The hypoglossus nerve (XII cranial nerve pair): anatomical considerations and complications after injuries – a literature review

The hypoglossal nerve (XII cranial nerve) is the tongue’s motor supply. The hypoglossal nerve trajectory can be separated into two main parts: intracranial and extracranial. Objective: Considering the rarity of hypoglossus nerve injury, and that when it occurs it results in clinical implications that should be known by the Medical and Dentistry professionals, the aim of this study was to carry out a literature review on the anatomy of the hypoglossal nerve and possible causes of injuries and ways to treat this type of complication. Material and methods: A literature review was carried out in the international Pubmed database. The literature review included 19 articles from 1965 to 2021. The keywords used were: “hypoglossus nerve”, “injury”. Of the 19 articles, 10 were used for this literature review. Among the 9 articles that were discarded, 5 did not address the objective of this work and 4 did not present the available text. All types of articles were considered (1 literature review, 6 case reports and 3 original articles). Conclusion: The knowledge of the hypoglossal nerve anatomy is for surgical interventions, partial resections, and tongue reconstructions. The causes listed in the present literature review are intubation, the covid-19, procedures performed in the carotid area and occipital condyle fracture. In relation to treatment approaches, no specific protocol has been invented until now.