North Sydney Orthodontics

Crooked teeth and Bite problems

‘Crooked teeth’ is the commonest complaint of patients seeking orthodontic treatment. How we treat crooked teeth depends on the specific problem. We always aim to position the teeth to create a functional and aesthetically pleasing smile. This may include consideration of the jaw shape and potential growth. Orthodontic anomalies can be categorized into variations of alignment, bite problems, dental disease, cosmetics (tooth size and shape). They also involve functional problems such as jaw pain and obstructed nasal breathing and digit sucking or abnormal swallowing patterns .

Alignment Problems of the teeth

These problems create a local irregularity within one or other jaw. However, they usually have only a minor effect on the bite of the teeth. Treatment of alignment problems is usually achieved very reliably and efficiently with invisalign or braces.

Crooked Teeth : Missing teeth

One or more congenitally missing teeth occurs in 2-5% of the population. Depending on which tooth is affected, this may create aesthetic problems such as asymmetry and spacing. Treatment aims to either completely close the space or localize the space to permit tooth replacement.

Crooked teeth : spacing

Localized spacing can be caused by missing teeth, small teeth, or a combination of both. Space closure is straightforward, but stability is often poor and requires long term retention.

Crooked teeth : Crowding

Crooked teeth, including crowding and irregularity, are the commonest orthodontic complaint. Treatment involves alignment of the teeth. However, it may also require dental extractions if the dentition is excessively protrusive. In this case extraction included a lower incisor which had compromised gum health

Crooked teeth : Extra Teeth

Rarely an obstruction is created by supernumerary (extra ) tooth or teeth. The treatment is extraction of the extra teeth and align the remaining teeth. In this example the extra tooth is denoted by S.

Crooked teeth : over-retained primary teeth

Primary teeth usually drop out as their succeeding tooth emerges. Sometimes primary teeth fail to shed and become an obstruction. In this image over-retained primary teeth are denoted by X. These teeth will need to be extracted

Crooked Teeth : Transposition – teeth swapped around in the wrong order

Vary rarely the position of two adjacent teeth swap, either partially or completely. Treatment can involve correcting the teeth back to the normal sequence or aligning them into a good compromise with cosmetic camouflage. This case shows a transposition of 3 and 4

Crooked Teeth: Impeded emergence of incisors

Front teeth sometimes don’t grow into the mouth normally because of an obstruction, usually an abnormal extra tooth, or a malformation of the roots. This problem is noticed around age 7–8 years and is a compelling, though uncommon, reason for early treatment.

Crooked teeth : Impeded emergence of canine teeth

Canine teeth regularly fail to grow into the mouth because they have formed in an ectopic position. Alignment of ectopic canines is best performed as early as possible, any time after 11 years of age.

Crooked teeth : Impeded emergence of first molars

Impeded first molars are an uncommon problem that appears around age five to six. It often leads to early loss of the primary second molar and early dental crowding. Sometimes the problem resolves on its own. However, orthodontic treatment is often needed to regain the arch space and keep it.

Crooked teeth : Impaction of second molars

Impaction of the 2nd molars (tooth 7) by a wisdom tooth (tooth 8) is an occasional problem. Surgical removal of the wisdom teeth and exposure of the buried 2nd molar is the recommended treatment

Crooked teeth : Impaction of third molars

Orthodontic alignment for impacted wisdom teeth (tooth 8) is usually considered if tooth 7 or 6 is poor quality or if tooth 5 is missing. Usually impacted wisdom teeth are extracted but if you are considering orthodontic alignment check with us before

Bite Problems

Bite problems refer to how the top teeth relate to the lower teeth when closed together (biting). Bite problems can be caused by a local tooth misalignment, but mostly result from a misalignment of the jaws. Bite problems can be more difficult to correct than alignment problems. Early orthodontic intervention can help with some bite problems, but jaw imbalance is a long-term issue.

Bite problems : Crossbite of the back teeth

A cross-bite of the back teeth is caused when the upper back teeth are too narrow to fit around the outside of the lower teeth. Commonly a slight narrowing causes the lower jaw to deviate to one side to allow the teeth to mesh more. This results in a facial asymmetry and the jaw joints being stretched on one side. Prompt treatment is essential to prevent the facial asymmetry becoming permanent – this can resemble Class 3 jaw growth, but it is not caused by jaw size.

Bite problems : Crossbite of the Front teeth

A cross-bite of the front teeth without a jaw size discrepancy can be due to overcrowding or just irregularity of the teeth. The top tooth or teeth bite inside the lower teeth. If the cross-bite causes a dental interference which makes the jaw deviate on closure it should be treated early to prevent tooth wear and jaw joint dysfunction.

Bite problems : Scissor bite of the back teeth

A scissor bite occurs when (usually) upper side teeth bite completely outside of the lower teeth. The teeth are then free to continue growing down as there is nothing stopping them

Bite problems : Class 2 growth (relative lower jaw deficiency)

Most commonly this condition is caused by deficient growth of the lower jaw. The facial proportions reflect the underlying jaw bone sizes, and the lower lips can be hard to close at rest (incompetent). Non-surgical treatment is best started before the peak growth velocity in the 10–12 age group. More..

Bite problems : Class 3 growth (relative lower jaw excess)

This condition can be caused by deficient growth of the upper jaw, excessive growth of the lower jaw, or a combination of both. Class 3 growth pattern can be evident at an early age, but often continues to worsen until the early 20s, and so caution is advisable before starting definitive treatment. Early maxillary expansion and protraction can be a useful intervention. More..

Bite problems : Deep bite

Teeth continue to emerge from the gums until they find something to bite against. When any tooth is unopposed, it tends to overgrow. Until it occludes on an opposing tooth, the tongue, the lip, or a foreign body. A deep overbite can be a dental health issue. It can cause the teeth to bite the gum attachment of opposing teeth, stripping gums and exposing roots. A deep bite occurs when there is no opposing tooth in a normal horizontal relationship (overjet). The incisors then overgrow vertically. It is common when the lower jaw growth is slightly deficient. It is also common when the vertical growth of the face is reduced. Deep overbite usually arises with other orthodontic problems and can be treated using a variety of different methods.

Bite problems : Open bite

Open bite can result from a developmental stage during the transition from primary to permanent dentition. It may be prolonged if the tongue is postured forward or a thumb-sucking habit is present. In teenagers and adults without tongue or digit habits, the open bite is common. It results from a vertical growth discrepancy of the face. Moreover, there is a strong association between obstructed nasal breathing and open bite. This condition has long been challenging to correct. However, new techniques have proven effective at correcting this problem.

Bite problems : Jaw Asymmetry

Asymmetry often arises with a jaw size discrepancy. It can also involve a small difference in arch width between the upper and lower jaws. Correcting the alignment of the teeth often improves mild asymmetries. Noticeable asymmetry may be caused by missing teeth. The severity of the asymmetry will determine the correct treatment, but jaw surgery is required to obtain facial symmetry.

Problems caused by dental disease, dental injury and dental treatment

Although dental health has improved greatly in recent decades, teeth still deteriorate to the point where extraction is unavoidable. Moreover, this can affect the position of the teeth and lead to other problems later. In the right situation, orthodontic treatment can help, in combination with other forms of dental care. Occasionally, orthodontic treatment offers an alternative to more expensive options such as tooth replacement.

Tipped teeth following previous extractions

Following the loss of teeth, the adjacent teeth can tip into the space. Biting forces may then not pass down the long axis of the root. As a result, this leads to breakdown of the bone support and gum attachment. The best way to prevent this is prompt tooth replacement. However, once this has happened, orthodontic uprighting of the tipped teeth is indicated.

Space closure for teeth of poor prognosis

The loss of damaged teeth creates instability in the bite and may lead to tipping or drifting. Replacing the tooth is a natural solution. However, orthodontic space closure may improve the alignment of the remaining teeth. It can also avoid expensive tooth replacements. In fact, in most cases, space closure is the cheapest long-term option.

Cosmetic Improvement

Orthodontic treatment usually improves the appearance of the dentition. Moreover, this often comes as an added bonus to dental health and functional benefits. Additionally, improvement in aesthetics is the commonest reason patients seek orthodontic correction.

Jaw pain and nasal obstruction

Occasionally painful jaw joint symptoms are present or are the main reason for seeking orthodontic treatment. This is a complicated problem. Many factors have been proposed to influence jaw pain, however malocclusion has been shown to have an inconsistent relationship and has largely been excused as a primary cause of problems. Stress is a consistent culprit and because pain is a perception in the brain it is not surprising that psychological factors play a part as well as primary pathology or damage of the joints. More recently difficulty with nasal breathing and obstructive sleep apneoa have been implicated in the many causes of jaw joint pain. Occasionally the problem is due pain originating elsewhere in the head and neck region, and some practitioners believe the problem can relate to body posture. There is no evidence to suggest that carefully planned and executed orthodontic treatment causes jaw joint problems and unfortunately not much evidence to suggest that it will cure the problem either. Patients suffering jaw joint pain may benefit from discussing this problem with a dentist (who may recommend a dental splint to relax the mouth muscles) or a chiropractor / physiotherapist who may undertake physical therapy for symptomatic relief.  Sometimes headaches and facial pains are associated with this condition but headaches may also be a sign of other types of disease arising in the head and neck area which may require medical investigation.