It is a rare genetic disorder that causes prominence in the lower part of the face.
Cherubism is a rare autosomal dominant disease of the jaw and maxilla. Approximately 200 cases have been reported by medical journals, most of which are men.
The appearance of people with the disorder is caused by a loss of bone in the jaw that the body replaces with excessive amounts of fibrous tissue.
In most cases, the condition fades as the child grows, but in some even more rare cases, the state continues to deform the face of the affected person. Cherubism also causes premature loss of primary teeth and lack of erection of permanent teeth.
The degrees of cherubism vary from mild to severe. The osteoclastic and osteoblastic remodeling contributes to the change of normal bone to fibrous tissue and the formation of cysts. The name indicates that the patient’s face is enlarged and disproportionate due to fibrous tissue and atypical bone formation.
Bone-like sponge formations cause early tooth loss and permanent dental eruption problems. The condition also affects the orbital area, creating an upward eye appearance.
The effects of cherubism can also interfere with normal movement and speech of the jaw. It has been found that the maxilla is more severely affected in most cases than the jaw bone. Some patients with lower internal orbital growths and cysts may lose vision.
Although the condition is rare and painless, those affected suffer the emotional trauma of disfigurement.
It is believed that the cause of cherubism can be traced back to a genetic defect resulting from a mutation of the SH3BP2 gene of chromosome 4p16.3. Modifying the SH3BP2 gene increases the production of excessively active proteins from this gene.
The effects of SH3BP2 mutations are still under study. Still, researchers believe that the abnormal protein alters critical signaling pathways in cells associated with maintaining bone tissue and some immune system cells.
Cherubism is autosomal dominantly linked, which means that the phenotype exhibited is determined by the dominant allele while the normal allele is recessive. A copy of the dominant allele is enough to cause the disorder.
Because the condition was found to be dominant, the phenotype of the disorder tends to be seen in all generations with some level of severity. Therefore, the parents or mothers afflicted with children with cherubism transmit the phenotype to both the daughters and the children.
Cherubism has also been found from the random mutation in an individual with no family history of the disease. However, it is not well understood why men express the condition more frequently.
Children with cherubism vary in severity in their maxillary and mandibular bony injuries. The disease is expressed in 80 to 100% of all those affected. Studies of multiple generations of families with the gene found that all children developed cherubism, but 30-50% of girls show no symptoms.
Cherubism is usually diagnosed first around age seven and continues until puberty and may or may not continue to progress with age.
Chemical imbalance is usually diagnosed when dental anomalies are found. These anomalies include premature deciduous teeth and abnormal growth of permanent teeth due to displacement by cysts and lesions.
The only definitive way to correctly diagnose the condition is through sequence analysis of the SH3BP2 gene.
The initial study of the patient is usually done using X-rays and CT scans. Neurofibromatosis may resemble cherubism and may accompany the condition. Genetic tests are the final diagnostic tool.
The removal of tissue and bone by surgery is the only treatment available. However, the treatment must be determined individually since cherubism changes and improves over time.
Severe cases may require surgery to remove bulk cysts and the jaw and maxilla fibrous growth. Surgical bone grafting of cranial facial bones may be successful in some patients. Surgery is preferred for patients 5 to 15 years old.
In general, orthodontic treatment is required to avoid permanent dental problems that arise from the malocclusion bite, the permanent teeth lost and not erupted.