Table 2. Types of trigeminal nerve injuries following oral surgery.

IAN: Inferior alveolar nerve; MSCs: Mesenchymal stem cells; ESS: Endoscopic sinus surgery.

Type of Injury	Definition	Clinical Features	Prognosis	Examples
Neuropraxia	Temporary conduction block without axonal disruption	Numbness or tingling; full recovery expected within weeks	Excellent; typically resolves in 4–6 weeks	Stretching or compression during third molar extraction
Axonotmesis	Disruption of axons with intact connective tissue sheaths	Paresthesia, dysesthesia; gradual recovery over months	Fair to good; recovery via axonal regeneration	Crush injury during implant placement or osteotomy
Neurotmesis	Complete severance of the nerve including connective tissue	Complete sensory loss; often with painful dysesthesia	Poor; requires surgical repair	Nerve transection during osteotomy or cyst enucleation
Compression neuropathy	Injury due to prolonged mechanical or chemical pressure	Dull, aching pain; sensory deficits; may worsen over time	Variable; may require decompression	Overfilling root canal sealer impinging on IAN
Chemical neurotoxicity	Damage from chemical agents in close proximity to nerve tissue	Burning pain, altered sensation, hyperalgesia	Variable; depends on exposure duration	Extrusion of irrigants or medicaments into IAN canal
Thermal injury	Nerve damage from heat generated by surgical instruments	Immediate sharp pain, followed by numbness or dysesthesia	Variable; may need microsurgical intervention	Use of high-speed drills without adequate irrigation