Will a slight overbite mean you have a small upper jaw (maxilla), and small lower jaw (mandible)?

Teeth not jaw : An overbite, also called deep bite, is caused either by the over eruption of the top teeth or an overdevelopment of the bone surrounding the teeth. Many malocclusions (bite problems) are caused by the size of your jaws but an overbite is not one of them.

No: A slight horizontal overbite of about 2mm and a slight vertical overbite of about 25% is normal.

It's the opposite!: A slight overbite refers to a slightly more protruded (larger) upper jaw and a smaller lower jaw. A smaller upper jaw compared to the lower jaw is referred to as an underbite.

NO: There is real confusion surrounding these terms: an overbite to an orthodontist is the vertical overlap of front teeth, what most lay persons mean when they say overbite to an orthodontist is called overjet, and is a measure of horizontal over/underlapment of front teeth. Much confusion about this: i think that orthodontists should change their terminology so as to reduce confusion when educating.