Table 1. | Aetiological factors and mechanism of traumatic inferior alveolar nerve injury [21-82] |
Intraoperative aetiological factor | Indirect or direct; mechanism | Postoperative aetiological factor | Indirect; mechanism |
---|---|---|---|
Traumatic local anaesthesia | |||
Chemical (cytotoxic) injury by local anaesthetic | Indirect; endoneurial oedema, compression and secondary ischemia Direct; IAN degeneration | Injection needle trauma to epineurial blood vessels or inferior alveolar artery | Indirect; hematoma with reactive fibrosis and scar formation, compression and secondary ischemia |
Injection needle | Direct; transection of multiple IAN fibres and entire fascicles | ||
Implant drill | |||
Partial intrusion into MC | Indirect; hematoma and secondary ischemia | Thermal injury | Indirect; inflammation of bone and IAN with secondary ischemia |
Full intrusion into MC | Direct; mechanical trauma - encroach, transection, or laceration and/or compression and primary ischemia of IAN | ||
Chemical (cytotoxic) injury by irrigation solution | Direct; IAN degeneration | ||
Thermal injury | Direct; IAN degeneration | ||
Dental implant | |||
Partial intrusion into MC | Indirect; hematoma or/and deposition of debris, compression and secondary ischemia | Infection | Indirect; inflammation of bone and IAN with secondary ischemia |
Implant is too close to MC | Indirect; bone and IAN stress, compression with secondary ischemia | ||
Full intrusion into MC | Direct; mechanical trauma - encroach, transection, or laceration and/or compression and primary ischemia of IAN | ||
Chronic stimulation | Indirect; implant is situated aside of or on top of the nerve with chronic neuropathy formation | ||
Wrong operation technique | |||
Scalpel | Direct; mental nerve injury or transection | Soft tissue swelling | Indirect; mental nerve compression caused by soft tissue oedema |
Soft tissue reflection and retraction | Direct; mental nerve injury caused by reflection, retraction and pressure | ||
Soft tissue suturing | Direct; mental nerve compression caused by suture material |