"local trauma: e.g. inferior alveolar nerve injury, post-genioplasty, etc."
"Numb chin syndrome is caused by a lesion of the trigeminal nerve, occurring anywhere from the central pathways to the mental nerve terminal branch. There are protean aetiologies for numb chin syndrome, which can broadly be categorised into malignant and non-malignant causes. Overall, the most common causes are local non-malignant odontogenic pathology and occult malignancy 4."
"vasculitis, autoimmune and connective tissue diseases: e.g. giant cell arteritis, sarcoidosis, etc."