Malocclusion of teeth
Crowded teeth; Misaligned teeth; Crossbite; Overbite; Underbite; Open bite
Malocclusion means the teeth are not aligned properly.
Causes
Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). The upper teeth should fit slightly over the lower teeth. The points of the molars should fit the grooves of the opposite molar.
The upper teeth keep you from biting your cheeks and lips, and your lower teeth protect your tongue.
Malocclusion is most often hereditary. This means it is passed down through families. It may be caused by a difference between the size of the upper and lower jaws or between the jaw and tooth size. It causes tooth overcrowding or abnormal bite patterns. The shape of the jaws or birth defects such as cleft lip and palate may also be reasons for malocclusion.
Cleft lip and palate
Cleft lip and palate are birth defects that affect the upper lip and the roof of the mouth.
Other causes include:
- Childhood habits such as thumb sucking, tongue thrusting, pacifier use beyond age 3, and prolonged use of a bottle
- Extra teeth, lost teeth, impacted teeth, or abnormally shaped teeth
- Ill-fitting dental fillings, crowns, dental appliances, retainers, or braces
- Misalignment of jaw fractures after a severe injury
- Tumors of the mouth and jaw
There are different categories of malocclusion:
- Class 1 malocclusion is the most common. The bite is normal, but the upper teeth slightly overlap the lower teeth.
- Class 2 malocclusion, called retrognathism or overbite, occurs when the upper jaw and teeth severely overlap the bottom jaw and teeth.
- Class 3 malocclusion, called prognathism or underbite, occurs when the lower jaw protrudes or juts forward, causing the lower jaw and teeth to overlap the upper jaw and teeth.
Symptoms
Symptoms of malocclusion are:
- Abnormal alignment of teeth
- Abnormal appearance of the face
- Difficulty or discomfort when biting or chewing
- Speech difficulties (rare), including lisp
- Mouth breathing (breathing through the mouth without closing the lips)
Exams and Tests
Most problems with teeth alignment are discovered by a dentist during a routine exam. Your dentist may pull your cheek outward and ask you to bite down to check how well your back teeth come together. If there is any problem, your dentist may refer you to an orthodontist for diagnosis and treatment.
You may need to have dental x-rays , head or skull x-rays , or facial x-rays. Diagnostic models of the teeth are often needed to diagnose the problem.
Dental x-rays
Dental x-rays are a type of image of the teeth and mouth. X-rays are a form of high energy electromagnetic radiation. The x-rays penetrate the body...
Head or skull x-rays
A skull x-ray is a picture of the bones surrounding the brain, including the facial bones, the nose, and the sinuses.
Treatment
Very few people have perfect teeth alignment. However, most problems are minor and do not require treatment.
Malocclusion is the most common reason for referral to an orthodontist.
The goal of treatment is to correct the positioning of the teeth. Correcting moderate or severe malocclusion can:
-
Make teeth easier to clean and decrease risk of
tooth decay
and periodontal diseases (
gingivitis
or
periodontitis
).
Tooth decay
Dental cavities are holes (or structural damage) in the teeth.
Periodontitis
Periodontitis is inflammation and infection of the ligaments and bones that support the teeth.
-
Eliminate strain on the teeth, jaws, and muscles. This lessens the risk of breaking a tooth and may reduce symptoms of
temporomandibular joint disorders (TMJ)
.
Temporomandibular joint disorders (TMJ)
Temporomandibular joint and muscle disorders (TMJ disorders) are problems that affect the chewing muscles and joints that connect your lower jaw to y...
Treatments may include:
- Braces or other appliances: Metal bands are placed around some teeth, or metal, ceramic, or plastic bonds are attached to the surface of the teeth. Wires or springs apply force to the teeth. Clear braces (aligners) without wires may be used in some people.
- Removal of one or more teeth: This may be needed if overcrowding is part of the problem.
- Repair of rough or irregular teeth: Teeth may be adjusted down, reshaped, and bonded or capped. Misshapen restorations and dental appliances should be repaired.
- Surgery: Surgical reshaping to lengthen or shorten the jaw is needed in rare cases. Wires, plates, or screws may be used to stabilize the jaw bone.
It is important to brush and floss your teeth every day and have regular visits to a general dentist. Plaque builds up on braces and may permanently mark teeth or cause tooth decay if it is not properly removed.
Brush and floss your teeth
Tooth decay and gum disease are caused by plaque, a sticky combination of bacteria and food. Plaque begins to build up on teeth within 20 minutes af...
You will need a retainer to stabilize your teeth after having braces.
Outlook (Prognosis)
Problems with teeth alignment are easier, quicker, and less expensive to treat when they are corrected early. Treatment works best in children and adolescents because their bones are still soft and teeth are moved more easily. Treatment may last 6 months to 2 or more years. The time will depend on how much correction is needed.
Treatment of orthodontic disorders in adults is often successful, but may require longer use of braces or other devices.
Possible Complications
Complications of malocclusion include:
- Tooth decay
- Discomfort during treatment
- Irritation of mouth and gums (gingivitis) caused by appliances
- Chewing or speaking difficulty during treatment
When to Contact a Medical Professional
Call your dentist if toothache, mouth pain, or other new symptoms develop during orthodontic treatment.
Prevention
Many types of malocclusion are not preventable. It may be necessary to control habits such as thumb sucking. Finding and treating the problem early allows for quicker results and more success.
References
Dean JA. Managing the developing occlusion. In: Dean JA, ed. McDonald and Avery's Dentistry for the Child and Adolescent . 10th ed. St. Louis, MO: Elsevier; 2016:chap 22.
Tinanoff N. Malocclusion. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 309.
-
Prognathism - illustration
Prognathism is a descriptive term for a jaw (lower or upper) that protrudes forward beyond the plane of the face.
Prognathism
illustration
-
Teeth, adult - in the skull - illustration
This is a picture of normal teeth with an overjet. Some bone has been cut away to reveal the roots of the teeth.
Teeth, adult - in the skull
illustration
-
Malocclusion of teeth - illustration
Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). Malocclusion is the most common reason for referral to an orthodontist. Most malocclusion is mild enough not to require treatment. If a severe misalignment is present, orthodontics and/or oral surgery may be required.
Malocclusion of teeth
illustration
-
Dental anatomy - illustration
The appearance of normal teeth varies, especially the molars. Abnormally shaped teeth can result from many different conditions. Specific diseases can have a profound effect on tooth shape, tooth color, time of appearance, or absence of teeth.
Dental anatomy
illustration
-
Prognathism - illustration
Prognathism is a descriptive term for a jaw (lower or upper) that protrudes forward beyond the plane of the face.
Prognathism
illustration
-
Teeth, adult - in the skull - illustration
This is a picture of normal teeth with an overjet. Some bone has been cut away to reveal the roots of the teeth.
Teeth, adult - in the skull
illustration
-
Malocclusion of teeth - illustration
Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). Malocclusion is the most common reason for referral to an orthodontist. Most malocclusion is mild enough not to require treatment. If a severe misalignment is present, orthodontics and/or oral surgery may be required.
Malocclusion of teeth
illustration
-
Dental anatomy - illustration
The appearance of normal teeth varies, especially the molars. Abnormally shaped teeth can result from many different conditions. Specific diseases can have a profound effect on tooth shape, tooth color, time of appearance, or absence of teeth.
Dental anatomy
illustration
Review Date: 2/22/2016
Reviewed By: Michael Kapner, DDS, general and aesthetic dentistry, Norwalk Medical Center, Norwalk, CT. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.