Not enough bone for implants: grafts, sinus lifts and zygomatic implants

If a dentist has told you there is not enough bone for implants, you are usually being offered one of four routes: build the bone up with a graft, lift the sinus floor and graft beneath it, use shorter implants that fit the bone you have, or anchor long zygomatic implants in the cheekbone. Each can work. Most of them take longer than a single short trip, and the one that can be done quickly is specialist surgery with its own risks.

Why the bone is missing

After a tooth is lost, the ridge of bone that held it tends to shrink over time. In the upper back jaw there is a second problem: the maxillary sinus sits directly above the roots of the back teeth, so once the teeth are gone there may be only a few millimetres of bone between the mouth and the sinus. The Cochrane review cited below describes this combination as a common problem when placing implants in the upper back jaw.

Whether you actually lack bone, and how much, is a measurement, not an impression. It is normally assessed on a 3D scan (cone beam CT, or CBCT). Ask to see the scan and for the measurements to be written down.

The options, in plain terms

Bone grafting

Bone is added to widen or heighten the ridge. It can be your own bone (autogenous — taken from elsewhere in the mouth or, for large reconstructions, the hip), or a substitute: processed human or animal bone, or synthetic material, often combined with a membrane. A systematic review by Al-Nawas and Schiegnitz (European Journal of Oral Implantology, 2014; 52 studies in the qualitative review, 14 in the meta-analysis, minimum mean follow-up of 10 months) found implant survival in sinus and ridge augmentation broadly similar whichever material was used — for example 97.4% with substitute materials and 98.6% with the patient’s own bone in ridge augmentation — and concluded there was no evidence that the patient’s own bone was superior. The authors flagged that defect size and graft volume were poorly described in the underlying studies.

Sinus lift (sinus floor elevation)

The lining of the sinus is lifted and graft material placed underneath, creating height for implants in the upper back jaw. There are two main approaches. The lateral window approach opens a small window in the side wall of the sinus and suits larger lifts. The transcrestal (crestal or osteotome) approach works up through the implant hole itself; the Cochrane review describes it as less invasive and usually done together with the implant.

The recognised complications are specific. Stacchi and colleagues (International Journal of Oral & Maxillofacial Implants, 2017; 21 randomised and 11 prospective controlled trials) found that perforation of the sinus membrane occurred in 15.7% of lateral-window procedures overall, and was the most frequently reported complication during surgery; bleeding from vessel injury was rare (0.4%). A later review by Hsu and colleagues (Clinical Implant Dentistry and Related Research, 2022; 74 studies, 4,411 sinus lifts) listed membrane perforation, wound breakdown, graft exposure or failure and sinusitis as the complications most often needing treatment after lateral-window lifts, and found more perforations and sinusitis with the lateral approach than the transcrestal one. Some studies reported positional vertigo after transcrestal lifts.

Short implants

Where some bone remains, shorter implants may avoid a graft altogether. The Cochrane review by Esposito, Felice and Worthington (2014; 18 randomised trials, 650 patients) looked at four trials comparing short implants (5 to 8.5 mm) with sinus lift where 4 to 9 mm of bone remained. At one year after loading there was not enough evidence to say either approach lost more implants or bridges, but there were more complications at sites treated with a sinus lift. One year is short, and the authors rated the evidence moderate quality.

Zygomatic implants

For a severely shrunken upper jaw, very long implants can be anchored in the cheekbone (zygoma), avoiding grafting; in some protocols teeth are fitted straight away. A systematic review and meta-analysis by Brennand Roper and colleagues (International Journal of Implant Dentistry, 2023; 18 studies, 1,349 zygomatic implants in 623 patients, mean follow-up about six years) reported mean implant survival of 96.2% at six years and prosthesis survival of 94%; survival was higher with immediate loading (98.1%) than delayed loading (95%). Sinusitis was the most common biological complication, with a prevalence of 14.2% at five years. An earlier review by Chrcanovic and Abreu (Oral and Maxillofacial Surgery, 2013; 42 studies) recorded sinusitis, soft-tissue infection, numbness and oro-antral fistulas (an opening between mouth and sinus), warned these were probably under-reported, and stated that the procedure “requires very experienced surgeons” because the eye socket and brain lie close by. It also noted that most failures were found at or before the stage about six months after placement.

Healing time is the real conflict with a one-trip package

Grafts and sinus lifts are usually done in one of two ways. In a simultaneous (one-stage) approach the implant goes in at the same operation as the graft. In a staged (two-stage) approach the graft is placed first and left to heal, and the implants follow in a second operation. The Cochrane review notes that the staged approach “requires an additional surgical episode”.

The trials in that review show what the waiting looks like. In one (Torres 2009), patients with up to 4 mm of bone had the sinus grafted first and implants placed six months later, and implants were then left unloaded for a further six months. In another, grafts healed for six months, then implants were placed and left submerged for four months. Iliac crest block grafts in a third were left to heal for three to four months before implants.

So a plan to graft, place implants and fit permanent teeth in one short visit deserves a direct question. It may be that your case suits a simultaneous approach, short implants or zygomatic implants — a clinician who has examined you and your scan has to decide that. But if staging is needed, you are looking at at least two trips spread over months. See how many days implants take and implants in one trip for the wider timeline; All-on-4 versus All-on-6 covers the full-arch plans often discussed alongside these options.

Questions to ask before you agree

• What exactly is the bone deficit, in millimetres, and where? May I have the CBCT scan and report?
• Which procedure are you proposing, and why this one rather than short implants, a graft or a staged approach?
• Is it simultaneous or staged? How many months between each stage, and how many trips?
• What graft material will be used — my own bone or a named substitute — and where would my own bone be taken from?
• For a sinus lift: lateral window or transcrestal? What happens if the membrane tears during surgery?
• For zygomatic implants: who places them, what is their training, and how many have they placed? Is this done under sedation or general anaesthetic, and where?
• If sinusitis, infection or a failed implant appears after I fly home, who treats it, who pays, and will you send full records and implant details to a dentist at home?

Get the answers in writing, alongside an itemised quote that separates the scan, each surgical stage, graft materials, implants, temporary teeth and final teeth. The site publishes no prices; our guides on what a treatment quote should include and questions before paying a deposit explain what to check.

Checking the facility and the surgeon

You can see which authorised facilities declared sinus lift or dental and zygomatic implants on the Ministry register. A declaration means the facility listed the treatment, not that it performs it well. If a clinic does not appear, it may be listed under a different legal name or spelling, so search before drawing conclusions. To check the individual surgeon, see how to check a doctor in Turkey, and for the wider picture read our guide to dental implants in Turkey.

Nothing here is advice about your own mouth. Whether you need a graft, a sinus lift, short implants or zygomatic implants is a decision for a qualified clinician who has examined you and your scans.