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A series of computer-generated, nearly invisible aligners that fit over the teeth.
Aligner Systems
Comfortable, removable aligners that gradually move your teeth into position.
invisible Braces
These systems are a simple, fast and invisible way to align teeth.
Fixed appliances
A variety of brackets depending on your individual needs and requirements.
Sectional systems
With simple Newtonian mechanical principles the teeth can be moved.
There are several methods of Prealign that Dr Mew uses.
Orthodontic Self-Assessment

This page will help you:

  • perform a self-assessment of your orthodontic situation
  • understand which treatments may be possible for your situation
  • understand the terminology that orthodontists use to analyse and describe malocclusion.

Please refer to our Glossary of Orthodontic Terms whenever you need to while doing this simple self-assessment.

Orthodontists can treat all the conditions discussed below, but you may have limits on the treatments that you want to undergo. For example, most people would rather not have teeth extracted, and few want surgery.

Simple self-assessment steps:

  1. Locate your first permanent molar. Assuming you have all your natural teeth, it will be tooth number 6 counting back from the front centre line.

    Compare lower tooth number 6 to upper tooth number 6. In an ideal situation lower number 6 is further forward by half its width and further in (toward the tongue) by half its width. Ideally all side teeth bite together with the tips alternately interlocking, i.e. biting into the troughs or spaces between the opposing teeth. This ideal situation is called a Class I molar relationship.

    If the lower molar is set back you have a Class II molar relationship. If the lower molar is set forward you have a Class III molar relationship.
  2. Locate your very front teeth. These are upper and lower teeth number 1 when counting from the midline. Bite your teeth together and look at the point on the back of upper tooth number 1 that lower tooth number 1 touches. Divide the back of upper tooth number 1 into thirds. If the teeth do not actually touch due to a vertical gap between the upper and lower teeth, imagine a line running up to touch the upper tooth.

    You have a Class I incisor relationship if lower tooth number 1 touches the middle third of upper tooth number 1. If it touches the back third or beyond you have a Class II incisor relationship. If it touches the front third or beyond you have a Class III incisor relationship.
  3. Look to see if you have spacing or crowding in your dental arches.
  4. Compare the position of the tips of your upper and lower front teeth in the horizontal (overjet) and vertical (overbite or open bite) planes.

This simple self-assessment gives you some idea of your situation. The molar teeth give an indication of the position of the bones of the upper and lower jaw.

A Class I molar relationship is the most common position of the back teeth, present in 60% of people and many who have straight teeth. The most common incorrect position for the back teeth is a Class II molar relationship, present in about 30% of people. Class III molar relationships are far less common, seen in about 3% of people within the UK. The molar position tends to reflect the shape of your face: people with Class II tend to have short jaws; people with Class III have jaws that stick out.

It is very difficult to change the jaw position of an adult. The options are surgery or total dedication with orthotropic postural appliances. Because most people would decline both options, treatment of Class II or Class III molar relationships is likely to involve compensating for the problem.

The list of treatment options below is not complete. Many conditions overlap and this list is only intended to be a guide.

Class I molars

Almost any form of treatment will work, including fixed braces, Invisalign, Invisible braces or other aligner systems. Treatment with aligner systems is limited with very rotated teeth such as the canine teeth (teeth number 3 when counted from the midline), very crowded or spaced teeth.

Class II molars

Elastics running from the front of the upper dental arch to the back of the lower dental arch can correct mild Class II conditions, but this treatment requires care to avoid lengthening the whole face, which then looks worse. Treatment can be camouflaged with slimming (trimming the teeth, not good for the teeth but better than tooth extraction) or extracting teeth in the upper dental arch, and adding a lower tooth or space, usually between teeth 5 and 6 where it is out of sight.

Gentle elastics can be used with Invisible brace systems, Invisalign or other aligner systems in mild Class II situations. Invisalign or other aligner systems can cope with extractions or opening spaces but take longer than fixed braces and the roots of the teeth are not moved. The sectional system often is perfect as a prealign phase prior to Invisalign.

Class III molars

The opposite of treatment in Class II molar relationships.

Crowding or Spacing

Spacing can be closed but it is important not to pull the front teeth back if they are providing support to the lip. Crowding can be corrected by widening the dental arches or through extractions. Dr. Mew normally tries to avoid extracting teeth, but expansion of the dental arches is not very stable unless supported by a change in the tongue position, which is not easily achieved in an adult. Fixed appliances are the best form of treatment for both of these situations. Invisalign and other aligner systems work well if there is reasonable crowding or mild spacing, while Invisible braces are good for spacing or crowding only at the front of the dental arches.

Class II or III incisors (includes upper front teeth sticking out)

Usually occurs and is treated with the same class of molar relationship, but can exist independently as a result of lower tongue posture (Class III incisors) or the lower lip catching under the upper front teeth (Class II incisors). Mild cases can be treated with any appliance, with care to affect the habit which may change when the problem (structure) is corrected. The treatment of upper teeth that are very tipped or stick out requires great care. This situation is often associated with gum disease which MUST be treated prior to moving the teeth. It can be made worse by fixed appliances and it is best to use the sectional system, but Invisible braces can be appropriate. Invisalign and other aligner systems should be avoided as the aligners will not flex adequately over the teeth, which can then be damaged.

Open bite

Associated with a forward resting tongue posture, an open bite will often return if tongue posture is not treated by widening the dental arches to provide alternative room. Unless there is a very pronounced forward tongue posture it is easy to close a gap in the bite with fixed appliances and vertical elastics. Open bite can be treated with TADs and vertical elastics, but treatment is more difficult with Invisalign or other aligner systems and usually requires unsightly attachments on all the front teeth. Treatment with Invisible braces systems is also more difficult.

WARNING: closing an open bite against a pronounced forward tongue posture or thrusting tongue can jiggle the teeth backward and forward. This can destroy the roots.

Deep bite

Associated with a bilateral posterior lateral tongue / tongue splinting, where the sides of the tongue rest over the back teeth. A deep bite often returns after treatment if the tongue is not given more space, usually accomplished by widening the dental arches. Very deep bites more than 6 mm are best treated with bases arches from the sectional system as teeth can be damaged by a fixed appliance system. Deep bites are difficult to treat with Invisalign or other aligners and Invisible braces, but a mild deep bite can be left untreated or treated with any system.


Overjets are usually treated as part of the molar relationship or incisor relationship.

More information

Quality care
Our commitment is to provide quality orthodontic care to the best standards possible
Initial Assesment
Book your orthodontic smile consultations.
Perform a self-assessment and understand the treatment thats right for you..
Lip and tongue exercises to change the position of the teeth, improve the lips and hollow the cheeks
Orthodontic Terms
Glossary of Orthodontic Terms, meaning of orthodontic terms or orthodontic definitions.
Case Studies
Before and after photos of Dr Mew's work

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