Fractures of the frontal sinus are one of the fractures situated between the cranial region and the facial region. They account for 5% to 15% of facial fractures [1] . They result from high kinetic energy trauma due to the thickness of the anterior wall, which is solid and resistant [2] . These are potentially serious fractures, with the main risk being meningoencephalic damage. The main circumstances of injury are road traffic accidents (RTAs), interpersonal violence, falls and sports accidents [3] [4] [5] . Diagnosis is based on clinical signs, confirmed by craniofacial CT scans. The classification of frontal sinus fractures and their management are not standardized, because of the diversity of algorithms proposed by authors [6] - [13] . In fact, the management of these fractures depends on answering two fundamental questions: which fractures, if not treated, will lead to an immediate or late complication? And what is the appropriate surgical procedure if treatment of the fracture is considered necessary [14] ? Whatever the answers to these two questions, the main concern remains complications, which may be short-term (meningitis, brain abscess) or long-term (mucocele, osteitis) and could be fatal for the patient [15] . In Burkina Faso, although the technical facilities are inadequate, frontal sinus fractures are managed in the maxillofacial surgery and neurosurgery departments. However, in the absence of a specific study on this subject in our context, there is great variability in the management of these fractures between surgical teams. A review of the management of frontal sinus fractures in our context is imperative in order to harmonies practices and achieve optimal patient care. The aim of this study is to report on the management of frontal sinus fractures at the Yalgado Ouédraogo University Hospital (CHUYO).

This was a descriptive cross-sectional study collected retrospectively from 01 January 2016 to 31 December 2018. It included all patients admitted to the Stomatology/Maxillofacial Surgery and Neurosurgery departments of the CHUYO for frontal sinus fracture confirmed by a craniofacial CT scan. A frontal sinus fracture was defined as continuous, open or closed solutions for one or both walls of the frontal sinus (Figure 1). The urban setting was defined as all the provincial capitals of Burkina Faso, and the rural setting as the departmental capitals, villages and farming hamlets. The consultation delay was defined as the time between the injury and the first admission to the CHUYO. The surgical intervention delay is defined by the time between the injury and the first surgical intervention at the CHUYO. The patient’s general condition was evaluated using

the World Health Organisation (WHO) classification scale, which ranges from 0 to IV. Stage 0: corresponds to normal activity with no restrictions. Stage I: corresponds to a restriction of important physical activities, but the patient is ambulant and able to do light work. Stage II: corresponds to a patient who is ambulant and able to look after himself, but unable to do any work and bedridden for less than 50% of his time. Stage III: corresponds to a patient who is capable of much more limited self-care and spends more than 50% of their time in bed or in a chair. Stage IV: corresponds to a patient who is completely bedridden and unable to take care of themselves. The patient remains totally confined to bed or in a chair.

The types of injury have been classified according to the Ioannides et al. [10] classification of frontal sinus fractures. It comprises four types, the first three of which are subdivided into subtypes defined by the letters a, b, c, d or e. The Ioannides et al. [10] classification is as follows:

- Type I: Fractures of the anterior Wall

● Ia: Without dislocation, no damage to the nasofrontal duct.

● Ib: High fracture of dislocation, not of the nasofrontal duct.

● Ic: Fracture with bone loss, not of the nasofrontal duct.

● Id: Low fracture with involvement of the nasofrontal duct.

● Ie: Fracture of all anterior wall with involvement of the nasofrontal duct.

- Type II: Posterior Wall fractures

● IIa: No dislocation, no cerebrospinal fluid (CSF) leakage.

● IIb: Dislocation and/or bone loss, no CSF leak.

● IIc: Dislocation and CSF leak.

● IId: Extensive and comminuted for the posterior wall with the CSF leak.

- Type III: Fractures of both the anterior and the posterior walls

● IIIa: Type I + IIa or IIb.

● IIIb: Type I + IIc or IId.

- Type IV: Comminuted fractures of all complex nasofronto-ehtmoido-orbital

The variables studied were the following: epidemiological (age, sex, socio-professional categories, residence, circumstances of occurrence of the injury), clinical (consultation delay, physical signs, type of frontal fracture and associated facial and extra-facial injuries), therapeutic (medical treatment, non-surgical treatment, surgical delay, approaches, surgical procedures), evolutionary (favourable, complications and sequelae).

The data were collected by filling in a data collection form containing the study variables from the patient’s medical records, hospitalized patients’ registers, emergency registers and operative report registers. The data were processed and analysed using Epi info 7.2 software.

The confidentiality of the information collected and the anonymity of the patients were respected.

A total of 102 cases of frontal sinus fractures were reported, giving an annual average of 34 cases. This average is higher than that reported by Mabika et al. [16] and Mahran et al. [5] , who reported respective averages of 12 and 25.6 cases per year. The high frequency of frontal sinus fractures in this study could be explained by the fact that the data were collected in two departments (maxillofacial and neurosurgery) and by the predominance of RTAs (90.20%) frequently involving drivers of two-wheeled machines (98.20%) without helmets. Mabika et al. [16] and Mahran et al. [5] also found that RTAs predominated in 72.22% and 49% of cases respectively. In developed countries, on the other hand, the incidence of frontal sinus fractures has declined over the last 20 years thanks to improved living standards and the use of public transport [17] . Fractures of the frontal sinus seem to be the prerogative of young males and this was confirmed by this study which reported a mean age of 29.9 years and 94.10% of males [4] [5] [16] [18] .

The clinical signs found in this series are consistent with those reported in the literature [19] . Type III of frontal fractures according to the classification of Ioannides et al. [10] , accounted for more than half the cases (51.9%). Lopez et al. [20] made the same observation, with a frequency of 50.1%. On the other hand, Mahran et al. [5] , Bell et al. [21] and Schultz et al. [4] reported a predominance

of anterior wall fractures (Type I of Ioannides et al.) with frequencies of 53%, 59.5% and 89.7% respectively. Mabika et al. [16] , on the other hand, reported the predominance of type IV frontal fratures according to Ioannides et al. [10] . The type of injury varied from one author to another. The absence of helmets in all the patients in this series is thought to be correlated with the extent of the injuries (fractures of both tables of the frontal sinus). Furthermore, structurally, the posterior table is thin (0.1 - 4 mm) and generally offers little protection to the intracranial contents, whereas the anterior table has an average thickness of 2 - 12 mm and requires a pressure of approximately 360 - 1000 pounds for a fracture to occur [2] . Consequently, the majority of frontal sinus fractures are secondary to high kinetic energy impacts, with a significant risk of associated facial and extra-facial injuries [2] . This would explain the predominance of associated maxillofacial fractures (45.10%) and cranioencephalic injuries (44.12%) found in the patients in the present study. Johnson et al. [3] also found that 79.6% of patients had associated maxillofacial fractures and 61.8% cranioencephalic injuries. In addition to these injuries, Schultz et al. [4] reported intra-thoracic injuries (17%), intra-abdominal injuries (5%), vertebral column (13%) and long bone fractures (17%), which were not found in this study. The management of frontal sinus fractures in our setting often involves both maxillofacial surgeons and neurosurgeons. Surgical abstention (conservative treatment) was observed in 80.39% of patients. This frequency is comparable to Schultz et al. [4] who observed conservative treatment in 80.4% of patients. However, Lopez et al. [20] found that conservative treatment represented an average frequency of 32.9% of cases following a review of the literature. According to the management algorithms for frontal sinus fractures proposed by the authors, there is no consensus on the indication for conservative treatment [7] [8] [19] [21] . For some authors, it is indicated in cases of non-displaced fractures (less than 1 - 2 mm) of the anterior wall [8] [21] . For others, the indication for conservative treatment depends on whether the nasofrontal canal and the posterior table of the frontal sinus have been affected [7] [19] . However, in the present study, conservative treatment was indicated not only in cases of non-displaced frontal sinus fractures but also in situations where there was a financial barrier to surgery.

Surgical management was performed in 19.61% (20) of patients under general anaesthesia. The average time to surgery was 6.6 days. This was less than the 12 days reported by Chegini et al. [11] . However, for Bellamy et al. [15] , a delay of more than 48 hours was associated with a high risk of complications. There is no consensus among authors as to the ideal delay for surgical intervention, since it is thought to be related to the type of injury [6] [15] [16] . Indeed, correction of anterior table fractures should be delayed by at least 7 to 10 days following the trauma to allow resolution of swelling and clear delineation of the frontal deformity [6] .

The aim of surgical treatment of frontal sinus fractures is to preserve sinus function, ensure a seal between the nasal cavity and the brain, prevent infection and restore facial aesthetics [11] . To achieve this, several approaches and surgical procedures have been reported [7] [8] [21] .

The coronal approach was preferred in 70% of cases in this series. It is the preferred approach [5] [21] . It has the advantage of better exposure to bony injuries. However, it is more invasive, extends the operating time and results in more blood loss. The main disadvantage is the occurrence of alopecia, which can be avoided by a zigzag incision [19] . The approach can be made through the traumatic wound (tans-cicatricial), as was the case in the present study in 25% of patients. This frequency was higher than that reported by Mabika et al. [16] and Mahran et al. [5] , who reported frequencies of respectively 16.7% and 8.5% of cases. The trans-cicatricial approach allows easy, direct and non-invasive exposure of the frontal sinuses, but has the disadvantage of scarring which can be minimised by respecting the skin tension lines [8] .

The choice of this approach was motivated by the existence of a relatively large forehead wound that could be used as a minimally invasive approach with minimal scarring. A direct forehead incision was made in one patient in this series. The direct transcutaneous approach to the forehead allows direct access to the fracture site with less operating time and blood loss than the coronal approach. However, it is responsible for unsightly forehead scars and hypoesthesia secondary to damage to the supraorbital and supratrochlear nerves [8] . Finally, the endoscopic approach, which was not used in this study, is an alternative to the other approaches. It is less invasive and makes it possible to check the integrity and patency of the nasofrontal canal. However, closed reduction is best suited to simple anterior table fractures with few fragments. The major disadvantage is that it is impossible to assess the effectiveness of the reduction with any certainty [8] [22] . Equipment for the endoscopic approach is not available in our context.

In terms of surgical procedures, Reduction of the front embarrure plus fixation with a screw plate was performed in 13 (65%) cases. It is indicated for displaced anterior table fractures (greater than 2 mm) with or without posterior table involvement. It may be the only treatment, as in the study by Bell et al. [21] , where it represented 58% of the treatment. In the case of loss of substance of the anterior table, reconstruction may be performed using biomaterials or a graft [6] [16] . The only iliac graft taken in this series was used for this reconstruction. The economic profitability of the graft motivated our choice of biomaterials, which are not accessible to the majority of patients. Cranialization of the sinus was performed in 11 (55%) cases. This frequency is higher than those reported by Mahran et al. [5] , Lopez et al. [20] and Schultz et al. [4] , who reported frequencies of 28.5%, 17.2% and 6.2% of cases respectively. In fact, it is indicated in complex, comminuted fractures of the posterior wall of the frontal sinus involving the nasofrontal canal. This is an invasive procedure involving complete resection of the posterior wall of the frontal sinus, meticulous removal of the entire sinus mucosa, milling of the bony walls and obturation of the nasofrontal canal [19] [21] . It was frequently performed in this study because of the severity of the injuries and the surgeon’s experience. Sinus obliteration, which is indicated in certain fractures of the frontal sinus with damage to the nasofrontal canal but with a stable posterior table, was not performed in this study. It consists of filling the sinus cavity with autologous grafts or biomaterials. However, grafts, particularly fat grafts, are more effective due to their high biocompatibility [19] . The dural repair was carried out in 8 (40%) cases in the form of direct sutures or by plasty according to the principles described. It follows the obliteration or cranialization of the frontal sinus [19] . This repair was indicated for fractures of the posterior wall of the frontal sinus associated with damage to the dura mater with or without cerebrospinal fluid drainage. Even if all the aims of frontal sinus fracture management outlined above have been achieved, long-term follow-up is essential. Patients were monitored for periods ranging from one to three months, during which time complications and sequelae were noted. Complications such as meningitis (6 cases), brain abscesses (1 case) and sequelae such as frontal depression (30 cases), unsightly scars (30 cases), chronic headaches (7 cases), persistent rhinorrhoea (3 cases) and anosmia (1 case) were noted in the patients who received conservative treatment. These same complications have been reported by other authors with varying frequency [3] [5] [15] . The occurrence of certain complications could be explained by the financial barrier, which prevented surgery from being performed on eligible patients. In addition, only three patients were vaccinated against pneumococcal disease, for the same reasons of financial need. As for the patients who were operated on, the after-effects were unsightly scars (7 cases) and frontal depression (3 cases). These sequelae can be explained by the importance of soft tissue injuries and insufficient correction of the fractures of the anterior table of the frontal sinus.

The limits of this study are attributable to its retrospective nature. As the data were collected from medical records, it was difficult to explain with certainty all the information collected, as the patient was not present. In addition, follow-up lasted between one and three months, which is insufficient in relation to the occurrence of certain complications such as mucoceles and osteitis of the frontal bones. Finally, the data are not so recent, as the study involved patients from 2016 to 2018. Indeed, the work was part of a medical thesis that began in 2019 and was not defended on time. However, although more recent data is required, it has provided insight into the management of frontal sinus fractures in our setting.

Fractures of the frontal sinus are relatively frequent in our context. However, their management remains a challenge in view of the financial barrier to care and the limited technical resources available. Complications and sequelae result, making management complex in the context of limited resources. Prevention through compliance with road safety measures, including the wearing of helmets, and the removal of financial barriers to care, could both reduce the number of cases and improve the way patients are managed.

The authors declare no conflicts of interest regarding the publication of this paper.

Coulibaly, A., Gane-Bang, P., Biogo, J.W.-T., Traoré, I. and Konsem, T. (2024) Frontal Sinus Fractures: Management at the Yalgado Ouedraogo University Hospital Centre (Burkina Faso). Open Journal of Stomatology, 14, 42-54. https://doi.org/10.4236/ojst.2024.141004