Malocclusion, Epidemiology, Etiology

  1. what % of people exhibit a Class I occlusion with no orthodontic problems?
    30%
  2. what % of people have a Class I occlusion but have malopposed teeth/rotation/crowding?
    50-55%
  3. what % of people have a class II occlusion?
    25% - lower molar distally positioned
  4. what % of people have a class III occlusion?
    <1% - lower molar mesially positioned
  5. what 3 planes are viewed to look at malocclusion
    • 1. sagittal
    • 2. vertical
    • 3. transverse
  6. what % of americans exhibit malocclusion?
    60%
  7. list 2 characteristics of crowding
    • 1. increases with age
    • 2. more common in mandibular
  8. list 2 characteristics of diastemas
    • 1. 26% of youth have diastemas but most self-correct
    • 2. blacks are 2x more likely to have >2mm diastemas
  9. what racial relationships are seen in terms of Class II/III occlusions
    • 1. Class II most common in whites
    • 2. Class III most common in blacks, hispanics, asians
    • 3. asians have highest occurance of Class III
  10. list 3 reasons for a need of ortho tx
    • 1. psychosocial problems
    • 2. oral function
    • 3. injury/disease (class II max. inc. more likely to have trauma)
  11. list 3 specific causes of malocclusion
    • 1. teratogens
    • 2. skeletal growth disturbances
    • 3. muscle dysfunction
  12. list 5 examples of muscle dysfunction
    • 1. atrophy/lost of musculuature (due to motor nerve damage)
    • 2. hyperfunction (results in facial asymmetry)
    • 3. Muscle weakness (cerebral palsy)
    • 4. acromegaly (excessive growth hormone; creates skeletal class III)
    • 5. hemimandibular hypertrophy (unilateral excessive growth of mandible; more likely in girls)
  13. what % of malocclusion is attributed to hereditary factors?
    40%
  14. which type of development, skeletal or dental, has more of a familial correlation?
    skeletal
  15. how does age relate to skeletal and dental estimates?
    increase in age = increase in skeletal inheritance estimates; decrease in dental inheritance estimates
  16. how does chewing pressure affect arch size?
    increase use of jaws/increase biting force = increase dimension of jaws/dental arch
  17. how are chewing pressures associated with eruption?
    • - long faced patients: lower biting force, teeth erupt farther
    • - different biting force is more likely an effect than a cause of malocclusion
  18. skeletal traits are influenced by? dental traits are influenced by?
    • skeletal: genetic
    • dental: environmental
  19. list the ages of when permanent mandibular canine, lateral, centrals, first and second molars erupt
    • Central Incisors/1st Molars: 6
    • Lateral Incisors: 7
    • Canine: 11
    • 2nd Molars: 12
  20. List the ages of when permanent maxillary canine, lateral, central, 1st and 2nd molars erupt
    • 1st Molar: 6
    • Centrals: 7
    • Laterals: 8
    • Canines/2nd Molars: 12
  21. define leeway space
    a space that develops due to the difference in size between permanent canine/PMs and primary canine/molars. Permanent Mandibular 1st molar moves forward into this space. allows for the formation of a class I occlusion.
Author
thezidane
ID
44424
Card Set
Malocclusion, Epidemiology, Etiology
Description
lecture 2
Updated