Abstract
Why NOT may mean that aligners are accepted as preferred treatment modality.
Why NOT may also mean why this modality should be discouraged as a possible treatment. This editorial focuses on that.
Aligners are a way of moving teeth into desirable positions and provide an esthetic alternate to conventional braces. Much has been published about its success. Also, the company has been successful in its “direct to patients” campaign and more patients are opting for it.
As per claims, more than 2 million patients were treated with a leading aligner provider. It would be fair to approximate that around more than 20 million aligner sets would have been produced till now (including other aligners providers with an average of 10 set per patient). This amount of the plastic generated from aligners will be soon enough to cover entire city of Mumbai, Spain, New York, Beijing, and so on in coming times. Adverse effects and environmental hazards from aligner usage are a reality. However, these are underreported and both professionals and patients are unaware of it.
This editorial is to draw your attention to the flip side of treatment with aligners.
Well-documented adverse effects that are reported include difficulty in breathing, sore throat, swollen throat, swollen tongue, swollen lips, hives and itchiness, anaphylaxis, airway obstruction/laryngospasm, chest pain, cough, nausea, difficulty swallowing, dry mouth, headaches, swelling of eyes, blisters or sores of lips, fatigue, burning blisters or ulcerations on tongue, swelling of gums, airway obstruction, and many more. 1 These were reported on MAUDE website, USA (Manufacturer and User Facility Device Experience) database. Despite these, no change in marketing or treatment strategy is reported by the manufacturers.
In an in vitro cytotoxicity study, oral epithelial cells exposed to Invisalign aligners eluate showed increase cell death, compromised membrane integrity, and reduced cell-to-cell contact and mobility which may be the mechanism for isocyanate allergy. 2
Plastic is an established environmental hazard. It basically harms animals through entanglement and ingestion at all levels of the food chain. More than 50% of the oxygen we breathe is provided by phytoplankton that is living on the surface of the oceans. It is made up of plant microorganisms and is capable, through photosynthesis, of making organic matter from light, carbon dioxide, and nutrients, and releasing oxygen into the air. As the planet’s “thermostat,” it exchanges energy and heat with the atmosphere. 3
Plastics break down into smaller pieces called microplastics, which act as poison for the plankton. Destruction of these organisms abrupt the environment’s mechanism to maintain temperatures and hence leads to global warming.
Plastic may move teeth, but is terrible for the environment. —Kevin Dillard
As per World Environment meet, 3 an ambitious target of restricting the global warming to 1.5° as acceptable increase in temperature by 2030 was agreed upon. The pressure is on the developed countries to lead by example. Citizens need to be more aware of the impending doom if they do not directly take responsibility. As orthodontists, we need to be more aware of our environment and seek alternate treatment modalities other than plastic.
Aligners contribute immensely to plastic production (aligners trays for patients and thermoplastic 3-dimensional (3D) models on which aligners are fabricated). Both are single-use plastic which cannot be recycled and hence are accumulating in the environment. Various thermoplastic materials, or combinations of materials, are being used for fabrication of 3D models. These include polyvinyl chloride, polyurethane, polyethylene terephthalate, and polyethylene terephthalate glycol.
Also, environment (mouth has harsh environment) induces changes in plastic and the additive agent bisphenol A (BPA) is released. It is a known carcinogen as it alters cell membrane properties and enables mutation. BPA is an industrial component commonly used in synthesis of polycarbonate plastics, epoxy resin, and other polymer materials (3D models). The underlying mechanisms of BPA-induced multiorgan toxicity are well summarized, involving the receptor pathways, disruption of neuroendocrine system, inhibition of enzymes, modulation of immune and inflammatory responses, as well as genotoxic and epigenetic mechanisms. 4
“Grow vs Live” is a constant debate in consideration. Should technology advancements happening be embraced despite their negative impact on the environment?
In conclusion, it is to be noted that the adverse effects of aligner treatment and its environmental ill effects are poorly reported. So is the case for orthodontics. Currently, the aligners delivered should have Drug Controller General of India approval and carry a disclaimer about its adverse effects. This article is not even commenting on the drawbacks of aligners pertaining to biomechanics. We approach it positively with the mindset that technology will eventually catch up. However, we must focus on alternate eco-friendly modalities giving similar advantages. Providers need to do more testing and share findings. AS A RULE, PLASTIC MUST BE AVOIDED WHEREVER OTHER POSSIBILITIES EXIST.
