A cyst has been found in my jaw: can I have implants, and when?

A jaw cyst is a sac with fluid or semi-fluid contents that develops inside the bone; a tumour, by contrast, is a solid mass formed by abnormal cells. Cleveland Clinic's patient page writes that the vast majority of these growths are benign, that many cause no symptoms, and that they are often found by chance on a dental X-ray. The most common type is a cyst that develops at the root tip of a dead or inflamed tooth (a radicular cyst); second among odontogenic cysts comes the dentigerous cyst, which forms around the crown of a tooth that has stayed buried in the jaw. The same source lists cysts and tumours together and writes that a biopsy determines the type; one of these tumours, ameloblastoma, which grows slowly in the lower jaw, can come back in up to 20% of cases. That is why the definite diagnosis is made not by an image but by a biopsy, or by examining the removed tissue under a microscope.

A study from Switzerland shows clearly how common incidental findings are. At the University of Bern, 404 cone beam CT scans taken for implant planning were reviewed, and at least one incidental finding turned up in 82% of them, an average of 1.9 findings per scan. The most common finding was thickening of the sinus lining. Root-tip cysts larger than five millimetres and other odontogenic cysts were each seen in about 1% of patients, and no malignant tumour was found in any of the 404 scans. The findings led to a need for further dental treatment in 31% of cases and for referral to another specialist in 5%. So a cyst on a CBCT scan is usually a manageable finding, but it is not a detail to ignore.

The odontogenic keratocyst has a place of its own within this picture. Its share among jaw cysts is reported as between 2% and 21.8% in published series, and as 14.8% in the Hacettepe archive. The keratocyst is seen most often in the back of the lower jaw and in the ramus, the part of the jawbone that rises upwards. Because of its aggressive behaviour, its high recurrence rate and the gene changes found in it, the World Health Organization moved it into the tumour category in 2005 and named it the keratocystic odontogenic tumour. In the 2017 classification it returned to the cyst category; the reasons given were that it can also regress with less aggressive treatment, and that the genetic changes linked with it are also seen in other cysts that are not tumours. The explanation of how recurrence happens, proposed in 1976 and still cited today, lists three routes: the cyst wall not being removed completely, new cysts developing from small satellite cysts left behind, and a new cyst forming in a neighbouring area.

It is not possible to give a single figure for recurrence rates, and that in itself tells you something. In the literature compiled by a study published in the Journal of Maxillofacial and Oral Surgery in 2024, rates range from 2.5% to 62%: from 17% to 56% in series where the cyst was simply removed, and from 1% to 8.7% when removal was combined with shrinking the cyst first or with a chemical adjunct such as Carnoy's solution. In the same study's own series of 180 patients, the cyst came back in 27.2% of patients within five years. Four features were found to predict recurrence independently: extension into soft tissue, perforation of the bone's outer shell, a multi-chambered appearance on imaging, and satellite cysts seen on examination. The figures are so scattered because treatment methods, follow-up periods and ways of reporting differ; there is no randomised trial comparing the methods directly.

Data from Turkey is particularly instructive on the length of follow-up. In Hacettepe University's series, in which the cyst was removed and the surrounding bone surface was also cleaned, the cyst came back in 14.8% of 27 patients followed for an average of five years. Recurrence appeared after 4.5 years on average, between 3 and 6 years. The authors write that a keratocyst can always come back, but that most recurrences are seen in the first 5 to 7 years, and they recommend extending follow-up to at least 10 to 15 years. In the same series, two of the four recurrences were in toothless jawbone; the authors link these to an initial operation that had not been thorough enough. For implants, the meaning is clear: the toothless bone where the implant will sit is also where a recurrence can appear.

More than one keratocyst raises a separate question. Cleveland Clinic writes that these cysts can be a sign of Gorlin syndrome, an inherited condition that also raises the risk of skin cancer. The Hacettepe series also excluded from its analysis patients who had several cysts at once and had been diagnosed with this syndrome. If the syndrome is suspected, follow-up is not limited to the jaw, and the implant plan also has to take this long follow-up into account.

After a cyst is removed, the cavity can fill with bone by itself, but this takes time. A Korean study published in Scientific Reports measured the volume of the cavity on CBCT scans before and after surgery in 44 patients who had a cyst removed. Patients were scanned at different times rather than followed year by year: on average 33.5% of the cavity had filled in those scanned between 6 and 12 months, 74.5% in those scanned between one and two years, and 74.2% in those scanned later. With cysts of three cubic centimetres or larger, the remaining cavity was clearly larger and the outer contour of the bone had changed; healing was better in those under 30 and in women. The authors write that additional procedures such as bone grafting can be considered for large cysts. In another retrospective study of 73 patients from Italy, placing graft material and a membrane in the cavity after removing root-tip cysts in the upper jaw did not significantly change bone filling at 12 months: an average of 75% in the group without a graft and 82% in the group with one. In the Italian study, the filling rate falls as the cyst gets bigger; in the Korean study, size did not affect the rate, but with large cysts the cavity left behind stayed larger in volume.

Data looking directly at implants after a keratocyst, however, is scarce. A series from India published in the National Journal of Maxillofacial Surgery includes 20 patients who had a keratocyst removed from the back of the lower jaw; the cyst cavity was left to heal without a graft, and once enough bone was seen to have formed, 48 implants were placed in 19 patients. Over five years of follow-up the cyst did not come back, and one patient lost an implant, probably because the bone that had formed was weak. Its limits are plain too: it is a small, retrospective series from a single surgeon; smokers and people with systemic diseases were not included; Carnoy's solution was added to the cleaning of the surrounding bone in every patient; 3 of the 20 cysts were of the orthokeratinised type, which has a low tendency to recur; and the timing of the implants is given as six months in the article's abstract and as one year in its methods section. We could not find a study comparing implant timings. The practical line today rests not on a set time but on the bone seen on the follow-up image and on the known type of cyst.

From our point of view, the topic matters in a jaw with a history of cysts and more than one missing tooth. Diagnosing and treating a cyst in the area of a single tooth is a job for your dentist and an oral and maxillofacial surgeon. With many missing teeth, however, the plan has to take into account whether the cyst area has healed, what the pathology report says, and follow-up that will go on for years. Whichever implant method is chosen, a cyst cavity whose healing has not been confirmed on imaging does not count as a foundation for an implant.

The distinction below shows the general line of published series and clinical practice. The decision is made by the dentist who reads your images and your pathology report.

The sequence below shows the steps generally followed for a patient who has a cyst in the jaw and is considering implants in the future. How long each step takes varies with the type and size of the cyst.

1. 1

   Reading the image

   On the CBCT scan, the dentist assesses the borders of the growth, whether it has one chamber or several, whether it has perforated the outer shell of the bone, and how it relates to neighbouring teeth, the nerve and the sinus. This information makes it possible to plan treatment, but it does not make a diagnosis.

2. 2

   Biopsy and pathology

   The definite diagnosis is made by examining the tissue sampled or removed under a microscope. Ask for a copy of the report; if another dentist needs to plan treatment years later, it will be the most valuable document you have.

3. 3

   Treating the cyst

   Most cysts are removed in a single session. With large keratocysts, a window is first opened to shrink the cyst, and the main removal is carried out months later. To reduce the risk of recurrence, cleaning of the bone surface or a chemical adjunct may be added.

4. 4

   Monitoring how the bone fills in

   Follow-up images show how far the cavity has filled. With large cysts, the remaining cavity and a changed bone contour can bring a decision about a graft into the picture.

5. 5

   The implant plan and the follow-up plan, together

   If the bone is sufficient and the type of cyst is known, implants are planned. With a keratocyst, the plan includes regular X-ray check-ups in the years after the implant too.

6. 6

   Questions you can ask your dentist

   What type of cyst does the report say it is? If it is a keratocyst, is it parakeratinised or orthokeratinised? Were satellite cysts seen? Was the cyst removed in one piece, and was any additional procedure carried out? What is the check-up schedule? Has the bone at the implant site been confirmed on a CBCT scan? Is an assessment for a syndrome needed?

7. 7

   Send us your images if more than one tooth is missing

   If you are considering implants in a jaw with a history of cysts and more than one missing tooth, send the panoramic X-ray or CBCT scan you have through the form, together with the pathology report if you have one; the dentist who will carry out the treatment reads the image, and we will reply within 24 hours. This is a preliminary assessment; the final decision is made after an examination and a CBCT scan.

In the period after a cyst, an implant is not the only option, and it is usually discussed together with the other topics below.

A history of cysts does not rule out implants, but problems arise when the order of steps or the follow-up is skipped. These are the traps met most often.

The sequence below shows the general course for a patient considering implants after a cyst has been removed. Timings vary with the type and size of the cyst and with your age.

1. The first weeks after surgery

   The soft tissue closes, and swelling and tenderness ease. Follow your surgeon's instructions on eating and oral hygiene; with large cavities, you may be asked to avoid hard foods that would put strain on the area.

2. The first year

   The cavity fills gradually. In the Korean study, a third had filled on average in those imaged between 6 and 12 months; in the Italian upper jaw series, cavities without a graft had filled by an average of 75% at 12 months. The pace varies with the patient and the cyst. Follow-up images are taken to monitor both the filling and any recurrence.

3. The second year

   Most of the filling is complete by this point. The implant decision is made not by the calendar but by the bone seen on the follow-up CBCT scan.

4. The years after the implant

   With a history of keratocyst, regular X-ray check-ups continue. The authors of the Turkish series recommend extending follow-up to at least 10 to 15 years.

You will not find figures here. In a jaw with a history of cysts, the scope of a quote is set by these items:

Diagnosis and imaging

The biopsy, the pathology examination and the number of follow-up CBCT scans vary with the type of cyst and the length of follow-up.

How many stages the cyst treatment has

A small cyst removed in a single session and a large keratocyst that is shrunk first and removed months later are not the same job.

Whether a graft is needed

If the cavity can be expected to fill by itself, no material is needed; with large cavities whose contour has been lost, a graft and a membrane may be added.

The number of implants and the type of teeth

How many teeth are missing, how many implants are planned and which fixed teeth will be made on top are the items that do most to set the total.