In cases of extensively impaired intraoral wound beds, commonly seen after secondary or tertiary closure in palatal clefts, oroantral fistulae, osteo(-radio) necrosis and as a lack of attached gingiva or vestibulum depth after ablative tumour surgery, standard local flaps such as Axhausen’s cheek transposition flap, Rehrmanns’s trapezoid flap or simple palatal flaps are no longer possible due to extensive scarring, malperfusion and a lack of mobilizable tissue. Frequently, microvascular flaps serve as reliable options in situations of large defect sizes, however in selected clinical cases free flap surgery would be considered as a vast overtreatment neglecting the reconstructive needs of the local conditions. Hence, innovative but reliable local flap procedures need to be considered as back-up strategies in the armamentarium of today’s oral and maxillofacial surgery.
In the following we discuss a safe, reliable and highly useful indication extension of the buccal flap in hostile wound beds affected by a multitude of surgeries and adjuvant therapy. Introduced in the mid 1970s the buccal flap has experienced many modifications (11, 12). It may be harvested as an axial pattern flap including the facial artery as a main vessel as well as a random pattern flap, furthermore its thickness may reach from thin myomucosal flaps up to pedicled buccal fat pad integration (8, 13). Traditionally the myomucosal random patterned buccal flap, as described by Mann et al. in the late 1990s, serves as an option for primary closure of wide palatal clefts or as a back-up procedure for palatal lengthening in cases of cleft associated velopharyngeal dysfunction (9, 10). Beside the indications for cleft treatment there are a multitude of intraoral surgical procedures that demand soft tissue coverage in regions where dehiscence and infection play a key role in heavily pre-treated, malperfused and scarred wound beds. Even though the usage of allogenic and xenogenic grafts in pre-implantologic surgery, due to their easy handling, has become vastly popular these methods are not applicable in most cases of complex maxillofacial defects even if their anatomic diameter may not exceed the size of standard case in dental surgery surgery (14–16). Especially in preirradiated, malperfused tissue the application of xenogenic membranes may result in wound infection with consecutive tissue contraction and scarring that hampers the challenges of intraoral rehabilitation. Hence, the application of safely perfused local tissue is inevitable for treatment success.
We applied the buccal flap in ten patients who overall received 16 flaps and had undergone a multitude of surgeries in advance (minimum 5 times, maximum 35 times). The surgical indications were closure of palatal fistulas after tumour resection and cleft surgery, pre-implantological soft tissue improvement by vestibuloplasties, mucosal covering of autogenous bone transplants and defect closure after the resection of osteoradionecroses. The surgeries were uneventful, all flaps were harvested without complications such as malperfusion or injury of the pedicle and suited the initial treatment indication. In two cases (12.5 %) the palatal fistulae could not be closed completely but were transposed from clinically apparent (nasal food and fluid regurgitation) to clinically silent (no food and fluid regurgitation). Both patients were heavily pre-treated with up to 35 surgical attempts in different hospitals and private practices to close the fistulae. However, when considering the buccal flap as an option for intraoral soft tissue reconstruction certain aspects need to be borne in mind.
Firstly, the defect location determines the origin of the pedicle. Anterior pedicled flaps may be indicated in tissue shortage of the anterior half of the oral cavity up to the first premolar and cover the entire vestibulum and hard palate of the harvested flap site, whereas posterior pedicled flaps mostly serve as a coverage for the dorsal half of the oral cavity including the soft palate. In both cases distal flap perfusion seems to be limited when the myomucosal flap extends a length-to-base relation of over 3:1. To preserve the aesthetic unit of the lips and prevent extraoral deformities due to tension or distortion a gap of 1 cm to the angle of the mouth should be kept in anteriorly pedicled flap. Posterior pedicled flaps the retromolar trigone should not be incised to prevent bleeding and secure sufficient flap perfusion. Independently of the pedicle location a flap mobilisation over the median sagittal plane is not recommended as pulling and stressing the pedicle results in immediate malperfusion followed by dehiscence or flap loss. Due to masticatory movements and speech which, often result in tension of the pedicle, buccal flaps for tissue coverage in the lower jaw are more sensitive for wound healing disorders then defect closures in the upper jaw. However, in both cases as soon as the flap crosses the alveolar crest or the teeth the need of a spacer in form of an occlusal splint needs to be considered to avoid biting and injuring the pedicle. During the mixed dentition period tooth gaps may provide a natural corridor which prevents pedicle squeezing.
A clear advantage or the buccal flap compared to other pedicled flaps used for intraoral reconstruction is its blood supply. The random pattern nutrition allows a secure and vessel independent harvest even in patients with heavily pre-treated and perfusion compromised tissue. Especially in hostile necks where the lack of facial arteries or the damage of both lingual arteries may lead to a necrosis of tongue flaps or a reduced security in nasolabial flaps the buccal flap is a reliable alternative (17, 18). Besides it usually offers a larger and more versatile amount of movable tissue compared to classical local flaps such as Rehrmann’s trapezoid flap or Axhausen’s cheek flap.
However, meticulous wound care is needed to promote uneventful healing. Therefore, we highly recommend nasogastric tube feeding for at least five days, regular mouth rinsing with Chlorhexamed 0,2% and careful tooth brushing. When the nasogastric tube is removed a soft diet should be kept until the cut of the pedicle. Current literature provides inconsistent data concerning the time of transplant autonomisation, reaching from two to six weeks (19, 20). Depending on the local wound situation our patient collective showed a very wide time range of 63.17 days (median 41.5 days, minimum 23 days, maximum 133 days) for pedicle incision. The maximum time of division (133 days) was due to a prolonged orthodontic treatment to prepare the upper jaw for cleft osteoplasty with an autogenous bone transplant and exceeded the clinical appearance from which point on a cut of the pedicle would have been uneventful. Furthermore, the patient suffers from a CHARGE-syndrome that demanded medical intervention during which no maxillofacial treatment was possible. In four cases a pedicle removal was not performed as the lower surface of the flap was completely sutured to the wound bed and aligned with the local mucosa. Nevertheless, the two-stage removal of the pedicle may be seen as a main disadvantage in buccal flap treatment. The intraoral wound situation appears inconvenient and pre-surgical patient education and careful patient selection are needed to ensure best conditions for uneventful healing. As all patients in our collective showed a long history of surgical and adjuvant pre-treatment the buccal flap served as a final back-up for local would management before referring to microvascular tissue replacement. This aspect provides a high patient motivation but justifies the inconvenient time of intraoral pedicle carriage and the temporary restrictions to nutrition, speech and oral hygiene. In our experience, the pedicled buccal flap therefore represents a reliable and practical alternative in selected cases of impaired wound bed and intraoral soft tissue scarcity in demanding local situations for oral and maxillofacial surgeons.