Localization of the inferior alveolar nerve in mandibular surgery; an experimental study in rabbits

Tooth loss may occur at any age as a result of trauma, caries, periodontal diseases and other reasons. Alveolar bone tends to resorb after tooth extraction. This situation causes difficulties for implant surgery and prosthetic rehabilitation. This phenomenon results in decreased alveolar bone height in the maxilla and in the posterior mandible as well. Therefore localization of the inferior alveolar nerve has great importance during dental implant surgery. In last few decades intraoperative localization of motor nerves has been widely studied. On the other hand, sensorial nerve localization has gained a role in clinical practice recently. Detrimental consequences such as lip paresthesia may occur after dental implant placements due to close contact of dental implant drills or dental implants iteself. In order to prevent such complications the localization of inferior alveolar nerve gains great importance during the surgery. The aim of the present study was to determine the location of the inferior alveolar nerve within the mandible using an electrical stimulation device intraoperatively. In the present experimental study, six New Zealand rabbits were used. A nerve stimulator (Tracer III®- Portex, Smith's Medical, Kent, United Kingdom) was used as stimulating device. The recording and isolated stimulating electrodes were manifactured and calibrated particularly for this study. The frequency of stimulation was set as 1 Hz. The range of the stimulator was 0,5-5 mA. The duration of the stimulation was evaluated in 0,05; 0,1; 0,3; 0,5 and 1 ms. The action potentials were detected by compound action potential technique. The data were analyzed statistically. In conclusion, intraoperative localization of the inferior alveolar nerve within the bone tissue was achieved via stimulation technique and this technique offers a reliable, objective method of evaluating the distance of the inferior alveolar nerve in bone tissue. However the technique needs to be further studied to be used clinical settings.