06 October 2022

---

How to increase the mobility of the inferior alveolar nerve in transposition and surgical reposition of the nerve

Lara Figini

---

Injuries to the inferior alveolar nerve (IAN) are unfortunately not negligible complications in oral surgery and maxillofacial surgery. They may occur during treatments such as the removal of the lower third molar, orthognathic surgery, removal of benign and malignant tumors, the implant placement and in endodontic treatments, in addition to cases of mandibular fracture.  

AN injury can greatly affect a patient's quality of life, leading to paresthesia and prolonged or chronic pain. However, repositioning of the IAN can be used as a treatment, including IAN transposition (IANT) and lateralization (IANL) to avoid injury. Unfortunately, surgical space is often limited, and the mobility of the IAN within the jaw is insufficient during these procedures. A method proposed by surgeons is the removal of part of the bone around the mental foramen (MF) to offer greater mobility to the IAN. 

Materials and methods 

In a study published in October 2019, the authors examined how the mobility of the inferior alveolar neurovascular bundle (IAN) changes with or without removing the bone around the MF. 

Six fresh-frozen cadavers (11 sides) were dissected in this study. Osteotomy in the buccal cortical bone was performed from 5 mm posterior to the MF to the distal edge of the second molar with a high-speed drill and osteotome. Next, the distance from the lateral surface of the buccal cortical bone to the retracted IAB was measured with and without removing the bone around the MF. 

Results 

The distance from the lateral surface of the buccal cortical bone to the retracted IAB without removing the bone around the MF was 0 mm on all sides. After removing the bone, the mean distance changed by 4.71 § 1.41 mm (range 2.837.90). There was no statistically significant difference between the right and left sides. 

Conclusions 

From the data of this study on cadavers, it can be concluded that the removal of the bone around the MF mental foramen ensures a greater mobility of the inferior alveolar nerve IAN, facilitating the transposition treatment or repositioning of the nerve necessary in some cases in oral surgery or implantology. 

Clinical implications 

Transposition and repositioning of IAN nerves are procedures used to treat and avoid injury to these nerves during oral and maxillofacial surgery. The method presented in this study could help the surgeon to increase the mobility of the lower alveolar nerve by reducing the risk of injury or damage. 

"Anatomical study: the potential movement of the inferior alveolar nerve." Kikuta S, Iwanaga J, Kusukawa J, Tubbs RS. Oral Surg Oral Med Oral Pathol Oral Radiol. 2019 Oct;128(4):353-356. doi: 10.1016/j.oooo.2019.03.014. Epub 2019 Apr 1.