Shares of Misonix Inc. tumbled more than 18 percent Thursday after the Farmingdale medical device maker said that it will not file its annual report on time.

The company said the board of directors’ audit committee has determined that “deficiencies existed in the company’s internal control over financial reporting” as of June 30, the end of its fiscal year.

Misonix also said that on Tuesday it named Joseph Dwyer as interim chief financial officer and installed former CFO and senior vice president Richard Zaremba as senior vice president, finance.

In a filing with the Securities and Exchange Commission, Misonix said that the audit committee is still considering whether the financial reporting deficiencies “constitute one or more material weaknesses.”

The company reported a net loss of $1 million to $1.3 million on net sales of $23.1 million in preliminary results for the fiscal year ended June 30. That compared to net income of $5.6 million on net sales of $22.2 million in the prior year.

Calls to Zaremba were not immediately returned.

Misonix shares fell $1.13 to close at $5.00 on the Nasdaq Stock Market Thursday.

advertisement | advertise on newsday

In August, the company announced that board member Stavros G. Vizirgianakis, 46, was taking over as interim chief executive, replacing Michael McManus Jr., who resigned from the board of directors and retired as president and CEO.

Misonix makes ultrasonic medical devices used in spine surgery, neurosurgery and orthopedic surgery, and to remove damaged tissue from wounds.