This article is directed more toward university professors to assist them in understanding the bone tissue samples they view histologically.
Sclerotic bone is a common pathological finding in routine radiographs. A common type of sclerotic bone known to all dentists is condensing osteitis. However, there are many different causes of sclerotic bone and they include vascular infarct, infection such as osteomyelitis, neoplasms, inflammation, genetic mutations, trauma, and metabolic diseases such as hyperparathyroidism and Paget’s disease.
The term sclerosis is defined as
- pathological hardening of tissue especially from overgrowth of fibrous tissue or increase in interstitial tissue
- an inability to adapt
While there are many different causes of sclerotic bone and each of them have differing clinical characteristics, the most common cause of sclerotic bone in the human skeleton is inflammation. Osteoarthritis and atherosclerosis are inflammatory diseases, and both produce sclerotic bone lesions. In dentistry, the most common sclerotic lesions are caused by condensing osteitis and cadaver bone grafts.
A common denominator of sclerotic lesions caused by inflammation is that they are all protective. They are formed by the body in order to defend itself and contain the damage being caused by the inflammation. In coronary heart disease (atherosclerosis), the calcium deposits are not just areas of mineral deposition in the affected arteries, but actual bone formation. Atherosclerosis results in a buildup of fatty plaques in the artery wall. A coronary infarct occurs when fatty plaques rupture and the contents move into smaller vessels and cause a blockage. In order to stop the fatty plaques from rupturing, bone is formed around the plaques to prevent their rupture. The bone formed in atherosclerosis is a result of inflammation causing the conversion of smooth muscles cells in the artery wall to convert into mineralizing cells. The bone formed in our artery walls is irreversible due to the lack of cells that can resorb the sclerotic bone. If chelation therapy, which is designed to remove the bone mineral in the arterial wall, were successful it would likely result in a significant increase in the potential for a coronary infarct, which shows how a little knowledge can be dangerous.
Sclerotic bone has been researched extensively in osteoarthritis. Current thinking is that overload causes an inflammatory response in the subchondral bone. This inflammatory response causes the thickening and stiffening of the bone in order to support the cartilage lining the joint.
The nature of sclerotic bone has been studied extensively in atherosclerosis and osteoarthritis, but minimally in condensing osteitis and cadaver bone grafts, but we can use the knowledge gained in studying sclerotic bone in joints to gain an better understanding of sclerotic bone in the jaws.