Post-implant neuropathy of the trigeminal nerve. A case series

The incidence of implant-related inferior alveolar nerve injuries (IANI) is steadily increasing within the UK population.

This study prospectively reviewed thirty cases (35% male; 65% female) of implant-related IANI seen in a specialist nerve injury clinic.Methods Neurosensory examinations were carried out to ascertain a quantifiable rating of the perception, pain profiling and functional difficulties. Data were analysed using SPSS software.

Patients were aware of signing consent forms for the surgery in 11 cases and 8 of those felt they were not explicitly warned about nerve injury. Over 70% of patients were referred after six months post injury. Implant surgery planning involved intra-oral films only (30%), CBCT (10%), dental pantomograph (50%) and long cone peri-apical radiographs (48%). However, no radiographic evidence pre- or postoperatively was provided by the referring practitioner in 15% of cases. Intra-operative problems included bleeding and neurological symptoms. Proximity of the implant bed or implant to the inferior alveolar canal was evident radiographically. This showed contact with roof inferior alveolar nerve canal in 44% of cases, protrusion into the canal in 20% of cases, crossing of the canal in 20% cases and distance in one case, presumed to be due to local anaesthetic injury. All patients presented with a demonstrable neuropathy, which included neuropathic pain (50%) that interfered with speaking, kissing and socialising.

Consent, preoperative planning and appropriate referral were inadequate in provision of mandibular implants in this patient group. Recommendations have been proposed to improve practice and possible novel strategies are suggested for the prevention and improved management of these complications.