In the name of GOD

Definition and History of Orthodontics

Presented by:

Dr Somayeh Heidari

Orthodontist

Reference:

Contemporary Orthodontics

Chapter 1

William R. Proffit, Henry W. Fields, David M.Sarver. Fifth Edition 2012. Mosby

Orthodontics

and

Dentofacial Orthopedics

• 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 orthodontics

appeared.

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. • extraction was frequent.

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

Normal Occlusion

except there are aberrations in the size of teeth

Line of occlusion

Normal Occlusion

Angle’s classification

• Normal occlusion

• Class I malocclusion

• Class I malocclusion

• Class I malocclusion

Class I malocclusion

Class II malocclusion

Class III malocclusion

by the early 1900 • the treatment of malocclusion instead alignment of irregular teeth • the intact dentition became an important goal of orthodontics • opposing tooth extraction • less attention paid to facial proportions and esthetics • abandon extraoral force

in the 1930 • extraction of teeth was reintroduced into orthodontics to

Enhance facial esthetics and achieve better stability of the occlusion relationships

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

Europe functional jaw orthopedics

United states extraoral force

in the early 21th century

• more emphasis on dental and facial appearance

• greater degree of patient involvement in planning treatment

• much more older orthodontic patients

Paradigm shift

from skeletal and dental relationships

toward

oral and facial soft tissue

Soft tissues The major limitation on orthodontic treatment The major consideration in judgment of treatment success

Soft tissue paradigm Angle paradigm Parameter

Normal soft tissue proportions and adaptations

Ideal dental occlusion

Primary treatment goal

Functional occlusion Ideal jaw relationships Secondary goal

Ideal soft tissue proportions define ideal hard tissues

Ideal hard tissue proportions produce ideal soft tissues

Hard/soft tissue relations

Clinical examination of intra oral and facial soft tissues

Dental casts, cephalometric radiographs

Diagnostic emphasis

Plan ideal soft tissue relationships and then place teeth and jaws as needed to achieve this

Obtain ideal dental and skeletal relations, assume the soft tissue will be OK

Treatment approach

Soft tissue movement in relation to display of teeth

TMJ in relation to dental occlusion Functional emphasis

Related primarily to soft tissue pressure/equilibrium effects

Related primarily to dental occlusion Stability of results

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

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.

Functional Problem

• chewing

• swallowing

• speech

• temporomandibular Dysfunction (TMD)

chewing

• adults with sever malocclusions routinely report difficulty in

chewing, and after treatment, patients usually say that their

masticatory problems are largely corrected.

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.

speech

• in patients with sever malocclusion it can be difficult or

impossible to produce certain sounds.

• effective speech therapy may require some preliminary

orthodontic treatment.

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.

• 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.

C.R

C.O

Injury and dental disease

• increased overjet

• increased overbite

• dental caries

• periodontal problems

• 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

resulting in a fracture of the tooth and/or devitalization of the

pulp.

• so, reducing the chance of injury when incisors protrude is not

a strong argument for early treatment.

• 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.

• 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.