Growing up with less than a perfectly straight teeth can often cause one to be self-conscious about smiling. Orthodontic treatment is the popular choice for those looking to achieve that ideal smile. There are some known general discomforts and dangers of wearing braces, such as jaw pain and headaches; tissue damage inside the mouth, which can lead to serious infections; and increased likelihood for tooth decay and gum disease, since braces often prevent one from brushing and flossing effectively and thoroughly. However, the less known and less obvious dangers of orthodontic treatment are the more dangerous effects that can cause genotoxic damage (gene damage) to the patient.
The treatment process begins with a panoramic dental radiograph, which is a 2-dimensional dental X-ray examination of the mouth. Ionizing radiation is a well-known mutagen and carcinogen, as it has the ability to deposit energy within the cells, thereby contributing to its unique characteristics as a genotoxic agent. Skin cells of the cheek are under direct radiation exposure at a panoramic radiography examination, making them the primary target for radiation-induced damage.
The analysis of micronuclei has become a standard approach for the assessment of chromosomal damage in human populations and can be used as an early indicator of the development of long-term health problems. Micronuclei are mini nuclei that are produced in cells when mitosis, or cell division, is mutated. Micronucleus deposits contain abnormal genetic material that was lost from the genome during mitosis as a consequence of toxic exposure of cells to radiation or chemical agents. Cheek cells were obtained from healthy individuals immediately before and 10 days after they underwent panoramic radiographic examination. The results showed a statistically significant increase in the frequency of micronuclei in cheek cells after exposure to radiography, indicating that panoramic radiography may induce genotoxic effects in cheek cells.
The metals of the fixed orthodontic appliances also pose genotoxic risks. Fixed orthodontic appliances include brackets, bands, and arch wires made of stainless steel, nickel-titanium, or nickel-cobalt alloys. Although the metal appliances used in orthodontic treatments are made to be highly resistant to corrosion, these metal appliances can release metal ions since corrosion events are very frequent in the oral cavity. The materials used in dentistry are exposed to several aggressive physical-chemical events, such as high concentrations of oxygen and chloride mixtures in saliva, tartar, and plaque, and acid product waste from bacterial metabolism.
These aforementioned studies have shown that there are genotoxic risks of being an orthodontic patient. Panoramic dental radiography exposes orthodontic patients to ionizing radiation, with the cheek cells as the primary target for the deposition of energy, resulting in a slight increase in the number of micronucleated cheek cells, meaning that cell division was clearly mutated. Additionally, although the amount of metals released from orthodontic appliances in saliva or blood samples were significantly below the average dietary intake and did not reach toxic concentrations, studies show that even nontoxic concentrations could be sufficient to induce genotoxic effects in cells from the mouth.
While there are genotoxic effects of being an orthodontic patient, the key is to keep in mind that as a patient, one is not constantly being exposed to these DNA damaging factors. Although they are shown to be genotoxic, these effects become greater with increased exposure. The average patient wears braces for approximately two years, which is generally not enough exposure for the genotoxic effects to be lethal.
From “Micronucleus Test in Buccal Epithelium Cells from Patients Subjected to Panoramic Radiography.” Dentomaxillofacial Radiology and “In Vivo Study on Metal Release from Fixed Orthodontic Appliances and DNA Damage in Oral Mucosa Cells.” American Journal of Orthodontics and Dentofacial Orthopedics