Trigeminal Nerve Injury Following Lower Third Molar Extractions in Somerset <scp>NHS</scp> Foundation Trust: A Review of Cases and Management Protocol

ABSTRACT Introduction Inferior alveolar nerve (IAN) and/or lingual nerve (LN) injury is a known complication of oral surgery and maxillofacial procedures, such as local anaesthetic injection, third molar surgery, dental implant placement, trauma, orthognathic surgery, submandibular gland surgery, endodontic therapy and intubation. There is no universally agreed modality for treatment of nerve injury associated with mandibular third molars. Consensus recommendations on the management of IAN cases have been put forward by experts; however, there remains a large scope for further research. This may be as a result of low prevalence and lack of comparative studies. Aim In this report, we review the incidence of IAN and LN injury following lower third molar extractions in the Oral and Maxillofacial Department at Somerset NHS Foundation Trust and assess compliance with our local trigeminal nerve injury (TNI) protocol management and documentation. Method Data was collected over an 18‐month period, from June 2021 to December 2022, of cases of lower wisdom teeth removal, to include age, gender, type of impaction, side, as well as detailed insights into pre‐operative, intra‐operative, and post‐operative assessment and management. Results A total of 252 lower wisdom teeth were extracted during this time period. Twelve cases of TNI were reported, five of which involved injury to the lingual nerve only (two of which were bilateral); three involved injury to the IAN only, and four involved both the IAN and lingual nerves. All cases reported symptoms of paraesthesia; one patient also experienced loss of taste, and three patients reported intermittent pain to the lower lip. By 6 months post‐operatively, the symptoms had completely resolved in 5 cases (41.7%). One patient showed no improvement following initial pharmacological management and underwent microscopic decompression of the lingual and inferior alveolar nerves and steroid injection. There was significant recovery in sensation 5 months post‐decompression. One patient was lost to follow up due to death from other causes. The remaining 5 patients (41.7%) experienced significant improvement, with paraesthesia localised to a very small area of the lower lip/chin/tongue only. Conclusion Our calculated incidence for LN injury was 4.37% and 2.78% for IAN injury. This project highlighted the importance of pre‐operative assessment, surgical planning and post‐operative management of iatrogenic trigeminal nerve injury. There was good compliance with our departmental protocol for IAN and the pharmacological management.