· The upper front teeth extend too much over the lower teeth (overjet). · When biting together, the upper front teeth cover most of the lower teeth (deep bite). · The upper front teeth are inside or behind the lower front teeth (underbite). · When biting together, the upper and lower front teeth do not meet (open bite). · Crowding-this occurs when teeth do not have enough room to erupt from the gum. · Spacing problems. · When biting together, the lower jaw shifts to one side or the other. · The center of the lower and upper teeth does not align correctly. · You find it difficult to chew. · You experience uneven or excessive wear on the teeth. · Finger or thumb-sucking habits continue after age six or seven.