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Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). Ideally, all upper teeth fit slightly over the lower teeth. The points of the molars fit the grooves of the opposite molar. The upper teeth keep the cheeks and lips from being bitten and the lower teeth protect the tongue.
Malocclusion means the teeth are not aligned properly. Malocclusion is most often hereditary, which means the condition is passed down through families. There may be a difference between the size of the upper and lower jaws or between jaw and tooth size, resulting in overcrowding of teeth or in abnormal bite patterns.
Variations in size or structure of either jaw may affect its shape, as can birth defects such as cleft lip and palate. Other causes of malocclusion include:
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 of malocclusion include:
Most problems with teeth alignment are discovered by a dentist during a routine exam. The 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, the dentist will usually refer you to an orthodontist for diagnosis and treatment. Dental x-rays, head or skull x-rays, or facial x-rays may be required. Plaster or plastic molds of the teeth are often needed.
Ex. 21.Complete the sentences with proper words given in italics:
1.Malocclusions may be symptomless or they may produce … from increased … on the oral structures. 2.Teeth may show abnormal signs of wear on the … surfaces or decay in areas of tight overlap. 3. Chewing may be difficult. Malocclusion is most often found during a routine dental …. 4. A dentist will … a patient's occlusion by watching how the teeth make contact when the patient bites down normally. 5. The dentist may ask the patient to … down with a piece of coated paper between the upper and lower teeth; this paper will leave colored … at the points of contact. 6. When malocclusion is suspected, photographs and x-rays of the face and … may be taken for further study.
Check, eat, chewing, bite, stress, mouth, examination, pain, marks, cheek, painless, symptom.
Ex. 22. Read the following text, divide it into logical parts and entitle them:
Very few people have perfect teeth alignment. However, most problems are so minor that they do not require treatment. Malocclusion is the most common reason for referral to an orthodontist. By treating moderate or severe malocclusion, the teeth are easier to clean and there is less risk of tooth decay and periodontal diseases (gingivitis or periodontitis). Treatment eliminates strain on the teeth, jaws, and muscles, which lessens the risk of breaking a tooth and may reduce symptoms of temporomandibular joint disorders. The goal is to correct the positioning of the teeth. Braces or other appliances may be used. 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. One or more teeth may need to be removed if overcrowding is part of the problem. Rough or irregular teeth may be adjusted down, reshaped, and bonded or capped. Misshapen restorations and dental appliances should be repaired. Surgery may be required on rare occasions. This may include surgical reshaping to lengthen or shorten the jaw (orthognathic surgery). Wires, plates, or screws may be used to stabilize the jaw bone. Clear braces (aligners) without wires may be used in some patients.
It is important to brush and floss your teeth every day and have regular visits to a general dentist. Plaque accumulates on braces and may permanently mark teeth or cause tooth decay if not properly cared for. You may need a retainer to stabilize your teeth after having braces.
Problems with teeth alignment are easier, quicker, and less expensive to treat when they are corrected early. Treatment is most successful in children and adolescents because their bone is still soft and teeth are moved more easily. Treatment may last 6 months to 2 or more years, depending on the severity of the case.
Treatment of orthodontic disorders in adults is often successful but may require longer use of braces or other devices. Possible Complications include tooth decay, discomfort during treatment, Irritation of mouth and gums (gingivitis) caused by appliances, chewing or speaking difficulty during treatment. Call your orthodontist if toothache, mouth pain, or other new symptoms develop during orthodontic treatment.
Many types of malocclusion are not preventable. Control of habits such as thumb sucking may be necessary in some cases. However, early detection and treatment may optimize the time and method of treatment needed.
Ex. 23. Translate into English:
1. Вади розвитку зубів різноманітні. 2.Серед них розрізняють вади кількості зубів (адентія, позакомплектні зуби), вади розміру зубів (мікродентія, макродентія), вади форми зубів та вади тканин зубів (гіпоплазія). 3.Вади розвитку зубів, порушуючи естетичність прикусу, ведуть до цілого ряду анатомічних та функціональних змін зубо-щелепної системи. 4. Серед вад розвитку адентія займає одне з перших місць. 5. Найчастіше зустрічається адентія других премолярів, бокових різців, третіх постійних молярів. 6. Одна з причин – спадковість. 7. Лікування адентії залежить від кількості відсутніх зубів і від виду аномалій прикусу, яка виникла на тлі даної патології. 8. Лікування дітей з повною адентією тимчасових і постійних зубів складається з виготовлення повних знімних протезів.
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