cast analysis

cast analysis

The Study model provides a three dimensional view of the maxillary and mandibular dental arches in all three planes of space,.i.e, sagittal, vertical and transverse planes.
Model analysis allows us to carefully examine several parameters such as dentition, jaw relationships, and make objective measurements for detailed evaluation and treatment planning, also help in detecting midline discrepancies

Study model

the role of study cast at orthodontic treatment: 1. Record real teeth, alveolar bone, the palate and the base bone morphology and location. 2.Dentofacial deformity analysis conducted 3. Comparison in the course of treatment
4. Compared the efficacy before and after treatment 5.One of the essential legal basis

Study model

Requisites of study models
• Should accurately reproduce all the teeth and soft tissues without any distortion
• 2. Should be trimmed symmetrical on either side,so that the base of maxillary cast is trimmed parallel to the occlusal plan, upper and lower cast base should be parallel.
• 3. Posterior surface should be trimmed, such that when placed on their back they should reproduce the occlusal plane.
• 4. Should reproduce the alveolar process as much as possible.

Cast Analysis

Cast analysis
1.Arch Length &Arch Perimeter analysis
• dental space Analysis : Arch Required Arch Available
Arch space= Arch Required - Arch Available

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Requirements to do cast analysis

• Well prepared study models
• Vernier calipers
• Divider
• Ruler
• Brass wire
1-Symmetry
A transparent ruled grid is the simplest tool to use to establish symmetry. When it is placed over the maxillary cast and lined up with the midpalatal raphe, any distortion of arch form and shifts of dental units can be determined quickly

Principles of mixed dentition analysis

mixed dentition analysismethods

Curve of Spee

Curve of Spee

Flat Deep

Moyer prediction table

Use four mandibular incisor to estimate the distance of lower , the maxillary canine, premolar from mesial to distal .But this estimate has a tendency to over-estimate.
Low incisor 19.5 20.0 20.5 21.0 21.5 22.0
maxillary 20.6 20.9 21.2 21.3 21.8 22.0
mandibular 20.1 20.4 20.7 21.0 21.3 21.6

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• Model Analysis
Width evaluation
Arch width can be divided into three parts:
The preceding width (inter-canine width)
Middle arch width (first premolar width of the central inter-nest)
Posterior segment arch width (the first permanent molars between the width of the central nest)

the preceding width

Middle arch width
Posterior segment arch width