The frontal bone is a part of the human skull that consists of three portions – the squamous part, the orbital part and the nasal part. The frontal bones make up the bony part of the forehead, part of the bony orbital cavity holding the eye and part of the nose (bony area) respectively.
The squamous part marks the flat and biggest part – the main forehead region. The orbital part is the horizontal and second biggest region of the frontal bone, forming the roofs of the orbital and nasal cavities. The smallest part, the nasal part, forms the nasal bone and frontal part of the maxilla to form the root of the nose.
Frontal bones derive their name from the Latin word for forehead, frons.
Frontal bones usually consist of two pieces at birth, separated by a frontal suture, which is obliterated by the eighth year. The lower part of the frontal bone though persists as two pieces throughout life. The frontal sinuses begin to develop at the end of first year or the beginning of second year. In some cases, the frontal sinus might also develop at birth, attaining their full proportion after puberty.
The frontal sinus is a pyramidal air filled cavity within the frontal bone. Usually asymmetrical in shape, the frontal sinus has two walls, the anterior and posterior tables. The anterior table is stronger but the posterior table is closer to the frontal lobe of the brain. The floor of the frontal sinus is formed by a weak membranous bone.
Fractures in the frontal bone
Fractures that involve the frontal bone are very uncommon and rare. They account for about 5 -15% of all facial injuries. But most injuries are fatally serious because this area is very close to the frontal lobe of the brain, making it prone to be affected by any injuries to the protective bone structure. The fractures to the frontal bones are considered head injuries because of this close proximity to the brain. Frontal bone injuries could be caused by assault, road traffic accidents or other industrial accidents.
Many times of fracture patterns can occur in frontal bones based on the type and depth of the injury sustained. Therefore, the surgeon doing the treatment should have an in depth knowledge of dealing with not only the fractures but also other secondary affected areas that might lead to complexities. Depressed frontal bone fractures might occur in patients with maxillofacial trauma.
Surgery or treatment factors for frontal bone fractures are challenging problems involving neurosurgical, plastic and maxillofacial surgery problem. Surgeons find it extremely challenging to replace the small bony fragment by rigid bone plate fixation during surgery or treatment if the frontal bone is comminuted. Camouflaging the defect without functional difficulties is also an option.
Maxillofacial fractures might be a result of blunt or penetrating injury. Blunt injuries might be occurring from vehicular accidents, or sport related trauma, or other occupational injuries and falls. Gunshot wounds, stabbings and shrapnel hits due to explosions cause penetrating injury. Frontal bone fractures’ treatment methods might vary with every surgeon but the most common methods include observation, open reduction and internal fixation, and treatment to anterior table. Certain anatomic parameters need to be evaluated before the surgeons can decide on the surgery or treatment options.
Goals for surgery and surgical treatment also include protection of intra-cranial contents, prevention of secondary complications, restoration of contour to aesthetic appearances, return of normal frontal sinus function. The responding surgeon performs surgery and treatment based on the priority order of these goals, with protecting the brain coming first, followed by reconstructing the sinus safely, and then handling the functional deformities and aesthetic contouring.
Assessing the injuries to the frontal bone
Since the frontal bone is just above the eye socket, patients should undergo complete ophthalmic examination to rule out injury to the eye or it surrounding nerves or bones.
The frontal bone’s proximity to the brain means that the surgeons take complete CT scan of the brain to evaluate any secondary injury or fatal effects.
Intercranial complications might also arise due to traumatic injuries to the frontal bones and thus surgeons make sure to monitor the patient’s consciousness continuously before and after surgery.
Frontal bone fractures are rare for a certain reason – a great force is required to actually cause damage or fracture in the frontal bone and it is not easy or common. Therefore, the great force might also have damaged the other, softer areas like the eye socket.
Cosmetic relevance of frontal bone fractures
While performing surgery or treatment for frontal bone fractures, surgeons must also note other tertiary complications that might arise. The bone’s proximity to the brain and eye might mean extra diagnosis and treatment to ensure that the injuries and effects are not fatal. And mainly because the bone itself is the main one that forms the upper part of the face, any wrong treatment might disfigure the face and result in drastic cosmetic issues.
Dr. Debraj Shome is an experienced cosmetic and facial plastic surgeon who excels in the treatment of frontal bone fractures and other injuries. He has performed many successful surgeries that have also focused on the cosmetic angle of treating ailments to the frontal bone and surrounding areas.