Neurosensory function and implant survival rate following implant placement with nerve transpositioning: a case study

In patients with extensive bone resorption, implant placement posterior to the mental foramen is a problematic surgical procedure. This paper reports the results in 6 patients (aged 20-61) with edentulous areas in the posterior part of the mandible, in whom 26 Nobelpharma implants were placed, including 17 with transposition of the inferior alveolar nerve allowing the use of implant fixtures of at least 10 mm in length. Subsequent neurosensory function, based on British Medical Research Council definitions, and implant survival rate were examined. In all cases, postoperative numbness occurred in the lower lip and mental area. Three years after surgery, while one patient had completely recovered neurosensory function, five patients still experienced partial numbness, although this was not perceived as a problem by those patients. The implant survival rate was 100% approximately three years after surgery. The results suggest that a higher implant survival rate is likely when longer fixtures are used, but this is also more likely to lead to slight long-term neurosensory dysfunction.