The nerve that supplies skin over the angle of mandible, if involved in parotid injuries forms a part of anatomical basis for gustatory sweating:

(b) Greater auricular nerve(Ref. Cummings, 6th ed., 1254)The nerve that supplies skin over the angle of mandible is Greater auricular Nerve. Sometimes during parotid surgeries, Greater auricular Nerve also gets injured along with the Auriculotemporal Nerve. In this situation with the aberrant regeneration of the Auriculotemporal Nerve, the parasympathetic fibres (of the auriculotemporal nerve) to salivary glands become aberrantly connected with the sympathetic cholinergic fibres to sweat glands of the skin overlying the parotid as well as overlying the angle of mandible (the territory of Greater auricular nerve).