The frontal bone forms the arch of the skull. It is associated with the senses (vision and smell), performing a dual function, and consists of two departments: horizontal and vertical. The horizontal section is divided into unpaired nasal and paired orbital parts.
The frontal bone consists of four parts: two orbital, frontal scales and nasal. Frontal scales have the following surfaces: frontal (external), cerebral (internal) and two temporal (lateral). The frontal bone in the process of evolution changed, frontal tubercles developed, as a result of which the forehead changed tremendously: it became convex from the sloping one. The frontal surface is convex in front, smooth, in the midline there is a slightly noticeable elevation. In the anterior sections, the outer surface of the scales passes into the orbital surface. The frontal bone (the surface of the scales) is separated from the temporal surface by an arcuate temporal line.
Diseases
Frontal bone hyperostosis or Morgagni-Morel-Stuart syndrome has been known to science for more than 250 years, but even today, scientists' interest in this pathology has not waned. As a result of this disease, mental, vegetative-vascular and metabolic-hormonal disorders are observed. Some authors attribute obesity, hypertension, and persistent headache to the main symptoms of hyperostosis. Often this ailment is combined with mental disorders (atrophic myotonia, cerebral disorders, cerebrovascular accident, rheumatoid infection). However, no clear etiological factor has yet been established.
Frontal bone osteoma is a fairly rare disease characterized by the formation of a benign tumor. It is suggested that the etiology of osteoma is associated with a hereditary factor (the probability of transmission of the pathology to direct descendants is 50 percent), congenital exostoses are also described.
Pathogenesis of the disease
Three types of osteomas are known: hard, spongy, and cerebral. A solid osteoma consists of a dense substance (plates), which are located parallel to the surface of the neoplasm. The cerebral type of osteoma contains extensive cavities that are filled with bone marrow.
According to Virchow, two more types of tumors are distinguished: heteroplastic (formed from connective tissue), hyperplastic (formed from bone tissue). The first group includes osteophytes - minor layers on the bone tissue. If they occupy the entire circumference of the bone, then they are called hyperostosis. If the bone mass is issued in the form of a neoplasm in a limited place, then this is exostosis, if it is enclosed inside the bone - enostosis.
Clinical signs of osteoma
Osteomas that develop on the inner surface of the frontal bone are accompanied by frequent headaches, epileptic seizures, memory disorders, symptoms of increased intracranial pressure. If the tumor is localized in the "Turkish saddle", hormonal imbalance may occur. With localization in the area of the paranasal sinuses, diplopia, exophthalmos, ptosis, anisocoria, decreased vision, etc. develop.
Most often, osteomas are localized on the external (lateral) surface of the bone. Osteomas localized on the outer plate of the bones of the skull appear in the form of a dense, painless and motionless formation. The diagnosis is based on clinical and radiological data. With extracranial tumor growth, respiration, smell are disturbed, and the facial skeleton is sometimes deformed.
Yet most often osteomas spread intracranially. Such neoplasms destroy the posterior wall of the frontal sinuses, cause compression of the brain substance. If an infection joins this pathological process, arachnoiditis, brain abscess, meningitis develop. Differentiate the disease from osteogenic sarcoma and osteomyelitis. Neoplasms are removed surgically.