正畸治疗前的模型分析和投影测量分析

❖ In a child with a well-proportioned face, there is little or no tendency for the dentition to be displaced relative to the jaw during growth.
❖ But the teeth often shift anteriorly or posteriorly in a child with a jaw discrepancy.
Three assumptions
01
Correct anteroposterior position of incisors
02 The space available will not change
because of growth.
03 All the teeth are normal in size
Dental cast analysis
❖ Symmetry ❖ Space analysis ❖ Estimating of unerupted permanent teeth ❖ Tooth size analysis
Symmetry
❖ Transparent ruled grid placed over dental cast ❖ Oriented to the midpalatal raphe ❖ Spot asymmetries in arch form , and tooth position
teeth and incisal edge of anteriors.
片段法
铜丝法
Step two: Calculation of required space
Measure the mesiodistal width of each erupted tooth from contact point to contact point.
Alignment (Crowding): Space Analysis
Space Analysis
❖ Dental cast
❖ Computer algorithm
Step one: Calculation of available space
Measuring arch perimeter from the mesial of one first molar to the other, over the contact points of posterior
Space Analysis
Three assumptions
01 Correct anteroposterior position of incisors
02
The space available will not change because of growth.
03 All the teeth are normal in size
Analysis of Diagnostic Records
Two parts
Dental cast analysis to evaluate space excess or deficiency and symmetry within the dental arches
Cephalometric analysis of dentofacial relationships
Symmetry
Lateral drift of incisors
Drift of posterior teeth
(Crowding, C lost 3 blocked out) （Early loss of E)
Pendulum
Dental cast analysis
❖ Symmetry ❖ Space analysis ❖ Estimating of unerupted permanent teeth ❖ Tooth size analysis
Three assumptions
01
Correct anteroposterior position of incisors
02 The space available will not change
because of growth.
03 All the teeth are normal in size
Operator : Zhou Ling
Supervisor: Prof. Li Date: 2013.6.6
Chapter outline
1 The Problem-Oriented approach 2 Clinical Evaluation 3 Analysis of Diagnostic Records 4 Orthodontic Classification 5 Development of a Problem List
Dental cast analysis
❖ Symmetry ❖ Space analysis ❖ Estimating of unerupted permanent teeth ❖ Tooth size analysis
Mix Dentition Estimating of Unerupted Permanent Teeth
Estimating of Unerupted Permanent Teeth
Radiograghic
Prediction table
Interaction
Protrusion
Retrusion
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Crowding
❖ Crowding and protrusion are different aspects of the same phenomenon.
❖If there is not enough room to properly align the teeth, the result can be crowding, protrusion, or (most likely) some combination of the two.