P1-ORTHO-PPT 3

What is the rationale for orthodontic treatment?

the need for treatment depends on the impact of malocclusion and whether treatment is likely to provide a demonstrable benefit to the patient

what are the potential risk for orthodontic treatment

root resorption

loss of periodontal support

demineralization

enamel damage

Intra-oral soft tissue damage

Pulpal injury

extra-oral damage

relapse

explain each potential risk of orthodontic treatment

root resorption

loss of periodontal support

demineralization

enamel damage

Intra-oral soft tissue damage

Pulpal injury

extra-oral damage

relapse

explain each potential risk of orthodontic treatment

root resorption - consequence of tooth movement

loss of periodontal support - apical migration of the periodontal attachment and alveolar bone support

demineralization - predisposes plaque retention

enamel damage - due to trauma and wea to appliances

Intra-oral soft tissue damage - direct trauma inside the mouth, allergies included

Pulpal injury - excessive apical root movement

extra-oral damage - headgears, detrimental effect to the facial profiles of the patient

relapse - return of features of the following malocclusion.

why do we use orthodontic indices?

to measure treatment need

manage demand and support prioritization through some form of rationing

Indices designed to evaluate the need for orthodontic treatment

Index of orthodontic treatment (IOTN)

who developed IOTN?

brook and shaw in the United Kingdom

two components of IOTN and define each

dental component - based on occlusion and appearance

esthetic component - derived from the comparison of the dental appearance and standard photographs

complete the table from IOTN measurement:

1-4:

: Borderline need

:

1-4: no need/slight need

5-7: borderline need

8-10: definite need

who needs orthodontic treatment?

psychosocial problems

oral function

relationship to injury and dental disease

study of causation and origination

etiology

what are the major etiologic factors

disturbances in embryologic development

hereditary influences

environmental influences

what are the different disturbances in embryologic development

1. teratogens

2. fetal alcohol syndrome

3. treacher collins syndrome

4. cleft lip and palate

chemicals and other agents capable of producing embryologic defects if given at the critical time

teratogens

cleft lip and palate causing teratogens

aspirin(acetyl salicylic acid)

cigarette smoking(hypoxia)

dilantin(phenytoin

teratogens that cause treacher collins syndrom

thalidomide

13-CIS retinoic acid (accutane)

valium

deficiencies of midline tissue of the developing brain(neural plate)

fetal alcohol syndrome

what causes fetal alhocol syndrome

exposure to very high maternal ethanol level

what is the other name for treacher collins syndrome

mandibulofacial dysostosis

3 characteristics of fetal alcohol syndrome

short palpebral fissure length

thin upper lip

smooth philtrum

generalized lack of mesenchymal tissue in the lateral part of the face

treacher collins syndrome

describe treacher collins syndrome

- underdevelopment of the lateral orbital and zygomatic areas

- narrow arches of the maxilla and mandible

the mutation of this gene causes treacher collins syndrome

TCOF1 gene

most common congenital defect involving the face and jaws

cleft lip and palate

it is due to the failure of maxillary process to fuse

cleft lip and palate

what are the different growth disturbances in fetal and prenatal period

1. fetal molding and birth injuries

2. birth trauma to the mandible

types of fetal molding and birth injuries

intrauterine molding

birth trauma to the mandible

examples of intrauterinne molding

midface deficiency and pierre robin sequence

what causes intrauterine molding

position of the fetus

and

pressure on fetal face which causes distortion

extreme mandibular deficiency at birth

pierre robin sequence

effects of pierre robin sequence

very small mandible

obstructed airway

cleft palate

common cause of birth trauma to mandible

forceps delivery

what are the different progressive deformities in childhood

1. childhood fractures of the jaw

2. muscle dysfunction

most common childhood fracture of the jaw

unilateral condylar fracture

examples of muscle dysfunction in progressive deformities in childhood

torticollis

muscular dystrophy

twisting of the head with excessive tonic contraction of the neck muscles on one sde

torticollis

muscles involved in torticollis

sternocleidomastoid

(sternum, clavicle, mastoid process)

effects of muscular dystrophy

long face

excessive eruption of posterior teeth

narrowing of maxillary arch and anterior open bite

distortion of facial proportions and mandibular form

disturbances arising in adolescence / early adult life

Hemimandibular hypertrophy

acromegaly

due to the proliferation of the condylar cartilage, sudden excessive unilateral growth of the mandible causes ____________

hemimandibular hyperthrophy

hemimandibular hyperthropy is common in ___________

females 15-20 y/o

treatment for hemimandibular hyperthropy

constructive surgery to remove affected condyle

cause of acromegaly

excessive amounts of growth hormone from the anterior pituitary gland tumor

class III excessive mandibular growth and its treatment

acromegaly and remove tumor

this disturbance happens after the closure of growth plates

acromegaly

happens before the closure of growth plates

gigantism

disturbances of dental development

1. congenitally missing teeth

2. malformed and supernumerary teeth

3. traumatic displacement of teeth

what stage of development causes missing teeth

proliferation

total absence of teeth

anodontia

absence of many but not all teeth

oligodontia

absence of only few teeth

hypodontia

describe the characteristics of a person with ectodermal dysplasia

thin, sparse hair and absence of sweat glands, development of alveolar process, and multiple missing teeth

associated with anodontia and oligodontia

most common abnormality(size)

malformed and supernumerary teeth

most commonly malformed teeth

1st: 3rd molars

2nd: Maxillary lateral incisors

3rd: mx/mn second premolar

most common supernumerary totth

mesiodens

morphodifferenntiation nstage affects what of the tooth?

shape and size or form

initiation andn proliferation stage affects what of the teeth

number

miscarriage is common during

first trimester

mixed dentition starts at what age

6 y/o

example of traumatic displacement of teeth and define

dilaceration - distortion of root form

hereditary influences

hapsburg jaw

mandibular prognathism in the european hapsburg family

hapsburg jaw

describe hapsburg jaw

disproportionate size of the teeth and jaws

improper occlusal and skeletal relationship

different environmental influences

- equilibrium consideration

- masticatory function

- habits

different habits that can influence oral disturbances

- thumb sucking

- tongue thrusting

- mouth breathing

effects of thumbsucking

- negative pressure inside the mouth

- excessive overjet

- supernnumerary posterior teeth

- flared and spaced maxillary incisors

- lingually positioned lower incisors

- anterior open bite

- narrow upper arch

what causes adenoid facies

mouth breathing

effects of mouth breathing in adenoid facies

- narrow width dimension

- protruding teeth

- lip separated at rest