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British Journal of Oral and Maxillofacial Surgery 57 (2019) 151–156

Microvascular reconstruction and dental rehabilitation of

benign severely atrophic jaws and defects of the alveolar
ridge: our philosophy in 2019
Gian Battista Bottini ∗ , Christian Brandtner, Christoph Steiner, Jörn Wittig, Felix Hartig,
Corina List, Alexander Gaggl
Department of Oral and Maxillofacial Surgery, University Hospital of the Private Medical University Paracelsus, Müllner Hauptstraße 48, A-5020
Salzburg, Austria

Received 5 October 2018; accepted 9 January 2019

Available online 23 January 2019

Abstract

We deal regularly with patients who present with severe atrophy of the jaws, compromised soft tissue, or penetrating defects of the alveolar
ridge that are not the result of malignant disease. For these patients we use microvascular bony flaps together with dental implants and
implant-supported prostheses. The purpose of this retrospective study was to present our current management and the lessons we have learned
over a 16-year period while treating 86 patients for these indications with 87 microvascular bone flaps. We used a transoral approach for the
anastomosis in 60 flaps, thereby avoiding visible scars, and inserted 281 dental implants to support fixed or removable dental prostheses. Two
femoral flaps developed partial necrosis, and seven implants were lost. Eighty-five of the 86 patients were satisfied with the improvement in
their orofacial function and aesthetics. Poor oral hygiene, active osteomyelitis, and severe bruxism are absolute contraindications.
© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Keywords: free flap; microvascular reconstruction; dental rehabilitation; dental implants; jaw atrophy; alveolar ridge defect

Introduction the maxilla is paper-thin, or because there are high risks of

fracture or close proximity to the inferior alveolar nerve in
We often deal with patients who present with generalised, the mandible.
severe atrophy of the jaw (class V–VI according to the Other patients have segmental defects of the alveolar
Cawood and Howell classification),1 and where removable ridge including: loss of the premaxilla; alveolar and palatal
tissue-borne dentures cannot offer adequate retention, sta- clefts with persisting oronasal fistulas in patients with cleft
bility, and support. Most of these patients have already had palate; the results of severe trauma; or iatrogenic defects
many augmentations and dental implants that have subse- after debridement for osteomyelitis or removal of large cysts.
quently failed, resulting in additional defects. In these cases Ultimately they are all “dental amputees”, affected by con-
short implants are not indicated, either because the bone of siderable reduction in their quality of life2 and wishing to
smile, chew, and speak with confidence.
The purpose of this retrospective study was to present our
∗ Corresponding author. current management protocol, and describe the lessons that
E-mail addresses: g.bottini@salk.at (G.B. Bottini),
c.brandtner@salk.at (C. Brandtner), c.steiner@salk.at (C.
we have learned in treating these challenging cases over a
Steiner), j.wittig@salk.at (J. Wittig), f.hartig@salk.at (F. Hartig), 16-year period (Table 1).
corina.list@wienkav.at (C. List), a.gaggl@salk.at (A. Gaggl).

https://doi.org/10.1016/j.bjoms.2019.01.002
0266-4356/© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
152 G.B. Bottini, C. Brandtner, C. Steiner, et al. / British Journal of Oral and Maxillofacial Surgery 57 (2019) 151–156

Table 1
Checklist and decision tree for rehabilitation of “dental amputees”.
1. Patients with poor oral hygiene, acute osteomyelitis, psychiatric
disorders, severe bruxism, or substance abuse are excluded from
treatment with implants and reconstruction
2. If there is a history of failed dental implants and augmentation, we
consider a microvascular flap
3. Influence of the degree of atrophy of bone — if it is:
* mild — we use graftless approaches
* moderate — we use grafts
* severe — we use flaps
4. Influence of soft tissue conditions — if they are:
*good we use graft-less/grafts
* poor we use flaps
5. Influence of length of localised alveolar bone defect: — if it is: Fig. 2. Position and exposure of the recipient’s vessels for intraoral anasto-
* <3 cm we use grafts mosis (facial artery and vein).
* >3 cm we use flaps

A total of 136 dental implants were inserted in those flaps

(3.4 implants/flap) 4–6 months after microvascular surgery,
loading taking place 4–6 months after implantation. Six
vestibuloplasties were done later to improve the condition
of the peri-implant soft tissues.

Series 2:2011–2018

Building on the experience of the first series, we have since

treated 46 patients with similar diagnoses. We retrospectively
analysed their records for diagnosis, treatment, complica-
tions, and outcomes.
We have excluded all tumour-related reconstructions
Fig. 1. Maxillary defect in a patient with a cleft after loss of teeth as a result
(immediate reconstructions after resections of head and neck
of periapical and marginal periodontitis and complete resorption of a bone tumours and delayed reconstructions for osteoradionecro-
graft with loss of three dental implants from peri-implantitis. sis, non-union, or medication-related osteonecrosis of the
jaws). We also excluded two non-compliant patients: one
with extremely poor oral hygiene and the other with severe
Patients and methods parafunctional habits and bruxism who later developed a
psychiatric disorder.
Series 1: 2003–2010 There were 20 men and 26 women, with a mean (range)
age of 45 (15–79) years.
Between 2003 and 2010 the senior author treated 40 patients Eight patients had generalised severe atrophy as a result of
at another unit. In this group, 14 patients had been edentu- longstanding edentulism, one had oligodontia, and one had
lous for some time, and 10 of them had generalised, severe, pycnodysostosis. Three had localised segmental defects of
atrophy of the jaw. Other conditions included post-traumatic the alveolar ridge as a result of edentulism, and they all had
defects (n = 16), cleft palate (n = 5), and debridement for a history of failed dental implants and augmentations. Six
osteomyelitis (n = 5). Eleven of the maxillary defects com- further patients had post-traumatic defects, and the others
municated with the nasal cavity or the maxillary sinus. had cleft palate (n = 16), segmental defects after debridement
Thirty-five of the 40 patients had already had 1–6 previous for osteomyelitis (n = 8), and removal of a large cyst (n = 3).
failed attempts at reconstruction and dental rehabilitation in For reconstruction of these 46 patients we used MFC flaps
the form of implants, osteodistraction, free non-vascularised (n = 39), FFF (n = 5), scapular flaps (n = 2), and one DCIA flap
autografts, and xenografts (Fig. 1). Most of these patients (one patient had two flaps). We reconstructed the maxilla in
presented with extensive scarring and atrophic soft tissues. 35 cases (Fig. 3) and the mandible in 12. As well as raising
The first intervention in all cases was reconstruction of the an MFC flap, we also harvested non-vascularised bone grafts
alveolar ridge with microvascular free flaps (medial femoral from the anterior iliac crest (n = 9) to improve the contours
condyle (MFC) (n = 18), deep circumflex iliac artery (DCIA) of the reconstructed segment (onlay grafts), for filling the
(n = 12), and fibular free flaps (FFF) (n = 10), for a total of 21 gaps between the MFC and native bone, or using it as a graft
reconstructions of the mandible and 19 of the maxilla). Of to lift the sinus floor. We covered the onlay grafts with the
those cases (27/40) had intraoral anastomoses (Fig. 2).3,4 vascularised periosteum of the MFC flap.
 G.B. Bottini, C. Brandtner, C. Steiner, et al. / British Journal of Oral and Maxillofacial Surgery 57 (2019) 151–156 153

Fig. 3. Maxilla after reconstruction of the alveolar ridge with a medial Fig. 4. Outcome after implant-borne fixed dental prostheses.
femoral condylar flap.
Series 2: 2011–2017
Surgical techniques for raising the FFF, scapular, and
DCIA flaps have been described extensively elsewhere.5–7 Two of the MFC flaps in this group partially necrosed and
For the MFC flap, we refer to the descriptions by Gaggl required debridement, but we could still insert implants in
et al,8 Brandtner et al,9 and Wong et al.10 We never used the flaps after they had healed. We lost 4/145 implants (3%).
a tourniquet. We were able to anastomose the vessels by a In one patient with DCIA flaps, we had to remove two
transoral approach in 33 of the 47 flaps. In the remaining 14 implants (out of three) because of recurrent osteomyelitis
flaps, we used an extraoral approach consisting of a 3 cm long of the transplant. The infection spread from the recipient
submandibular incision within a skin crease. site to the flap and proved refractory to medical treatment
The mean (range) duration of hospital stay was 13 (6–31) despite several courses of targeted antibiotics intravenously.
days. The same patient developed a haematoma of the abdominal
Four months after flap surgery with FF, DCIA, and scapu- wall and later a hernia despite the use of a mesh to prevent
lar flaps, and six months after MFC flaps, we defined in herniation. After removal of two implants and debridement,
3-dimensions the ideal number and positions of the implants this patient is currently free from infection. The third implant
according to the principle of backward planning (Planmeca has partially integrated but cannot support a dental prosthe-
® ® sis. We are not planning to insert any more implants given
ProMax 3D Max, software Planmeca Romexis ).
the high risk of recurrence of osteomyelitis in this case.
We used surgical guides to locate the ideal position for the
We had one case of sensitivity and motor deficit of the
implants at operation. For particularly complex cases we used
® lower extremity (complex regional pain syndrome) after
surgical navigation templates (Implant 3D software, Med
harvest of an MFC flap that resolved in six months with
3D, positioning device X1med 3D, Schick Dental).11 We
physiotherapy.
inserted a total of 145 dental implants (Straumann), roughly
Forty-five of the 46 were satisfied with their improvements
three implants in each flap (range 1–6), all submerged.
in orofacial function and aesthetics.
We loaded the implants four months after insertion in FF,
DCIA, and scapular flaps, and six months after MFC flaps,
because of the softer consistency of the bone in this flap. We Discussion
favour implant-supported removable overdentures in cases
of total edentulism, and fixed dental prostheses for localised Different options are available for reconstructing and rehabil-
defects. itating patients with advanced atrophy of the jaw: graft-less
(short and tilted implants, zygomatic implants, and osteodis-
traction), bone grafts, and free flaps.
Results
Graft-less
Series 1: 2003–2010
Using short or tilted implants is the simplest and most
In the first series, all transplants healed. Three patients cost-effective solution and can be done safely under local
reported hypoaesthesia of the lateral thigh after harvest of anaesthesia with minimal trauma and a short recovery time.
the DCIA flap, and one revision of a scar at the donor site It is more straightforward and has fewer complications than
was necessary after harvest of a FFF. Three implants out of augmenting and inserting standard implants.12,13 However,
136 (2%) did not osseointegrate. Functional and aesthetic short and tilted implants cannot be used when the alveolar
results were satisfactory in all cases (Fig. 4). ridge is missing entirely, when the basal bone is paper-thin
154 G.B. Bottini, C. Brandtner, C. Steiner, et al. / British Journal of Oral and Maxillofacial Surgery 57 (2019) 151–156

(maxilla), or when they would cause a mandibular fracture The second is soft tissue atrophy, as when the recipient bed
(residual mandible height less than 6 mm) or injury to the has depleted vascularity and atrophic or scarred soft tissues
neurovascular bundle. such as in patients with cleft palate, after trauma, or after
Zygomatic implants require considerable skill and general multiple operations. Thirdly, we use them for localised pen-
anaesthesia. They are associated with severe immediate com- etrating defects of the alveolar ridge more than 3 cm long.
plications (such as perforation of the orbit or the brain), or We use four bony flaps for these conditions:
delayed complications such as recurrent sinusitis and infec- 1. The MFC flap: which is ideal for localised defects.
tions even years after placement.14,15 Their failure rate is high Gaggl et al were to our knowledge the first to describe its
(11%)15 and their removal can be challenging, so we do not use in the reconstruction of the alveolar ridge in 2008.8 Its
use them. advantages over the FFF are lower donor site morbidity and
Osteodistraction can augment the alveolar ridge, either much greater flexibility in size, design, and indications. The
by splitting the bone or using distractors.16,17 However, this cuff of soft tissue is thin, like the gingiva. Grafts harvested
technique has limitations: osteodistraction in three directions from the iliac crest can then be added to the MFC with a
is not possible and the basal bone has to be high enough reduced risk of resorption, despite poor vascularity at the
with sufficient vascularisation and regenerative potential for recipient site, if the vascularised femoral periosteum of the
it to be successful. Distractors are technique-sensitive and MFC flap covers them.
can require regular long-term follow-up and good compliance The MFC flap is suitable for placement of an implant
from the patient. Given these difficulties we have abandoned because of the thin cortical layer. The bone is soft, and this
them, despite achieving good outcomes. must be borne in mind when inserting dental implants. For
this reason, we delay loading the implants for six months.
Bone grafts Patients can then usually bear weight immediately and make
a full recovery of power and range of movement in a matter
Autografts have osteoconductive, osteoinductive, and osteo- of weeks. We refrain from dissecting the infrapatellar branch
genetic potential.18 The drawbacks are complications that are of the saphenous nerve to avoid sensory disturbance in the
related to harvest and donor-site morbidity. Bone grafts func- infrapatellar area.
tion as scaffolds that are gradually resorbed and substituted 2. The FFF: for which the primary indication is gener-
by living bone. Their “take” depends on the recipient bed alised severe atrophy in the maxilla and the mandible (class
and, when local vascularity is poor, creeping substitution is V–VI according to Cawood and Howell).1 We also use it for
not possible and the graft is lost.19 bridging continuity defects in severely atrophic mandibles. It
For a severely atrophic maxilla, Chiapasco et al combined offers plenty of bone of excellent quality for placement of an
interpositional bone grafts with a Le Fort I osteotomy to implant, and can be cut to follow the curves of the alveolar
improve intermaxillary relations.20 However, they excluded ridge.24
patients with extensive scarring because of the high risk of It is not suitable for normal mandibles unless it is “double-
maxillary necrosis, and instead used reconstruction with a barrelled”,7 and is not an option if the peroneal artery is
FFF.20 the dominant or sole supply to the foot, as is sometimes the
case in patients with peripheral vascular disease.25 Donor-site
Free flaps morbidity consists of pain and disturbance of gait, whereas
complications are seromas, sensory and motor lesions, and
The size of a critical-sized bone defect is a matter of debate. prolongation of recovery.7
Schemitsch pointed out that not only size matters but also 3. The DCIA flap: which is well-suited for reconstruction
anatomical location, condition of soft tissues, age, and comor- of defects up to 10 cm long in the alveolus and the basal
bid conditions.21 Allsopp et al made a systematic review to bone in normal mandibles. We also use it for reconstructing
identify a cut-off value between grafts and vascularised flaps maxillary defects that extend up to the midline (alveolus and
in the reconstruction of a bony defect, but could not find palate). It is associated with more serious donor site mor-
any convincing evidence to pinpoint a value, though they did bidity than the MFC or the FFF flaps (dysaesthesia, pain,
concede that vascularised transplants outperform grafts as disturbance of gait, hernia, and seromas), but this depends
their length increases.22 Benlidayi et al showed that, even on the volume of the muscle cuff. It may be quite bulky or
in a healthy animal model with greater healing potential difficult to raise with a small soft tissue component, particu-
than a human and with optimal soft tissue conditions, free larly in overweight patients, so its volume can be excessive
bone flaps maintain their microscopic architecture better than for reconstruction of defects of the alveolar ridge.
grafts because they do not degenerate with resorption and 4. The scapula flap: because it is flat, it is suitable for
substitution.23 We have identified three main indications for covering palatal and alveolar defects that extend beyond the
using microvascular flaps for reconstruction of the alveolar midline, and subtotal or total maxillary defects. However,
ridge in patients without tumours. only the lateral margin and the tip offer enough height for
The first is hard tissue atrophy - generalised severe atrophy placement of implants, and even those areas can be too thin in
of the jaw (class V–VI according to Cawood and Howell).1
 G.B. Bottini, C. Brandtner, C. Steiner, et al. / British Journal of Oral and Maxillofacial Surgery 57 (2019) 151–156 155

Table 2 Ethics statement/confirmation of patients’ permission

Specific indications for a bony flap according to the size and morphology of
the bony defects and the jaws involved. No ethics approval or patients’ permission was required for
Bony defect Flap this paper. Patients’ permission was not required as no iden-
1. Localised defects of alveolar bone in both Medial femoral tifying information is included.
jaws condyle
2. Generalised severe atrophy of the alveolar Free fibular
bone in both jaws
3. Continuity defects in the severely atrophic Free fibular
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