Frontal sinus cranialization with obliteration of the frontal sinus outflow tracts is rarely needed but may be required with extensive comminution of the anterior and posterior walls of the frontal sinus. There is little in the literature about treatment of chronic larger defects of the anterior cranial fossa that communicate with the nose and drain externally after cranialization. We present a 49-year-old man who experienced extensive facial trauma requiring cranialization of the frontal sinus. Three years later, the patient presented with a chronic draining forehead wound that extended into the previously cranialized frontal sinus space with communication of the anterior cranial fossa and the internal nose. After thorough irrigation and debridement, the remaining dead space was found to be large and communicated with the nose, making autologous grafts a poor choice. A pericranial flap was not an option due to the previous soft tissue trauma. A paramedian forehead flap was deepithelialized and rotated into the space, obliterating the dead space and closing the communication between the nose and the anterior cranial fossa. Six months postoperatively, there are no signs of recurrence. The deepithelialized paramedian forehead flap should be considered for obliterating large dead spaces and closing off the communication between the cranial base and the nose.