1. Pacific Northwest Implant Studio and General Dentistry in Eugene, Ore., shut down unexpectedly. The landlord of the building posted a notice citing failure to pay as the reason for the abrupt closing.
2. SmileDirectClub shut down its global operations immediately Dec. 8 after efforts to recapitalize the business failed.
3. NorthStar Orthodontics in Park Rapids, Minn., will permanently close Jan. 15. A reason for the closure was not provided.
4. A Wisconsin dental practice closed one of its locations Dec. 21 after 13 months of operation because the main dentist relocated.
