Iatrogenic displacement of lower third molar roots into the sublingual space: report of 6 cases

To describe the clinical characteristics of patients who have had sublingual displacement of a mandibular third molar root, to identify potential risk factors, and to provide the clinician with information on how to prevent and treat this complication.

A retrospective analysis was performed of a series of 6 patients who underwent third molar removal with accidental displacement of a root into the sublingual space. All patients were attended at the Department of Oral Surgery, Faculty of Dentistry, University of Barcelona (Spain) from 2000 through 2010.

Four patients were men, and the mean age was 38.2 ± 11.3 years. In 1 case, the fragment was removed immediately after the complication, in the same surgical procedure. In 4 cases (66.7%), the displaced root remained asymptomatic (mean follow-up, 25.5 mo), and only 1 patient presented symptoms (swelling and pain in the sublingual region). A second surgical procedure using an intraoral approach was used to extract the displaced fragment in 2 patients. These 2 cases presented transitory nerve impairment of the lingual and inferior alveolar nerves, respectively.

Accidental displacement of a lower third molar root into the sublingual space is an uncommon complication. When the fragments are small, surgical removal of the displaced roots seems to be unnecessary, because patients usually remain symptom free. When surgery is needed, a considerable incidence of complications should be expected.