Sensory impairment of the lingual and inferior alveolar nerves following removal of impacted mandibular third molars

In a prospective study 1106 impacted mandibular third molars were removed f rom 687 patients. Clinical, radiographic, and surgical factors were recorde d. Postoperatively, we examined the modalities of common sensation in order to assess sensory deficit. The patients were followed up, until complete r estitution occurred, or, if the sensibility failed to recover, for at least 6 months. A total of 3.6% of the operated sides demonstrated impairment of labial sensation, and 2.1% of lingual sensation. The vast majority of thes e disturbances subsided completely during the follow-up period. The inciden ce of persisting sensory diminution after 6 months was 0.91% for the inferi or alveolar, and 0.37% for the lingual nerve. However, the degree of the pe rsisting deficit was slight in most instances. The relationship between the recorded factors and the alteration of sensation was analysed by using the chi (2) test. For the inferior alveolar nerve we found the patient's age, the development of the roots, the degree of impaction, and the radiographic position of the nerve canal to be significantly correlated to sensory defi cit, as well as the surgical procedures in the depth of the socket and the intraoperative opening of the mandibular canal. As far as the lingual nerve is concerned, general anaesthesia and the individual operator were the mai n factors predictive of nerve damage.