Tieu Dental Data Breach Exposes Sensitive PHI and PII

On March 5, 2026, Tieu Dental Corporation disclosed a data breach that impacted sensitive patient and employee information.

According to a notice filed with the California Attorney General, the incident involved unauthorized access to the company’s network between July 28 and July 29, 2025. During this window, an external actor gained access to Tieu Dental’s systems and may have removed files containing both personally identifiable information (PII) and protected health information (PHI).

The breach was discovered after a detailed forensic investigation, which determined that the attacker accessed and potentially exfiltrated files from the network.

On Jan. 11, 2026, Tieu Dental identified that the compromised files included full names combined with one or more of the following: date of birth, Social Security number, medical records, treatment plans, prescription information and health insurance details.

Additionally, the breach was disclosed to the Massachusetts Attorney General and on the company's website.

The company has not disclosed the exact number of individuals affected but has so far affected two individuals in Massachusetts.

Tieu Dental Corporation's response

To support those who may have been impacted, Tieu Dental is offering a complimentary one-year membership to Experian IdentityWorks, an identity protection service that provides credit monitoring and identity theft resolution support.

Impacted individuals will receive instructions on how to activate this service in the official notification letter.

Tieu Dental is also advising affected individuals to take several precautionary steps:

• Monitor credit reports for suspicious activity
• Place a fraud alert or security freeze on credit files with the major credit bureaus
• Review health insurance statements for unfamiliar charges or services
• Contact their insurance provider for a year-to-date report of services paid

Anyone with questions or who did not receive a notification letter but believes they may be affected can call the dedicated response line at 844-425-3616, available Monday through Friday, 9 a.m. to 9 p.m. Eastern time, excluding holidays.