Most people appear to have an overjet of a good few millimetres – say up to five – and I’ve read that anything along these lines is fine and it’s not until you go seven mil or more that it’s considered excessive. Indeed, I’ve noticed that even for many people whose incisors would seem to have a close overlap it’s usually because the upper anterior teeth are tipped backwards; if their teeth were straightened there would still be an overjet present.
And here’s the thing, people with incisors that appear to just overlap in a way that we’re all told is a characteristic of a perfect class I occlusion often look as if they’ve got too much chin, and maybe something of a flattish face as a result. By contrast most people that have something of a mild overjet – and that appears to be the majority of people – look great and have a well proportioned mouth and chin. Is it just the way I’m looking at things – or my imagination – that’s leading me to believe most have overjets? That is, an overjet in excess of the type that is obviously necessary to ensure your front teeth overlap in a class I occlusion and don’t meet edge to edge.
I thought at first it was maybe because I live in Ireland and that possibly everyone here has misaligned teeth.
However, since my new found interest in observing other people’s teeth, I’ve been over in England and the same situation prevails there too. Most people have overjets, it seems. Now admittedly these aren’t exactly the two places that many Americans would look to as beacons of beautiful dentition – think the Simpsons Halloween episode involving the Big Book of British Smiles – but are mild overjets the norm everywhere and therefore the actual definition of a normal bite. And surely a normal bite is what all of us snaggle toothed peeps are aiming for?!!
) is a case in point. Her upper incisors leaned forward and yet she had a 13mm overjet. 
) The second thing is that I really can't shake my suspicion that there are loads of people with mild overjets - so many that they might actually be the majority. It just so often looks this way when I catch glimpses of people's teeth!! 
) they're used for cutting. Call it 1mm to 3mm is "nomral". All cases of course are different and also depending on size of teeth etc, you can go over. But that's the range that orthodontics would try to achieve whether surgery, extractions or camouflage. Honestly I don't think anyone wants to go for a look of having an overjet. 
people even have veneers to reduce the overjet if they don't do braces. As mentioned above you'd have to see people clenching in order to note that they have an overjet. Perhaps you're thinking of where people have their top fronts flared forward instead when they are smiling. It can look like an overjet but there is still contact at the back with the bottoms.
