier approaches.

As with other advanced surgical procedures, training and experience make a substantial difference to patient outcomes. Zygomatic implants present some unique challenges compared to conventional implants. There is considerable anatomical variation in zygoma bone between patients. Due to this variation, the angled approach required, the proximity to sensitive structures and other challenges, 3D scanning and treatment planning are particularly advantageous for zygomatic procedures. 3D treatment planning and computer guided implant surgery have a huge role to play in further increasing the safety and efficiency with which these procedures can be carried out by oral surgeons or dentists of all experience levels. For example, 3D models can now be printed, giving
surgeons an opportunity to practice on a replica of their patient’s precise anatomy prior to surgery. International ZAGA centres provide a network of highly qualified oral surgeons who share their experience and collaborate with each other in research and advancement of ZI techniques for the rehabilitation of fully edentulous patients with advanced bone atrophy.

If you are dealing with a complex or urgent case, such as a patient with a severely atrophic maxilla, consider referring your patient to the Centre for Oral-Maxillofacial and Dental Implant Reconstruction, a ZAGA centre based in Manchester. The clinic offers the latest patient-centric treatments and technologies. Putting the patient first is at the heart of everything we do. The team is well-versed in complex procedures, including block grafting, vertical GBR, 3D customised allografts and, of course, zygomatic dental implants, allowing us to find the right solution for your patient’s specific needs. The experienced and friendly team will put your patient at ease, while keeping them safe with strict adherence to hygiene and safety protocols.

While zygomatic implants have numerous advantages, they can be an intimidating treatment modality, as by definition they require deeper penetration into the patient’s bone tissue than conventional dental implant procedures. However, with astute diagnosis, case selection and planning, zygomatic implants can actually be a more reliable and expedient oral rehabilitation path in certain instances. Dental implants are very much not a one-size-fits-all proposition. Ultimately, the best possible results and highest satisfaction can be achieved by drawing on clinical experience to provide tailored, patient-centric treatment to suit each individual patients different anatomical, functional and aesthetic needs.

References available on request.