Implant displacement into the mandible: an unusual complication during implant surgery.

In contrast with problems regarding initial stability of dental implants in the posterior maxilla, heat generation during bone drilling is one of the complications that can occur in the mandible which is usually composed of dense bone. This report presents an unusual case of implant displacement into the mandibular posterior area of a middle-aged woman. This problem was presumably caused by poor bone density, loss of cortical bone engagement, and differences in bone quality between the alveolar bone and the basal bone.