1. I HAVE A VERY LARGE OVERJET/OVERBITE
People have many types of dental smile, be they beautiful or ugly there are many
types in the dental spectrum. Most fall within the normal ranges, but some will fall
outside the spectrum and are called malocclusions.
In a series of dental articles, Dr Raj Kumar will try to explain what dental
malocclusions are, how you get them and how to get them treated.
He has over 20 years of dental and cosmetic experience and is well versed in
treatments that are tried and tested. He will give an unbiased view on how Invisalign
can help in most orthodontic problems with before and after examples.
Don’t call me an overbite! I’m an overjet!!
In a normal bite the upper and lower teeth are usually close to each other and with
about 2-4mm of vertical overlap. The vertical overlap is called overbite and the
amount the teeth stick out horizontally is called an overjet.
In the case below the overbite is about 2mm and the overjet is about 1mm.
I will discuss overbites in another article, but most people get confused and call their
overjet problem an overbite.
The overjet is usually anything that is greater than 4mm which would require treating.
The teeth may look fine from the front but it’s the side view that is most obvious.
How did I get an overjet?
There are many reasons and I have listed most:
1 Patient may have been a digit sucker as a child. The thumb or finger
prevents the teeth from developing and meeting together; this is termed
a tooth discrepancy
2 Having a dummy in the mouth for prolonged periods as a child can
cause an overjet
3 The action of digit sucking can prevent the lower jaw from growing
forwards and also push the upper jaw up and forward instead; this is
termed a jaw discrepancy

2. 4 The afflicted may be called Goofy, Duck face, Chinless wonder etc
5 Chewing on a pen/nails as an adult can also create a small overjet
6 Where there is a jaw discrepancy the teeth can only be pulled together
so much. Sometimes jaw repositioning surgery is needed
7 Sometimes you can inherit the flared teeth from your family
8 Sometimes the jaw discrepancy is also inherited
9 Tongue thrust can also cause the teeth to be pushed outwards
10 The side and back teeth can collapse inwards towards the tongue, even
after orthodontic treatment and push the front teeth outwards
My dentist told me that I need my jaw broken and reset to correct my overjet
Patients with extreme overjets greater than 10mm/1 cm may have a situation where
the lower jaw is set back and their side profile is not great.
The jaw difference can be corrected once the teeth are pulled inwards but most
patients do not opt for surgery. The lower jaw is broken and then positioned forward
to meet the upper jaw. The jaws are splinted with metal braces for about 6 weeks
whilst the jaw sets.
This is an extreme treatment and is not recommended except in extreme cases where
the facial appearance is obvious.
Most patients have full lower lips that mask the lower jaw position. Most patients are
happy just top get straight teeth instead
Will Invisalign help me?
Invisalign is an orthodontic treatment and will help reduce the overjet. In cases of
extreme overjet it is recommended that you get help from a very experienced
Invisalign dentist.
The teeth are gently pulled inwards to meet the lower teeth. It is possible that the
lower teeth may also need correcting before the overjet can be reduced.
I regularly treat patients with very large overjets (12mm) and find no problems with
Invisalign. It takes about 15 months but the results speak for themselves.

3. This is a case treated by myself over 15 months. No teeth were removed in this case
as we had spaces at the front.
The ideal anterior occlusion has been achieved with Invisalign and a little planning.
Conclusion
Having a large overjet should not stop you living a happy life. But if it gets on your
nerves then Invisalign can definitely help. Be prepared for about 12 months of
treatment, but what is 1 year out of a lifetime of happiness?
Dr Raj Kumar BDSLDSRCS Clinical Speaker for Invisalign