How close or involved the roots of your wisdom teeth are to the nerve canal, the depth of impaction and the type of procedure carried out for its removal, will all affect the risk of this complication. Thus a detailed assessment of your wisdom tooth
must be made of this before hand.
Both your Lingual and Inferior Dental (ID) nerve supplying the tongue and teeth/lower lip respectively are at risk from stretching or bruising during the removal of lower wisdom teeth.
A simple fully erupted tooth is unlikely to have any involvement, particularly if a clear gap exists between the nerve canal and the roots of the wisdom tooth. A deep impaction requiring extensive bone removal in the region of the nerve carries a somewhat higher risk.
All dentists must warn you that nerve damage, though rare, is a possibility and you need to be aware of this. If some persisting numbness does occur most of the time this will heal spontaneously over the course of a few weeks; this may even take months. During this time you will start to feel the sensation slowly coming back while total numbness may change to a tingling as the nerve fibres regenerate.
If after 6 months there has been no improvement then it is likely that some permanent damage has been sustained; this occurs in about 0.5% of cases. A consultation with a neuro- surgeon to discuss the possibilities of surgery and regeneration should be considered.
Nerve damage is actually a risk any time an injection is given. It is very very rare that it happens, but it can and has been known to. It most often happens when an ID block is being given in the lower jaw and happens from the needle hitting and damaging the nerve while the injection is given.
If the dentist hits the nerve (which by the way we are aiming for) a sharp ‘electric shock’ will be felt. When this happens the nerve goes numb very rapidly. Nearly all the time, when this happens the anaesthetic will just wear off as normal without any lasting damage. The aim of the local anaesthetic injection is to place anaesthetic near the nerve. The chance of actually hitting it is incredibly small because the nerve is tiny. I give injections all day everyday and for me it may happen a couple of times a year.