Surgical options in oroantral fistula management: a narrative review

Abstract

Abstract An oroantral fistula (OAF) is a pathological abnormal communication between the oral cavity and the maxillary sinus which may arise as a result of failure of primary healing of an OAF, dental infections, osteomyelitis, radiation therapy, trauma, or iatrogenic complications. With the presence of a fistula, the maxillary sinus is permanently open. Microbial flora passes from the oral cavity into the maxillary sinus, and the inflammation of the sinus occurs with all potential consequences. In literature, various techniques have been proposed for closure of OAFs. Due to the heterogeneity of the data and techniques found, we opted for a narrative review to highlight the variety of techniques discussed in the literature. Techniques of particular interest include the bone sandwich with resorbable guided tissue regeneration (GTR) membrane and platelet-rich fibrin (PRF) used alone as both a clot and a membrane. The great advantage of these techniques is that no donor site surgery is necessary, making the outcome valuable in terms of time savings, cost and, more importantly, less discomfort to the patient. Additionally, both bony and soft tissue closure is performed for OAF, in contrast to flaps, which are typically used for procedures in the sinus area. The reconstructed bony tissue regenerated from these techniques will also be appropriate for endosseous dental implantation.

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R E V I E W Open Access
Surgical options in oroantral fistula
management: a narrative review
Puria Parvini
1
, Karina Obreja
1*
, Robert Sader
2
, Jürgen Becker
3
, Frank Schwarz
1,3
and Loutfi Salti
1
Abstract
An oroantral fistula (OAF) is a pathological abnormal communication between the oral cavity and the maxillary
sinus which may arise as a result of failure of primary healing of an OAF, dental infections, osteomyelitis, radiation
therapy, trauma, or iatrogenic complications. With the presence of a fistula, the maxillary sinus is permanently open.
Microbial flora passes from the oral cavity into the maxillary sinus, and the inflammation of the sinus occurs with all
potential consequences. In literature, various techniques have been proposed for closure of OAFs. Due to the
heterogeneity of the data and techniques found, we opted for a narrative review to highlight the variety of
techniques discussed in the literature. Techniques of particular interest include the bone sandwich with resorbable
guided tissue regeneration (GTR) membrane and platelet-rich fibrin (PRF) used alone as both a clot and a membrane.
The great advantage of these techniques is that no donor site surgery is necessary, making the outcome valuable in
terms of time savings, cost and, more importantly, less discomfort to the patient. Additionally, both bony and soft
tissue closure is performed for OAF, in contrast to flaps, which are typically used for procedures in the sinus area.
The reconstructed bony tissue regenerated from these techniques will also be appropriate for endosseous dental
implantation.
Keywords: Oroantral, Fistula, Flaps, Grafts, Maxillary sinus, Complication management, Oral surgery
Background
An oroantral fistula (OAF) can be defined as an epithelia-
lized pathological unnatural communication between the
oral cavity and the maxillary sinus [1]. The term oroantral
fistula is used to indicate a canal lined by epithelium that
may be filled with granulation tissue or polyposis of the
sinus membrane [2]. They can arise as late sequelae from
perforation and last at least 48–72 h. An oroantral fistula
(OAF) may develop as a complication of maxillary molar
or premolar extraction due to the proximity of the bicus-
pid apices and molars to the antrum [3]. Furthermore,
oroantral fistula might originate following the removal of
maxillary cysts or tumors, facial trauma, dentoalveolar or
implant surgery, and infection or may even be iatrogenic
in nature. Oroantral fistulas are common between the
ages of 30 and 60 [1]. Apparently, studies reported sexual
dimorphism in oroantral fistula, with males showing more
frequency than females [1,4]. This difference can be
explained by a higher overall frequency of traumatic tooth
extraction in men [5].
Clinically, the patient may experience one or more dis-
turbances which draw attention to the oroantral fistula.
Symptoms and signs comprise, pain, foul or salty taste, al-
teration in voice resonance, inability to blow out the
cheeks, air shooting from the fistula into the mouth when
blowing the nose, and escape of liquids from the mouth
through the nose [5].
At a later stage, the formation of an antral polyp, which
is visible through the defect intraorally, is possible. The es-
tablishment of oroantral communication can be con-
firmed by the Valsalva method. The patient is instructed
to expel air against closed nostrils, while the clinician
checks if air hisses from the fistula into the mouth. A his-
sing noise from air leakage through the maxillary sinus
and nose indicates a positive test. In some cases, the test
of blowing through the nose or mouth does not provide a
positive answer, particularly when the fistular canal is filled
with inflammatory changed nasal mucous membrane.
Additionally, a test with a blunt probe will confirm the ex-
istence of an oroantral fistular canal. However, to confirm
* Correspondence: obreja@med.uni-frankfurt.de
1
Department of Oral Surgery and Implantology, Carolinum, Johann Wolfgang
Goethe-University, Frankfurt, Germany
Full list of author information is available at the end of the article
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clinical findings, the clinician needs to radiologically in-
spect the site via a panoramic radiograph or a computed
tomography (CT).
Radiologically, in the computed tomography (CT) or
cone beam computed tomography (CBCT), the oroantral
fistula might show as sinus floor discontinuity, opacification
of the sinus, or communication between the oral cavity and
the sinus. In addition, focal alveolar atrophy and associated
periodontal disease may be observed [6]. In chronic OAF,
there is generalized mucosal thickening. Recent studies re-
vealed that an oroantral fistula should be closed within
24 h. After this period, the inflammation of the sinus
through contamination of the oral cavity makes it impos-
sible to effectively conduct the treatment [7,8]. Guven re-
ported that sinus infection can occur with any size and
duration of the fistula canal [3]. Accordingly, symptoms as-
sociated with inflammation in the sinus should be cured
medically with antibiotics before closure of an (OAF) to
avoidimpaireddrainage.Withouttreatment,fistula often
leads to chronic OAFs, which usually lead to severe chronic
inflammatory thickening of the sinus membrane. Closure
of the defect aims to prevents oral bacteria and food debris
from penetrating the sinus. According to different authors,
small fistulae tend to heal spontaneously, whereas larger fis-
tulae rarely heal [3]. Surgery is indicated if a fistula does not
heal within 3 weeks [2,3,9].Theaimofsurgeryistore-
move the diseased bone and to resect the thickened epithe-
lium along the borders of the fistula [3,9].
Historically, several methods of OAF closure have been
reported in the literature. However, none of these methods
are proved to be superior to the others. Additionally, each
method presents certain advantages and disadvantages.
The goal of this literature is to provide a review of the sur-
gical treatment strategies of OAFs, including their advan-
tages and disadvantages.
Materials and methods
A narrative literature review of articles and case reports for
oroantral fistula has been conducted in the PubMed data-
bases of published English literature. Articles published until
April 2018 were reviewed. In addition to 262 articles on the
closure of oroantral, 4 articles on the closure of antrooral
fistula in humans, and 5 articles in animals, citations were
referenced to identify further relevant articles. According to
Visscher’s classification, the treatment strategies for OAFs
closure can be broadly categorized into autogenous soft tis-
sue grafts, autogenous bone grafts, allogenous materials, xe-
nografts, synthetic closure, and other techniques [10]
(Fig. 1). New techniques were included in this classification.
The studies and number of cases are listed in Table 1.
Autogenous
Closure of OAF can be achieved using different flap tech-
niques, each of which presents both advantages and
limitations. Three types of flaps are most widely used: a
buccal flap, a buccal fat pad (BFP) flap, and a palatal flap.
In 1936, Rehrmann [11] described the use of a buccal
advancement flap. Krompotie and Bagatin reported that
the rotating gingivovestibular flap can also be applied for
closure of an antrooral fistula. This technique is a modi-
fication of a vestibular flap with the aim of preventing
the lowering of the vestibular sulcus, which regularly ac-
companies the application of vestibular flaps [12]. The
flap with its simplicity, reliability, and versatility is the
most commonly used method for OAF closure [5,13].
In this technique, a broad-based trapezoid mucoper-
iosteal flap is created after excising the epithelialized
margins and giving two vertical release incisions to de-
velop a flap with adequate dimensions to be sutured
over the defect. Its broad base enables a better blood
supply to the flap. Flap coverage is improved by horizon-
tal periosteal incisions. Falci et al. described a modifica-
tion of this technique for OAF closure. The mucosal
margins of the fistula were sutured together prior to the
reflection of the buccal flap. Then, the buccal flap was
pulled over this sutured site and tucked under the pal-
atal flap, which was elevated simultaneously with the
buccal flap [13]. Killey, in 1972, studied 362 cases using
this technique. The results revealed success in 336 (93%)
cases [5]. However, the potential disadvantage of using
this flap for OAF closure is the reduction of buccal sul-
cus, which makes it difficult to use prosthesis in the fu-
ture [1]. Other disadvantages include postoperative pain
and swelling as a result of the reflection of a mucoper-
iosteal flap. Currently, a reduction in the buccal sulcus
can be overcome by implant-retained overdentures.
Môczáir [14] described closing alveolar fistulas by the
buccal sliding flap, shifting the flap one tooth distally.
This technique produces only a negligible change in the
depth of the buccal vestibule. A drawback of this ap-
proach is that it requires a large amount of dentogingival
detachment in order to facilitate the shift, which may re-
sult in gingival recession and periodontal disease.
The first description of a technique for closing oroantral
fistula using a full-thickness palatal flap based on greater
palatine artery dates back to Ashley [15]. Advantages of
the palatal flap include high vascularity, generous thick-
ness, and quality of tissue. Moreover, this flap is more re-
silient, less prone to infection, very resistant to lacerations,
and does not lead to lowering of the vestibule. However,
the most significant disadvantages are flap necrosis [15],
exposed bony surface, pain, and development of surface ir-
regularities as a result of secondary epithelialization post
operatively [2]. In 1980, Ehrl employed this technique with
wide fistulas of 1 cm in diameter [16]. The technique con-
sists of excising the epithelium from its edges and incising
the palatal fibro-mucosa so as to create a flap with a pos-
terior base, supplied by the greater palatine artery. The
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 2 of 13

anterior extension of the flap must be wide enough to ex-
ceed the diameter of the bony defect and long enough to
allow lateral rotation. Tension-free suturing should be
performed [8].
The palatal flap has different forms that can be classi-
fied by thickness, namely, mucoperiosteal, or by the dir-
ection of movement, namely, straight advancement flap,
rotation advancement flap, hinged flap, pedicled island
flap, anteriorly based flap, submucosal connective tissue
pedicle flap, and submucosal island flap.
The palatal mucoperiosteal rotation flap is particularly
recommended for the late repair of oroantral fistula [8].
The base of the flap should be broad enough to cover
the defect. A full-thickness palatal flap is typically per-
formed lateral to vascular supply and 3 mm apical to the
marginal gingiva of the teeth. The mucoperiosteal flap is
raised from the anterior to posterior, rotated, and su-
tured to secure a tension-free closure of the fistula. [8].
With this technique, kinking formation at the rotation
point and the base of the flap may compromise the vas-
cular supply [8]. The most important advantages of the
technique are rich vascularization, excellent thickness,
and easy accessibility.
The palatal straight advancement flap is of limited use
due to the inelastic nature of the palatal tissue, which re-
duces its lateral mobility. For the same reason, it is suitable
fortheclosureofminorpalataloralveolardefects[17].
The palatal hinged flap has been used successfully to
close small fistula of the hard palate, i.e., those less than
2 cm in diameter in a one-stage operation [18]. The pro-
cedure is based on raising a full-thickness flap directly
adjacent to the fistula based along one fistula edge and
turning this like a hinge over the fistula so that its buccal
surface will lie uppermost in the fistula. The main ad-
vantage of this technique is that only a small raw area
for granulation is left behind following closure of OAF.
Another single-stage local flap is the palatal pedicled is-
land flap. It offers the great advantages of a rich vascular
supply, adequate bulk, and mobility. In elevating the flap,
incisions are performed according to the amount of donor
tissue required to resurface the oral fistula. Incisions can
be made at the junction of the hard and soft palate and
within 5 mm of the dentition. This allows for harvesting a
flap that can be rotated 180° without strangulation of the
vascular pedicle. This procedure is the preferred flap for
many surgeons because of its versatility, simplicity, and
Fig. 1 Treatment strategies for OAF closure
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 3 of 13

Table 1 Studies on surgical techniques for closure OAFs
Author year No. of participants Method
Autogenous soft tissue flaps
Lin et al. 1991 16 Buccal flap
Ehrl 1980 175 Palatal flaps
Anavi et al. 2003 63 Palatal mucoperiosteal rotation flap
Choukas 1974 1 Palatal straight advancement flap
Hynes 1955 ? Palatal hinged flap
Henderson 1974 1 Palatal pedicled island flap
Salins et al. 1996 12 Palatal anteriorly based flap
Dergin et al. 2007 ? Modified submucosal connective tissue flap
Ito and Hara 1980 13 Submucosal connective tissue pedicle flap
Yamazaki et al. 1985 7 Submucosal island flap
Marcantonio C et al. 2015 1 Palatal pedicle flap
Lee et al. 2002 21 Random palatal flap
Guerrero-Santos et al. 1966 10 Tongue flap
Pourdanesh et al. 2013 1 Temporalis muscle flap
Autogenous bone grafts
Proctor 1969 18 Iliac crest
Haas et al. 2003 3 Chin bone grafts
Watzak et al. 2005 4 Retromolar bone grafts
Peñarrocha-Diago et al. 2007 1 Zygomatic bone
Kapustecki et al. 2016 20 Autogenous bone graft and platelet-rich fibrin
Allogenous
Gattinger 1984 23 Fibrin glue in combination with a collagen sheet
Stajcic 1985 16 Fibrin glue
Frenkel 1990 29 Lyophilized dura
Aladag et al. 2018 24 Modified Caldwell-Luc
George 2018 1 Leucocytes- platelet-rich fibrin
Assad et al. 2018 2 Platelet-rich fibrin (PRF) clot and (PRF) membrane
Xenografts
Mitchell 1983 30 Lyophilized porcine dermis
Shaker et al. 1995 40 Lyophilized porcine dermis (Zenoderm)
Ogunsalu 2005 1 Bio-Guide (porcine collagen membrane) and Bio-Oss (bovine bone grafting material)
Synthetic/metals closure
McClung and Chipps 1951 4 Tantalum foil
Goldman 1969 1 Gold foil technique
Al Sibahi and Shanoon 1982 10 Self-curing polymethylmethacrylate
Becker et al. 1987 20 Dense hydroxylapatite
Becker et al. 1987 20 Hydroxylapatite implants
Thoma et al. 2006 20 Root analog made of β-tricalcium phosphate
Steiner et al. 2008 8 36-gauge pure aluminum plates
Procacci et al. 2016 12 Functional endoscopic sinus surgery and titanium mesh
Other techniques
Götzfried and Kaduk 1985 Animal study Prolamin gel
Waldrop and Semba 1993 2 Guided tissue regeneration
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 4 of 13

mobility [19]. The technique is ideal for the closure of
posterior fistula due to its ability to transfer large
well-vascularized area of tissue. Furthermore, the donor
site defect, which overlies the hard palate, decreases the
donor site morbidity. Therefore, use of this procedure is
limited in closure of anterior defect as a result of stretch-
ing of these vessels when the flap is advanced too far an-
teriorly. The palatal anteriorly based flap is particularly
useful for closure of large oroantral fistula and correction
of defects at the tuberosity region. The procedure involves
a lateral transposition of mucoperiosteum of the posterior
third of the hard palate with an anteriorly based palatal
flap. The flap is raised to bridge large defects without leav-
ing any considerable exposed raw area [20]. The modified
submucosal connective tissue flap was designed by Dergin
et al. [21] for closure of OAF. Elasticity of the flap pre-
vents folding formation and allows for better manipulation
and adaptation in the closure of an OAF in the second
and third molar region. Another advantage is that no pal-
atal acrylic plate is required postoperatively. In this tech-
nique, an H-type window-like incision is made in the
palatal mucosa 4 mm from the gingival margins of the
posterior teeth, with the medial incision 2–3mmfromthe
midline. After excising the fistula wall and curetting the
granulation tissue, the mucosa of the two minor flaps of
the H-type window-like incision is raised and separated
from the underlying connective tissue without jeopardiz-
ing the continuity of the mucosal flap. The underlying vas-
cularized connective tissue is dissected in the
premolar-canine region, where the incisive and greater
palatine arteries anastomose. The connective tissue is
raised with periosteum and rotated. The rotated flap is
passed through a full-thickness tissue tunnel that had
been previously prepared on the palatal side of the OAF.
The flap is inserted under the buccal mucosa and sutured
without any tension. The H-type minor flap is also sutured
and left for primary healing. Hara and Ito designed the
submucosal connective tissue pedicle flap by dividing the
flap into an upper mucosal layer and underlying connect-
ive tissue layer to overcome the problem of bone exposure
at the donor site [22]. The technique is achieved by separ-
ating the full-thickness palatal flap into a mucosal layer
and an underlying connective tissue layer. The submuco-
sal connective tissue flap is used to close the fistula, and
the mucosal part of this flap is then returned to its original
position and sutured in place to obtain primary closure.
They reported that the healing at the donor site occurred
within 1 month [22]. The disadvantages of this technique
are the difficulty of the dissection and possibility of injur-
ing the blood supply [22]. A submucosal island flap is in-
dicated in the closure of a large oroantral fistula. With this
technique, a palatal pedicle flap based on the greater palat-
ine vessels is formed. Depending on the size, shape, and
location of the fistula, the anterior part of the submucosal
connective tissue flap is made. In addition, the anterior
part of the submucosal connective tissue is used to design
the island flap. After raising the palatal mucoperiosteum,
the island flap is passed under the alveolar tissue bridge
across the defect and sutured to the edge of the fistula
without tension. The significant advantages of this flap are
ample blood supply and mobility without tissue bunching
[23]. In addition, healing is satisfactory without denuded
bone. Yamazaki concluded that the dissection of the pal-
atal flap into the epithelial layer and the underlying con-
nective tissue does not pose technical difficulty [23]. A
palatal pedicle flap is used to close an OAF with the ad-
vantages of preserving keratinized mucosa and buccal sul-
cus depth in the area of the fistula. The flap is a one-stage
procedure. Preoperative procedure includes making a
self-curing acrylic resin plate over the patient’s cast model.
The first surgical step is excision of the epithelial fistula
wall, followed by division of the flap on the palatal mucosa
through an incision, superficially to the periosteum. The
flap is passively positioned and thoroughly sutured. The
donor site is then protected with surgical cement and held
in place by the self-curing acrylic resin plate. The acrylic
plate is fixed with bone screws and maintained in place
for 10 days [24]. The ratio of length to thickness of the
flap is critical for the survival of the palatal pedicle flap,
thus splitting of the flap should be carried out very judi-
ciously [24]. The Random palatal flap is considered an ad-
equate option for closure of oroantral fistula in difficult
locations such as in the tuberosity area. Lee et al. reported
a success rate of 76% of random palatal flaps in 21 patients
[25]. He pointed out that the most important factor deter-
mining the clinical outcome of palatal flaps was an appro-
priate length to width ratio. The random palatal flap is
based on the anastomoses spread throughout the palate;
all rely on greater palatine artery for nutrition. The buccal
fat pad (BFP) is a lobulated mass of adipose tissue sur-
rounded by a thin fibrous capsule, located between the
buccinator muscle medially, the anterior margin of the
Table 1 Studies on surgical techniques for closure OAFs (Continued)
Author year No. of participants Method
Hori et al. 1995 8 Interseptal alveolotomy
Grzesiak-Janas and Janas 2001 61 Laser light
Logan et al. 2003 1 Palatal splint
Kitagawa et al. 2003 2 Third molar transplantation
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 5 of 13

masseter muscle, and the mandibular ramus and zygo-
matic arch laterally [26]. The buccal pad of fat is exposed
through a 1 cm long vertical incision in the reflected peri-
osteum posterior to the zygomatic buttress. Thereafter, it
is gently manipulated by pressing extraorally below the
zygomatic arc. Finally, the fat pad is sutured to the palatal
tissue, covering the oroantral fistula [27]. The BFP derives
its blood supply from branches of the superficial temporal,
maxillary, and facial arteries. The advantages of this tech-
nique include good epithelialization of the uncovered fat
and a high rate of success due to the BFP’s ample vascular-
ity and proximity to the recipient site. Other beneficial
features of the BFP flap are the straightforward harvest
and minimal dissection required to harvest and to
mobilize the flap [28]. The study of the long-term effect-
iveness of the BFP technique in the closure of large OAFs
supported these features [29]. The disadvantage is the de-
crease in the vestibular height. It has been concluded that
closure of large defects could involve complications such
as graft necrosis or new fistulas [30]. The buccal fat pad is
a feasible option for cases with damage to the alveolar
buccal or palatal mucoperiosteum, cases that have failed
with other methods, and repairs of large defects in the tu-
berosity area [31]. However, success of the buccal fat pad
is extremely influenced by the communication size [32].
Free mucosal grafts (FMG) or connective tissue grafts
(CTG) are suitable for the closure of small to moderate
size defects in the premolar area as well as small to
medium size-persistent defects. In contrast to the tech-
niques described so far, the harvested grafts are not dir-
ectly vascularized. The flap initially receives its nutrients
within the first three postoperative days by diffusion
alone, so-called plasmatic circulation. After day 3, the
nutrition is provided by the ingress of blood capillaries
from the recipient bed for revascularization. However,
the size of the defect and the thickness of the graft play
a crucial role in plasma circulation and nutrition of the
transplanted cells. The main donor site for FMG/CTG is
the palate, the maxillary tuberosity or edentulous alveo-
lar ridges. Struder demonstrated that the thickest part of
the palate and the most favorable donor site is in the
premolar area [33]. The thickness of the mucosa de-
creases distally and becomes thicker once more in the
area of the tuberosity. However, the inadequate area is
small compared to the premolar area. To perform a
FMG, the wound margins of the recipient bed are
de-epithelialized according to the techniques already de-
scribed and the defect to be closed is measured. Using a
template, the size of the defect can be projected onto
the palatal premolar area and the graft can be harvested.
Within 3–4 weeks, the palatally exposed site heals com-
pletely above the free granulation. The donor site of the
subepithelial connective tissue graft extends from the ca-
nine region to nearly the palatal root of the first molar.
Free mucosal grafts (FMG) are suitable for closing the
OAF to the maxillary second premolar region. Laterally,
a distance of 2 mm from the gingival margin should be
considered the minimum and a minimum 2-mm zone of
the marginal gingiva should be maintained at the donor
site. Medially, the boundary is the vascular-nerve bun-
dles, which, depending on the anatomy of the palate, are
7, 12, or 17 mm away from the palatal cemento-enamel
junction. After the incision, the subepithelial connective
tissue is dissected and harvested according to the size of
the defect. The harvested grafts (FMG/CTG) are then
placed on the defect and adapted by sutures on the
de-epithelialized wound margins. The pedunculated sub-
epithelial connective tissue graft is particularly well
suited for covering defects in the molar region. Similar
to a non-pedunculated graft, this technique also uses a
variety of incision techniques. In our polyclinic, we pre-
fer to use the “trap door”technique favored by Wachtel
[34]. According to Wachtel’s technique, an incision is
performed at a distance of 2 mm from the gingival mar-
gin and extends, according to the extent of the defect, to
the canine region. Subsequently, the scalpel is then an-
gled off; a mucosal flap is prepared about 1.0–1.5 mm
medially and a step approximately 1.5 mm is made. The
subepithelial graft is then prepared mesially, medially,
laterally, and basally. An undermining “bridge”between
the alveolus or defect and the incision is prepared in the
mucosa, and the graft is then placed under the bridge in
the defect and fixed at the wound margins with sutures.
As with the pedunculated palatal rotation flap, the blood
supply to the graft is provided through the greater palat-
ine artery, the anastomosis of the nasopalatine artery
and sphenopalatine artery. In addition to the preserva-
tion of the vestibule and the associated favorable pros-
thetic options, the pedunculated subepithelial connective
tissue graft is applicable to the majority of possible de-
fects. Considering the blood supply by the greater palat-
ine artery, clinicians and patients can expect a high
probability of graft success. Due to its high elasticity, the
graft can be effortlessly adapted free of tension [8]. With
the use of this technique and the application of a step
according to Wachtel, the wound margins can be opti-
mally adapted and wound healing can be ensured by pri-
mary intention. Furthermore, there is no free exposed
area so postoperative complaints are low [35]. The dis-
advantages of this technique include the long duration,
high costs, and the ability of the surgeon [35].
The tongue is an excellent donor site for soft tissue
defects of the oral cavity, due to its pliability, position,
and abundant vascularity. Tongue flaps can be created
from the ventral, dorsal, or lateral part of the tongue
[36]. The surgical design of the flap is dictated by the lo-
cation of the defect. A lateral tongue flap has been de-
scribed as a suitable method for the closure of large
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 6 of 13

OAF [37]. The tongue flap has reported success rates
varying from 85 to 95.5% [37]. Complications of the
technique include hematoma formation that can com-
press the pedicle leading to necrosis of the flap, wound
dehiscence, and temporary loss of tongue sensation and
taste [38]. Additional disadvantages are the requirements
for general anesthesia and multiple operations. The tem-
poralis muscle flap is another distant flap, which can be
used for closure of orofacial region defects. It has been
indicated for one-stage closure of large oroantral com-
munications. The temporalis fascia is sectioned above
the arch to permit flap rotation. It is then brought into
the oroantral fistula through a tunnel created in the infra
temporal fossa. The temporalis muscle flap is far less
bulky, well-vascularized, and more pliable; with minimal
functional and esthetic sequelae; and in closer proximity
to the oral cavity [39].
The use of bone autografts for closing OAFs has been
recommended in the literature [40]. This procedure is
indicated in closure of defects larger than 10 mm or in
the case of failure of conservative methods to close the
defect [41]. Autografts harvested from the extraction
socket, retromolar area, zygomatic process, chin, or dis-
tant sites like the iliac crest have been used for repairing
the bony defect in maxilla [9,42]. Harvesting bone from
intraoral donor areas offer the advantage of reducing the
demands made on patients postoperatively.
Closure of OAF with a bone graft harvested from the
iliac crest should be indicated for large defects because of
the significant inherent donor site morbidity, prolonged
postoperative pain, and possible sensory disturbance [40,
43]. The use of monocortical bone grafts harvested at a
chin site block for closure of an OAF is recommended for
patients affected by maxillary atrophy requiring sinus aug-
mentation before implant placement [9]. A monocortical
block graft is harvested at the chin by using a trephine
with an inner diameter matching the size of the round
bony defect. The graft is then press-fit into the defect. Soft
tissue closure is established by using a flap.
A retromolar bone graft is a viable procedure for OAF
closure. However, harvesting of a retromolar bone can
occasionally be combined with removal of the third
molar, which may affect acceptance of the procedure by
patients [44]. When compared to chin bone grafts, the
significant disadvantage of the retromolar donor area is
the confined amount of bone available [45]. The incision
is made medial to the external oblique ridge in an anter-
ior direction and terminated in the first molar area to
avoid interference with the mental nerve branches. A
mucoperiosteal flap is elevated, and the exposed bone
area is evaluated in consideration of the amount of bone
needed at the defect site. A microreciprocating saw is
used to make the osteotomies. The bone block is care-
fully lifted to ensure that the inferior alveolar nerve is
not trapped within the graft. Osseous irregularities are
trimmed with chisels or by using a large bur. The flap is
repositioned and sutured [45].
Zygomatic bone is a suitable donor site for OAF clos-
ure. The technique is indicated when a modest amount
of bone is needed [46]. In this procedure, an incision is
made through the alveolar mucosa about 5 mm above
the mucogingival junction, starting between the first and
second molars, and proceeds anteriorly to the first pre-
molar area. A full-thickness flap is raised with a perios-
teal elevator. The dissection extends to the inferior
aspect of the infraorbital nerve and around the inferior
half of the body of the zygoma. The lateral border of the
maxillary sinus is visualized, and the inferior border of
the orbital rim is palpated. Bone harvesting is started
just above the inferior border of the zygomatic rim and
lateral from the maxillary sinus. The incision is closed
with running or interrupted resorbable sutures [46].
This method offers the advantage of proximity of the
donor area to the recipient area, which minimizes surgi-
cal time and patient discomfort [46]. Moreover, surgical
postoperative complications after zygomatic bone har-
vesting are minimal.
Recently, auricular cartilage graft has been used for the
closure of OAFs. A full-thickness flap is raised at the de-
fect site [47]. A semicircular incision is then made poster-
iorly over the conchal cartilage. The conchal cartilage with
overlying perichondrium is exposed with a blunt dissec-
tion. The harvested auricular graft is then adapted on the
defect site and sutured with the surrounding tissue. The
mucoperiosteal flap is then advanced and sutured with the
palatal tissue. The technique is biocompatible, highly re-
sistant to infection, and easy to harvest. Additionally, it
does not require vascularization for the integration to the
recipient site. Consequently, there is a decrease in the fail-
ure rate of the graft [47]. A disadvantage of this procedure
is the potential formation of a defect at the donor site.
The use of septal cartilage especially for larger oroantral
fistulas was documented [48]. A buccal mucoperichon-
drial flap is raised, generally starting two teeth mesial and
ending, and if feasible, one tooth distal to the site of the
fistula. An incision is performed at the caudal end of the
septal cartilage, and a mucoperichondrial flap is raised on
one side. A cartilage island is outlined and dissected free.
The cartilage is trimmed and insinuated into defect as a
horizontal plate [48]. Saleh et al. obtained a success rate of
95.7% in their study using septal cartilage [48].
According to Aladag et al., the modified Caldwell-Luc
Approach is a satisfactory method to close oroantral de-
fects [49]. In the technique, which includes endoscopic
examination using the Caldwell-Luc approach, the inside
of the maxillary sinus is explored fully. The bone graft
can be harvested from the bone of the anterior wall of
the maxillary sinus by accessing the surgical entry tract.
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 7 of 13

The positive features of the technique include the use of
autogenous grafts, easy and adequate harvesting of the
graft along the surgical route, and no need for a flap.
Among its disadvantages are the fact that it requires
endoscopic surgical equipment and experience.
An autogenous bone graft and platelet-rich fibrin
(PRF) membrane as a treatment strategy for closure of
OAF has also been proposed [50]. PRF is a product of
centrifuged blood. The biochemical components of PRF
are well-known as factors acting synergistically in the
healing process. This includes platelet-derived growth
factor (PDGF), whose components are the reason why
PRF has anti-inflammatory properties. The PRF mem-
brane covers the graft, while the components contained
in it have positive impact on its integration. A trapez-
oidal mucoperiosteal flap is formed in the oral cavity
vestibule. The alveolar width of alveolus and the average
height of alveolar bone lamina from the side of the oral
cavity vestibule and from the side of the palate are mea-
sured intraoperatively. The next stage depends on the
cavity diameter and involves collection of monocortical
bone blocks from the mental protuberance or mandible
oblique line. The bone blocks are formed in a way which
makes it possible to wedge them in the cavity and tightly
close the defect. The graft is stabilized using a bicortical
screw or a titanium mini-plate. Bone irregularities are
smoothed. The graft and surrounding bone are covered
with a PRF membrane. Thereafter, the membrane is
tightly sutured without tension the vestibule flap [50].
More recently, triple-layered was introduced by George
[51]. This novel technique uses leucocytes-platelet-rich fi-
brin (L-PRF) membrane concomitantly with the buccal
advancement flap and buccal fat pad. The platelet-rich fi-
brin membrane is placed over the buccal fat pad and com-
pletely covered by a buccal advancement flap. The positive
feature of the L-PRF membrane is expediting the healing
process by producing growth factors and leucocytes.
TheuseofPRFaloneasaclotandamembranefor
the closure of OAFs was documented by Assad et al.
[52]. They advocated closing OAFs by using PRF indi-
vidually. PRF was prepared by taking blood samples
into glass-coated plastic tubes without anticoagulant.
The samples were centrifuged immediately. A fibrin
clot was formed in the middle part of the tube. Then, it
was separated from other acellular plasma and red
blood cells. Thereafter one third of the fibrin was cut
off and inserted gently into the OAF. The remaining
two thirds of the clot were pressed gently with sterile
dry gauze to drive out the fluids and form the mem-
brane. The OAF site was covered with the membrane
which was sutured to the gingival margins. PRF can be
considered an autologous biomaterial and as well as a
membrane. PRF as a membrane and grafting material
facilitates formation of mineralized tissue due to
osteoconductive and/or osteoinductive properties pos-
sibly inherent in PRF.
Allogenous materials
Multiple techniques have been described for the closure
of OAFs using lyophilized fibrin glue of human origin
[53]. In this technique, the fibrin glue is prepared and
injected into the socket, together with the collagen sheet.
Stajčićet al. stressed the importance of inserting the syr-
inge above the floor of the antrum to protect the clot from
airflow [53]. The technique is simple with few postopera-
tive complaints. Importantly, there is no need to raise
flaps; hence, the intraoral anatomy remains intact [54].
According to the manufacturer, the major disadvantages
of the procedure are the risk of transmitting viral hepatitis
and the preparation time required for the fibrin glue [53].
The use of lyophilized dura for closure of OAF was re-
ported by Kinner and Frenkel [55]. In this technique, the
sterilized dura is placed in a saline solution to regain its
pliability. Thereafter, it is cut to size to make it cover the
bony margins of the defect. Sutures are placed at each cor-
ner of the graft and then it is covered with a plastic plate
for protection. The dura is exfoliated after 2 weeks. The
simplicity of the technique and non-surgical approach
make it an attractive option for OAF closures. However,
the risk of transmitting pathogens is a main disadvantage.
Xenografts
Lyophilized porcine dermis for closure of OAFs has been
described in the literature [56,57]. The technique re-
ported good results when the porcine graft was either ex-
posed to the oral environment or covered with buccal and
palatal sliding flaps [56,57]. According to Mitchell and
Lamb covering the graft by buccal and palatal flaps is not
necessary [56]. The main advantage of the collagen is po-
tential incorporation into the granulation tissue, and thus,
no need to remove it prior to complete healing [56].
Ogunsalu achieved both bony (hard tissue) and soft
tissue using Bio-Gide® (porcine collagen membrane)
(Geistlich Biomaterials, Wolhusen, Switzerland) and
Bio-Oss® (non-sintered bovine bone materials) (Geistlich
Biomaterials, Wolhusen, Switzerland) to close OAFs
[58]. In this technique, the Bio-Oss® granules were sand-
wiched between two sheaths of a Bio-Gide® membrane
for the hard tissue closure of oroantral defect. There-
after, a full-thickness mucoperiosteal flap was raised and
the Bio-Oss®–Bio-Gide® sandwich placed underneath.
Then, the flap was repositioned, resulting in primary
closure. There was an excellent bony regeneration which
allowed placement of an endosseous implant. Radio-
graphically, bony healing of the defect was observed
after 8 months. The technique offers the unique advan-
tage that no donor site surgery is necessary. The
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 8 of 13

disadvantage in this technique is the need for a muco-
periosteal flap to cover the sandwich.
Synthetic closure of OAFs
Various synthetic materials have been used for OAF clo-
sures. Use of gold foil and gold plate for the closure of
OAFs was reported for the first time by Goldman and
Salman, respectively [59,60]. It is a simplified technique
for the closure of oroantral fistulas. The technique con-
sists of elevating the mucoperiosteum to expose the
bony margins of the fistula. Then, the opening is covered
with an overlapping margin of burnished gold foil.
The mucoperiosteal flaps are sutured across the gold
foil without attempting to realize primary closure. Gold
foil acts as a bridge for overgrowing sinus mucosa. After
6 weeks, the foil is exfoliated. A disadvantage of this
technique is that it is rather costly and the complete clos-
ure and healing requires a long period [57].
Aluminum plates were suggested for OAF closures
[61]. According to Steiner, 36-gauge pure aluminum
plate is used as a protective plate to aid in closure, using
the same technique as in the gold procedure. Buccal and
palatal tissues are approximated by sutures. Accordingly,
the aluminum plate is constantly visible. After several
weeks, the aluminum plate is removed from its initial
position as a result of formation reparative tissue under-
neath. In addition to malleability and smoothness fea-
tures, aluminum is inexpensive.
Tantalum is a highly biocompatible metal. It has been
used for closures of OAFs by McClung and Chipps [62].
Along the same lines as the gold technique, tantalum foil
is used as a protective plate to aid in closure. The Tanta-
lum foil was removed after 9 weeks. They reported for-
mation of granulation tissue following the closure.
Closure of OAFs by titanium plate with transalveolar
wiring fixation was documented [63]. The results re-
vealed good bony and soft tissue healing. Further, the
use of two different materials titanium plates and stain-
less steel wires did not result complication or distaste
because of galvanic current.
Polymethylmethacrylate has been introduced as an al-
ternative technique for closing OAFs [64]. After 24 h of
immersion in a sterilizing solution, the polymethyl-
methacrylate plate is placed over the defect. Mucoper-
iosteal flaps are then replaced without attempting to
cover the acrylic plate. The polymethylmethacrylate
plate is removed as soon as the edges become exposed.
One of the common disadvantages of this technique is
the required time for preparation.
Recently, a dual otorhinolaryngological/oral approach
was described in a patient with an OAF complicated by
maxillary sinusitis [65]. The investigators used the func-
tional endoscopic sinus surgery (FESS) technique in
combination with a titanium mesh to obtain optimal
reconstruction and stabilization of soft tissue. A
full-thickness vestibular flap was elevated, and the titan-
ium mesh was fixed on the defect. Mesh removal was
conducted after 6 to 18 months of healing based on
clinic and radiographic evidence of OAF closure. The
main disadvantage of this technique is the second sur-
gery needed to remove the mesh. Despite this drawback,
use of a titanium mesh assures predictable healing,
mechanic scaffolding, and tissue stability.
Zide and Karas used nonporous blocks of hydroxylap-
atite to close oroantral fistulas by carving the blocks to
fit the bony defect and encircling them with a wire for
stability when needed [66]. The investigators reported
natural extrusion of the blocks without recurrence of a
fistula [10]. The technique offers a number of advan-
tages, including ability to have a press-fit graft closure
and no morbidity associated with a second-site surgery.
Various sizes of hydroxylapatite implants have also
been used to close oroantral fistulas [67]. Further, the
remaining space in the socket was filled by hydroxylapa-
tite granules. Oral mucosa was approximated without
complete closure [10]. Considering extrusion, the tech-
nique resulted in no cases of hydroxylapatite implant ex-
trusion. Disadvantages include high costs and the need
for various implant sizes to allow for size selection.
The use of a bioabsorbable root analog made of
β-tricalcium phosphate for closure of oroantral fistulas
was proposed by Thoma et al. [68]. The root replicas
were fabricated chair side, using a mold of the extracted
tooth [10]. The investigators reported that the healing
was uneventful. However, fragmentary roots or overly
large defects prevent replica fabrication or accurate fit-
ting of the analog. The technique is simple and fast.
Other techniques
Kitagawa et al. advocated third molar transplantation as
a suitable option for closure of OAFs [69]. The investiga-
tors successfully closed two cases of OAFs by immediate
upper and lower third molar transplantation.
The donor teeth were carefully extracted and trans-
planted to the prepared recipient bed. Firm finger pres-
sure and light tapping provided good stabilization of the
tooth on the recipient bed and produced a complete
simultaneous closure of the OAF. Endodontic treatment
was carried out after 3 weeks. The researchers reported
that third molar transplantation was a simple and excel-
lent treatment option to close small OAFs. However,
third molar transplantations have some drawbacks: the
requirement of a sufficiently developed third molar of an
appropriate shape and size, and the risks of ankylosis
and root resorption if not carried out with proper
technique.
Hori et al. proposed interseptal alveolotomy as one of
possibilities for closure of OAFs [70]. The technique,
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 9 of 13

based on the Dean preprosthetic technique, is used for
the purpose of smoothing the alveolar ridge. The ex-
tended Dean technique is performed in such a way that
the interseptal bone is removed, followed by the fractur-
ing of the buccal cortex in the direction of the palate.
Sutures are used for soft tissue closure. The technique
offers the advantage of facilitating spontaneous postop-
erative healing with less postoperative swelling, sup-
ported by the bony base. The most important advantage
of this technique, compared with the buccal flap tech-
nique, is that it assures closure of soft tissue without cre-
ating tension. However, limitations of this method are
that it requires both a space of less than 1 cm between
the adjacent teeth and adequate alveolar ridge. More-
over, there is a risk of inflammation as a result of the re-
quired buccal bone fractures due to formation of bone
sequesters and possible imperfect soft tissue closure in
the case of an incomplete fracture.
Use of guided tissue regeneration has been docu-
mented by Waldrop and Semba [71]. This method uses
an absorbable gelatin membrane, allogenic bone graft
material, and a nonresorbable expanded polytetrafluoro-
ethylene (ePTFE) membrane. After flap reflection, an ab-
sorbable gelatin membrane is placed over the OAF with
its edges on the bony margins of the perforation, which
serve as a barrier for the bone graft material and prevent
displacement of the graft material into the antrum and
sinus epithelial cell migration. A layer of allogenic bone
graft material is put on the membrane. The nonresorb-
able ePTFE membrane is used to cover the bone graft
material, and the soft tissue flap is placed over the mem-
brane. This membrane promotes selective cell popula-
tion with subsequent regeneration. Eight weeks after
insertion, the barrier membrane is removed. After re-
moval of the inner aspect of the flap adjacent to the
ePTFE membrane, the mucoperiosteal flap is replaced.
Closure of the OAF was clinically confirmed by bone
formation, although this was not confirmed histologi-
cally. One of the disadvantages of this technique is the
need for an additional surgery to remove the nonresorb-
able ePTFE membrane. A further disadvantage is the
need for a full-thickness flap. Götzfried and Kaduk de-
veloped an alternative procedure to close OAFs without
surgical intervention [72]. According to the investiga-
tors, prolamin occlusion gel is directly injected into the
perforation and hardens within a few minutes to form a
barrier. One week later, granulation tissue is formed and
the prolamin gel completely dissolves after 2 to 3 weeks
[72]. This technique proved to be well tolerated by pa-
tients and results in fewer postoperative complaints
compared with other procedures [68]. The disadvantage
of this technique is chiefly its high material cost. Add-
itionally, the technique is less appropriate for closure of
OAFs greater than 3 mm [68].
Biostimulation with laser light for closure of OAFs was
suggested by Grzesiak-Janas and Janas [73]. In this
method, 61 patients were subjected to 3 cycles of extra-
oral and intraoral irradiation with a CTL 1106 biostimu-
lative laser of 30-mW power with a tip-emitting light of
830-nm wavelength for 10.5 min and for four consecu-
tive days. The researchers demonstrated a complete
closure of OAFs. This technique eliminates the need for
a surgical procedure. The technique has the disadvan-
tage of being expensive and requires many visits to ac-
complish complete closure.
Logan and Coates described a procedure that provided
closure of OAF in immunocompromised patients [74].
Theoroantralfistulawasde-epithelialized under local
anesthesia, and the patient wore an acrylic surgical splint
continuously for an 8-week period. The acrylic surgical
splint covered the fistula and the edentulous area including
the hard palate. The investigators reported complete heal-
ing of the oroantral fistula after 8 weeks. The technique is
considered a very useful option when a surgical interven-
tion is contraindicated because of immunosuppression.
Discussion
A comprehensive review of available surgical and
non-surgical methods for closure of OAFs has been de-
scribed. The databases were selected to be comprehen-
sive and to cover a broad range of methods for closure
of OAF. A limitation of this review is the fact that
reporting of new techniques for closure of OAF was
mostly in case reports. Therefore, randomized controlled
clinical trials were not implemented to assess the quality
and feasibility of the new treatment strategy. Accord-
ingly, further research is recommended to investigate
the success of varied techniques. It is recommended to
investigate the condition of antral mucosa. Successful
closure of the oroantral fistula should be preceded by the
complete elimination of any sinus pathology [17]. Add-
itional surgery may be required to remove the diseased
lining if severe sinusitis is present prior to antrum ex-
posure [75]. Considering the different interventions
available to close OAFs, it is important to identify the
best intervention techniques to help clinicians to man-
age patients with OAF efficiently. The choice of the pro-
cedure is controversial. Most oral and maxillofacial
surgeons prefer either buccal or palatal flaps in case pri-
mary suturing of the soft tissue cannot adequately close
the oroantral fistula. Others claim that palatal flaps are
preferable because of their ample blood supply. A review
of literature on advantages of the palatal flap revealed
features of abundant vascularity, satisfactory thickness,
and resistance to laceration. Recently, because of the
continued need for implant rehabilitation, bony closure
of OAFs is increasingly being employed in the closure of
oroantral fistula. Closure of OAFs with bone grafts
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 10 of 13

harvested from intraoral donor sites paves the way for
implant surgery in terms of sinus lifting. However, au-
togenous bone grafting has some negative aspects in-
cluding the necessity for a second surgical procedure for
bone harvesting and concerns about donor site morbid-
ity. Therefore, other grafting materials have been investi-
gated for closure of OAFs [76]. It is quite evident that
the mechanical properties, biological behaviors and
biodegradation mechanisms vary for different graft ma-
terials. Unlike allografts or xenografts, by nature, allo-
plastic or synthetic materials limit the risk of cross
infection transmission of pathogens. Alloplastic mate-
rials are easy and simple; however, their disadvantages
include being time consuming and high cost and requir-
ing exfoliation, which may limit their use as an alterna-
tive surgical technique for closure of OAF. Another
consideration is that, the alloplastic material procedures
do not influence the buccal vestibular depth. Moreover,
the use of alloplastic materials would result in an area
free of raw for granulation following closure of the de-
fect. Recently, the use of platelet-rich fibrin for closure
of OAF is simple, inexpensive, and may be an effective
method for closing OAF. However, it needs more
evidence-based data. In view of the foregoing discussion,
this literature review provides an overall general theoret-
ical point of view to make sense out of available tech-
niques for closure of OAFs.
Summary and conclusion
By reviewing the literature, we can conclude that in select-
ing the surgical approach to close an oroantral fistula, dif-
ferent parameters have to be taken into account, including
location and size of fistula as well as its relationship to the
adjacent teeth, height of the alveolar ridge, persistence,
sinus inflammation and the general health of the patient.
A small oroantral fistula of less than 5 mm in diameter
can be closed immediately and effectively by suturing the
gingiva with a figure eight suture.If this does not provide
adequate closure,a flap procedure is indicated. The clos-
ure of an oroantral fistula can be performed by different
techniques. Buccal flaps are often indicated in closure of
small to moderate size defects. However, reduction of
buccal vestibular height like the Rehrmann flap follow-
ing this procedure makes it difficult to use prosthesis in
future. Alternatively, the buccal advancement flap, and
harvesting retromolar bone, prolamin gel, acrylic splint,
guided tissue regeneration (GTR), and bone grafts can
be successfully used for closures of OAF of less than
5 mm. However, over recent years grafts including free
mucosal (FMG) or connective tissue grafts (CTG) are in-
creasingly being used to close small to moderate size de-
fects in the premolar area. The combination of the
buccal flap and the buccal fat pad is appropriate for fis-
tulae located in the second and third molar area.
Closure of defects larger than 5 mm can be performed
using one of the following procedures: combination of
an endoscopic and per-oral BFP flap approach, BFP flap,
pedicled buccal fat pad, modified submucosal connective
tissue flap, distant flaps, autogenous bone grafts, allogen-
ous, synthetic materials/metals, and other techniques.
Ideally, the Bio-Gide®-Bio-Oss®
−
Sandwich technique
(Geistlich Biomaterials, Wolhusen, Switzerland) achieves
both bony and soft tissue closure of OAF. In any case, it
should be clear here that the technique for closure the
OAF always depends on the indication and as well as
the experience of the surgeon. It is often easier for a be-
ginner to use a PTFE membrane or Rehrmann flap than
to mobilize elaborate flap techniques and structures
which are at risk, e.g., bone graft transplantation (BGT),
injury of the arteria palatina and corpus adiposum buc-
cae (buccal fat pad). Moreover, when searching deeply
for the nervus faciali, injury of the nerve may occur. The
dentist must be able to assess his abilities and, accord-
ingly, choose the therapy to close the OAF.
Abbreviations
BFP: Buccal fat pad; BGT: Bone graft transplantation; CTG: Connective tissue
grafts; FMG: Free mucosal graft; GTR: Guided tissue regeneration;
OAF: Oroantral fistula; PRF: Platelet-rich fibrin
Acknowledgements
Not applicable
Funding
No funding to declare.
Availability of data and materials
All data generated or analyzed during this study are included in this
published article.
Authors’contributions
PP made substantial contributions to the conception and design of the
narrative review, did the literature research and interpretation of the literature
research. KO was a major contributor in writing the manuscript. RS, JB, and FS has
made substantive intellectual contributions. LS was a major contributor in writing
the manuscript and interpretation of the literature research and performed the
figure and chart. All authors read and approved the final manuscript.
Ethics approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Competing interests
Puria Parvini, Karina Obreja, Robert Sader, Jürgen Becker, Frank Schwarz, and
Loutfi Salti declare that they have no competing interests.
Publisher’sNote
Springer Nature remains neutral with regard to jurisdictional claims in published
maps and institutional affiliations.
Author details
1
Department of Oral Surgery and Implantology, Carolinum, Johann Wolfgang
Goethe-University, Frankfurt, Germany.
2
Department for Oral,
Cranio-Maxillofacial and Facial Plastic Surgery, Medical Center of the Goethe
University Frankfurt, Frankfurt am Main, Germany.
3
Department of Oral
Surgery, Universitätsklinikum Düsseldorf, Düsseldorf, Germany.
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 11 of 13

Received: 14 August 2018 Accepted: 2 November 2018
References
1. Yilmaz T, Suslu AE, Gursel B. Treatment of oroantral fistula: experience with
27 cases. Am J Otolaryngol. 2003;24:221–3.
2. Borgonovo AE, Berardinelli FV, Favale M, Maiorana C. Surgical options in
oroantral fistula treatment. Open Dent J. 2012;6:94–8.
3. Güven O. A clinical study on oroantral fistulae. J Craniomaxillofac Surg.
1998;26:267–71.
4. Amaratunga NADES. Oro-antral fistulae- a study of clinical, radiological and
treatment aspects. Br J Oral Maxillofac Surg. 1986;24:433–7.
5. Killey HC, Kay LW. Observations based on surgical closure of 362 oroantral
fistulas. Int Surg. 1972;57:545–9.
6. Abraham JJ, Berger SB. Oral-maxillary sinus fistula (oroantral fistula): clinical
features and findings on multiplanar CT. Am J Roentgenol. 1995;165:1273–6.
7. Yalçın S, Emes Y. Surgical treatment of oroantral fistulas: a clinical study of
23 cases. J Oral Maxillofac Surg. 2011;69:333–9.
8. Anavi Y, Gal G, Silfen R, Calderon S. Palatal rotation-advancement flap for
delayed repair of oroantral fistula: a retrospective evaluation of 63 cases.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003;96:527–34.
9. Haas R, Watzak G, Baron M, Tepper G, Mailath G, Watzek G. A preliminary
study of monocortical bone grafts for oroantral fistula closure. Oral Surg
Oral Med Oral Pathol Oral Radiol Endod. 2003;96:263–6.
10. Visscher SH, van Minnen B, Bos RR. Closure of oroantral communications: a
review of the literature. J Oral Maxillofac Surg. 2010;68:1384–91.
11. Rehrmann VA. Eine methode zur schliessung von kieferhohlen perforationen.
Dtsch Zahnartl Woc0068enzeitschr Dtsch Zahnärztl Wschr. 1936;39:1136.
12. Lin PT, Bukachaevsky R, Blake M. Management of odontogenic sinusitis with
persistent oro-antral fistula. Ear Nose Throat J. 1991;70:488–90.
13. Falci SGM, Dos Santos CRR. Modification of the vestibular mucoperiosteal
flap technique for closure of oroantral fistula. J Craniofac Surg. 2015;26:e
659. https://doi.org/10.1097/SCS.0000000000002069.
14. Môczáir L. Nuovo methodo operatiopela chisura delle fistole del seno
mascellase di origina dentale. Stomatologiia (Roma). 1930;28:1087–8.
15. Ashley RE. Method of closing antro-alveolar fistula. Ann Otol Rhinol
Laryngol. 1939;48:632–42.
16. Ehrl PA. Oroantral communication. Epicritical study of 175 patients, with special
concern to secondary operative closure. Int J Oral Surg. 1980;9:351–8.
17. Awang MN. Closure of oroantral fistula. Int J Oral Maxillofac Surg. 1988;17:
110–5.
18. Hynes W. Fistula in the hard palate following cleft surgery. Br J Plast Surg.
1957:377–84.
19. Genden EM, Lee BB, Urken ML. The palatal island flap for reconstruction of
palatal and retromolar trigone defects revisited. Arch Otolaryngol Head
Neck Surg. 2001;127(7):837–41.
20. Salins PC, Kishore SK. Anteriorly based palatal flap for closure of large oroantral
fistula. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1996;82:253–6.
21. Dergin G, Gurler G, Gursoy B. Modified connective tissue flap: a new approach
to closure of an oroantral fistula. Br J Oral Maxillofac Surg. 2007;45:251–2.
22. Ito T, Hara H. A new technique for closure of the oroantral fistula. J Oral
Surg. 1980;38:509–12.
23. Yamazaki Y, Yamaoka M, Hirayama M, Shimada H. The submucosal island flap
in the closure of oroantral fistula. Br J Oral Maxillofacial Surg. 1985;23:259–63.
24. Marcantonio C., Palmirri M., Gorga DV, Pereira M de Oliveira, Nicoli LG, Jorge
WA. Use of a palatal pedicle flap for closure of an oroantral fistula. Rev
Gaúch Odontol, Porto Alegre 2015; 63: 496–501.
25. Lee JJ, Kok SH, Chang HH, Yang PJ, Hahn LJ, Kuo YS. Repair of oroantral
communications in the third molar region by random palatal flap. Int J Oral
Maxillofac Surg. 2002;31:677–80.
26. Hai-Ming Z, Yi-Ping Y, Ke-Ming Q, Jia-Qi W, Zhi-Fei L. Anatomical structure
of the buccal fat pad and its clinical adaptations. Plast Reconstr Surg. 2002;
109:2509–20.
27. Egyedi P. Utilization of the buccal fat pad for closure of oroantral
communication. J Maxillo fac Surg. 1977;5:241–4.
28. Yang S, Jee YJ, Ryu DM. Reconstruction of large oroantral defects using a
pedicled buccal fat pad. Maxillofac Plast Reconstr Surg. 2018;40:7.
29. Daif ET. Long-term effectiveness of the pedicled buccal fat pad in the
closure of a large oroantral fistula. J Oral Maxillofac Surg. 2016;74:1718–22.
30. Martín-Granizo R, Naval L, Costas A, Goizueta C, Rodriguez F, Monje F,
Muñoz M, Diaz F. Use of buccal fat pad to repair intraoral defects: review of
30 cases. Br J Oral Maxillofac Surg. 1997;35:81–4.
31. El-Hakim IE, El-Fakharany AM. The use of the pedicled buccal fat pad (BFP)
and palatal rotating flaps in closure of oroantral communication and palatal
defects. J Laryngol Otol. 1999;113:834–8.
32. Singh J, Prasad K, Lalitha RM, Ranganath K. Buccal pad of fat and its
applications in oral and maxillofacial surgery: a review of published
literature (February) 2004 to (July) 2009. Oral Surg Oral Med Oral Pathol Oral
Radiol Endod. 2010;110:698–705.
33. Studer SP, Allen EP, Rees TC, Koubo A. The thickness of masticatory mucosa
in the human hard palate and tuberosity as potential donor sites for ridge
augmentation procedures. J Periodontol. 1997;68:145–51.
34. Thalmair T, Fickl S, Wachtel H. Coverage of multiple mandibular gingival
recessions using tunnel technique with connective tissue graft: a
prospective case series. Int J Periodontics Restorative Dent. 2016;36:859–67.
35. Yabroudi F, Dannan AA. Comparison between submucosal connective
tissue palatal flap and conventional pedicle palatal flap for the closure of
oroantral fistulae. Internet J Dent Sci. 2009;8:5.
36. Kim YK, Yeo HH, Kim SG. Use of the tongue flap for intraoral reconstruction:
a report of 16 cases. J Oral Maxillofac Surg. 1998;56:716–9.
37. Sielgel EB, Bechtold W, Sherman PM, Stoopack JC. Pedicle tongue flap for
closure of an oroantral defect after partial maxillectomy. J Oral Surg. 1977;
35:746–9.
38. Buchbinder D, St-Hilaire H. Tongue flaps in maxillofacial surgery. Oral
Maxillofac Surg Clin North Am. 2003;15:475–86.
39. Pourdanesh F, Mohamadi M, Samieirad S, Banimostafaee H, Sadeghi HM.
Closure of large oroantral communication using coronoid process pedicled
on temporalis muscle flap: a new alternative approach. J Craniofac Surg.
2013;24:1399–402.
40. Proctor B. Bone graft closure of large or persistent oromaxillary fistula.
Laryngoscope. 1969;79:822–6.
41. Cockerham S, Wood WH, Lind K. Closure of a large oroantral
communication by bone grafting. J Oral Surg. 1976;34:1098–100.
42. Peñarrocha-Diago M, García B, Gomez D, Balaguer J. Zygomatic bone graft
for oral-antral communication closure and implant placement. J Oral
Implantol. 2007;33:305–9.
43. Joshi A, Kostakis GC. An investigation of post-operative morbidity following
iliac crest graft harvesting. Br Dent J. 2004;196:167–71.
44. Misch CM. Harvesting of ramus bone in conjunction with third molar
removal for onlay grafting before placement of dental implants. J Oral
Maxillofac Surg. 1999;57:1376–9.
45. Nkenke E, Radespiel-Tröger M, Wiltfang J, Schultze-Mosgau S, Winkler G,
Neukam FW. Morbidity of harvesting of retromolar bone grafts: a
prospective study. Clin Oral Implants Res. 2002;13:514–21.
46. Kainulainen VT, Sàndor GK, Oikarinen KS, Clokie CM. Zygomatic bone: an
additional donor site for alveolar bone reconstruction. Technical note. Int J
Oral Maxillofac Implants. 2002;17:723–8.
47. Ram H, Makadia H, Mehta G, Mohammad S, Singh RK, Singh N, Singh G. Use
of auricular cartilage for closure of oroantral fistula: a prospective clinical
study. J Maxillofac Oral Surg. 2016;15:293–9.
48. Saleh EA, Issa IA. Closure of large oroantral fistulas using septal cartilage.
Otolaryngol Head Neck Surg. 2013;148:1048–50.
49. Aladag I, Gunhan F, Songu M, Imre A, Pinar E. Endoscopic repair of
persistent oroantral communications using the Caldwell-Luc approach. J
Craniofac Surg. 2018;29:703–5.
50. Kapustecki M, Niedzielska I, Borgiel-Marek H, Różanowski B. Alternative method
to treat oroantral communication and fistula with autogenous bone graft and
platelet rich fibrin. Med Oral Patol Oral Cir Bucal. 2016;21:608–13.
51. George E. Triple-layered closure of an oroantral fistula: a case report. Int J
Oral Maxillofac Implants. 2018;33:e33–6. https://doi.org/10.11607/jomi.5725.
52. Assad M, Bitar W, Alhajj MN. Closure of oroantral communication using
platelet-rich fibrin: a report of two cases. Ann Maxillofac Surg. 2017;7:117–9.
53. StajčićZ, TodorovićLJ, PetrovićV. Tissucol® in closure of oroantral
communication. A pilot study. Int J Oral Surg. 1985;14:444–6.
54. Gattinger B. Der verschluß von mund-antrum-verbindungen mit dem
lyophilisierten fibrinklebesystem. Zahnartzl Prax. 1984;35:8.
55. Kinner U, Frenkel G. Alternative Methoden des Verschlusses von
Mund-Antrum-Verbindungen; Die plastische Deckung der Kieferhöhle
mit lyophilisierter Dura mit alkoholischer Prolaminlösung. ZWR.
1990;99(890):892–6.
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 12 of 13

56. Mitchell R, Lamb J. Immediate closure of oro-antral communications with a
collagen implant. A preliminary report. Br Dent J. 1983;154:171–4.
57. Shaker MA, Hindy AM, Mounir RM, Geaisa KM. Competent closure of chronic
oroantral fistula with Zenoderm. Egypt Dent J. 1995;41:1237–42.
58. Ogunsalu C. A new surgical management for oro-antral communication: the
resorbable guided tissue regeneration membrane—bone substitute
sandwich technique. West Indian Med J. 2005;54:261–3.
59. Goldman EH, Stratigos GT, Arthur AL. Treatment of oroantral fistula by gold
foil closure: report of case. J Oral Surg. 1969;27:875–7.
60. Salman L, Salman SJ. Oro-antral closures using gold plate. N Y State Dent J.
1966;32:51–5.
61. Steiner M, Gould AR, Madion DC, et al. Metal plates and foils for closure of
oroantral fistulae. J Oral Maxillofac Surg. 2008;66:1551–5.
62. McClung E, Chipps J. Tantalum foil used in closing antro-oral fistulas. U S
Armed Forces Med J. 1951;2:1183–6.
63. Ahmed WM. Closure of oroantral fistula using titanium plate with
transalveolar wiring. J Maxillofac Oral Surg. 2015;14:121–5.
64. Al Sibahi A, Shanoon A. The use of soft polymethylmethacrylate in the
closure of oro-antral fistula. J Oral Maxillofac Surg. 1982;40:165–6.
65. Procacci P, Alfonsi F, Tonelli P, Selvaggi F, Menchini Fabris GB, Borgia V, De
Santis D, Bertossi D, Nocini PF. Surgical treatment of oroantral
communications. J Craniofac Surg. 2016;27:1190–6.
66. Zide MF, Karas ND. Hydroxylapatite block closure of oroantral fistulas: report
of cases. J Oral Maxillofac Surg. 1992;50:71–5.
67. Becker J, Kuntz A, Reichart P. Verschluß von Mund-Antrumperforationen durch:
Hydroxylapatitkeramik. Dtsch Z Mund Kiefer Gesichts Chir. 1987;11:92–5.
68. Thoma K, Pajarola GF, Grätz KW, Schmidlin PR. Bioabsorbable root analogue
for closure of oroantral communications after tooth extraction: a
prospective case-cohort study. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod. 2006;101:558–64.
69. Kitagawa Y, Sano K, Nakamura M, Ogasawara T. Use of third molar
transplantation for closure of the oroantral communication after tooth
extraction: a report of 2 cases. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod. 2003;95:409–15.
70. Hori M, Tanaka H, Matsumoto M, Matsunaga S. Application of the
interseptal alveolotomy for closing the oroantral fistula. J Oral Maxillofac
Surg. 1995;53:1392–6.
71. Waldrop TC, Semba SE. Closure of oroantral communication using guided
tissue regeneration and an absorbable gelatin membrane. J Periodontol.
1993;64:1061–6.
72. Götzfried HF, Kaduk B. Okklusion der Mund-Antrum-Verbindung durch eine:
alkoholische Prolaminelösung; Tierexperimentelle Studie und erste klinische
Erfahrungen. Dtsch Z Mund Kiefer Gesichts Chir. 1985;9:390.
73. Grzesiak-Janas G, Janas A. Conservative closure of antro-oral communication
stimulated with laser light. J Clin Laser Med Surg. 2001;19:181–4.
74. Logan RM, Coates EA. Non-surgical management of an oroantral fistula in a
patient with HIV infection. Aust Dent J. 2003;48:255–8.
75. Abubara A, Cortez A, Passeri L, De Moraes M, Moraes R. Evaluation of
different treatments for oro-antral/oronasal communication experiences of
112 cases. Int J Oral Maxillofac Surg. 2006;35:155–8.
76. Betz RR. Limitations of autograft and allograft: new synthetic solutions.
Orthopedics. 2002;25(5 Suppl):561–70.
Parvini et al. International Journal of Implant Dentistry (2018) 4:40 Page 13 of 13