Displacement of lower third molar into floor of mouth: a single institutional experience

Purpose: The displacement of the tooth/tooth fragment into the floor of mouth sometimes happens during the lower third molar surgery and the patients are usually referred to oral and maxillofacial surgeons. To date, however, there is no consensus how to manage the displaced tooth due to the lack of available data. Methods: In this study, we have retrospectively analyzed the management of the displaced lower third molar into the floor of mouth. Our institute experienced seven cases during 2010 to 2020. Results: Incidence rate of the lingual nerve injury caused by displacement of the lower third molar was 1/7. Six patients out of seven underwent surgical removal of the displaced fragment. The direct approach was used when the fragment was palpable superficially and the fragment was horizontally located away from the lingual plate (2 cases), while when the fragment was not palpable, or was palpable and adjacent to the lingual plate, the lingual mucoperiosteal flap was selected (4 cases). Conclusion: We conclude that the palpation and preoperative diagnosis with computed tomographic images are significantly important to decide a better and most effective surgical approach.