Definition and History of Orthodontics

Transcription

1

2 In the name of GOD

3 Definition and History of Orthodontics Presented by: Dr Somayeh Heidari Orthodontist

4 Reference: Contemporary Orthodontics Chapter 1 William R. Proffit, Henry W. Fields, David M.Sarver. Fifth Edition Mosby

5 Orthodontics and Dentofacial Orthopedics

6 Early Orthodontic Treatment

7 primitive orthodontic appliances go back at least to 1000 BC. in the 18 and 19 centuries a number of devices for the regulation of the teeth were described. after 1850 the first texts that systematically described orthodontic appeared.

8 Norman kingsley the author of Oral Deformities text book. among the first to use extraoral force to correct protruding teeth. a pioneer in the treatment of cleft palate. emphasis the alignment of the teeth and correction of facial proportions. little attention was paid to bite relationships. extractions for crowding or malalignment were frequent

9 Edward Angle development of a concept of occlusion in the natural dentition. the first dental specialist and the father of modern orthodontics. development of Angle s classification of malocclusion in the 1890 : the first clear and simple definition of occlusion the upper first molars were the key of occlusion

10 Normal Occlusion except there are aberrations in the size of teeth

11 Line of occlusion

12 Normal Occlusion

13 Angle s classification Normal occlusion Class I malocclusion Class I malocclusion Class I malocclusion

14 Class I malocclusion

15 Class II malocclusion

16 Class III malocclusion

17

18 by the early 1900s: the treatment of malocclusion instead alignment of irregular teeth maintaining an intact dentition became an important goal of orthodontics opposing tooth extraction less attention paid to facial proportions and esthetics abandon extraoral force the best esthetics always were achieved when the patient had ideal occlusion

19 an excellent occlusion was unsatisfactory if it was achieved at the expense of proper facial proportion it was impossible to maintain an occlusal relationship achieved by prolonged use of heavy elastics

20 in the extraction of teeth was reintroduced into orthodontics to Enhance facial esthetics and achieve better stability of the occlusion relationships

21 Cephalometric radiography measure the changes in tooth and jaw position produced by growth and treatment many malocclusions resulted from faulty jaw relationships jaw growth can altered by orthodontic treatment

22 Europe functional jaw orthopedics

23 United states extraoral force

24 Modern Treatment Goals: The Soft Tissue Paradigm

25 Paradigm shift from skeletal and dental relationships toward oral and facial soft tissue

26 Soft tissues Both the goals and limitations of modern orthodontic and orthognathic treatment are determined by the soft tissue of the face, not by the teeth and bones.

27 Parameter Primary treatment goal Ideal dental occlusion Angle paradigm Soft tissue paradigm Normal soft tissue proportions and adaptations Secondary goal Hard/soft tissue relations Ideal jaw relationships Ideal hard tissue proportions produce ideal soft tissues Functional occlusion Ideal soft tissue proportions define ideal hard tissues Diagnostic emphasis Dental casts, cephalometric radiographs Clinical examination of intra oral and facial soft tissues Treatment approach Functional emphasis Obtain ideal dental and skeletal relations, assume the soft tissue will be OK TMJ in relation to dental occlusion Plan ideal soft tissue relationships and then place teeth and jaws as needed to achieve this Soft tissue movement in relation to display of teeth Stability of results Related primarily to dental occlusion Related primarily to soft tissue pressure/equilibrium effects

28

29

30

31 Who Needs Treatment?

32 Protruding, irregular or maloccluded teeth can cause three types of problems for the patient: 1- psychosocial problems because of facial appearance 2- problems with oral function 3- greater susceptibility to trauma, periodontal disease or caries

33 Psychosocial Problems Psychic distress caused by dental or facial conditions is not directly proportional to the anatomic severity of the problem. The impact of a physical defect on an individual also will be strongly influenced by that person s self-esteem.

34 in a low-income population, early partial treatment to improve rather than totally correct obvious malocclusion does produce psychosocial benefits. the major reason people seek orthodontic treatment is to minimize psychosocial problems related to their dental and facial appearance.

35 Functional Problem chewing swallowing speech temporomandibular Dysfunction (TMD)

36 chewing adults with sever malocclusions routinely report difficulty in chewing, and after treatment, patients usually say that their masticatory problems are largely corrected.

37 swallowing sever malocclusion may make adaptive alterations in swallowing necessary. less sever malocclusions tend to affect function, not by making it impossible but by making it difficult, so that extra effort is required to compensate for the anatomic deformity.

38 speech distorted speech is rarely noted even though an individual may have to make an extraordinary effort to produce normal speech

39 TMD pain in and around TMJ may result from pathologic changes within the joint, but more often is caused by muscle fatigue and spasm. muscle pain almost always correlated with a history of clenching or grinding the teeth as a response to stressful situations or of constantly posturing the mandible to an anterior or lateral position.

40 some types of malocclusion (especially posterior crossbite with a shift on closure) correlated positively with TMJ problems while other types do not, but even the strongest correlation coefficients are only 0.3 to 0.4. orthodontics as the primary treatment of TMD, almost never is indicated.

41 Injury and dental disease increased overjet increased overbite dental caries periodontal problems

42 protruding maxillary incisors can increase the likelihood of an injury to the teeth: about one chance in three most of the time the result is only minor chips in the enamel so, reducing the chance of injury when incisors protrude is not a strong argument for early treatment.

43 extreme overbite, so that the lower incisors contact to the palate, can cause significant tissue damage, leading to loss of the upper incisors in a few patients. extreme wear of incisors also occurs in some patients with excessive overbite.

44 current data indicate that malocclusion has little if any impact on the teeth or supporting structures. presence or absence of dental plaque is the major determinant of the health of both the hard and soft tissues of the mouth. occlusal trauma is a secondary, not a primary, etiologic factor in the development of periodontal disease.

45 Could orthodontic treatment itself be an etiologic agent for oral disease?

46 In summery, it appears that both psychosocial and functional handicaps can produces significant need for orthodontic treatment. The evidence is less clear that orthodontic treatment reduces the development of later dental disease.

47