Etiology of Malocclusions- FINAL - Dr. Retrouvey Flashcards
Predisposing factors to malocclusion include:
- Genetics
- Functional matrix
- Disturbances in embryologic development
- traumas
Primary etiological sites include:
- neuromuscular system
- Bone
- Teeth
- Soft tissues
List diseases associated with the following primary etiologic sites:
- neuromuscular system
- bone
- teeth
- soft tissues
- cerebral palsy (results in severe malocclusion)
- Osteogenesis imperfecta (Col1a1 and Col1a2)
- Ectodermic dysplasia
- sclerodermia
Disturbances in embryologic development may be due to:
teratogens
May interfere with cellular differentiation during pregnancy:
teratogens
Some examples of teratogens include:
alcohol, drugs, pollution, poor nutrition
We used to think that cleft lip and palate could be due to teratogens but the idea has shifted now to them being due to:
genetics
most common craniofacial abnormality:
cleft lip & palate
Crouzon syndromes is a type of:
craniosynostosis
Crouzon syndrome (cranosynostosis syndrome) is caused by:
early fusion of sutures
(lower jaw develops normal, orbits close early)
Crouzon is characterized by:
- bulging eye
- small maxilla
What is a typical treatment for crouzon syndrome:
distraction osteogenesis
Craniosynostosis (Crouzon’s syndrome) is purely a ____ disease
bony
Disease characterized by underdevelopment of the mid face & eyes that seem to bulge from their sockets:
crouzon’s syndrome
Disease characterized by underdeveloped cheek and jawbones, a prominent nose, broad mouth, and characteristically small chin with steep lower jaw angle:
treacher collins
When the maxillary and mandibular jawbones are both under developed this is considered:
Bimaxillary retrusion
In dentistry when you have syndromes, these are typically associated with:
hypodontia
(Exception CCD)
Disease characterized by:
- delayed closure (ossification) of the space between the bones of the skull (fontanels)
- Premature closing of coronal suture
- Protruding jaw and protruding brow bone
- wide nasal bridge due to increase space between the eyes
- high arched palate or possible cleft palate
- short stature
- scoliosis of spine
cleidocranial dysplasia
Describe the mandible of a patient with CCD:
Typically a class III because of hypertrophy mandible (protrusion)
Dental abnormalities of CCD patient include:
failure to lose baby teeth and delayed or absent formation of teeth, slow eruption of secondary teeth
Osteogenesis imperfecta, the ___ is affected
dentin
What class of malocclusion is often seen in OI patients?
class III malocclusion as well as posterior open bite
- midline deviation
- asymmetry: repercussion on the condyles
- posterior open bite
- lack of chewing capability
These are all characteristic of:
OI
Type of osteogenesis imperfecta characterized by less bone but still good bone, majority of OI patients
Type I
Type of osteogenesis impercta characterized by weak bone and lots of fractures, more severe, and DI
type III and IV
What is one of the most significant aspects of osteogenesis imperfecta?
Dentinogenesis imperfecta
If one OI member of the family have DI:
all the other OI members of that family will have DI as well
Discuss the prevalence of DI in the following types of OI patients:
Type 1:
Type 4:
Type 3:
1: 20%
4: 40-60%
3: 100%
In what disease discussed is all of the teeth NOT affected in the same manner?
dentinogenesis imperfecta
Down syndrome can be characterized with underdevelopment or hypoplasia of the mid face region meaning:
smaller and retrusive maxilla contributes to class III malocclusion
Is the maxilla or mandible smaller due to Down syndrome?
maxilla (mandible is normal)
The open bite in a patient with down syndrome is due to:
Thick tongue pushing on the teeth (not genetics)
The condyles are considered:
growth sites
Condition in which one condyle is absent creating significant malocclusion:
condylar dysplasia
(the muscles still all the patient to have semi-function)
A lot of syndromic patients have significant:
cranial base alterations
Position and projection of the upper and lower jaws rely on:
cranial base
30% of people have ____ occlusion
normal occlusion
50-55% of people have ____ occlusion
class I malocclusion
15% of people have _____ occlsuion
class II malocclusion
1-4% of people have ____ occlusion
class III malocclusion
Malocclusion occurs in ___ dimensions
3
Angle classification of occlusion is based on:
AP relationships
retrognathic jaw =
class II
prognathic jaw:
class III
Are most class II malocclusions a result of maxillary prognathism or mandibular retrognathism?
mandibular retro
40% of our class II patient are actually:
bimaxillary retrognathic
Even among the same type of malocclusions, there is:
phenotypic diversity
A very common type of class III malocclusion that is characterized by overjet and overbite is:
edge-to-edge (wears down incisors)
prevalence of malocclusions depends on the:
popluation
What percent of southeast asians display malocclusion?
15%
What percent of middle easterns display malocclusion?
10%
What percent of indians display malocclusion?
~1%
What percent of europeans display malocclusion?
1-4%
The genetics of class III malocclusions are focused on:
mandibular prognathisms
Family and twin studies of genetic of class III malocclusion suggest a ____ as a primary cause of class III malocclusions
polygenic model
what aspects make up the polygenic model responsible for class III malocclusion?
genes + environment + condylar cartilage
What is used to determine the chromosome loci associated with the genetics responsible for class III malocclusion?
linkage analysis studies
A deep bite refers to a ____ problem
vertical
A unique characteristic to open bites is that sometimes you have a _____ stage in which they will resolve themselves
transitory
