Dental Malocclusion: Causes, Types, and Treatments

A dental malocclusion is an alteration in the way of biting. Find out why it happens, the different types, and how it's treated.

Written and verified by la odontóloga Vanesa Evangelina Buffa.

Last update: 20 February, 2024

Occlusion refers to the relationship between the teeth themselves and between the teeth of the upper jaw and those of the lower jaw when biting. When this correlation is altered, and the dental elements aren’t in the position they should be in, then we’re talking about a dental malocclusion.

When closing the mouth, the upper teeth slightly exceed the lower ones, and the cusps of the upper molars fit into the pits of the lower ones. In addition, each tooth corresponds to a specific location and alignment in the dental arch. This maintains harmony in the bite.

If this doesn’t happen, the normal functions of the mouth and the health, aesthetics, and quality of life of the patient are affected. For this reason, when there’s a dental malocclusion, treatment is necessary. Let’s explore the root causes of these disorders, the different types, and how they can be corrected.

The causes of dental malocclusion

There are several reasons that can lead a person to develop dental malocclusion. In general, it’s the combination of different factors that causes variations in the way a person bites. According to a descriptive observational study published in the Gaceta Médica Espirituana, malocclusions are multifactorial and arise from the interaction between environmental and hereditary factors.

These are some of the conditions that influence the growth of the bones and the positioning of the teeth and, therefore, predispose individuals to the appearance of dental malocclusions:

• Heredity: Genetics influence the way you bite, the size of the bones, and the location of the teeth in the arch. For this reason, it’s common to observe similar characteristics in the mouths of several members of the same family.
• Dysfunctional habits: Some repetitive and impulsive habits in children often cause malocclusions. For example, the interposition of the tongue or lips when swallowing, mouth breathing, and onychophagia. Prolonged use of a bottle or pacifier and finger sucking after the age of 2 also predispose children to develop bite problems.
• Loss of teeth: The early loss of milk teeth affects the correct eruption of the final teeth. As a consequence, it’s common for crowding and malpositions to arise and for occlusal relationships to be lost. The absence of definitive pieces also alters the bite and the position of the antagonistic and neighboring elements.
• Defective dental treatments: Due to iatrogenesis or lack of maintenance, the presence of fillings, crowns, or damaged or poorly adapted prostheses alter the way a person bites.
• Other situations: Cleft lip and palate, mouth tumors, extra teeth, or trauma to the jaws are conditions that alter occlusion.

Diagnosis and types of dental malocclusions

The diagnosis of dental malocclusion is made by an orthodontist after an exhaustive study of the patient. For this, the professional uses clinical examination, impression taking, study models, bite records, and x-rays and photographs of the inside and outside of the mouth.

In any case, sometimes there are symptoms associated with changes in the bite that warn of the presence of a problem:

• Difficulty speaking or pronouncing certain phonemes correctly.
• Missing teeth.
• Incorrect position or alignment of the teeth.
• Lack of contact between some teeth when biting.
• Problems chewing and eating.
• A strange appearance of the face.
• Mouth breathing.
• Snoring or sleep apnea.
• The habit of biting or sucking their lips or cheeks.
• Noises when opening and closing the mouth.

If there’s a dental malocclusion, an evaluation of the case by an orthodontist will confirm the diagnosis.  Treatment is planned depending on the type of problem, its severity, the cause that originates it, and the age of the patient.

Bite problems can be grouped into different categories. The classification system proposed by E. Angle in 1899 is the most widely used and accepted in the field of orthodontics. As a review of the classification of skeletal and dental malocclusions explains, Angle’s classes are based primarily on the relationship between the upper and lower first molars.

Based on this categorization, below we’ll explain the different types of malocclusions.

Class I dental malocclusion

In this type of dental malocclusion, the upper and lower first molars relate to each other correctly. The bibliography reports that it’s the most frequent malocclusion. It’s even more common than normal occlusion.

Although the jaws have a proper relationship with each other, there’s some condition that interferes with the bite. It’s the dental elements that are in incorrect positions. There may be gaps, crowding, misplaced pieces, or overbites.

If the relationship of the jaws with respect to the skull is considered, different situations can occur:

• Both maxillary bones have a normal position with respect to the head.
• The two bones are in a posterior position with respect to the skull.
• Both the upper and lower jaws are advanced (biprotrusion) with regard to the head.

Class II

This type of dental malocclusion is characterized by an advanced position of the upper jaw compared to the lower one. Therefore, the first molars have a disproportionate relationship.

The imbalance can be due to different situations:

• The mandible is retracted, and the maxilla is in the correct position.
• The upper jaw is forward, and the lower jaw is in the correct position.
• The upper jaw is protruded, and the lower jaw is retracted.

The patient is characterized by having very advanced upper teeth. Studies associate this problem with harmful oral habits such as mouth breathing, lip sucking, finger sucking, and prolonged use of a bottle or pacifier.

Class III dental malocclusion

This dental malocclusion is characterized by prognathism, which is the projection of the lower jaw forward. The lower jaw is more advanced than the upper jaw, and therefore, the lower teeth protrude in front of the upper ones.

At the bone level, the following situations may occur:

• The upper jaw is retracted, and the lower jaw is in a normal position.
• The upper bone is located in the normal position, and the mandible is advanced.
• The combination of both: The upper jaw retracted, and the lower jaw advanced.

The treatment of this dental malocclusion is the most complex, so early interventions are important in order to improve the prognosis. In any case, according to a study published in the Dentistry Journal, this problem is the least frequent.

Other dental malocclusions

In any of the classes mentioned above, the following situations may occur:

• Diastemas: This is the excessive separation between the teeth. The exaggerated space is caused by very small teeth or by a very large jaw. It can also arise from the early loss of temporary elements or from the habit of tongue thrusting.
• Crowding: There’s no space in the dental arch, and the teeth overlap. Crowded teeth have an impact on the aesthetics, oral functions, and dental hygiene of the patient, which increases the risk of suffering from cavities and gum problems.
• Overbite: The upper teeth excessively cover the lower ones when biting.
• Open bite: The upper teeth don’t come into contact with the lower ones when occluding, which creates a space between the two jaws. This affects the patient’s speech, swallowing, and chewing.
• Crossbite: There’s an alteration in the transverse relationship of the jaws. One or several lower dental elements occlude outside the upper ones.

Treatments for dental malocclusion

The best time to reverse dental malocclusion is during childhood and adolescence. Taking advantage of the bone growth and tooth replacement that are typical of these stages reduces treatment times and complexity. In any case, there are therapeutic alternatives that can be applied at any time in life.

Orthodontics is the branch of dentistry that’s responsible for correcting bite problems. This specialty has different strategies to treat each dental malocclusion.

The choice of the procedure depends on the type of alteration to be corrected, the causes, its severity, the age of the patient, their needs, desires, and possibilities. These are the most frequently used approaches.

Orthopedics and interceptive orthodontics

This consists of placing removable appliances during the temporary and mixed dentition stage in childhood. These attachments guide the growth of the jaws and also mobilize the teeth.

Studies published by the journal Reaciamuc suggest that interceptive procedures reverse or reduce the severity of malocclusions. This increases the well-being of the child before adolescence and facilitates future approaches in the event that subsequent treatments are necessary.

Corrective orthodontics

Corrective orthodontics is performed in adolescents when all the permanent teeth have already erupted. However, it’s also effective in adults. Its main objective is to correct the position of the teeth and achieve a harmonious and balanced bite.

Depending on the patient’s preferences and the orthodontist’s recommendations, different appliances are used:

• Fixed orthodontic appliances: Here, we’re referring to classic wires and brackets that apply gentle and constant forces on the teeth to gradually move them to their correct position. There are options in various materials, and some of them offer excellent aesthetic results.
• Transparent aligners: These are an aesthetic, removable, and comfortable option for patients. They’re transparent trays that are replaced periodically and fulfill the same function as fixed appliances.

Surgical treatments

Complex or severe dental malocclusions require surgical procedures as part of orthodontic treatment. However, this isn’t always necessary.

In some cases, it may be appropriate to extract one or more teeth to create space in the mouth. This allows the other elements of the arch to be located in a more suitable position. They’re usually applied to treat significant dental crowding, severe protrusions, supernumerary teeth, or when the size of the teeth is too large for the space available in the dental arch.

As a review article from the VHL Regional Portal explains, it’s important that orthodontists comprehensively assess the real need to remove teeth or not. Although the procedure brings benefits in some cases, when an unnecessary extraction is performed, the entire orthodontic treatment is prolonged.

On the other hand, in cases of adult patients with very severe malocclusion, orthodontic treatments are complemented with orthognathic surgeries. These surgical procedures are combined with appliances to correct skeletal problems in the jaws.

They’re performed when there’s a significant discrepancy between both jaws and when bite, facial aesthetics, and oral functions are compromised. Through orthognathic surgery, the bones are reshaped, trimmed, and repositioned to achieve a proper relationship between the arches.

Orthodontists work with maxillofacial surgeons to plan and execute procedures comprehensively. An article in the International Journal of Health Sciences explains that collaboration between professionals is essential for successful treatment.

Controls to diagnose and treat dental malocclusion

Dental malocclusion affects the structures and functions of the mouth, the aesthetics of the face, and the quality of life of the person who suffers from it. Fortunately, there are effective solutions, both for children and adults, which allow for correcting the problem and achieving a healthy and functional smile. Going to the dentist regularly and from an early age is the key to detecting and treating these disorders as soon as possible.