LAUSR

Abstract Rationale: In surgery of the lower jaw, the application of computer-assisted navigation is complicated and challenging due to the mobile nature of the mandible. In this study, we presented a computer-assisted navigation surgery for removal of the foreign body in the lower jaw with a mandible reference frame, basing on the strategy that the mandible is independent as an entity. Patient concerns: A 41-year-old male patient, identified as having a broken fissure bur that displaced into the mandibular lingual soft tissue, was referred to our department. The fissure bur broke accidentally and then displaced into the soft tissue when the patient underwent extraction of the left mandibular impacted third molar. Diagnosis: A metallic foreign body in the left lower jaw, confirmed by orthopantomography. Interventions: A computer-assisted navigation surgery with a customized mandible reference frame. Outcomes: The broken bur was removed successfully. Satisfactory wound healing and mouth opening was achieved, without postoperative complications. Lessons: Surgeons should be alert to the presence of broken bur in the lower jaw and avoid its displacement into deep facial space, and computer-assisted navigation with a mandible reference frame is recommended for removal of the foreign body in the lower jaw.