The partial removal of BFP or “partial buccal lipectomy” aims to sculpt the lower face and reduce rounded faces. The procedure is related to the concept of an “inverted triangle of youth” that may increase the beauty. This concept is defined by an angular facial appearance resulted from a leaner face with a high malar region (3,6). In 1980, Epstein (10) first reported the BFP removal to improve the facial aesthetics. Although it is not a novel procedure, nowadays there is an extensive commercial marketing with appeal to facial aesthetics (6), and the procedure is disseminated as a routine. Thus, this systematic literature review aimed to identify the current state of BFP removal and the possible effects.

In the reviewed literature, the procedure can be indicated for cases with rounded faces or with presence of BFP pseudoherniation (2-4,8,10). When pseudoherniation is diagnosed, the patient shows a small rounded contour irregularity in the cheek due to weakening of BFP fascia (8). Patients with rounded faces show cheek/midface fullness despite appropriate weight for height (3,10). In both cases, the procedure’s goal is to reduce midface fullness, highlight the zygomatic prominence and the mandibular body, and remove any soft tissue asymmetry (3,10,14). Only one absolute contraindication was found in the literature, the procedure is contraindicated for patients with hemifacial atrophy, where BFP atrophy is a well-known component (1).

Another possible indication is as adjunct procedure in facial feminization surgery, aiming to change the characteristics of a male face to a female one. The female face usually has a triangular shape, with the base of an inverted triangle in a line drawn between the maximum prominence of each zygoma and the apex to the chin (16). Thus, as reported, the BFP removal may enhance those aspects and outcomes.

Concerning the long-term effects and facial aging, none of the included studies evaluated those features. Krupp (4) (1986) theorized that a severe weight loss associated with BFP removal could result in deep hollows in the cheek, however this situation was not found in the included studies. Matarasso (3) (1991) reports that there is a weak relationship between corporeal fat and BFP size, and even with aging and the characteristic loss of fat, the BFP remain in a relatively fixed size, demonstrating BFP resistance to lipolysis (2,4). Thus, patients with excessive BFP size will maintain this volume trough aging, and its removal may result in a general aesthetic improvement through time. However, it is important to highlight that there is a lack of knowledge regarding to the long-term effects of the procedure and its role in the facial aging.

The maintenance of BFP size over time is confirmed by image studies. Generally, the volume of the BFP is constant in adults (8). Volumetric evaluations show that the BFP grows between childhood and adult life, increasing from 4000 mm3 to 8000 mm3, and between the 20 and 50 years’ declines to 7000 mm3 (9). Also, volumetric analysis demonstrate that BFP is not always symmetric, especially in post-trauma patients (14). Therefore, a preoperative MRI should be the chosen image exam to determine the extension and symmetry of BFP (8). It is interest to observe that any of the included studies reported on the use of preoperative image exams for surgical planning. Thus, would be desirable to future studies the preoperative imagining evaluation in order to define the real necessity of those exams.

Regarding the selection of the surgical technique, there are two approaches to BFP removal: associated with facelift procedure (rhythidectomy) or by intraoral incision. When associated with rhythidectomy, it is expected impairment of buccal and zygomatic branches of the facial nerve (2). Thus, the safer method is to approach the BFP through intraoral incision (3,8,10,14). This incision can be performed at bite level or in maxillary gingivobuccal sulcus. The main difference between these incisions is the relationship with parotid duct, however no difference was observed in the studies regarding to complication rates or procedure’s difficulty. Xu and Yu (7) (2013) demonstrated a case series of BFP removal concomitant to masseter muscle detachment, which the incision at bite level seems more indicated. Nonetheless, there is no comparative study between those techniques, so the indications, damage to adjacent structures and postoperative aspects should be evaluated by future clinical trials.

The complication rate of the included studies, considering the reported results, amounts to 8.45% of the treated patients. This list included hemorrhage, facial asymmetry, and trismus. Although the reported complications are considered minor, injuries to parotid duct and facial nerve may occur (3-4,10,14). Engdahl, et al. (15) (2012), reported a massive hemorrhage of internal maxillary artery after intraoral BFP removal, in which the patient almost died. The lack of information about complications suggests that prospective clinical trials should be performed in order to define the potential complications of the technique.

It is important to highlight the differences between intraoral approach and face lift procedure. Besides the anesthesia regimen, the surgical anatomy is completely different. Most of complications are related to chosen approach and not to BFP removal itself. The face lift presented major complications as impairment of buccal and zygomatic branches (2). Those complications occurred due to damage to structures involved in the facial approach (3). The most important structure related with intraoral approach is the parotid duct. As reported, to avoid damage to this structure, the incision is preconized above (maxillary gingivobuccal sulcus) or below (at bite level) of the duct.

Although BFP removal may be performed isolated, a variety of associated procedures were found in this systematic review, including face lift, submental lipoplasty, rhinoplasty, malar, and chin implants, lip augmentation, masseter detachment and Botulinum toxin (BTX-A) injection (2-4,6-7,10,14). This high number of procedures occurred due to the aesthetic purpose of BFP removal. Usually, those patients seek not only for rounded face correction but also for others plastic procedures (6). Regarding to anesthesia regimen, both local and general were observed. Generally, the intraoral BFP removal is performed under local anesthesia (3,10), however the presence of concomitant procedures may indicate general anesthesia.
It is important to notice that none of all included articles was a clinical trial, hence all had a high risk of bias according to PRISMA evaluation. This fact shows a limitation of this systematic review, because there is a lack of clinical studies about BFP removal and its effects. This information shows the need of randomized clinical trials to compare the different methods of technique, to evaluate long-term effects in facial aging and function and to report complication types and rates.

In conclusion, all studies reported that BFP removal has an initial favorable outcome regarding facial aesthetics. The presented complication rate was low, without severe damages reported. However, the need of preoperative image exam, long-term effects in facial aging, and difference between intraoral techniques are not clear. Moreover, the amount of removal is not described and if it is excessive may result in an unfavorable outcome.