Usually, the discomfort patients feel from orthodontic treatment is concentrated around the teeth. It can include increased sensitivity to cold and sour foods, pain, a tingling ache, discomfort when biting on food, and pain from sores on the lining of the mouth. Some patients report a swollen lymph node, which feels like tenderness along the edge of the lower jaw when pressed. Rarely, but not impossibly, there may also be a headache. This happens in more sensitive patients and often goes hand in hand with teeth clenching or nervous tension.
This answer is for general information. Your own case needs an examination by an orthodontist.