Apart from some routine extractions patients may also undergo the removal of wisdom teeth.
For most adolescents, this may occur following the completion of their orthodontic treatment. Those who start their orthodontic treatment later or as an adult may have wisdom teeth removed to create further space when treatment starts if appropriate.
Developing canines sometimes erupt outside their normal position. The upper canines have a long pathway of eruption and can sometimes be “impacted” on the roof of the mouth, near to the root of the upper lateral incisor.
Upper canines can also try to emerge on the lip side of the lateral incisor (second tooth from the front), often high up under the lip. Lower canines impact much less frequently but can move right across in front of the roots of the lower incisors.
Orthodontic treatment can involve the surgical uncovering of the canine. The orthodontist can then place a bracket on the tooth and can pull it into place using braces on all the other teeth.
If the canine is too deep, the surgeon will bond a bracket on the crown of the canine. A chain is attached to the bracket. Using braces on all the other teeth, the orthodontist uses the chain to progressively pull the canine into place.
Other teeth that may be impacted include upper central incisors, upper and lower premolars and lower second molars. Braces are used to reposition these teeth or to close spaces if they have to be extracted because they cannot be repositioned.
Jaw Surgery or Orthognathic Surgery
Orthognathic surgery is a specialised branch of oral and maxillofacial surgery that is concerned with the correct positioning of the upper and lower jaws and their teeth in relation to each other and the remainder of the face.
A small percentage of orthodontic patients have a jaw difference that is so great that, if they were treated by braces alone:
These patients can be treated with a combination of braces and jaw surgery. The braces are used to correct any crowding, spacing, rotations of the teeth, or other irregularities before the jaw surgery.
The most important role of the braces is to position the upper and lower front teeth in the best position within the upper and lower jaws so that when the jaws are repositioned, the teeth are then correct in the remainder of the face and in relation to each other, upper against lower. This pre-surgical repositioning of the teeth is called decompensation. This orthodontic stage of the overall treatment does not attempt to correct or compensate for the jaw differences. Surgery will do this stage of the correction.
The usual procedure for those having jaw surgery involves the initial placement of braces to correct the teeth (extractions may be needed) over a few months. When teeth have been fully aligned within each jaw, the surgery is carried out with the braces still on the teeth. The surgery is done all completely inside the mouth and there are no scars on the outside. The surgeon uses the braces to control the new jaw positions with elastic bands and to settle the teeth after the surgery. So the braces continue for several months after the surgery.
Small Lower Jaw
For most people with protruding upper front teeth, this protrusion is a combination of the upper front teeth being forward in the upper jaw and the lower jaw being back in relation to the upper jaw. If the difference between the upper and lower front teeth is not too great, braces can correct the bite by moving the upper and lower teeth only, in effect camouflaging or compensating for the difference between the jaws.
However, in cases where the jaw difference is too great, consideration needs to be given to the surgical repositioning of the tooth-bearing portion of the lower jaw to correct its position with the upper front teeth. This will also place the lower jaw in a more ideal position with the remainder of the face.
Prominent Lower Jaw
Orthodontic camouflage for patients with a prominent lower jaw is much more limited than for those who have protruding upper front teeth. For a patient whose lower front teeth bite ahead of the uppers, the amount that the upper front teeth can be tipped forward and the lower front teeth tipped back is very limited. Orthognathic surgery for the correction of these 'Skeletal III' jaw discrepancies is only carried out when the patient has completed jaw growth. In males, this is usually from 18 years and about 16 years for females.
Although the lower jaw may appear to be prominent in approximately 40% of cases, the upper jaw is often also back a little in the face. Therefore, the correction may involve surgical forward movement of the tooth-bearing portion of the upper jaw along with backwards movement of the lower jaw. Otherwise, it may just involve the backward movement of the lower jaw or, less often, the forward movement of the upper jaw only.
Jaw surgery may be required to correct a facial asymmetry where the lower jaw or chin point is noticeably off to one side compared to the nose or upper lip or the level of the eyes. If the upper arch of teeth is tipped as a compensation for the lower jaw position, a surgical procedure involves moving both jaws.
Vertical Maxillary Excess
Some people, when smiling show an excessive amount of gum between the upper lip and the teeth. This is often associated with a narrow face. Surgery involves moving the tooth-bearing portion of the upper jaw up, under the upper lip and then positioning the lower jaw and chin point to match this new position.
A severe functional problem arises when only the back teeth meet when a person tries to bite together. The lack of any vertical overlap or contact between the front teeth is known as an anterior openbite. The surgery for this jaw discrepancy is similar to that for vertical maxillary excess.
Mini-implants, Mini-plates or Temporary Anchorage Devices
Mini-implants or mini-screws are small, specially designed screws that are placed in the bone between the teeth. As they are anchored in the bone, they can act as a very strong anchor, allowing the orthodontist to use elastics or springs to move a group of teeth or a tooth without placing any strain on any of the other teeth. This technique can allow tooth movements that couldn't be carried out or would take too long. Relatively few patients require these appliances but, when used, they can make an otherwise impossible treatment become a successful treatment.
The mini-screws are placed with only a little local anesthetic in a relatively minor procedure.
Mini-plates require a little more surgery for their placement as part of the plate is under the gum. Their main advantage is that they stay in place longer than mini-screws, which are more prone to loosening. They can also be placed further away from the roots of the teeth, ensuring no damage.