Mental Nerve Damage after Lower Wisdom Tooth Extraction?

My husband recently had his two lower wisdom teeth extracted by a dentist in a Mexican border town.  He complained that the dental surgeon used unnecessary force in removing the tooth on the left side and worries that he may have nerve damage.  His lower lip and the area beneath his mouth is numb and he says it feels very tight at times.  Is it likely he has damage to the mental nerve?  Who would we go see to diagnose?  Another dentist?  Is this something that can be fixed, or must he wait for it to heal itself?

Thank you in advance.

[scottma]

Seeing a neurologist is advised.