Development of the Primary & Permanent Dention (Part II) Flashcards
Two characteristics of tooth eruption sequence of permanent dentition:
- variability
- sex differences
What do we mean by saying the permanent dentition eruption is variable?
The eruption pattern sequence of the permanent dentition is more variable than that of deciduous dentition
Describe the sex difference in regard to tooth eruption sequence in permanent dentition:
girls are ahead of boys in calcification, and except for the thirds molar, girls are ahead of boys by an average of 5 months in eruption
T/F: Boys are ahead of girls in calcification
False- girls are ahead of boys
T/F: Girls are ahead of boys by an average of 5 months in eruption, excluding the third molars
True
What are the three rules of sequence (timing of eruption):
- Timing is consistent within a dentition
- both sides should erupt at the same time
- Different eruption sequences explain most frequently crowded teeth
Explain the following statement:
“timing is consistent within a dentition”
Children who erupt any tooth early or late tend to acquire others early or late
T/F: Tooth eruption should occur bilaterally
true
Different eruption sequences explain most frequently crowded teeth including:
- maxillary cuspids
- mandibular second cuspids
What is a local influences that accelerate tooth eruption?
if the primary tooth is extracted DURING active eruption of permanent tooth (more than 2/3 of the root formed)
What do we mean by active eruption of a permanent tooth?
more than 2/3 of the root is formed
What is a local influence that slows permanent tooth eruption?
When a primary tooth is extracted BEFORE active eruption of a permanent tooth (before root formation)
What causes a change in arch width with the permanent dentition:
the increases are tied to alveolar process growth (both dental eruption & vertical process growth)
What occurs during alveolar process growth?
- Dental eruption
- Vertical process growth
Vertical alveolar process growth occurs during:
general growth spurts
Compare the vertical alveolar process growth between the maxilla and mandible:
different rates
Vertical alveolar process growth occurs at different rates for the maxilla and mandible: divergent maxillary process translates into:
more arch width growth
What causes the rate of growth maxillary vertical alveolar process to be more drastic than the mandible?
the divergent maxillary process
What causes arch width changes? (3)
- dental eruption
- wider placement of permanent teeth
- apposition of alveolar bone to support these teeth
Maxillary arch-
- increases occur during _____
- increases occurring during ____
- large increase occurs during _____
- growth spurts
- eruption of incisors
- eruption of the cuspids
What dilemma do we constantly face as dentist with tooth eruption?
Moderate crowding
Describe the “arch perimeter changes” in the maxillary arch: (3)
- variable
- no difference between sexes
- factors which limit loss includes greater labial angulation of incisors, greater increases in arch width and smaller leeway space
In regard to arch perimeter changes with the maxillary arch, what factors limit loss?
- greater labial angulation of incisors
- greater increases in arch width
- smaller leeway space
Describe the curve of spee in the following image:
Normal
Describe the curve of spee in the following image:
Steep
What is a reasonable option for impacted third molars?
Prophylactic extraction
T/F: Extraction of third molars to avoid orthodontic relapse has a strong correlation
False- weak correlation
