Complications in connection with implantological measures will occur with greater frequency in the future, purely from the point of view of quantity, owing to the increasing number of implantations. One of the most serious, yet extremely rare consequences of implantation is fracture of the mandible. It occurs predominantly in older patients with extremely atrophic mandibles, especially if the dental implants are anchored bicortically, or after explantation of dental implants. The risk of a fracture is increased in addition by weakening of the mandible as a result of osteomyelitis, especially in patients with weak immune systems. In order to avoid fractures of the mandible, therefore, endosseous implants should not be placed into extremely atrophic mandibles, unless the opposing corticalis is protected or only after alveolar augmentation. Furthermore, close scrutiny is advisable during clinical and radiological post-check-ups, so that any periimplantitis or bone infections, which additionally increase the risk of mandibular fracture, can be detected in good time.