An occlusion is decided
by the position of upper and lower teeth. In a normal
occlusion, the lower front teeth should touch the
inner surface of the upper front teeth. One-third
of the outer surface of lower front teeth should
be covered by the upper front teeth. The distance
between the outer surface of lower front teeth and
the inner surface of upper front teeth should be
2mm to 4mm.
If the upper teeth are projected more forward than the lower teeth, 'projected upper teeth' results.
However, if the lower teeth are projected more forward than the upper teeth, 'reversed bite' results.