Implant-based rehabilitation of edentulous mandibular posterior sectors tends to be complicated by the presence of bone atrophy. Following tooth loss, cortical bone suffers greater resorption on the vestibular than on the lingual aspect, and patients typically present narrow and low alveolar crests. In cases of moderate to severe mandibular atrophy, the bone height between the alveolar crest and the dental canal is small, and sometimes limited to only a few millimeters. Implant placement in such situations is very difficult, and implies the risk of inferior alveolar nerve damage. In certain cases bone grafting may be considered to restore the alveolar crest. We present a case of severe mandibular atrophy in which inferior alveolar nerve repositioning and implant placement were carried out. Such nerve repositioning may constitute a treatment alternative in patients with severe posterior sector mandibular atrophy and a consequent risk of dental nerve damage during the placement of dental implants.