Other procedures such as endodontic therapy, simple incision and drainage procedures, mandibular and mental foramen injections and mandibular osteotomies have also been associated with injury to the IAN or lingual nerve. More recently, there has been sharp increase in the number of patients with IAN injury as a result of mandibular endosseous implants violating the inferior alveolar canal. While most episodes of postoperative altered sensation resolve spontaneously, some patients will have more significant injuries that may require treatment in a timely fashion. The most challenging aspect of these types of cases is deciding which patients with altered sensation will benefit from surgical treatment. This can only be determined after serial neurosensory examinations over a course of several months. The degree of neurosensory improvement or lack thereof at monthly neurosensory examinations enables us to properly diagnose the type and severity of the nerve injury.
The duration of follow up for a patient with a suspected nerve injury is dependent upon what nerve is injured and the presenting symptoms. Intrabony injuries to the IAN can be followed longer before committing a patient to neurosurgery. This is directly attributable to the “guiding influence” of the mandibular canal. Therefore, it is not uncommon for patients with IAN anesthesia to be followed up to 6 months before considering surgery.
The management of an injured lingual nerve is quite different. Since this nerve is not housed and protected by a rigid bony canal, the likelihood that good adaptation of the damaged axons will occur is very low. In fact, injured regions of a lingual nerve are usually encased in fibrous scar tissue that impedes spontaneous healing. Therefore lingual nerve injuries are followed for 3-4 months and if no improvement is documented surgical therapy should be considered. The main goal of surgical treatment is to establish neural continuity. This can now be accomplished with the use of microsurgical instrumentation and techniques. It is important for us as oral health and disease management experts to be familiar with these type of injuries and their management so that the incidence of such may be reduced, and, when such injuries do occur, we will be able to properly evaluate, treat or refer on a timely basis.
