Shared characteristics and procedures
The three cases shared the following characteristics: the mandibular continuity was maintained with a vertical bone defect of at least 1 cm over a segment of at least 5 cm, and the distance between the inferior alveolar nerve or the base of the mandible and the alveolar ridge was smaller than 5 mm.
Two cases were due to extreme mandibular atrophy and pathological fracture, and in one case, the reconstruction of the height of the mandible was necessitated by a previous oncological surgery.
Regardless of the underlying cause, our objective with the reconstruction of the alveolar process was making aesthetic implant treatment possible and creating keratinised gingiva where possible. The latter is a basic prerequisite of long - term success in implant prosthetics [5,6,7,8]. In all presented cases, autologous vertical augmentation with free microvascularised flap was utilised.
An obvious advantage of vertical augmentation is that the surgical shaping of the dental alveolus allows the preparation of an aesthetically pleasing prosthetic work i.e. the teeth do not have to be excessively long to fit the increased vertical dimension. This way, the lips are also supported properly by the teeth, smoothing the wrinkles around the mouth, so the end result makes an even more natural impression [9].
During the reconstructive surgeries, the recipient site was prepared using external incision. In cases where the fibular flap was harvested without a skin paddle, the gingiva of the alveolar process was accessed without incision. In such cases, we consider it important to mobilize the gingiva to the highest possible extent to provide enough space for the flap. This is crucial also because the larger the vertically augmented component, that is, the farther the grafted bone distends from the plane of the floor of the mouth, the easier it is to induce keratinised gingival attachment on the site.
The alveolar process and the teeth support the lips in the frontal region and the cheek in the posterior region [9]. In the frontal region, the lip turns slightly outwards, thereby increasing the visibility of the vermilion border. In cases where the necessary mobilization of the gingiva without intraoral incision was considered infeasible, a fibula flap with a skin paddle was harvested.
The fibula flap was harvested from the donor site using a lateral incision according to Gilbert [10]. Transplantation to the recipient site was carried out according to Hidalgo et al. [11]. The flap was prepared using either a 3 mm muscle cuff or a perforator skin flap. When osteotomy was necessary for the adaption of the bone flap, the procedure was done carefully protecting the periosteal and vascular integrity of the flap. The flap was fastened to the recipient site using mini plates and screws. Suturing on the arterial side was done end-to-end using 8/0 polypropylene suture between the peroneal and the facial or the thyroid arteries. Suturing on the venous side was done either end-to-end between the peroneal and external jugular veins or end-to-side between the peroneal and the internal jugular veins.
The patients spent 10 days in hospital after the surgery. Postoperative antibiotic prophylaxis consisted of amoxicillin with clavulanic acid (1200 mg) and metronidazole (500 mg) iv. three times a day for a week, starting on the day of the surgery.
For each individual case, postoperative follow-up was scheduled at 1, 3, 6 and 12 months after the surgery, and then at 12-month intervals.
Case 1
The patient was a 59-year-old female who suffered a pathological fracture caused by the extreme atrophy of the mandible in 2012. Before the pathological fracture, the patient had struggled for altogether 12 years trying to have a properly fitting removable prosthesis made - to no avail, given the extreme atrophy. It turned out from the patient’s history that she had been treated for fracture of the right mandibular angle 11 years before, with miniplate osteosynthesis. Due to the extreme atrophy, though, one of the miniplates had to be completely removed 5 years later, as it had become exposed. The treatment of the pathological fracture (Fig. 1A) was done using free vascularised fibula flap for the vertical augmentation of the entire corpus of the mandible. This way, the risk of repeated fracture was eliminated and implant insertion became possible. The fibula flap was adapted without intraoral incision. The gingiva was mobilised to a great extent to provide enough space for the fibula flap, which is important because the larger the vertically augmented component, the easier it is to gain gingival attachment, especially in the frontal region [12]. The results bore this point out (Fig. 2C). Implantation took place 6 months after the reconstructive surgery. The patient received a locator-retained overdenture.
The panoramic x-ray taken at the 6-year follow-up (Fig. 1 bottom) revealed 2 mm horizontal bone resorption around the implant in the 33 position. No sign of inflammation was observed. The maximum probing depth around the implants was 2 mm and there was no bleeding on probing (Fig. 2C).
Case 2
The second case was also a pathological fracture of the severely atrophic mandible (Fig. 3 top). The 68-year-old female patient underwent reconstructive surgery in 2015. We used fibula graft with skin paddle because of the destruction of the mucosal tissue resulting from the compound fracture. Ten months after the surgery, we placed 6 implants and the skin flap was thinned to provide optimal gingival cover. On the 6 implants, we anchored a fixed, screw-retained, full-arch bridge. Similarly to Case 1, this patient had spent one and a half decades prior to the surgery trying to have properly fitting dentures made. Given the high degree of atrophy, all attempts failed. The applied reconstructive treatment restored function and the patient’s facial contours too (Fig. 4).
The panoramic x-ray taken at the 5-year follow-up (Fig. 3 bottom) revealed no bone resorption around the dental implants. Clinical examination confirmed no inflammation. The probing depths around the implants did not exceed 2 mm, and no bleeding on probing was detected.
Case 3
The fourth case involved reconstructive bone surgery of the left fronto-lateral portion of the mandible (Fig. 5 top). The patient was a 51-year-old male, who had previously undergone radical tumor surgery and soft tissue reconstruction with radial free flap with skin paddle. Two years after the oncological surgery, in 2008, as part of a series of reconstructive surgeries, our aim was to correct the shape of the alveolar ridge to prepare it for implant-based prosthetic treatment. To reach that end, free vascularised fibula flap was used. The skin flap was also corrected to provide optimal gingival cover. This way, we reached near ideal conditions for subsequent dental rehabilitation (Fig. 6). Implant placement was possible 10 months after the surgery. The patient received a locator-retained overdenture. The postoperative radiograph taken at the 5- year follow-up showed no bone resorption around the implants (Fig. 5 bottom) and the clinical examination revealed no sign of inflammation. The probing depths around the implants did not exceed 2.5 mm and no bleeding on probing was detected.
