Dental implant displacement into the mandibular body: a case report

Abstract

Posterior mandible region is considered a highly predicable place for primary stability during dental implant placement. Although, this region can present a significant decrease in bone density, which can lead to implant dislocation during insertion. The present case reports an unusual dislocation of dental implant in a 59 old healthy patient's mandible and a secure solution for this kind of complication. During the drilling, bone quality type IV was observed. In sequence, implant was abruptly inserted in the perforation site and dropped into the bone marrow. Panoramic radiograph showed the implant inside bone marrow, close to mandibular base. The implant was removed through the surgical site. The screw of the implant prosthesis transfer was used to reach the displaced implant. A second implant with the same dimensions as the first one, differing by the external hexagon, was inserted into the same implant site. Therefore, the authors strongly recommend the use of the presented technique prior to osteotomy on mandibular body, reserving the second in the impossibility of reaching the internal connection of the displaced implant.

Removal of a Horizontally Displaced Dental Implant below the Mandibular Canal

“…As a complication, hypoesthesia with varying severity of the alveolar nerve was reported in seven cases after removal of the implants. The directions of implant displacement were same or similar to the axis of the original osteotomy; in eight cases the implants were displaced in the lingual direction relative to the lower alveolar nerve [2,4,6,22], in two cases-buccally [2,19], in three cases-vertically [23,24], and in the other five cases the direction was not described. The X-ray examinations before implant placement revealed no bone defects, reduced bone density, or other pathology at the sites of implantation.…”

“…Low bone density of trabecular bone is observed only in 15-20% of the cases [27,30]. Accidental implant displacement in the posterior mandible is mostly associated with overpreparation of the implant site, subcrestal implant positioning, poor BIC, and insufficient or a lack of primary stability [2,18,23,24]. The low bone quality and density contribute to implant displacement during surgery [6].…”