Paget's Disease And Other Jaw Bone Diseases

About

Paget's disease of the bone, called Osteitis deformans, literally means deformity in the bone. The exact cause of this deformity is still not clear. The disease has been recognized in 1877. It was considered a rare disease until recently.

The change in perception occurred because routine radiographic examinations or bone scan detected the condition in a number of individuals who are otherwise healthy.

Causes of Paget's Disease

The common cause of bone deformity for Paget's is a bit vague. Earlier it was thought to be an inflammatory disease. In fact, the person after whom the disease is named, Paget himself believed that the condition is inflammatory.

Later, it was theorized that Paget's is a circulatory disturbance, because the bone in this condition becomes excessively vascular. In other words, the bone receives blood supply in excess of its requirements. There have been suggestions that the alteration in the bones is similar to the development of arteriovenous aneurysms.

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Another cause suggested by a scientist named Jaffe is that there is a failure in the mechanism that replaces the bone constantly through a process called creeping replacement. Again there have been pros and cons, and this theory does not hold much water. Finally, it has been theorized that Paget's is caused by a slow virus, the origins of which are as yet unknown. Ultimately the cause of the disease still remains a mystery.

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Features of Paget's Disease

There is no specific identifying feature that sets apart this disease from other conditions. It is usually detected as an afterthought, and patients rarely go to their doctor with complaints specific to the condition. The disease is a chronic, slowly progressing one, and it is very rarely found in the young. This more frequently affects men than women.

The main feature of the disease is the slowly growing bone. The increasing bone density does not seem to have the ability to stop.

In most cases, patients complain that their dentures are not fitting since the bone has become too large for them. This is the way most cases of Paget's are detected. Another example, especially in the western countries, is that of an ill-fitting hat because the skull keeps on growing. Some of the other features of this disease are:

• Bone pain
• Severe headache
• Deafness - This is due to the constriction of the VIII cranial nerve, the vestibulocochlear nerve in its foramen as the bone closes in on it.
• Facial paralysis- Here again the closure of the foramen is the cause for paralysis. It could affect just one side of the face or both sides depending on which foramen is involved.

• Spinal deformities
• Bowing of the legs
• Broadening and flattening of the chest
• Patients assume a 'simian' appearance due to the uncontrolled deposition of bone.
• Teeth become enlarged, loosen and may shift their positions in the jaws.
• The lips are too short to cover the huge proportion to which the jaws have grown.
• Fractures are uncommon and when they do occur, the healing is normal.

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Treatment for Paget's Disease

There is no treatment for Paget's disease.

It is rarely a cause for death unless it involves major foramina that affect vital nerves. Vitamins, hormones and radiation have all been used to treat the disease, but with limited success. Anti-bone hormones like the parathormone have also been given, with mixed results.

Diseases of the Jaw Bones

Bone is a unit of the human skeleton that is largely composed of calcium. Any disease that alters the calcium balance in the body affects the bones in some way.

Of interest in the oral scenario are the two main bones that make up the middle and the lower third of the face, and are responsible for the shape of the face and its characteristic features to a large extent. One is the upper jawbone called the maxilla and the other is the lower jaw called the mandible. Some diseases of the bones arise as a result of some problem in later life, and some diseases are developmental in nature.

Developmental Diseases of the Jaw Bones

1. Agnathia
2. Micrognathia
3. Macrognathia
4. Facial Hemiatrophy

Agnathia

Agnathia, derived from Gnathus meaning the jaws, is the total absence of either one or both the jawbones. This is a very rare condition. However, the partial absence of the lower jawbone or the mandible is a much more common condition which affects many infants in this part of the world.

Micrognathia

Micrognathia is when your lower jaw is underdeveloped or smaller than usual. Most cases of micrognathia are congenital, which means people are born with the condition.

It mainly occurs in children who are born with certain genetic conditions, such as trisomy 13 and progeria. It can also be the result of fetal alcohol syndrome. In some cases, this problem goes away as the child’s jaw grows with age.

Macrognathia

Macrognathia literally means a large jaw. This is most easily made out in a hormonal condition called acromegaly. Here growth is continuously stimulated due to excessive secretion of the growth hormone. The mandible is most often affected in this case giving rise to a condition where the bone protrudes.

A slight degree of protrusion is desirable in models to give them that classical look, but then again this is a technically wrong position of the jaws. In acromegaly, in addition to large jawbones, the teeth are also abnormally large.

Facial Hemiatrophy

Here one side of the face is underdeveloped, leading to an asymmetrical appearance. The tongue on the affected side is heavily shrunk. The roots of the teeth are unusually small and sometimes may lead to premature exfoliation or falling off.

An unusual disease that affects all bones in the body, but shows a strong affinity for the jaws is the Paget's disease. This disease is not strictly developmental in nature, but genetic predilection cannot be ruled out.