Lecture 2 Flashcards
What is the purpose of mixed dentition analysis (MDA)?
the purpose is to calculate the differences between the amount of dental arch space available and that required for accommodating the permanent teeth for planning either a preventive or interceptive approach
What is Lee-Way space?
The size difference between the primary & permanent teeth
The space occupied by the primary canines and molars is ______ compared to the space required for the corresponding permanent teeth (canine + two premolars)
GREATER THAN
Why is determining the space analysis in primary dentition important?
It becomes fundamental in the treatment plan that might involve:
- extractions
- eruption guidance
- space maintenance
- space gain
- simple monitoring
The available space in the arch can be _____, _____ or ____ than the unerupted teeth
equal; greater; smaller
what are the three categories of methods for a mixed dentition analysis (MDA)?
- use regression equations
- use radiographs
- combination of BOTH
Of the three MDA categories which method is most widely used?
Regression equations
(Moyers probability & Tanaka & Johnston equation)
What are the two regression equations used in MDA?
Moyers probability & Tanaka & Johnson equation
What is the major drawback with MDA methods and space analysis?
The applicability only AFTER the eruption of mandibular permanent incisors
A mixed dentition analysis that allows one to estimate the space available in the arch for permanent:
Tanaka & Johnston analysis
In Tanaka & Johnston, what is measured?
MD width of all lower incisors
For TJ analysis, you take the MD width of all lower incisors and add _____ for maxillary and add ____ for mandibular
11 maxillary; 10.5 mandibular
For TJ analysis, you take the MD width of all lower incisors and add 11 what are predicting?
maxillary arch canines and 2 premolars
For TJ analysis, you take the MD width of all lower incisors and add 10.5 what are you predicting?
mandibular arch canine and 2 premolars
“two times the width of the primary first molar + the MD width of the primary canine”
Boston university approach
In the boston university approach what is measured? Be specific
2x the width of the primary first molar + width of the primary canine
(2D +C)
The boston university approach measurements are taken on the:
lower arch
List the equation for boston university approach:
3+4+5 = 2D + C
Image with space maintainer (all permanent central incisors & permanent first molar, missing premolars, also some primary teeth remaining)
What is the function of the space maintainer?
Preventing the MD drift of the molars and shifting of the lower incisors
What does the space analysis in permanent dentition help to determine?
Helps determine the difference between the space available and the space required for the alignment of the permanent teeth
In permanent dentition space analysis, what does a (+) number mean?
more space is available than needed
In permanent dentition space analysis, what does a (-) number mean?
less space available than needed
In permanent dentition space analysis, what does the same number mean?
exact space present required for alignment of teeth
How can you perform the permanent denition analysis?
- measure the MD width of each tooth mesial to the permanent first molar
- the total sum of the width should correspond to the necessary space required
- compare the numbers together
List the important factors of space analysis in the permanent dentition:
- visualization
- localized
- arch perimeter
- segmental arch analysis
- digital 3D scanning
What is the most important factor in space analysis of permanent dentition
Visualization - Nothing is more important than clinical examination. Make sure to assess BOTH arches for overall evaluation of the teeth and their alignments
Describe localization in space analysis of permanent dentition:
Try to figure out where the problem is: anterior? posterior?
T/F: When evaluating arch perimeter in space analysis of permanent dentition, always compare each arch with the ideal arch in your mind
True
When you are dealing with a CROWDED arch, an accurate assessment of what is ideal?
ARCH CIRCUMFERENCE
What is the most accurate device to measure tooth mass (MD size)?
Digital caliper
T/F: A manual caliper is a better tool to measure tooth mass (MD size) than a digital caliper
False- a manual caliper can be used too, but with less accuracy and more human error
List steps of segmental arch analysis:
- measure M-D width of EVERY SINGLE TOOTH
- measure the mesial of the first molar to the distal of the lateral incisor
- measure the distal of the lateral incisor to the midline
Using digital devices to measure the width of each tooth by plotting the mesial and distal contact points of each tooth:
Digital 3D scanning
