Shares of SmileDirectClub slumped in after-hours trading Monday after the online orthodontics company reported a wider-than-expected third-quarter net loss on 18% lower revenue.

The loss widened to 23 cents a share from 11 cents in the year-earlier quarter. Revenue fell to $137.7 million from $168.5 million.

A survey of analysts by FactSet produced consensus estimates of a loss of 14 cents a share on revenue of $182.5 million.

SmileDirectClub is estimating fourth-quarter revenue at $120 million to $140 million and gross-profit margin at 70%. The FactSet survey of analysts is looking for revenue of $201.9 million.

“We are disappointed with our third-quarter results driven by the macroeconomic headwinds that are influencing the spending of our core demographic,” Chairman and Chief Executive David Katzman said in a statement.

“While we could not have anticipated the rapidly evolving nature of this impact on our consumer, we have responded quickly to focus our marketing on helping support them during this time, while we also move upstream with higher income demographics through the Challenger Campaign and investments in our dental-partner network.”