Malocclusion

Definition

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.

Description

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.

Diagnosis

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.

Treatment

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.

Prognosis

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.

Prevention

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.

Resources

ORGANIZATIONS

American Association of Oral and Maxillofacial Surgeons. 9700 West Bryn Mawr Ave., Rosemont, IL 60018-5701. (847) 678-6200. 〈http://www.aaoms.org〉.

American Association of Orthodontists. 401 North Lindbergh Boulevard, St. Louis, MO 63141-7816. (314) 993-1700. 〈http://www.aaortho.org〉.

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.

Malocclusion

Definition

Malocclusion is the misalignment of the upper and lower teeth when biting or chewing.

Description

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 child's appearance, speech, and/or ability to eat.

Demographics

Most children have some degree of malocclusion. Malocclusion usually does not require treatment except for cosmetic reasons. It is more likely to occur if the parents have malocclusion, the child sucks his or her thumb or a pacifier, or if a tooth is lost prematurely.

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 possibly from medical conditions such as enlarged tonsils and adenoids that lead to mouth breathing.

Malocclusions may cause no symptoms, or they may produce pain from the increased stress on oral structures. Teeth may show abnormal signs of wear on the chewing surfaces or decay in areas of tight overlap. Chewing may be difficult.

When to call the doctor

A dentist or orthodontist should be consulted if a child's teeth seem to be particularly misaligned or if a child complains of dental or jaw pain.

Diagnosis

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 child bites down normally. The dentist may ask the child 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 or plastic models of the patient's teeth from impressions. These models duplicate the fit of the teeth and are very useful in planning treatment.

Treatment

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 malocclusion. At any given time, approximately four million people in the United States are wearing braces, most of whom are children and teenagers.

Braces apply constant gentle force to slowly change the position of the teeth, straightening 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 gradually move.

Braces are not removable for daily tooth brushing. To prevent tooth decay , the child must be especially diligent about keeping the mouth clean and removing food particles that become easily trapped. Crunchy foods should be avoided to minimize the risk of breaking the appliance. Hard fruits, vegetables, 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. 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 is referred to 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. Often a retainer is initially worn all the time; its use is gradually tapered until it is only worn at night, and eventually not at all.

KEY TERMS

Braces —An orthodontic appliance consisting of 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 —In dentistry, 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 upper and lower teeth fit together during biting and chewing. Also refers to the blockage of some area or channel of the body.

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.

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. If the malocclusion is thought to be caused by the child sucking on fingers or a pacifier and the child is stopped early enough, the malocclusion may resolve spontaneously without treatment.

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.

Prognosis

Depending on the cause and severity of the malocclusion and the appliance used in treatment, a patient may expect correction of the condition to take two 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 time needed for treatment is also affected by how well the patient follows orthodontic instructions.

Prevention

In general, malocclusion is not preventable. It may be minimized by controlling habits such as thumb sucking. An initial consultation with an orthodontist before a child is seven years of age 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.

Parental concerns

Most of the time, malocclusion is treated for cosmetic reasons. Children, however, may not want treatment because they will have to wear braces. It is usually possible to schedule the beginning of treatment for a time that is convenient for the child and the parent. Talking with children or teenagers and obtaining their input about treatment may be beneficial in increasing compliance. Full compliance with the orthodontist's instructions helps to ensure that the treatment is successful.

Resources

BOOKS

Bishara, Samir E., ed. Textbook of Orthodontics. Philadelphia: Saunders, 2001.

Subtelny, Daniel J.Early Orthodontic Treatment. Chicago: Quintessence Publishing Company, 2000.

PERIODICALS

"Duration of Pacifier Use, Thumb Sucking May Affect Dental Arches." Journal of the American Dental Association 133, no. 2 (December 2002): 1610–12.

Kluemper, G. Thomas, et al. "Early Orthodontic Treatment: What are the Imperatives?" Journal of the American Dental Association 131, no. 5 (May 2000): 613–21.

ORGANIZATIONS

American Association of Orthodontists. 401 North Lindberg Boulevard, St. Louis, MO 63141-7816. (800) STRAIGHT Fax: (3314)-997-1745. Web site: </www.braces.org>.

American Dental Association. 211 East Chicago Avenue, Chicago IL, 60611-2678. (312) 440-2500. Web site: <http://www.ada.org>.

Tish Davidson, A.M. Bethany Thivierge

Malocclusion

Definition

Malocclusion is an abnormality 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, cross-bite, or overbite.

Description

Malocclusion may be seen as crooked, crowded, or protruding teeth, or disproportionately smaller or larger jaws. Malocclusion can affect a person's appearance, speech, and ability to eat. Usually by age seven, enough of the permanent teeth have come in for dentists to identify current malocclusion and anticipate future problems if teeth and bone are left untreated. Adults and children can be successfully treated for most problems related to malocclusion.

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, 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 not have symptoms, 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. Left untreated, crooked or crowded teeth can become worse, sometimes requiring costly treatment to correct serious problems that develop over time. Orthodontic problems can contribute to conditions that cause tooth decay and gum disease. They can also help cause abnormal wear of tooth surfaces, inefficient chewing function, excessive stress on gum tissue and supporting bone, as well as jaw misalignment, resulting in headaches and face or neck pain.

Diagnosis

Malocclusion is most often found during a dental examination or screening. A dentist or dental hygienist checks a patient's occlusion by watching how the teeth make contact when the patient bites down normally. The dentist asks the patient to bite down on a piece of coated paper placed 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 a plaster study model of the patient's teeth from impressions. These models duplicate the fit of the teeth and are very useful in treatment planning.

KEY TERMS

Braces —An orthodontic appliance consisting of brackets cemented to the surface of each tooth and wires of stainless steel or nickel titanium alloy. Braces treat malocclusion by gradually 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 worn to stabilize teeth in a new position.

Space maintainer —An orthodontic appliance worn to prevent adjacent teeth from moving into the space left by an unerupted or prematurely lost tooth.

Treatment

Malocclusion may be remedied by orthodontic treatment. Orthodontics is a specialty of dentistry that manages the growth, prevention, and correction of abnormal dental and facial relationships. Braces are the most commonly used orthodontic appliances in the treatment of malocclusion.

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 removable or fixed (cemented or bonded to the teeth) brackets, made of metal, ceramic, or plastic.

In most cases, braces are not removable for daily tooth brushing, so the patient must be especially diligent about keeping the mouth clean and removing bacterial plaque that is easily trapped, in order to prevent tooth decay. Foods that are crunchy should be avoided to minimize the risk of breaking the appliance. Hard fruits, vegetables, 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 other teeth 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. Experts recommend early treatment, which can help to guide the growth of the jaw, regulate the widths of the dental arches, correct thumb, finger, and other sucking habits, enhance swallowing and speech, and improve personal appearance and self-esteem. Adults are candidates for orthodontics to correct malocclusion, as well. Healthy teeth can be moved to more desirable positions at any age.

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 natural remedies, as well as vitamin and mineral supplements, may enhance recovery. Night guards and stress management are sometimes recommended to ease the strain on the jaw and to limit teeth grinding.

Prognosis

Depending on the cause and severity of the malocclusion and the appliance used in treatment, a patient should expect correction of the condition to take one to three years. Interceptive, or early treatment procedures, might take months or more. The time required to correct malocclusion depends on the growth of the patient's mouth and face, patient cooperation, and the extent of the problem.

Health care team roles

The general dentist or dental hygienist, during preventive oral care, is often the first health professional to see evidence of a malocclusion. The general dentist usually determines a patient's need to have the problem looked at by a specialist, such as an orthodontist. Dental assistants are ancillary personnel used in dentists' or orthodontists' offices to assist in the procedures.

Prevention

Malocclusion is preventable at times. It can be prevented by space maintenance and may be minimized by controlling habits such as finger or thumb sucking. Initial consultation with an orthodontist before a child is seven 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.

Resources

ORGANIZATIONS

Academy of General Dentistry. 211 East Chicago Ave., Chicago, IL 600611. (312) 440-4800. <http://www.agd.org>.

American Association of Oral and Maxillofacial Surgeons. 9700 West Bryn Mawr Avenue, Rosemont, IL 60018-5701. (847) 678-6200. <http://www.aaoms.org>.

American Association of Orthodontists. 401 N. Lindbergh Blvd. St. Louis, MO 63141-7816. (314) 993-1700. <http://www.aaortho.org>.

OTHER

OrthoFind. (310) 328-2020. <http://www.orthofind.com>.

Interview with Dr. Leslie Seldin, practicing general dentist and spokesperson for the American Dental Association. Office address: 40 Central Park. New York, NY 10019-1413. (212) 246-2398.

Lisette Hilton

Malocclusion

Definition

Malocclusion is an abnormality 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.

Description

Malocclusion may be seen as crooked, crowded, or protruding teeth, or disproportionately smaller or larger jaws. Malocclusion can affect a person's appearance, speech, and ability to eat. Usually by age seven, enough of the permanent teeth have come in for dentists to identify current malocclusion and anticipate future problems if teeth and bone are left untreated. Adults and children can be successfully treated for most problems related to malocclusion.

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, 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 not have symptoms, 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. Left untreated, crooked or crowded teeth can become worse, sometimes requiring costly treatment to correct serious problems that develop over time. Orthodontic problems can contribute to conditions that cause tooth decay and gum disease. They can also help cause abnormal wear of tooth surfaces, inefficient chewing function, excessive stress on gum tissue and supporting bone, as well as jaw misalignment, resulting in headaches and face or neck pain.

Diagnosis

Malocclusion is most often found during a dental examination or screening. A dentist or dental hygienist checks a patient's occlusion by watching how the teeth make contact when the patient bites down normally. The dentist asks the patient to bite down on a piece of coated paper placed 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 a plaster study model of the patient's teeth from impressions. These models duplicate the fit of the teeth and are very useful in treatment planning.

Treatment

Malocclusion may be remedied by orthodontic treatment. Orthodontics is a specialty of dentistry that manages the growth, prevention, and correction of abnormal dental and facial relationships. Braces are the most commonly used orthodontic appliances in the treatment of malocclusion.

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 removable or fixed (cemented or bonded to the teeth) brackets, made of metal, ceramic, or plastic.

In most cases, braces are not removable for daily tooth brushing, so the patient must be especially diligent about keeping the mouth clean and removing bacterial plaque that is easily trapped, in order to prevent tooth decay. Foods that are crunchy should be avoided to minimize the risk of breaking the appliance. Hard fruits, vegetables, 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 other teeth 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. Experts recommend early treatment, which can help to guide the growth of the jaw, regulate the widths of the dental arches, correct thumb, finger, and other sucking habits, enhance swallowing and speech, and improve personal appearance and self-esteem. Adults are candidates for orthodontics to correct malocclusion, as well. Healthy teeth can be moved to more desirable positions at any age.

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 natural remedies, as well as vitamin and mineral supplements, may enhance recovery. Night guards and stress management are sometimes recommended to ease the strain on the jaw and to limit teeth grinding.

Prognosis

Depending on the cause and severity of the malocclusion and the appliance used in treatment, a patient should expect correction of the condition to take one to three years. Interceptive, or early treatment procedures, might take months or more. The time required to correct malocclusion depends on the growth of the patient's mouth and face, patient cooperation, and the extent of the problem.

Health care team roles

The general dentist or dental hygienist, during preventive oral care, is often the first health professional to see evidence of a malocclusion. The general dentist usually determines a patient's need to have the problem looked at by a specialist, such as an orthodontist. Dental assistants are ancillary personnel used in dentists' or orthodontists' offices to assist in the procedures.

Prevention

Malocclusion is preventable at times. It can be prevented by space maintenance and may be minimized by controlling habits such as finger or thumb sucking. Initial consultation with an orthodontist before a child is seven 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.

KEY TERMS

Braces— An orthodontic appliance consisting of brackets cemented to the surface of each tooth and wires of stainless steel or nickel titanium alloy. Braces treat malocclusion by gradually 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 worn to stabilize teeth in a new position.

Space maintainer— An orthodontic appliance worn to prevent adjacent teeth from moving into the space left by an unerupted or prematurely lost tooth.

Resources

ORGANIZATIONS

Academy of General Dentistry. 211 East Chicago Ave., Chicago, IL 600611. (312) 440-4800. 〈http://www.agd.org〉.

American Association of Oral and Maxillofacial Surgeons. 9700 West Bryn Mawr Avenue, Rosemont, IL 60018-5701. (847) 678-6200. 〈http://www.aaoms.org〉.

American Association of Orthodontists. 401 N. Lindbergh Blvd. St. Louis, MO 63141-7816. (314) 993-1700. 〈http://www.aaortho.org〉.

OTHER

Interview with Dr. Leslie Seldin, practicing general dentist and spokesperson for the American Dental Association. Office address: 40 Central Park. New York, NY 10019-1413. (212) 246-2398.

OrthoFind. (310) 328-2020. 〈http://www.orthofind.com〉.

mal·oc·clu·sion / ˌmaləˈkloōzhən/ • n. Dentistry imperfect positioning of the teeth when the jaws are closed.