9 - Etiology of Malocclusion Flashcards
5% of malocclusions come from what?
Traumas
What are predisposing factors to malocclusion?
Genetics
Functional matrix (habits)
Traumas
What are the primary etiologic sites for malocclusions?
Bone
Hard tissues
What neuromuscular system can cause malocclusions?
Cerebral palsy
This affects the number of teeth and makes them pointy
Ectodermal dysplasia
What tetragons can interfere with pregnancies?
Alcohol
Drugs
Pollutions
This syndrome results from fusion of sutures
Crouzon’s syndrome
How can you correct crouzon’s syndrome?
Distraction osteogenesis
Crouzon’s syndrome:
A. Premature closure of all sutures
B. Larger orbit
C. Prognatic mandible
D. All of the above
A
What are characteristics of Treacher Collins?
- Underdeveloped cheeks and jawbones
- Prominent nose, broad mouth, and characteristically small chin with steep lower jaw angle
- May have cleft lip/palate
Does Cleidocranial dysplasia have hypodontia or hyperdontia?
Hyperdontia (extra teeth)
What are the characteristics of Cleidocranial dysplasia?
A. Supernumerary teeth
B. Delayed eruption
C. Prognatic mandible
D. All of the above
D
What class of malocclusion is associated with Osteogenesis imperfecta?
Class III
what malocclusion is associated with osteogenesis imperfecta?
class III
Posterior open bite = what class?
Class 3
What kind of bite does OI have?
Class III/posterior open bite
What are the types of OI?
Type 1
Type III
Type 4
What is the best version of OI?
Type 1
Do you have midline deviation in OI?
Yes
This is one of the most significant aspect of OI
DI
If one OI member of the family has DI, then
All other members will have DI
If you have type 1 OI, what are the changes you have DI?
20%
If you have type 4 OI, what are the chances you have DI?
40-60%
If you have type 3 OI, what are the chances you have DI?
100%
What are the characteristics of Down syndrome
- Hypoplasia of midfacial region
- Class III → posterior open bite
Angle classification is based on what relationship?
AP
In a normal skeletal relationship, describe the cranial base
Stable for life
What is the most common type of malocclusion?
Type 1
In what class do you get mandibular retrusion?
Class II
Class II malocclusion presents what?
Retrognathic mandible
Class III malocclusion presents what?
Maxillary hypoplasia/prognathism
What is suggested as the primary cause of class III malocclusion?
Polygenic model
Deep bite, Open bite, Cross bite can be caused by what?
- Transitory
- Skeletal
- Neuromuscular imbalance
- Combination (sleep apnea)
