A New Concept of Safety Distance to Place Implants in the Area of the Inferior Alveolar Canal to Avoid Neurosensory Disturbance

Stuart J. Froum, DDS/Marco Bergamini, DDS/Natacha Reis, DDS/Wendy Wang, BDS, MSc, MClinDent (Pros)/Martin Leung, DDS/Zev Kaufman, DDS/Sang-Choon Cho, DDS: Inferior alveolar nerve (IAN) damage following implant placement is a severe complication that can compromise a patient’s quality of life. Previous studies have suggested that a safety zone of 2 mm, if maintained, might avoid this problem. This retrospective study evaluates implants placed in closer proximity to the IAN without resulting in any postoperative neurologic complications and suggests a new concept of safety distance. A total of 60 consecutive patients receiving 101 mandibular implants < 2 mm from the IAN were included in this study. All enrolled patients had a CBCT scan done for radiologic assessment before implant placement and following final restoration. Measurements were obtained through cross-sectional views using Simplant software. In patients without neurologic disturbances, a mean distance of +0.75 mm was seen from the closest portion of the implant to the nerve bundle. In cases where a direct transection and/or compression of the nerve was not observed, the patients did not experience neurosensory disturbances.