The maxilla, which is in the mid-face, has several important functions, including mastication with attached teeth, supporting facial structures, and shaping the facial features. However, maxillary fractures can occur from injuries of various causes, potentially requiring surgery.

Maxillary fractures could result in functional changes and facial contour alterations, so ensuring an accurate and solid reduction is important. Using titanium implants for maxillary fracture reduction has been considered the gold standard, with advantages such as a short operating time and solid fixation. However, the disadvantages of titanium implants include the risk of foreign body reaction, palpation of the plates in area with thin skin, difficulties in subsequent computed tomography (CT) and magnetic resonance imaging (MRI) scans, the need for secondary surgery to remove them, and hindrance of facial bone growth in children. Recently, studies have investigated the potential of absorbable implants, which do not require secondary surgery for removal (unlike titanium implants), for maxillary fracture reduction [1-4].

Cyanoacrylate is an adhesive used for various tissues, including the skin, bone, and fascia, and its advantages include requiring a shorter time for adhesion than sutures and ease of use [5-8].

During the surgical reduction of comminuted maxillary fractures, larger fragments can be easily reduced and fixed, but it is difficult to reduce small fragments that are not fixed with screws [1-4]. In this study, we report a method of using absorbable implants to avoid secondary surgery for the removal of titanium implants, in combination with cyanoacrylate for accurate and solid reduction and fixation of small bone fragments that are not fixed with screws.

In this retrospective cohort study, patients were diagnosed with comminuted maxillary fractures and surgery was performed between January 2012 and December 2017. Between 2012 and 2014, there were 114 patients (98 males and 16 females) who underwent surgery using absorbable mesh and screws. The mean age was 40.2 years for males (range, 13–83 years) and 41.5 years for females (range, 18–74 years). Between 2015 and 2017, there were 121 patients (97 males and 24 females) who underwent surgery, with a mean age of 43 years for male patients (range, 14–75 years) and 56.2 years for female patients (range, 20–80 years). Of the 121 patients, 99 underwent surgery using absorbable mesh and screws with cyanoacrylate (79 males and 20 females). The other 22 patients underwent surgery using absorbable plates and screws with cyanoacrylate (18 males and 64 females) (Table 1).

There were no differences between the two groups with regard to any complications, such as malocclusion, infection, enophthalmos, diplopia, numbness and foreign body reaction. Based on the operator’s observations with the naked eye, the method using absorbable plates and screws with cyanoacrylate showed more precise alignment. In a comparison between the two groups using preoperative, postoperative, and follow-up CT scans, the use of absorbable plates and screws with cyanoacrylate led to more accurate reduction and solid fixation (Figs. 5, 6).

When only an absorbable plate was used, multiple bone fragments were fixed to the absorbable plate using screws one by one. However, when we used an absorbable plate with cyanoacrylate, we did not have to fix each of the multiple bone fragments using screws one by one. Additionally, cyanoacrylate made it possible for us to fix multiple small bone fragments that could not be fixed with screws. As a result, we saved time and used fewer screws.

Craniofacial fractures are fixed with titanium plates and screws because doing so is relatively quick and leads to rigid fixation. However, titanium plates may be palpable or cause a visible abnormal facial contour, and these plates may hinder CT and MRI scans. When foreign body reactions occur, patients often require secondary surgery to remove titanium plates and screws. Lastly, titanium plates and screws can induce bone deformities in children or adolescents, as their bones continue to grow [3]. To overcome these limitations, some studies have reported the use of absorbable plates and screws for the surgical treatment of craniofacial fractures. These studies have concluded that the use of absorbable plates and screws can produce comparable outcomes to those obtained using titanium plates, while complementing the limitations of titanium plates and screws [3-4,9-11].

Cyanoacrylate has been used as a tissue adhesive for multiple decades, and previous studies have found cyanoacrylate to show satisfactory outcomes, with advantages including a shortened time required for healing, a somewhat lower cost, and aesthetically favorable outcomes [5,12]. In addition to its use for skin sutures, cyanoacrylate is used in various other fields including tympanoplasty, cranial bone flaps, fistula of the meningeal artery, and maxillo-facial complex fractures [6,8,13]. Previous studies have described successful procedures yielding rapid and rigid fixation using cyanoacrylate, with no complications.

Although titanium plates and screws are the gold standard for the reduction and fixation of craniofacial fractures, they have some limitations. In a previous study, the authors fixed facial bone fractures using absorbable mesh and screws, which may complement the abovementioned limitations [4].

Another study reported that the thin areas of complex comminuted craniofacial fractures were difficult to reduce. In those cases, titanium plates and screws were utilized to fix larger bones, while small bones were fixed using cyanoacrylate [13].

In our study, we used absorbable mesh, plates, and screws (Biobsorb Fixbone plate) instead of titanium implants for surgery of comminuted maxillary fractures, in order to complement the limitations of titanium implants [4]. After reduction of a comminuted maxillary fracture, cyanoacrylate (LiquiBand, Surgical S [monomeric n-butyl and 2-octyl cyanoacrylates]) was applied to fix fragments of small and thin bones that could be fixed with screws as well as small bone fragments that broke apart during fixation with screws. Previous studies have recommended the use of titanium mesh over absorbable mesh to fix small bone fragments that are not fixed with screws in patients with comminuted maxillary fractures [3,4]. However, by applying the advantageous aspects of cyanoacrylate discussed in the previous study, we successfully reduced and fixed multiple small bone fragments in comminuted maxillary fractures by using absorbable implants with cyanoacrylate [13]. Using absorbable implants with cyanoacrylate might save time and broaden the choice of surgical methods for comminuted maxillary fractures.

As reported in a previous study, although cyanoacrylate is degraded in the body, its exact duration in the body and potential harms have yet to be elucidated [14]. Furthermore, a limitation of this study is that it did not incorporate an objective evaluation of the postoperative facial contour score, fixation strength and bone reduction. To improve these limitations, further studies with objective evaluations would be needed.

Although titanium plates and screws are traditionally used for the fixation of craniofacial fractures, this study suggests that using absorbable implants with cyanoacrylate could overcome the limitations of traditional titanium plates. We used only absorbable mesh instead of titanium plates to overcome these limitations, but multiple small bone fragments or thin bone fragments were difficult to fix with screws. To improve this limitation, we used absorbable implants with cyanoacrylate. As a result, multiple small bone fragments and thin bone fragments could be fixed. Using absorbable implants with cyanoacrylate for fixation of comminuted maxillary fractures might save time and provide an easier, more convenient, and solid surgical method. We hope that this study will provide an additional choice for clinicians who perform facial fracture surgery.