Angular skew refers to the asymmetry of facial expressions or corners of the mouth at rest. The angle of one side is higher or lower than the other side, resulting in an inclined appearance. This skew may be caused by muscle spasm, nerve injury or muscle imbalance of facial expression. Angular skew is usually related to facial paralysis, Bell's facial paralysis and so on.
A drooping mouth refers to a situation in which the corners of the mouth droop or cannot be completely lifted. This situation may be caused by facial muscle relaxation, nerve injury or drooping facial paralysis. Slowing corners of the mouth often show that corners of the mouth can't rise naturally, and facial expressions appear dull or lifeless.
It should be pointed out that both crooked mouth and drooping mouth may be symptoms of potential health problems, so if you or others have crooked mouth or drooping mouth, it is recommended to consult a doctor or facial plastic surgeon for further evaluation and diagnosis. They can provide more accurate diagnosis and appropriate treatment.