known causes of malocclusion Flashcards
what are the factors that control malocclusion
Herebditary factors
Interference with normal development
Trauma
Disturbance in normal function
how common is normal occlusion
35%
what percenet of the population is seen as handicapped
5%
what perecent of the pop seen as severe problem
20%
what percent of the pop is moderately affected
20%
what perecent of the pop is mildly affected
20%
what usually is the cause of handicapped occlusion
skeletal
what is the causes for malocclusion that is not specific
usually a complex interaction between genetic and environmental factors
what did we originally think caused malocclusion
Genetics
is malocclusion more common now or in the past
now, since in the past, people were very homogeneous
why also may be there more malocclusion today
Reduced size of jaw was faster than that of teeth
can civialization be a cause of maloccluded teeth
some change in the expression of genes may be a slight contributor to malocclusion
what may also be a cuase of maloccluded teeth in america
since genetic melting pot, leads to different characteristics of different cultures being present in one child
do children of interracial marriage have more malocclusio
no, not that simple
what did outbreeding show
There are no independently inherited tootha nd jaw characteritics that produce malocclusion when present
what did crossbreeding dogs do
Created malocclusions like that of humans
why was the dog breeding study not important
alot of the dogs had Achondroplasia
- not from mixing chacterisitscs
what is Achondroplasia
deficient growth of primary cartilage which causes midface deficiency and short limbs
what did studying interracial mixes in hawaii show about malocclusion
Do not show an increase in malocclusions
does heredity affect teeth or skelleton more
Skelton (teeth more affected by environment)
how to compare envirnoment and genetics for malloclusion
compair twins (identical and fraternal)
how does eruption occur in identical twins
In mirror images of each other
what is heritability
The proportion of variation in a given characteristic that is attributed to genetic over envirnomental factors
what does it mean to say hereditary is 1
100% of the variable is due to genetics
how much did lundstrom say hereditary gives maloccclusion
50% of malocclusion from identical twins especially skeletal and dental overjet
how much corrucini and potter show malocclusion say was genetic
almost 0
what embyronic feature leads to malocclusion
Fetal alcohol syndrome
what causes Microsomia
early loss of neural crest cells at the stage of origin and migration
what does Microsomia lead to
Underdevelopment of one side of the face
what can pressure against the developing face lead to
Interfere with normal development
what can cause pressure on the developming face
deficiency in amniotic fluid
pierre robin sequence
anomolad
what does disturbances of embryonic development lead to
Skeletal malocclusions without any other defects
pre-natal disturbances of dental leads to
class I malocclusions with normal sized jaw
extra deeth
weird shapped teeth
what is the most common extra tooth
Mesiodens
what are the most common missing teeth
Max lateral incisors
Mandibular 2nd premolars
what kind of children tend to have multiple congenitally missing teeth or extra
children with a syndrome
what is a common cause of missing teeth
Ectodermal dysplasia
does birth often lead to facial injuries
No, usually from before birth
what does the effect of trauma to the face and jaw lead to malocclusion go with what theory of growth
Functional matrix theory of growth
how is facial growth affected by an injury
by healing of facial and soft tissue injuries more than hard tissue injury
- especially scaring
if a tooth is displaced but not loss, what determines long term injury
the extent of soft tissue injury
what happens if the PDL is severly damaaged
Ankylosed(no more eruption or ortho able)
what happens if the PDL is mildly injured
abnormal development of the root can occur
what is the most common habit that may take teeth out of equilibrium
Thumb sucking
what malocclusion is seen most in thumb suckers
Protruding upper incisors
-upperward and forward pressure on upper teeth
what does thumb sucking do to arch width
Narrower, V-shapped maxillary arch
why does thumb sucking lead to narrow, V shaped maxilary arches
increased pressure against the teeth as the cheeks are tightened during suck
a lowered tongue posture
what besides thumb sucking can lead to malocclusion
tongue thrust swallow habit
mouth breathing
what kind of force tends to move teeth
Light force over a long time
what does mouth breathing lead to
open bites, long face malocclusions
what causes mouth breathing
Nasal obstruction
what part of occlusion has a strong inherited componenet
mandibuar possition
