Cherubism is displayed with genetic conformation and when excessive osteoclasts are found in the affected areas of the mandible and Maxilla. Large cysts will be present with excessive fibrous areas inside the bone. The fibers and cysts will be found among the trabecula of the Coronoid process, the ramus of mandible, the body of mandible and the maxilla regions. The maxilla will be affected up to and including the orbits and sometimes inside the lower orbits.Â The maxilla and zygomatic bones are depressed and eyes appear to gaze upward.Â The maxilla has been found to be more severely affected in most cases than the mandible bone. Some patients found with lower inner orbital growths and cysts may lose vision.
The disease is usually diagnosed when dental abnormalities are found. These abnormalities include premature deciduous teeth and abnormal growth of permanent teeth due to displacement by cysts and lesions. The only definite way to correctly diagnose the disease is by sequence analysis of the SH3BP2 gene. The gene has been found to have mis-sense mutation in exon 9.Â Initial study of the patient is usually conducted using x-ray and CT scans. Neurofibromatosis may resemble Cherubism and may accompany the disease. Genetic testing is the final diagnosis tool.
Because Cherubism changes and improves over time the treatment should be individually determined. Generally moderate cases are watched until they subside or progress into the more severe range. Severe cases may require surgery to eliminate bulk cysts and fibrous growth of the maxilla and mandible. Surgical bone grafting of the cranial facial bones may be successful on some patients. Surgery is preferred for patients ages 5 to 15.Â Special consideration should be taken when operating on the face to avoid the marginal mandibular branch of the facial nerve as well as the zygomatic branch of the facial nerve. Unintentional damage to these nerves can decrease muscle strength in the face and mandible region. Orthodontic treatment is generally required to avoid permanent dental problems arising from malocclusive bite, misplaced, and unerupted permanent teeth.Â Orthodontic treatment may be used to erupt permanent teeth that have been unable to descend due to lesions and cysts being in their path of eruption. In patients with orbital issues of diploia, globe displacement, and visual loss will require ophthalmologic treatment.
Since this disease is genetically linked genetic counseling may be the only way to decrease occurrences of Cherubism. The lack of severity of symptoms of the parents may be cause for failure to recognize the disorder. The optimal time to be tested for mutations is prior to having children. The disease results from a genetic mutation and this gene has been found to spontaneously mutate. Therefore there may be no prevention techniques available.
The face displays emotions and is the major form of communication method we use. The slightest amount of disfigurement of the face is easily noticed. While the Cherubism is not accompanied with pain the need to help children and adults afflicted is apparent. Because this disease is associated with the time of tooth eruption the disease may be helpful in discovering what factors of tooth eruption contribute to Cherubism. The disease is also useful in defining roles of the genes involved in disorganizing osteoclast activity. Further research of the mechanisms responsible for Cherubism could lead to discoveries and cures for many other bone diseases such as osteoporosis.
Mutations in theÂ SH3BP2Â gene have been identified in about 80 percent of people with cherubism. In most of the remaining cases, the genetic cause of the condition is unknown. TheSH3BP2Â gene provides instructions for making a protein whose exact function is unclear. The protein plays a role in transmitting chemical signals within cells, particularly cells involved in the replacement of old bone tissue with new bone (bone remodeling) and certainÂ immune systemÂ cells.
Mutations in theÂ SH3BP2Â gene lead to the production of an overly active version of this protein. The effects of SH3BP2 mutations are still under study, but researchers believe that the abnormal protein disrupts critical signaling pathways in cells associated with the maintenance of bone tissue and in some immune system cells. The overactive protein likely causes inflammation in the jaw bones and triggers the production of osteoclasts, which are cells that break down bone tissue during bone remodeling. An excess of these bone-eating cells contributes to the destruction of bone in the upper and lower jaws. A combination of bone loss and inflammation likely underlies the cyst-like growths characteristic of cherubism.
This condition is inherited in anÂ autosomal dominantÂ pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.Â In some cases, an affected person inherits the mutation from one affected parent. Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family.