Minimising Risk of Inferior Alveolar Nerve Injury

20 May 2025

The human body is wired together with nerves, carrying electrical impulses that relay information to and from the brain. Nerves regulate our thoughts, memory, feelings and movements. However, a damaged or severed nerve can cause intense pain and discomfort, inhibiting the body’s ability to properly function.

In dentistry, implant treatments carry the risk of nerve damage, especially to the inferior alveolar nerve (IAN). A serious complication, IAN injury can cause increased sensitivity for the patient, undermining the success of the treatment and leading to further management. Dental practitioners must understand the aetiology, risk factors and management techniques of IAN injury to best lower the chances of it occurring and prevent long-term dysfunction.

 

Getting on somebody’s nerves

The inferior alveolar nerve is a branch of the trigeminal nerve and supplies sensory innervation to the chin, lower lip, gingivae, molars, premolars and alveolar bone – what is felt in and around the oral cavity is heavily influenced by it.[i]

During dental treatments, there are several causes of IAN injury. Extraction of the mandibular third molar is a notable cause, with a 0.4-13.4% incidence,ⁱ whilst the second molar region accounted for 64% of reported IAN injuries.[ii] Inaccurate recognition of the IAN is reported as another frequent cause; the low bone density of the mandibular canal prevents it from appearing clearly on radiographs, leading to misjudgement on the location of the IAN and therefore a higher risk of damaging or severing it.ⁱⁱ

Whilst less common, local anaesthetic injections performed prior to treatment can cause direct or indirect damage to the nerve, causing compression injury. Other accidents during treatments that can damage the IAN include exposure of the inferior alveolar canal during surgery, drilling too deep, extensive use of surgical burs, and displaced tooth fragments.ⁱ

 

Big risks and big impacts

Several risk factors are also worth highlighting. Research has found that older demographics are likelier to experience IAN injury, with an average age of 63. Secondly, women accounted for over 60% of reported cases and are therefore at a greater risk than men.ⁱⁱ The exact association is unclear but mandible size, changes in bone metabolism due to hormonal changes, and the development of osteoporosis (which can cause excessive resorption of the alveolar ridge following tooth extraction) can be offered as explanations.ⁱⁱ

In mild cases, IAN injury can be short-term and manageable. At its extreme, IAN injury has the potential for permanent disability. Its main symptoms include numbness, abnormal sensations or pain (pins and needles, tingling, burning, sharp pain), and increased sensitivity when touching the face.[iii] The impact of this can affect patients massively, interfering with eating and drinking, speech, kissing, applying makeup and shaving.ⁱ Moreover, without the correct sensory information, patients may not feel tooth pain, leading to a higher risk of caries being undetected.

 

Manage and maintain

To best ensure patients have a smooth implant treatment with minimal risk to the IAN, dental practitioners should be meticulous with the diagnosis and identification of risk factors, including pre-existing disease and the close anatomic relationship between the tooth roots and the inferior alveolar canal.[iv] Having CBCT scanners can achieve superior visibility levels of the mandibular canal, too.[v]

However, in the wake of an accident, a damaged nerve can be treated with physical therapy or by internal and external decompression, microsurgery and removal of the implant. A consistent dental care routine everyday can also help maintain the health of the IAN, ensuring that oral health is optimal with no gingivae resorption.[vi]

 

Nerves of steel

Delivering successful implant treatments is vital for patients to eat, speak and smile with confidence. To stay up to date on the latest developments, consider a membership with the Association of Dental Implantology (ADI). With over 2,000 members, the community is open to all dental professionals, from students to senior clinicians. Offering a vast range of educational resources, superb networking opportunities and discounted services, a membership with the ADI takes your implant treatments to the next level.

The inferior alveolar nerve is integral for oral health and damage to it during treatment can have a huge impact on the patient’s quality of life. However, having a heightened awareness of its risk factors and knowing the best ways to avoid surgical accidents means dental practitioners can provide long-lasting implant treatments that satisfy the patient.

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