Normally, the upper teeth are in front of the lower teeth The upper two front teeth (incisors) are in anterior crossbite (behind) the lower teeth.
The teeth are angled outward, “protruding” from the mouth. (More commonly called “buck teeth”). Sometimes, the protrusion is caused by the jaw bones ie. the the top jaw is too far forward of the bottom. There may be crowding, additionally. Depending on the severity, growth modification appliances, extractions, or surgery in adults may be required.
“Opposite of a protrusion… teeth are angled inward.”
EXTRA TOOTH (SUPERNUMERARY)
Sometimes, extra tooth (arrow) may occur and causes the normal teeth to be in an incorrect alignment.