Zygomatic Implants
Introduction
Patients face many problems when they lose their teeth. The first and most important of these is the loss of chewing function, as well as aesthetic and speech disorders. The patient may also experience psychological problems and suffer loss of self-confidence in social environments. However, such cases have ceased to be a problem with new developments in the dentistry profession. Dr. Per-Ingvar Branemark first discovered osseointegration in 1965 by placing implants in the oral cavity. The aim of modern dentistry is to restore the patient’s lost functions and aesthetic needs.
Zygomatic implants (ZIs) were developed and introduced into dental practice by Prof. Per-Ingvar Branemark towards the end of the 1980s. Initially, they were designed to achieve fixed prosthesis retention in patients with excessive or complete maxillary bone loss (caused as a result of various oncological and traumatic reasons) and which were not suitable for traditional dental implants. Initially described in the Brenemark protocol as one implant in each zygomatic bone with 2 or 4 standard implants in the anterior region. Later, many surgical concepts and methods have been described in academic literature. Today, in cases where there is not enough strong bone in the anterior region for traditional dental implants, the concept of quadruple (quad) zygomatic implants has been introduced for the appropriate distribution of masticatory force to the implants.
What is a zygomatic implant?
Zygomatic implants (Fig. 1) are implants that are 30-50 mm long and 4 mm wide and are placed at a 45-degree angle from the palatal region to the zygoma bone (cheekbone). They extend parallel to the lateral (side) wall of the maxillary sinus and receive strong primary stability from the zygomatic process (protrusions from the frontal, maxilla and temporal bones of the skull). In many studies using two-stage protocols, survival rates of zygomatic implants have been reported to be 98-100%. There is a 6-month period to allow the bones to heal before loading these prostheses. Since the quality of the zygomatic bone is far superior to the quality of the posterior maxillary bone, and has a thicker and wider trabecular structure, it is excellent for anchoring the implants.
When are zygomatic implants used?
Although zygomatic implants are recommended by many experienced oral, dental and maxillofacial surgeons and dentists, they should not be considered as the first step of treatment. Surgery should be considered by very careful and experienced dental practitioners.
• In case of sufficient bone in the anterior part of the upper jaw and insufficient bone in the posterior part of the upper jaw for stabilising implants, zygomatic implants may be introduced to eliminate the need for grafting
• In case of long-term use of removable partial dentures for the posterior edentulous area adjacent to the patient’s front teeth, and where the edentulous area has suffered excessive bone loss
• In order to support the prosthesis in cases where the patient’s upper jaw bone has been removed for oncological and traumatic reasons
• A zygomatic implant might be necessary to avoid bone grafting in the case of a very large sinus cavity in the patient
When considering a zygomatic implants, the patient should be evaluated by highly experienced physicians. In making an evaluation they should be aware;
• of and treat any hard or soft tissue infection in the area where the zygomatic implant is intended to be placed
• of any infection in the sinuses should be meticulously examined by the surgeon using various methods (x-ray, tomogram, etc.)
What are the advantages of zygomatic implants?
• Less surgical intervention
• Generally shorter duration of treatment
• Minimal use of grafts (artificial bone material)
• Patients treated with zygomatic implants can easily use their existing total prostheses after the procedure
What are the disadvantages of zygomatic implants?
Despite the number of advantages listed above, there are also several disadvantages to this procedure. Zygomatic implants should definitely not be considered as the first approach in the treatment of patients with completely edentulous (toothless) upper jaws or molars. In very few cases Zygomatic implants are only introduced after being diagnosed by highly competent specialist physicians.
• As the surgical introduction of Zygomatic implants is technically difficult, it should be performed by highly-trained and experienced physicians, specialists who can handle any surgical conditions or complications that may arise during the operation
• There is a risk of damaging the orbit, lacrimal apparatus and facial nerves in the neighboring areas where the zygomatic implant is to be inserted
• Although this surgery is less risky than the ‘sinus-lift’ procedure, there is a risk of the patient developing sinusitis
• Speech anomalies may rarely occur where the implants exit the palatal bone
• In extremely rare instances, there is a risk of implant failure resulting in replacement
Conclusion
Our clinic confidently recommends the Zygomatic implant for the reasons briefly listed below;
1. Osseointegration (the integration of implants into bone) success rates of zygomatic implants are around 98% and above, which we consider extremely high
2. The procedure reduces surgical stages for the patient (grafting, sinus lift, etc.)
3. The procedure shortens the entire operation duration for the surgeon
4. The need for bone collection and grafting is eliminated
5. Precise placement of the zygomatic implant in the upper jaw bone allows the prosthetic part of the implant to exit the region of the upper first molar for strength
6. The procedure negates the need for a personal abutment at different angles when applying the prosthetic
7. Compared to traditional dental implants, the need for extra laboratory time is greatly reduced for zygomatic implants
8. The completion time of the procedure is similar to that of traditional dental implants
9. When considering the costs of bone grafting, the relative operation processes of zygomatic implants are not expensive
Dr. Tevfik Yavuz
