Minimally invasive rehabilitation of a severely atrophic and fully edentulous maxilla using 4-mm-ultrashort implants: A case report with 1-year follow-up


This case report describes an alternative minimally invasive treatment option using 4-mm-long ultrashort implants placed to rehabilitate a severely atrophic edentulous maxilla. The patient, coming from a full removable denture, asked for an implant prosthesis avoiding reconstructive surgeries and expensive procedures. Considering that the mean available bone was about 4.8 mm in height on Cone Beam Computed Tomography (CBCT) scans, 6 implants were placed where bone volumes were sufficient to receive 4-mm-ultrashort implants. Six months after implant placement an implant-supported bar-retained overdenture prosthesis was delivered. The healing process was uneventful and 1 year after loading the result appears clinically and radiographically stable and the patient is fully satisfied. The described approach, despite some prosthetic compromises, within all the limitations of this case report, might be applied in selected cases, reducing rehabilitative times, possible complications and costs. However, longer follow-ups on large number of patients coming from Randomised Controlled clinical Trials (RCTs) are necessary before making more reliable recommendations.


  • The patient asked for an implant prosthesis avoiding reconstructive surgeries.

  • 4-mm ultrashort implants to rehabilitate a severely atrophic edentulous maxilla.

  • The healing process was uneventful and 1 year after loading the result is stable.

  • The described approach may reduce rehabilitative times, complications and costs.


The rehabilitation of patients with fully edentulous maxillae can be a common clinical situation [ ]. For a long time, the usual solution to treat these cases has been a traditional removable full denture prosthesis. However, this method of treatment has a large number of limits, which currently makes it unacceptable by many patients.

Nowadays, with an increase in average life expectancy, clinicians often have to deal with completely edentulous patients with functional and aesthetic needs asking for implant rehabilitations [ ].

In cases of available bone volumes, it is possible to rehabilitate the upper jaw using various implants solutions. However, there are also clinical conditions with posterior bone atrophies, in these cases, it is possible to exploit the front patient’s bone tilting implants in different ways, also with immediate loading protocols [ , ]. Another option could be to place standard implants in the anterior non-atrophic bone performing posterior bone augmentation surgeries [ ].

Also, there are cases of extreme atrophy where there is no posterior or anterior available bone to receive any standard implants; in these situations, surgeons can apply different approaches. Various reconstructive techniques can be used to augment bone for long implant placement, the most known are Guided Bone Regeneration (GBR) with titanium meshes [ ], onlay bone grafts [ , ] and sinus lifting surgeries [ ]. However, these procedures are associated with postoperative complications, long rehabilitative times and tend to be expensive.

Zygomatic [ , ] and pterygoid [ ] implants placement can be an alternative to bone augmentation surgery in patients with a severely atrophic maxilla. Nevertheless, these kinds of rehabilitative treatments are often associated with hospitalization, general anesthesia, and require particular surgical skills.

So another option for the rehabilitation of severely atrophic upper jaws might be to place short implants. Encouraging short-term results on implants with a minimum length of 5 mm were reported in the literature [ ].

However, according to the authors’ present knowledge, there are no studies on extreme maxillary atrophies allowing the placement of only 4-mm-long implants. This case report describes a preliminary case of an extremely atrophic and fully edentulous upper jaw rehabilitated with 4-mm-supershort implants with results at 1 year after prosthetic loading.

Materials and methods

A 71-year-old female in good general health was referred, complaining about functional masticatory insufficiency at her upper jaw, asking for implant rehabilitation.

Clinical and radiographic baseline data (Orthopantomography, OPG) revealed a fully edentulous maxilla. Cone Beam Computed Tomography (CBCT) scans showed a mean residual bone height of about 4.8 mm with different levels of vertical and horizontal bone atrophy ( Fig. 1 ). At the time of the first examination, the patient wore a fully removable upper denture, which according to the anamnesis was delivered several years ago. Over time, the patient was no longer satisfied with the removable solution and asked for a cheap implant rehabilitation avoiding any reconstructive surgery.

Fig. 1
( a f ): Baseline Cone Beam Computed Tomography (CBCT) scans showing a fully edentulous maxilla with different degrees of extreme bone atrophy.

Trying to meet patient’s needs, a minimally invasive approach was proposed using implants with a length of 4 mm for subsequent implant-retained prosthetic rehabilitation. The patient underwent professional oral hygiene 2 weeks before surgery and gave informed consent for all the procedures. Two grams of amoxicillin were administered 1 hour prior to implant placement and the patient rinsed for 1 minute with 0.2% chlorhexidine solution just before surgery. The surgical procedure was performed under local anesthesia (4% articaine, 1:100,000 adrenaline). A crestal incision was made along the entire maxilla with distal releasing incisions and full-thickness flaps were elevated.

Six 4 × 4 mm transmucosal ultrashort implants (Twinkon 4, Global D, Brignais, France) were then placed where sufficient bone volumes were available. In case of less than 4 mm of residual bone, supershort implants where placed palatally and when needed a crestal sinus lifting approach, placing just collagen sponges to protect the sinus membrane, was performed [ ]. However, posteriorly, at least 2 mm of vertical residual bone were needed in order to stabilize the implants, so there were parts of the left maxilla not useable at all. At the end, all the implants had good primary stability.

Flaps were then closed with resorbable sutures and a post-surgical OPG was taken to verify the correct implant position ( Fig. 2 ). The patient was then prescribed 1 g of amoxicillin with clavulanic acid twice a day for 6 days, 600 mg of ibuprofen to be taken with meals twice a day for two days and oral betamethasone (4 mg the first day, 3, 2, 1 mg the followings). The patient was instructed to place 1% of chlorhexidine gel on the wound twice a day for 2 weeks and to avoid brushing and trauma on the surgical site; a soft diet was also advised.

Mar 21, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Minimally invasive rehabilitation of a severely atrophic and fully edentulous maxilla using 4-mm-ultrashort implants: A case report with 1-year follow-up
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