Zygomatic implants: the extra-sinus approach

Anchorage in the cheekbone

When the upper jaw has lost a great deal of bone, a removable denture can become difficult to wear and conventional implants may no longer find enough support. Zygomatic implants are then a rehabilitation option in some cases.

Longer than conventional dental implants, they are anchored in the zygomatic bone, at the level of the cheekbone. This allows anchorage to be sought beyond the resorbed area of the upper jaw. Their length and path are chosen according to each patient’s anatomy.

The aim is to support a prosthesis, most often fixed, to regain comfort and function. This anchorage is, however, neither a guarantee of immediate stability nor a permanent solution that needs no maintenance.

What does an extra-sinus approach mean?

With an extra-sinus path, the body of the implant runs outside the cavity of the maxillary sinus, along its outer wall, before reaching the zygomatic bone. This approach differs from the classic path through the sinus.

When the anatomy allows, it can limit the implant’s passage through the sinus and favour an emergence closer to the dental ridge, rather than towards the palate. This position can make it easier to design a less bulky prosthesis and to clean it.

The path is chosen according to the shape of the upper jaw, the sinus and the prosthetic needs. The extra-sinus approach is therefore not suitable for every patient and does not eliminate the risk of sinusitis. Covering the implant with soft tissue also needs particular attention.

Potential advantages for your treatment

• Avoiding some extensive bone reconstructions. Zygomatic anchorage can make it possible to avoid a major graft of the upper jaw and harvesting bone from another part of the body.
• Fewer stages. When a graft in several stages is avoided, the pathway to a functional prosthesis can be shortened.
• Fixed temporary teeth sooner. Immediate or early loading is possible under well-defined conditions, after checking the stability of the implants and the rigidity of the prosthesis.

A randomised study comparing zygomatic implants with bone reconstruction followed by conventional implants showed faster access to a functional prosthesis. This does not mean the protocol is better for every patient: the constraints and risks of both options must be compared.

Who may this solution be suitable for?

This option mainly concerns severe bone loss in the upper jaw, when conventional solutions are insufficient or would require major reconstruction. It may also be discussed after failed implants or grafts.

Having worn a denture for a long time, or a first opinion against implants, is not enough to make the indication. The assessment must compare short implants, other feasible implant configurations, bone reconstruction and removable prosthetic solutions.

Depending on the support available, zygomatic implants can be combined with conventional implants at the front. If the bone at the front is also very deficient, a set-up with four zygomatic implants may be considered by an experienced team.

Maxillofacial expertise and 3D planning

The proximity of the sinus, the eye socket and nerve structures requires a team with specific training and experience in this surgery. Dr Afshin Yousefpour’s background in maxillofacial and reconstructive surgery is part of this overall analysis of the anatomy and the rehabilitation plan.

Your assessment in Brussels or Waterloo combines a clinical examination with a medical and prosthetic evaluation. Appropriate 3D imaging — CBCT (3D scan) or another examination depending on the indication — must allow the whole implant path and the condition of the sinuses to be studied. An ENT opinion may be needed.

Digital planning helps prepare the procedure; it does not replace surgical judgement and does not eliminate the risks. The place of surgery, the anaesthesia and the monitoring are decided according to its complexity and your health.

From temporary teeth to the final prosthesis

A fixed temporary prosthesis can sometimes be fitted on the day of surgery or in the following days. This possibility remains conditional: if stability or safety conditions are insufficient, loading is postponed.

The final prosthesis is made later, after healing and once the plan is confirmed. A suitable diet and precise instructions are needed during this period. Check-ups and daily cleaning remain essential, even with a fixed prosthesis.

Encouraging results, with risks to be aware of

A prospective cohort study of extra-sinus implants reported favourable results at eight years. Its small size and the lack of a comparison group mean it cannot guarantee individual results or prove that this approach is superior.

Possible complications include pain, swelling, infection, sinusitis, a communication between the mouth and the sinus, altered sensation and tissue recession exposing part of the implant. Failure to integrate or a prosthetic complication may require further surgery. Injury to the eye socket is rare but serious.

Regaining fixed teeth can improve chewing comfort and quality of life. It does not mean getting back a set of natural teeth, nor a treatment that needs no maintenance.

Your questions about zygomatic implants

References and further information

• ITI Consensus, 2023 — indications, preparation and complications.
• Migliorança et al., 2012 — prospective extra-sinus cohort, eight-year follow-up.
• Retrospective study, 2018 — extra-sinus paths and prosthetic outcomes.
• Davó et al., 2018 — randomised comparison with bone reconstruction, one-year results.