Clinical Studies

Zygoma Zaga - 2 Clinical Studies

Clinical Study 1

Task – The client wanted to take a series of clinical studies about zygomatic implant rehabilitation and turn them into a cohesive series of articles. Here’s the first one.

Zygoma ZAGA article #1

Keywords – remote implant anchorage

Meta Title Remote Implant Anchorage – How It Helps In Challenging Cases

Meta DescriptionThe Zygoma implant is a bi-product of the remote bone anchorage concept. It was made for use in those with challenging maxillary defects. Here’s how it helps.

Article TitleRemote Implant Anchorage – How It Helps In Challenging Maxillary Defect Cases

One of the main challenges dental clinicians face when dealing with patients suffering from complex maxillofacial defects is prosthetic stability. In this article, we’ll talk about how such challenges can be overcome by using remote implant anchorage.

The subsequent loss of critical bone support for teeth often causes clinicians to search for supplemental areas of stability to avoid further and more serious prosthetic complications. The edentulous patient, for example, can be challenging to treat because of the limitations of any said options.

Aside from the liberal use of dental adhesives, some of the most effective means of treatment in patients with severe atrophy or trans-oral defects involve options such as vertical side wall engagement, 2-piece obturators and Occlusal Vertical Dimension (OVD) treatment. Each offers practical ways of creating dental stabilisation, but unfortunately, they come with limited success.

What about conventional dental implants?

The advent of osseointegration initially created a significant benefit for patients with missing teeth by placing dental implants directly into the maxillary bone. However, in particularly challenging maxillary defect cases, we know that such anchorage sites can be limited.

This prompted clinical professionals to further investigate the use of adaptive dental implants for remote implant anchorage. Initially, while this did allow for more extensive bone support to be incorporated into an implant design, such early designs were far from perfect.

While it’s true that early remote bone-anchored designs reduced problems like cantilever stress and aided cross-arch stabilisation, the main issue with these appliances was that they tended to project at divergent angles. This, in turn, complicated necessary procedures like impression-taking and restoration construction.

Furthermore, the limitation in implant lengths minimised the actual depth of this type of implant that could be placed into various tissue beds.

So herein lies the dilemma.

While we know that implant-supported prosthesis remains the gold standard option for those suffering from complex or challenging maxillofacial defect cases, a solution was required to overcome these significant challenges. Thankfully the answer may lie in Zygomatic implants.

Zygoma Implants

Zygoma implants were developed especially for patients with challenging maxillary defects. They are specially adapted dental implants anchored directly into the zygomatic bone arch (the bone that extends from the temporal bone at the side of the head to the upper maxilla jawbone).

Because zygomatic bone isn’t affected by tooth loss, it creates the perfect remote implant anchorage area – one close enough to the implant site yet far enough away so as not to be affected by bone tissue absorption. The longer length of a zygomatic implant means that (on paper at least) it offers the perfect vehicle for stabilising replacement bridges and-or replacement teeth.

Of course, the placing of zygomatic implants is not without its risks.

The process, for instance, can involve the careful manipulation of the implant around delicate anatomical structures such as the orbit and sinus cavity. Therefore, extensive surgical experience should be a minimum requirement for those who place them.

Since Zygoma implants were developed in the late 1990s, regular follow-up cases conducted at the Brånemark Osseointegration Centre in Göteberg, Sweden, have demonstrated a remarkably high success rate.

Data collected suggests that effective stabilisation in those with complex or severe maxillary defects using remote implant anchorage is significantly enhanced.

 But more importantly, any cantilever forces that were previously unavoidable when using conventionally-adapted implant designs can now be minimised by utilising Zygoma implants to create effective retention in anatomic areas. These areas might otherwise be unsuitable for dental implant placement without prior and extensive bone grafting.

The bottom line

It does appear then that remote implant anchorage is a crucial option when assessing and dealing with extreme maxillofacial defect cases. Moving forward, continual reporting of the success and failure rates of Zygoma implants is vital.

So far, evidence suggests that rehabilitating patients using zygoma implants is highly effective in those with this complex condition. That has to be a good sign for clinicians and patients alike – especially when seeking out the best possible outcome in a challenging environment.

Clinical Study 2

Task – The client wanted to take a series of clinical studies about zygomatic implant rehabilitation and turn them into a cohesive series of articles. This is the second in the series.

Zygoma ZAGA Article #2

Keywordzygomatic implants

Meta Title – Zygomatic Implants – A 7-Year Study – Zygoma ZAGA Centres 

Meta DescriptionThe concept of Zygomatic implants in edentulous patients is well documented. This article reports on a seven-year follow-up of some of those cases.

H1 Title – Zygomatic Implants – A 7-Year Follow-Up Report

Zygomatic dental implants were first introduced in the late 1990s by the ‘father of dental implantology’ Per Ingvar Branemark. Since then, thousands have been placed. In fact, over the last two decades, zygomatic implants have become a viable means of establishing stabilisation for a fixed restoration in the maxillary area without the need for bone grafting.

By anchoring the implant into the zygomatic (cheek) bone, patients can receive lifelike restorations even with complex or challenging maxillofacial problems. As such, zygoma implant solutions offer a lifeline to patients who otherwise face a lifetime of dental issues.

Moreover, this graftless approach allows for complete rehabilitation using either conventional ‘delayed’ implant placement or immediate loading techniques.

So while we know that Zygomatic implants have a reasonable success rate in the short term – e.g. in those critical first few months after placement – what about the long term?

We know, for instance, that problems can develop many months and even years down the line with conventional implants. Can the same be true for zygomatic restorations?

This article reports on a follow-up study, seven years in the making. So let’s dive in and take a look.

Firstly, patient selection

This prospective study carried out between 2003 and 2010 involved 36 patients fitted with 74 zygomatic implants and 98 conventional anterior maxillary implants across a two-year period.

The inclusion criteria for the study used zonal areas within the anterior maxilla to ensure equal predetermined bone depths. These were as follows:

  • Zone 1 (the upper central maxilla) – 7 -10 mm of bone remaining
  • Zone 2 (the lower right side) – less than 2mm of bone remaining
  • Zone 3 (the upper left side) 0-2 mm of bone remaining

Any patients with active sinus problems and/or those with 3mm or more bone in zone 2 were excluded from the study. As a result, all patients at the start of the study had equally limited bone and clear maxillary sinuses. All criteria were proven using 3-dimensional imaging technology.

Implants and methodology

Nobel BioCare Mk IV 4.0mm double-threaded implants were used alongside Nobel Speedy 4.0mm versions for placement in the anterior maxilla. For the posterior maxilla, machined zygomatic implants were placed.

All patients (14 men and 22 women) were treated under intravenous sedation. 13 patients had four anterior maxillary implants placed. At the same time, the remaining 23 received two anterior maxillary implants in conjunction with two posterior zygomatic implants.

All patients underwent immediate loading by converting their standard maxillary denture into a fixed provisional prosthesis. As for conventional implants, 54 MK IV Nobel BioCare implants were placed in the anterior maxilla area. 

Multi-unit abutments were then secured to each implant to allow the connection of a provisional and (eventually) a final fixed prosthesis. 

Survival criteria for implant-based restorations

It was agreed that six months after implant placement, an implant was classified as surviving if it continued to fulfil the supportive function. The criteria for survival was achieved by removing the fixed prosthesis and torque-testing each implant individually.

The results

At the first six-month follow-up, all but two of the 46 zygomatic implants placed had osseointegrated. The two failed zygomatic implants were removed and replaced by new versions.

Initially, standard and zygomatic implants were placed in varying lengths from 7mm to 52.5mm. The two failed zygomatic implants were 40mm and 45mm, respectively. These were replaced with 42.5mm versions. 

New Zygomatic implants were again placed into immediate load by reconnecting them to the original prosthesis. After six months of osseointegration, both implants underwent the same rigorous testing and were found to be stable.

These final two patients then received their definitive prosthesis, meaning that by the end of stage 2, all patients were deemed to have reached osseointegration.

What about other clinical outcomes?

Several similar studies, including Aparicio et al., reported acute sinusitis after zygomatic placement in some patients between the 12-month and two-year post-placement phase. Results were mirrored in this study, where three patients out of 36 experienced unilateral maxillary sinus infections around this same period.

However, because each was unable to respond to oral antibiotics, each patient was successfully treated using the latest Functional Endoscopic Sinus Surgery (FESS)

The conclusion

Out of 36 zygomatic implant patients, 31 were fully rehabilitated after six months, while the remaining five were fully rehabilitated after two years. During the remaining five years of the study, no further problems were reported.

Any edentulous patient suffering from complex or challenging maxillofacial issues can now undergo evidence-based, surgical and prosthetic solutions for 2-stage and immediate-loading protocols.

Given the right conditions, Zygomatic implants are a viable and predictable treatment option that gives orally-restricted patients a whole new lease of life.

If you want to learn more about how you can help patients with zygomatic implants, then contact the team at Zygoma ZAGA Centres. We have some of the most experienced and clinical minds in the field.

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