**4. Diagnosis of frontal sinus fracture**

The physical examination of patients with frontal sinus fractures is difficult because of soft tissue swelling. The detection of cerebrospinal fluid rhinorrhea which indicates a posterior table injury with a dural tear is an important preoperative finding. CSF rhinorrhea is rarely detected because the fluid drains from the oropharynx. The surgeon should attempt to obtain a sample of this by having the patient lean forward to allow drainage from the nose and test the fluid for glucose or β-2 transferrin to confirm the diagnosis. Other signs of frontal sinus fracture include supraorbital nerve anesthesia and a depressed frontal region [7]. The most common associated finding is a laceration of the supraorbital ridge (Figure 1), glabella, or lower forehead [8]. These lacerations are often extensive and may be contaminated by foreign material [9].

Plain skull radiographs including the Caldwell and lateral views are occasionally used. Sinus pathology is strongly suspected when the radiograph demonstrates air-fluid levels, a diffusely cloudy sinus, or pneumocephalus. Accurate serial 1.5 mm cuts computed tomography (CT)

frontal recess, but they also may drain above the ethmoid infundibulum, into it or above the

The frontal sinus is lined with pseudostratified ciliated columnar epithelium. The main source of blood supply to the frontal sinus is a diploic branch of the supraorbital artery [2].The frontal sinus also receives some blood supply from branches of the anterior ethmoidal artery [1].External venous drainage is through the angular and anterior facial veins. The deep drainage is through the foramen of Breschet which is located on the posterior wall of the sinus. This structure is responsible for communication with the subdural venous system in the

A frontal sinus fracture is a common injury in patients who suffer high-energy trauma from motor vehicle accidents or altercations [3].The frontal sinus fracture accounts for 5–15% of all fractures of the maxillofacial area [4] and is often associated with neurological deficit and other facial fractures [3].The involvement of the brain is not uncommon. It has been suggested that more than 80% of the patients with a fracture of both the anterior and the posterior wall have intracranial injuries, such as hemorrhages and cerebral contusions [5].Pain is a common symptom in conscious patients with a frontal sinus fracture. Lacerations are seen in 50% of patients. About 25% of patients have a visible depression of the forehead [6]. Other possible symptoms are epistaxis, problems with vision, edema and paresthesia of the supraorbital region. Leakage of cerebrospinal fluid, due to damage of the dura, is a common finding [4].Computed tomography (CT) is the gold standard in diagnosing the degree of involvement

The physical examination of patients with frontal sinus fractures is difficult because of soft tissue swelling. The detection of cerebrospinal fluid rhinorrhea which indicates a posterior table injury with a dural tear is an important preoperative finding. CSF rhinorrhea is rarely detected because the fluid drains from the oropharynx. The surgeon should attempt to obtain a sample of this by having the patient lean forward to allow drainage from the nose and test the fluid for glucose or β-2 transferrin to confirm the diagnosis. Other signs of frontal sinus fracture include supraorbital nerve anesthesia and a depressed frontal region [7]. The most common associated finding is a laceration of the supraorbital ridge (Figure 1), glabella, or lower forehead [8]. These lacerations are often extensive and may be contaminated by foreign

Plain skull radiographs including the Caldwell and lateral views are occasionally used. Sinus pathology is strongly suspected when the radiograph demonstrates air-fluid levels, a diffusely cloudy sinus, or pneumocephalus. Accurate serial 1.5 mm cuts computed tomography (CT)

ethmoid bulla.

subarachnoid space [1].

of the frontal sinus [3].

material [9].

**4. Diagnosis of frontal sinus fracture**

**3. Frontal sinus fracture**

472 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**industrial accident. Right: CT scan of the same patient reveals both anterior and posterior table fractures of the frontal sinus. Figure 1.** Left: A 52-year-old patient who has facial laceration due to an industrial accident. Right: CT scan of the same patient reveals both anterior and posterior table fractures of the frontal sinus.

**Figure 1. Left: A 52‐year‐old patient who has facial laceration due to an**

imaging in both the axial (Figure 2) and coronal planes should be obtained in all cases to determine the degree of injury to the anterior and posterior tables and nasofrontal ducts [10]. The CT scan allows for visualization of the brain, face, and orbits as well, which is often necessary because of the high rate of associated injuries [9]. Plain skull radiographs including the Caldwell and lateral views are occasionally used. Sinus pathology is strongly suspected when the radiograph demonstrates air‐fluid levels, a diffusely cloudy sinus, or pneumocephalus. Accurate serial 1.5

mm cuts computed tomography (CT) imaging in both the axial (**Figure 2**) and coronal planes should be obtained in all cases to determine the degree of injury to

**with blunt trauma to the head. Note that there is no sign of depression or asymmetry of the face. Right: CT scan of the same patient reveals frontal sinus fracture with severe bone depression. Figure 2.** Left: A 26-year-old patient who had a motor vehicle accident with blunt trauma to the head. Note that there is no sign of depression or asymmetry of the face. Right: CT scan of the same patient reveals frontal sinus fracture with severe bone depression.

Isolation of the neurocranium, cessation of any CSF leak, prevention of early and delayed postoperative complications and restoration of the preoperative facial aesthetics are the aims of treatment of frontal sinus fractures. The integrity of the posterior wall and/or involvement of the nasofrontal duct are the factors influencing treatment. The integrity of the posterior wall is the main factor for the separation of the intracranial contents from the outer environment. The nasofrontal duct involvement is the decisive factor for the potential dysfunction of the sinus mucosa. Closed fractures of the anterior wall of the frontal sinus without displacement do not require surgical treatment and only observation is required. The treatment of depressed fracture of the anterior wall without involvement of the nasofrontal duct is simple elevation of the fracture and plate fixation. However, if the duct is involved, the treatment should include the obliteration of the sinus cavity after the sealing of the injured duct. In this way the frontal sinus is treated as an isolated cavity precluding any potential mucosal regrowth from the nasal epithelium. If the posterior wall is involved the determinant of successful management of the frontal sinus fracture is removal of the displaced bony fragments of the posterior sinus wall, restoration of the dural integrity and complete isolation of the brain from potential communication with the nose

through the injured frontal sinus and cranialization of the frontal sinus [11].

**Figure 2. Left: A 26‐year‐old patient who had a motor vehicle accident**

**TREATMENT MODALITIES**

## **5. Treatment modalities**

Isolation of the neurocranium, cessation of any CSF leak, prevention of early and delayed postoperative complications and restoration of the preoperative facial aesthetics are the aims of treatment of frontal sinus fractures. The integrity of the posterior wall and/or involve‐ ment of the nasofrontal duct are the factors influencing treatment. The integrity of the posterior wall is the main factor for the separation of the intracranial contents from the outer environment. The nasofrontal duct involvement is the decisive factor for the poten‐ tial dysfunction of the sinus mucosa. Closed fractures of the anterior wall of the frontal sinus without displacement do not require surgical treatment and only observation is required. The treatment of depressed fracture of the anterior wall without involvement of the nasofrontal duct is simple elevation of the fracture and plate fixation. However, if the duct is involved, the treatment should include the obliteration of the sinus cavity after the sealing of the injured duct. In this way the frontal sinus is treated as an isolated cavity precluding any potential mucosal regrowth from the nasal epithelium. If the posterior wall is involved the determinant of successful management of the frontal sinus fracture is removal of the displaced bony fragments of the posterior sinus wall, restoration of the dural integrity and complete isolation of the brain from potential communication with the nose through the injured frontal sinus and cranialization of the frontal sinus [11].

### **6. Surgical approach**

The most common approach is the bicoronal flap. It has several advantages including provid‐ ing the best exposure of the frontal bone and the best cosmetic result in patients without alopecia. Its disadvantages are increased intraoperative blood loss and risk of injury to the frontal branch of the facial nerve. When using this approach, the hair is parted at the anticipated incision site and the tufts of parted hair are brought together and secured with small rubber bands on each side of the incision. Shaving of hair is not necessary. The incision site is infused with local anesthetic with 1:100,000 epinephrine in a subgaleal plane. The scalp is then incised from one temporal line to the other through the skin and subcutaneous tissues. A scalpel is used to incise the galea. Once the galea is violated, there will be an obvious separation between the galea and the pericranium. Bleeding from larger vessels should be tied off individually. The application of Raney clips minimizes the risk of bleeding. Finger dissection can then be used to elevate 2 to 3 cm on either sides of the incision, taking care to maintain the integrity of the pericranium. Overlying the temporalis muscle superiorly, the plane of dissection should remain in the loose areolar layer, which is deep to the temporoparietal fascia containing the frontal branch and superficial to the deep temporal fascia. In other areas overlying bone, the flap is raised in a plane immediately superficial to the pericranium. Carrying out the dissection in the correct anatomic plane minimizes the risk of injury to the frontal branch of the facial nerve. At the region of the zygomatic arch, the frontal branch of the facial nerve is most vulnerable to injury. If the dissection is carried within 1 to 2 cm of the arch, the plane of dissection should be one layer deeper in this area and dissection should be just deep to the superficial layer of the deep temporal fascia [12]. After the soft tissue has been retracted, the pericranium is incised several centimeters superior to the most superior aspect of the frontal sinus and raised inferiorly to a level approximately 1 cm below the inferior extent of the frontal sinus. Other options for incision include the midforehead and the gull wing incisions. These approaches offer decreased operative time, decreased blood loss, and decreased risk of injury to the frontal branch of the facial nerve. However, they also limit exposure, increase the incidence of damage of the ophthalmic branch of the trigeminal nerve, and leave more visible scars [13, 14].
