Key messages
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Compared to standard dental screw implants placed after building up the jawbone, longer screws placed in the cheekbone were less likely to fail and allowed working replacement teeth to be fitted much sooner, but led to more complications.
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Drilling the holes that receive the implant screws can be done with a standard rotary (spinning) tool or a vibrating tool that 'shaves' the bone (piezoelectric surgery). There may be little or no difference between the two methods in terms of how durable the implants or replacement teeth are, or the risk of complications, but rotary drills are probably faster.
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Few studies have looked at these issues. We need more and bigger studies to have more confidence about the benefits and risks.
What happens when people have no or few natural teeth?
When teeth are lost, the surrounding bone can gradually shrink because it is no longer stimulated by chewing. The amount of bone loss varies from person to person. It can be so severe that people are unable to wear removable dentures comfortably. This can make eating and speaking difficult and may affect confidence, well-being, and social relationships. Dental implants can help address these problems.
What are dental implants, and how do they help?
Standard dental implants are short screws (0.5 to 2 cm long) placed into the jawbone which act like artificial tooth roots. Dentists can attach permanent ('fixed') teeth to them, or removable or semi-removable dentures.
Cheekbone implants ('zygomatic implants') are longer: about 3 to 5 cm. They are used when the upper jawbone has shrunk so much that there is not enough bone left to hold standard implants securely. Cheekbone implants almost always support fixed teeth, not removable dentures.
With cheekbone implants, fixed teeth can often be placed on the same day as the implants. This is because they avoid the need for jawbone grafting, which is when a surgeon adds new bone (or bone-like material) to the jaw so it can support an implant. Bone grafting is complex, expensive, and time-consuming. It may require several surgeries and take more than a year before replacement teeth can be fitted.
Cheekbone implant screws can be placed using rotary drills or piezoelectric surgery, which uses sound vibrations to cut bone and may be less traumatic. Cheekbone dental implants can lead to complications, and the potential benefits need to be weighed against these risks.
What did we want to find out?
We wanted to find out if, compared to standard implants in grafted jawbone, cheekbone implants led to fewer:
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replacement teeth failures – where the teeth break or loosen;
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implant failures – where the implant screws become unstable;
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complications.
We also wanted to find out:
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which type of implant led to higher satisfaction and faster rehabilitation;
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which method for implant site preparation was faster for surgeons and preferred by people undergoing treatment.
What did we do?
We searched for studies that compared:
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cheekbone implants to standard implants in grafted jawbone in people with severe bone loss in the upper jaw; or
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different ways to prepare the cheekbone implant site.
We compared and summarised the study results, and rated our confidence in the evidence, based on factors such as study methods.
What did we find?
We found two small studies that followed participants for three years. They were both carried out in Europe. One compared cheekbone implants to standard implants in grafted bone, and involved 71 people. The other compared piezoelectric surgery to rotary drills for preparing the implant site, and involved 20 people.
Main results
After three years, compared to standard implants in grafted jawbone, cheekbone implants:
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may have led to fewer replacement teeth failures: for every 100 people treated, about 12 fewer people with cheekbone implants had problems with their replacement teeth;
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probably had fewer implant failures: for every 100 people treated, about 22 fewer people with cheekbone implants had problems;
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probably led to more complications: roughly four-fifths of people with cheekbone implants had complications, compared to about half of the people with standard implants.
We do not know which procedure left people more satisfied. However, people who received cheekbone implants probably received their new teeth much sooner – in a little more than 1 day – than those with standard implants, where it typically took 444 days before replacement teeth could be fitted.
In the study that compared two methods (piezoelectric surgery versus rotary drills) for preparing the implant sites, after three years, there may be little or no difference between them in terms of:
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replacement teeth failures;
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implant failures;
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complications;
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people's preference.
However, rotary drills probably made implant placement faster by more than 9 minutes.
What are the limitations of the evidence?
Our confidence in the evidence ranged from very low to moderate. We found only two studies testing these approaches, and they involved few people. More well-designed studies are needed to identify the best methods.
How up to date is this evidence?
The evidence is current to November 2025.
Read the full abstract
Dental implants are used for replacing missing teeth. Placing dental implants is limited by the presence of adequate bone volume permitting their anchorage. Several bone augmentation procedures have been developed to solve this problem. Zygomatic implants are long screw-shaped implants developed as a partial or complete alternative to bone augmentation procedures for the severely atrophic maxilla. One to three zygomatic implants can be inserted through the posterior alveolar crest passing through the maxillary sinus, or externally to it, to engage the body of the zygomatic bone. A couple of conventional dental implants may also be needed in the frontal region of the maxilla to stabilise the prosthesis. The potential main advantages of zygomatic implants could be that bone grafting may not be needed and a fixed prosthesis could be fitted sooner. Another specific indication for zygomatic implants could be maxillary reconstruction after maxillectomy in cancer patients.
Objectives
To assess the effects of zygomatic implants for the rehabilitation of people with severely atrophic maxillae requiring implant-supported prostheses by comparing: (1) zygomatic implants with or without bone augmentation procedures versus conventional dental implants in augmented bone; (2) zygomatic implants with or without conventional implants versus subperiosteal implants; (3) one type of zygomatic implant or technique versus another type or technique.
Search strategy
We used CENTRAL, MEDLINE, Embase, and two trial registers, together with reference checking and contact with study authors to identify the studies included in the review. We conducted searches in November 2025.
Selection criteria
Randomised controlled trials (RCTs) including participants with severely resorbed maxillae, who could not be rehabilitated with conventional dental implants, treated with zygomatic implants with and without bone grafts versus participants treated with bone augmentation procedures and conventional dental implants, with a follow-up of at least one year in function.
Data collection and analysis
Two review authors would have extracted data from eligible studies and assessed their risk of bias independently and in duplicate. The results of included studies were to be combined in meta-analyses using random-effects models where there were more than four studies, and fixed-effect models where there were less than four studies. We would have expressed the estimate of the intervention effect as mean difference for continuous outcomes and risk ratio for dichotomous outcomes, with 95% confidence intervals. Heterogeneity was to be investigated including both clinical and methodological factors.
Main results
We did not identify any RCTs which were eligible for inclusion in this review.
Authors' conclusions
At three years, zygomatic implants probably reduce time to rehabilitation compared with bone grafting (1.34 versus 444.32 days). They probably reduce implant failures and probably increase the risk of complications. Zygomatic implants may reduce prosthetic failures, but the estimates are imprecise. The effect on patient satisfaction remains uncertain.
Compared with piezoelectric surgery, rotary drills probably reduce implant placement time. For prosthetic failures, implant failures, complications, and patient preference, piezoelectric surgery may have little to no effect, and important benefit or harm cannot be ruled out because of very wide confidence intervals. Implant site preparation with piezoelectric surgery is probably slower and may not always be feasible in the presence of very dense bone.
Overall, the evidence base for both comparisons is limited and is affected by imprecision, which restricts the confidence with which these findings can be applied in clinical settings. More well-designed RCTs are needed to reduce the current uncertainty.
Funding
This Cochrane review was funded (in part) by Vita-Salute San Raffaele University, Milan.
Registration
Protocol: (2003): 10.1002/14651858.CD00415
Original review (2003): DOI: 10.1002/14651858.CD004151
Review update (2005): DOI: 10.1002/14651858.CD004151.pub2
Review update (2013): DOI: 10.1002/14651858.CD004151.pub3
