Quad Zygomatic Implants: Fixed Teeth With No Usable Jawbone

Quad zygoma describes a specific implant configuration: four zygomatic implants, two in each cheekbone, and no standard implants in the upper jaw whatsoever. Two implants per side means one placed more towards the front of the cheekbone and one further back, giving four widely spaced anchor points across the arch. Those four heads then carry a single rigid, one-piece bridge.

The name is simply arithmetic — "quad" for four. You will also see it written as quad zygoma, 4 zygomatic implants, or quadruple zygomatic rehabilitation. All describe the same idea. What matters is the word *no*: in a quad case, no part of the anchorage comes from the jawbone.

That is the difference from the more common arrangement, usually called a hybrid or single-zygoma case. In a hybrid case a surgeon places one zygomatic implant per side and combines it with two to four standard implants in whatever usable bone remains at the front of the upper jaw. A hybrid is the default when there is still bone to work with at the front. Quad zygoma exists for when there is not.

If you are still working out which category you fall into, start with the complete guide to zygomatic implants and our overview of implant options with bone loss.

The reason quad zygoma works where nothing else does comes down to which bone is doing the job. The upper jaw (maxilla) holds teeth, and bone that holds teeth behaves in a very particular way: once the teeth are gone, the body gradually reclaims it. Years of denture wear, gum disease, failed implants or failed grafts accelerate that process, and the sinuses tend to expand downwards into the space that is left. Eventually there is not enough height or width anywhere in the arch to hold a conventional implant.

The cheekbone is a different structure with a different job. It is part of the facial skeleton — a buttress that carries chewing load and protects the eye socket. Because its function has nothing to do with holding teeth, it does not shrink when teeth are lost. It is also largely dense cortical bone, which is exactly the kind of bone an implant needs for a firm mechanical grip.

In a quad case the four fixtures pass through or alongside the remaining jaw purely as a route, not as a foundation. All of the anchorage is above, in the two cheekbones. This is also why the bridge design is not optional: four implants placed at steep angles must be joined into one rigid framework so the arch behaves as a single unit rather than four separate posts. Surgeons and prosthodontists call this cross-arch splinting, and a quad case cannot be restored with individual crowns.

Bone grafting is not the wrong answer here — it is a well-evidenced route that rebuilds bone so standard implants can be used, and for many people it remains the better choice. The trade-off is different: grafting invests months of healing before implants can be placed, and it needs a viable foundation to build on. Quad zygoma trades that healing time for greater surgical complexity, and does not depend on the jaw at all.

A quad case is not simply a hybrid case with two more implants. Each cheekbone has to accommodate two long fixtures on separate paths that must not collide, must each engage enough dense bone, and must emerge in positions the bridge can actually use. Planning that geometry in three dimensions is the hard part, and it is done digitally before anyone operates.

Practically, this means more exposure of the surgical field on both sides, more work around both sinus walls, and more time under anaesthesia than a hybrid case. Published protocols for zygomatic surgery generally describe operating times in the region of two to four hours, and quad cases sit at the longer end of that range rather than the shorter one. Treatment is usually carried out under general anaesthesia or deep sedation.

There is also less margin for improvisation. In a hybrid case, standard implants at the front provide additional anchor points; if one zygomatic fixture cannot be placed as planned, the plan can often be adapted. In a quad case every one of the four fixtures is load-bearing, so a compromise in any single position affects the whole arch. That is the real reason quad zygoma is described as a demanding procedure — not because the individual steps are exotic, but because there is nowhere to hide an error.

The prosthetic side is harder too. Implant heads in a quad case tend to emerge further back and more towards the palate than in a hybrid case, so the bridge has to be designed around those positions. Patients often need a longer adjustment period for speech and tongue position, and hygiene access is less forgiving. A step-by-step walk-through of the wider protocol is on our zygomatic implant procedure page.

Zygomatic implants as a category have been in clinical use since the late 1980s and studied for more than twenty-five years, with pooled survival of around 95–96% — 95.21% cumulative at twelve years across 4,556 implants [4], and 96.2% over a mean 6.3-year follow-up in the 2023 ITI consensus review [3]. For the quad configuration specifically, the longest series we could identify followed 56 patients and 224 implants for a mean of 8.8 years, up to 17, and reported 97.8% implant survival [1]. That figure comes from one experienced centre rather than from pooled data across many, which is worth holding in mind.

The important caveat is that most of that literature is dominated by hybrid configurations. Quad zygoma is a smaller subset with fewer patients, shorter average follow-up and considerable variation in surgical technique between the groups reporting it. Published series are generally encouraging, but "encouraging in specialist centres" is not the same as "settled across the profession", and it would be misleading to present quad-specific figures as though they carried the same weight.

What the evidence supports fairly consistently is narrower and more useful: the cheekbone provides reliable anchorage, complications are dominated by sinus problems rather than catastrophic events, and outcomes correlate strongly with the experience of the operating team. That last point is the one to act on. Ask any provider how many zygomatic cases they complete each year, how many of those are quad cases, who manages complications, and what happens if an implant fails once you are home. A confident answer to all four is a better signal than any percentage on a website.

The honest summary for someone who has been told nothing can be done: for a meaningful number of people in that position, something can be done — but it needs a CBCT scan, a surgeon who does this regularly, and a realistic conversation about risk. Those three things, in that order.