Diagnosis, follow-up and treatment of inferior alveolar nerve lesions

ABSTRACT

Il The inferior alveolar nerve (IAN)  can be injured during impacted third-tooth extractions, implant procedures, or other procedures (removal of mandibular cysts, complex tooth extractions, endodontic procedures, etc.). Injuries due to truncal infiltration are usually transitory.

Clinical findings: On the same side as the injury, sensation is lost in the lower arch teeth, the vestibular mucosa, half of the lower lip, and half of the chin. In the months immediately following the injury, patients generally report experiencing paresthesia, which tends to subside in most cases. Severe paresthesia and pain occur in 15% of cases, with immediate onset or gradual in the first few months following the traumatic event.

Diagnosis: The initial diagnosis is based on symptoms and a cone-beam CT scan. Correct implant placement does not guarantee the absence of an IAN lesion, which is mostly due to the traumatic action of the implant site preparation drills. An instrumental trigeminal sensitivity test, performed at least 40 days after the lesion, confirms the loss of IAN function.

Prognosis: In most cases, spontaneous nerve regeneration in the mandibular canal resolves the clinical situation on its own. Typically, a small area of sensory deficit remains in the lower lip, which does not warrant microsurgical treatment. Painful lesions, however, do not tend to resolve on their own and require nerve reconstruction in the operating room.

Treatment: In the first few days, nerve regeneration supplements such as alpha-lipoic acid and L-acetylcarnitine are administered, along with corticosteroid therapy (to reduce ischemic damage related to nerve swelling within the canal). In cases of pain, urgent microsurgery is indicated, which can be performed even years after the nerve injury. Chronic cases or cases where microsurgery has been ineffective can be treated with pain therapy.

Clinical cases: videos and photographs of clinical cases and microsurgical interventions are shown.

Discussion: Ample time is given to discussion and answers to participants’ questions.

The webinar will present the  diagnostic/therapeutic algorithms summarizing the “good clinical practice recommendations”  developed by a multidisciplinary group of experts coordinated by Professor Biglioli on behalf of the Italian Society of Maxillofacial Surgery.