Learning Lab Analyses

Question 0

What are the steps involved in the moyers mixed dentition analysis?

Answer 0

1) measure mesio-distal widths of incisor teeth and calculate the sum of the mandibular incisor widths.
2) measure the arch space availible in both the maxillary and mandibular arch
(mesial of 1 to distal of 2) + (distal of 2 to mesial of 6) for each quadrant
3) determine predicted sizes of unerupted canines and premolars from the table at a 75% confidence interval. This is the “space required”.
4) compare arch space availible with the space required in each quadrant.
5) ascertain space needed for molar adjustment (horizontal distance for angles class I. If cusp tip is mesial to groove, its a negative)
6) calculate the effect of molar adjustment on arch space(total quadrant crowding)

Question 1

What is the use of the moyers mixed dentition analysis?

Answer 1

To consider the potential for crowding or decrowding changes as deciduous canines, first and second molars are shed by estimating the mesio-distal dimensions of the unerupted secondary canine, firt and secondary premolars.

Question 2

What factors can affect the accuracy of the moyers mixed dentition analysis?

Answer 2

Premature tooth loss
Prolonged tooth retention
Asymmetry
Tooth angulations
Facial pattern (affects arch form)

Question 3

What are the steps involved in the dental arch spacing/irregularity estimation?

Answer 3

1) measure maximum mesio-distal widths of each tooth on study casts and record in palmers notation
2) remeasure and find average values
3) determine arch space by either the segmental approach (1-3 + 4-6) or using a preformed Nitinol arch form
4) alignment is arch space availible - mesio-distal tooth dimensions

Question 4

What is the irregularity index and how is it measured?

Answer 4

A method used to express poor alignment of the dental arches.
Basically is the sum of the distance between contact points of adjacent teeth.

Question 5

what is the boltons analysis and what is its use?

Answer 5

To estimate the likelihood of the maxillary dental arch ocluding with the mandibular dental arch in an idealised Class I (Angle) relationship
It involves the
1) measurement of mesio-distal dimensions of 1 to 6 in each quadrant
2) comparison of tooth sizes in upper arch to lower arch by means of ratios
3) deciding whether an excess, ideal or deficien relationship exists

Question 6

what are the 5 characteristics assessed in the Ackerman-Proffit system of classification?

Answer 6

1) Alignment
2) Profile
3) Transverse
4) Sagittal
5) Vertical

Question 7

Describe Nolla’s stages of dental development

Answer 7

0. absence of crypt
1. presence of crypt
2. initial calcification
3. one third of crown completed
4. two thirds of crown completed
5. crown almost completed
6. crown completed
7. one third of root completed
8. two thirds of root completed
9. root almost completed, open apex
10. apical end of root completed