**6. Diagnosis of frontal bone fracture**

#### **6.1. Physical examination**

Findings suggestive of FBF include tenderness, paresthesia, forehead abrasions, lacerations, contour irregularities and hematoma. Forehead lacerations should be examined under sterile conditions to assess the integrity of the underlying bone. Through-and-through injuries of the frontal sinus have high morbidity, and prompt surgical treatment is indicated. Conscious patients should be questioned regarding the presence of watery rhinorrhea or salty-tasting postnasal dripping suspicious for CSF leak. Suspicious fluid can be grossly evaluated bedside with a "halo test". The bloody fluid is allowed to drip onto filter paper. If CSF is present, it will diffuse faster than blood and result in a clear halo around the blood. Glucose or β2 transferrin are the laboratory tests to confirm a CSF leak. [27]

#### **6.2. Radiological examination**

Plain radiographs do not adequately characterize FS fractures. Computed tomography (CT) is the gold standard for the assessment of FS injuries. Advances in the equipment used for CT imaging can now produce reformatted images of a very high quality. Patients are scanned in one axial plane, in a supine position with thin cut spiral CT, creating data set allowing generation of reformatted and reconstructed diagnostic images. Sagittal reconstructions can be made to evaluate the posterior wall defect. Special importance belongs to evaluation of the involvement and severity FSOT. [28]

Gross outflow tract obstruction (fracture fragments lying in the tract) can be observed in some cases. FSOT injury is strongly suggested when the CT scan demonstrates the involvement of the base of FS, the anterior ethmoid complex, or both. Fracture in the floor of the sinus can be seen best with sagittal and coronal views, anterior ethmoid cell injury with coronal more than axial views, and obstruction best with the coronal view (occasionally axial).Thus, the naso‐ frontal tract complex should be evaluated in the axial, coronal and sagittal planes. Unfortu‐ nately, the involvement of the FSOT is not always easily discernible with CT imaging. [16] Three-dimensional (3D) reconstructions may help to visualize the external contour deformity as well as associated facial skeleton injuries.
