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Malocclusion is a problem in the way the upper and lower teeth fit together in biting or chewing. The word malocclusion literally means "bad bite." The condition may also be referred to as an irregular bite, crossbite, or overbite.


Malocclusion may be seen as crooked, crowded, or protruding teeth. It may affect a person's appearance, speech, and/or ability to eat.

Causes and symptoms

Malocclusions are most often inherited, but may be acquired. Inherited conditions include too many or too few teeth, too much or too little space between teeth, irregular mouth and jaw size and shape, and atypical formations of the jaws and face, such as a cleft palate. Malocclusions may be acquired from habits like finger or thumb sucking, tongue thrusting, premature loss of teeth from an accident or dental disease, and medical conditions such as enlarged tonsils and adenoids that lead to mouth breathing.
Malocclusions may be symptomless or they may produce pain from increased stress on the oral structures. Teeth may show abnormal signs of wear on the chewing surfaces or decay in areas of tight overlap. Chewing may be difficult.


Malocclusion is most often found during a routine dental examination. A dentist will check a patient's occlusion by watching how the teeth make contact when the patient bites down normally. The dentist may ask the patient to bite down with a piece of coated paper between the upper and lower teeth; this paper will leave colored marks at the points of contact. When malocclusion is suspected, photographs and x rays of the face and mouth may be taken for further study. To confirm the presence and extent of malocclusion, the dentist makes plaster, plastic, or artificial stone models of the patient's teeth from impressions. These models duplicate the fit of the teeth and are very useful in treatment planning.


Malocclusion may be remedied by orthodontic treatment; orthodontics is a specialty of dentistry that manages the growth and correction of dental and facial structures. Braces are the most commonly used orthodontic appliances in the treatment of mal-occlusion. At any given time, approximately 4 million people in the United States are wearing braces, including 800,000 adults.
Braces apply constant gentle force to slowly change the position of the teeth, straightening them and properly aligning them with the opposing teeth. Braces consist of brackets cemented to the surface of each tooth and wires of stainless steel or nickel titanium alloy. When the wires are threaded through the brackets, they exert pressure against the teeth, causing them to move gradually.
Braces are not removable for daily tooth brushing, so the patient must be especially diligent about keeping the mouth clean and removing food particles which become easily trapped, to prevent tooth decay. Foods that are crunchy should be avoided to minimize the risk of breaking the appliance. Hard fruits, vege-tables, and breads must be cut into bite-sized pieces before eating. Foods that are sticky, including chewing gum, should be avoided because they may pull off the brackets or weaken the cement. Carbonated beverages may also weaken the cement, as well as contribute to tooth decay. Teeth should be brushed immediately after eating sweet foods. Special floss threaders are available to make flossing easier.
If overcrowding is creating malocclusion, one or more teeth may be extracted (surgically removed), giving the others room to move. If a tooth has not yet erupted or is prematurely lost, the orthodontist may insert an appliance called a space maintainer to keep the other teeth from moving out of their natural position. In severe cases of malocclusion, surgery may be necessary and the patient would be referred to yet another specialist, an oral or maxillofacial surgeon.
Once the teeth have been moved into their new position, the braces are removed and a retainer is worn until the teeth stabilize in that position. Retainers do not move teeth, they only hold them in place.
Orthodontic treatment is the only effective treatment for malocclusion not requiring surgery. However, depending on the cause and severity of the condition, an orthodontist may be able to suggest other appliances as alternatives to braces.

Alternative treatment

There are some techniques of craniosacral therapy that can alter structure. This therapy may allow correction of some cases of malocclusion. If surgery is required, pre- and post-surgical care with homeopathic remedies, as well as vitamin and mineral supplements, can enhance recovery. Night guards are sometimes recommended to ease the strain on the jaw and to limit teeth grinding.


Depending on the cause and severity of the mal-occlusion and the appliance used in treatment, a patient may expect correction of the condition to take 2 or more years. Patients typically wear braces 18-24 months and a retainer for another year. Treatment is faster and more successful in children and teens whose teeth and bones are still developing. The length of treatment time is also affected by how well the patient follows orthodontic instructions.


In general, malocclusion is not preventable. It may be minimized by controlling habits such as finger or thumb sucking. An initial consultation with an orthodontist before a child is 7 years old may lead to appropriate management of the growth and development of the child's dental and facial structures, circumventing many of the factors contributing to malocclusion.



American Association of Oral and Maxillofacial Surgeons. 9700 West Bryn Mawr Ave., Rosemont, IL 60018-5701. (847) 678-6200.
American Association of Orthodontists. 401 North Lindbergh Boulevard, St. Louis, MO 63141-7816. (314) 993-1700.

Key terms

Braces — An orthodontic appliance consisting or brackets cemented to the surface of each tooth and wires of stainless steel or nickel titanium alloy. Braces are used to treat malocclusion by changing the position of the teeth.
Impression — An imprint of the upper or lower teeth made in a pliable material that sets. When this material has hardened, it may be filled with plaster, plastic, or artificial stone to make an exact model of the teeth.
Occlusion — The way the upper and lower teeth fit together in biting or chewing.
Retainer — An orthodontic appliance that is worn to stabilize teeth in a new position.
Space maintainer — An orthodontic appliance that is worn to prevent adjacent teeth from moving into the space left by an unerupted or prematurely lost tooth.


malposition of the teeth resulting in the faulty meeting of the teeth or jaws. The condition should be corrected because it predisposes to dental caries, may lead to digestive disorders and inadequate nutrition because of difficulty in chewing, and can cause serious psychologic effects if there is facial distortion. Corrective treatment is provided by an orthodontist, who may apply appropriate dental appliances to improve the position of the teeth.


1. Any deviation from a physiologically acceptable contact of opposing dentitions.
2. Any deviation from a normal occlusion.


/mal·oc·clu·sion/ (-ah-kloo´zhun) improper relations of apposing teeth when the jaws are in contact.
Enlarge picture
(A), Normal occlusion; (B), Class I malocclusion; (C), Class II malocclusion; (D), Class III malocclusion. Note the position of the mesial cusp of the maxillary molar relative to the mandibular molar in each type of occlusion.


1. Faulty contact between the upper and lower teeth when the jaw is closed.
2. An instance of such faulty contact.


Etymology: L, malus + occludere, to shut up
abnormal contact between the teeth of the upper jaw and those of the lower jaw. See also Angle's Classification of Malocclusion (modified), occlusion.


1. Any deviation from a physiologically acceptable contact of opposing dentitions.
2. Any deviation from an ideal occlusion.


A poor physical relationship between the biting or grinding surfaces of the teeth of the upper jaw and those of the lower. Malocclusion is readily correctable by ORTHODONTIC TREATMENT.


1. Any deviation from a physiologically acceptable contact of opposing dentitions.
2. Any deviation from a normal occlusion.


malposition of the teeth resulting in the faulty meeting of the teeth or jaws. Malocclusion of the incisors is a common defect in all species and is treated as an inherited defect in many of them. See also bite (3), parrot mouth.
References in periodicals archive ?
In this study the authors found no relationship between malocclusion and otitis media with effusion, and no association was found with other confounding variables such as oral habits and natural and artificial feeding.
Cephalometric records of 40 Class II, division 1 caucasian subjects with Class II malocclusion before pubertal peak of mandibular growth were evaluated.
No malocclusion and dental defects were found in children from small towns and big cities.
The importance of the level of the lip line and resting lip pressure in Class II, Division 2 malocclusion.
Table 3 shows the percentage scores of individual malocclusion traits according to the DHC of the IOTN.
11) The prevalence of malocclusion in patients with cerebral palsy ranges from 59 percent to 92 percent, with Class II being the most common angle classification.
Malocclusion has been a major concern for most countries1 since the rising problem seems to be affecting more and more individuals, leading them to seek orthodontic correction.
Although there is evidence that malocclusion is associated with poorer socioeconomic status (4-6), with the presence of dental problems such as caries (7), tooth loss (6,8) and periodontal disease (9), results have been diverse and the association between these aspects and malocclusion is unclear.
Latino adolescents' self-perceived malocclusion is more correlated with quality of life than are examiner assessments.
Methods: A cross-sectional study was conducted with the participation of 240 observers who evaluated images of individuals before and after orthognathic surgery for the correction of malocclusion.