Orthodontic Cast Trimming

Question 1

___ are accurate plaster reproductions of the teeth and their surrounding soft tissues

Answer 1

Orthodontic study models

Question 2

This provides a three dimensional view of the dentition

Answer 2

Orthodontic study models

Question 3

What are the importance of study models

Answer 3

1. Useful in treatment planning
2. Provides a permanent record
3. Serves as a visual aid for dentist
4. Helps motivate the patent, as the patient can visualize the treatment
5. Needed for comparision at the end of the treatment

Question 4

What are the uses of study cast

Answer 4

A. Calculate total space analysis
B. Assess and record the following
1. Dental anatomy
2. Intercuspation
3. Arch form
4. Curves of occlusion
C. To evaluate occlusion, with aid of articulator
D. Measure progress during treatment
E. To detect abnormalities
F to provide a record before, immediately after, and several years following treatment for the purpose of studying treatment procedures

Question 5

Requirements of the study cast

Answer 5

1. Accurately reproduce the teeth and soft tissues without any distortion
2. Should be trimmed symmetrical on either side
3. Posterior surface should be be trimmed, such that when placed on their back, they should reproduce the occlusion
4. Reproduce alveolar process as much as possible

Question 6

It is the actual impression of dental arches and surrounding soft tissue structures

Answer 6

Anatomic portion

Question 7

Plaster base that supports te anatomical postion

Answer 7

Artistic portion

Question 8

Steps in construction of study models

Answer 8

1. Impressions taing
2. Disinfection of the impression
3. Casting the impression
4. Basing and trimming of the cast
   5 finishing and polishing of study models

Question 9

Mm of frontal view of study model

Answer 9

13mm

Question 10

Mm base of maxillary cast trimmed parallel to frankfort horizontal plane

Answer 10

13mm

Question 11

Mm base of maxillary cast trimmed parallel to frankfort horizontal plane

Answer 11

13mm

Question 12

Lateral view of study model

Answer 12

Posterior 7.0 - 7.5mm
Anterior 3.5 - 4.0mm

Question 13

The posterir surface of maxillary and mandibular cast should be trimmed to ___ plane

Answer 13

Flush terminal plane

Question 14

In the maxillary occlusal view of the study model. How many mm should be the adequate measurement

Answer 14

5-6mm

25deg - 5mm
70-90deg - 13mm

Question 15

Mm of mandibular occlusal view of study model

Answer 15

5-6mm
5-6mm
13mm
65 deg

Question 16

Astistic poriton of study model should be polished using ___

Answer 16

Fine grained sand paper

Question 17

What does the impression material records for studying the study casts

Answer 17

Dental anatomy
Intercuspastion
Arch form
Curves of occlusion