SmileDirectClub Inc. /zigman2/quotes/214109287/composite SDC -10.22% shares tanked more than 20% in the extended session Monday after the maker of clear plastic aligners reported a wider quarterly loss and sales missed the mark, saying it ran against macroeconomic headwinds. SmileDirect lost $89 million, or 23 cents a share, in the third quarter, compared with $13 million, or 11 cents a share, in the year-ago period. Revenue fell 18% to $138 million, the company said. Analysts polled by FactSet expected a loss of 14 cents a share on sales of $183 million. "We are disappointed with our third-quarter results driven by the macroeconomic headwinds that are influencing the spending of our core demographic," Chief Executive David Katzman said in a statement. The company guided for full-year 2021 revenue in a range between $630 million and $650 million. The analysts surveyed by FactSet expect 2021 revenue around $758 million. SmileDirect shares ended the regular trading day flat.