One of the most common causes of muscle twitching in the face and neck is ingestion of a stimulant, such as caffeine. If you have been drinking a lot of coffee or soda recently, that might be what is going on, and you can figure it out by discontinuing the caffeine and seeing if the twitches go away.
Another common cause is muscle fatigue. This is especially common in large muscles of the arms and legs after vigorous exercise, but it can also occur in the face and neck after a long day, for example, sitting at a desk working on a computer. This type of twitching will improve with rest. "Benign" twitching of the muscles can also be triggered, in some people, by lack of sleep or anxiety
, and these also will generally go away after a good night's sleep.
In rare cases, muscle twitching, especially if it does not go away, can be a sign of a serious medical problem. Therefore, you should definitely go see your primary care doctor
, who can perform a thorough physical examination and make sure that this is not a problem that you need to worry