Malocclusion (Bite Problems): Types, Effects and Treatment

Complaints about tooth alignment are usually expressed as "my teeth are crowded". Yet orthodontics deals with a second and often more decisive matter: how the teeth meet each other. A person's teeth may be neatly aligned while the upper and lower jaws close together in a mismatched way. This picture is called malocclusion. In this article we look at the types of bite problem, their causes, the difficulties they lead to and the treatment options.

What Counts as a Normal Bite?

In a harmonious bite the upper front teeth sit in front of the lower front teeth and overlap them slightly, while the back teeth contact their counterparts in the opposing jaw in an orderly way. This arrangement allows chewing force to be distributed evenly along the row of teeth. Malocclusion is a deviation from this relationship in one or more directions. Alignment (crowding) and bite are different but related subjects; for the alignment side see our article on crowded teeth.

Types of Bite Problem

Open Bite

When the teeth are closed, the upper and lower front teeth do not meet and a gap remains between them. It is often related to prolonged thumb sucking or tongue thrusting. Biting function is markedly affected; the person has difficulty tearing food with the front teeth.

Deep Bite

The upper front teeth overlap the lower front teeth more than usual; in advanced cases the lower teeth are barely visible. Contact between the lower incisors and the palatal tissue can cause irritation over time, and wear may be seen on the front teeth.

Crossbite

The upper teeth close inside the lower teeth rather than outside them as they should. When it is one-sided, the person may shift the jaw to one side when closing; because this can affect jaw development and the joint relationship, early assessment in childhood is advised.

Protruding Upper Teeth

The upper front teeth sit markedly forward of the lower teeth. This may arise from the angulation of the teeth or from a difference in position between the jaws, and the distinction changes the treatment plan. Protruding front teeth are a factor that increases the risk of trauma, particularly in children.

Protruding Lower Jaw

The lower teeth close in front of the upper teeth. It is usually related to differences in the size and position of the jaws, which is why assessment during the growth period matters.

Midline Shift

The midpoints of the upper and lower rows of teeth are shifted relative to one another. It can occur on its own or alongside other problems.

Causes

• Hereditary factors: Jaw dimensions and their positions relative to one another are largely determined by inheritance.
• Persistent habits: Thumb sucking, tongue thrusting and prolonged use of pacifiers and bottles can affect the bite during development.
• Mouth breathing: Continuous breathing through the mouth can change the balancing forces the tongue and lips exert on the dental arch.
• Early loss of baby teeth: Space loss affects both alignment and bite, which is why space maintainers matter.
• Drifting after tooth loss: Teeth adjacent to a gap tilt, opposing teeth over-erupt and the bite relationship is disturbed.
• Ill-fitting restorations: A filling or crown left high can change force distribution.

What Problems Does It Cause?

• Uneven chewing forces: Certain teeth taking excess load can set the stage for wear and cracks over time; our article on signs of a cracked tooth touches on this.
• Jaw joint and muscle complaints: A mismatched bite can affect the chewing muscles and the joint; a grinding habit aggravates the picture and a night guard may come into consideration.
• Gum problems: Areas that are hard to clean, together with excessive force, can adversely affect gum health.
• Tooth sensitivity: Worn enamel surfaces can lead to sensitivity; see our article on tooth sensitivity.
• Biting and speech: Biting is affected in open bite, and in some cases the production of certain sounds.
• Aesthetics and profile: The relationship between the jaws also affects the facial profile and cannot be ignored in smile planning. For a separate subject concerning gum visibility, see our article on gummy smile.

How Is It Assessed?

The type and source of a bite problem cannot be determined by looking at the teeth alone. Alongside clinical examination, radiographs (panoramic and cephalometric), intraoral digital scans or impressions and photographs are assessed together. The critical question here is this: does the problem arise only from the angulation of the teeth, or from the position of the jaws relative to one another? The answer directly determines the treatment plan; in the first case moving the teeth may be enough, while in the second, growth guidance or, at a later age, surgically assisted planning comes into consideration.

Treatment Options

In Childhood: Guiding Growth

While the jaws are still developing, appliances affecting the jaw relationship can be used. Appliances to widen the upper jaw in crossbite, and habit-breaking appliances in habit-related open bite, belong to this group. This is the main reason orthodontic assessment is advised at around the age of seven; for details see our article on early orthodontic treatment in children.

In Adolescence and Adulthood: Tooth Movement

Once the permanent dentition is complete, treatment rests on moving teeth through bone in a controlled way. The systems used include metal brackets, clear aligners and inner surface systems. In some cases extraction to create space, or additional anchorage methods such as mini screws, may be included in planning. For how treatment is planned in adulthood, our article on orthodontic treatment in adults may help.

Where Skeletal Differences Are Marked

In cases where the difference in position between the jaws is marked and growth is complete, a surgical approach planned together with orthodontic treatment may come into consideration. This decision is made by considering clinical findings, cephalometric assessment and the person's expectations together.

Restorative Support

Where worn teeth need reshaping or the bite height needs adjusting, restorative procedures can accompany treatment. For comprehensive smile planning see our Hollywood Smile page, and for digital planning our article on digital smile design. Sequence matters here: a restorative procedure carried out without arranging the bite relationship leaves the underlying load imbalance in place.

After Treatment

Once the bite has been arranged, a retention (retainer) stage is needed so the teeth and jaws maintain their new relationship. This stage is not an addition to treatment but an inseparable part of it; skipping retention can allow the result achieved to change over time.

Summary

Malocclusion concerns not the alignment of the teeth but the relationship between the upper and lower jaws. Open, deep and crossbite, along with differences in position between the jaws, are its main forms. Its effects are not limited to appearance: chewing, the jaw joint, tooth wear and gum health are all affected by this relationship. The treatment route is determined by whether the problem arises from the teeth or the jaw relationship, and by the person's stage of development.

This article is for general information. Assessing your bite and determining the appropriate treatment option requires clinical examination and radiological investigation.