Align Technology, which makes the Invisalign system, disclosed this week that it received a Nov. 18 warning letter from the FDA.
The letter accused the company of failing to comply with federal requirements to report serious side effects associated with medical devices. It cited some patient complaints about allergic reactions to the Invisalign trays such as swollen lips and mouth ulcers.
CEO Thomas Prescott told the San Jose Mercury News that the side effects have only affected a small percentage of its 1.3 million patients. The company says it has replied to the FDA to resolve the matter.