正畸治療前的模型分析和投影測量分析PPT通用課件

1、Orthodontic diagnosis: The development of a Problem ListOperator : Zhou LingSupervisor: Prof. Li Date: 2013.6.61534Development of a Problem List The Problem-Oriented approachClinical EvaluationAnalysis of Diagnostic RecordsOrthodontic ClassificationChapter outline2Analysis of Diagnostic RecordsTwo p

2、artsCephalometric analysis of dentofacial relationshipsDental cast analysisto evaluate space excess or deficiency and symmetry within the dental arches Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysisSymmetry Transparent ruled grid placed over d

3、ental cast Oriented to the midpalatal raphe Spot asymmetries in arch form , and tooth position Lateral drift of incisors (Crowding, C lost 3 blocked out)SymmetryDrift of posterior teeth（Early loss of E)Pendulum Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental

4、 cast analysisAlignment (Crowding): Space AnalysisDental cast Computer algorithmSpace Analysis Measuring arch perimeter from the mesial of one first molar to the other, over the contact points of posterior teeth and incisal edge of anteriors. Step one: Calculation of available space片段法銅絲法Step two: C

5、alculation of required spaceMeasure the mesiodistal width of each erupted tooth from contact point to contact point.Space Analysis 01 The space available will not change because of growth.02All the teeth are normal in size03Correct anteroposterior position of incisors Three assumptions InteractionPr

6、otrusionRetrusionCrowding 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.01 The space available will not change because of growth.02All

7、the teeth are normal in size03Correct anteroposterior position of incisors Three assumptions 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 wit

8、h a jaw discrepancy. 01 The space available will not change because of growth.02All the teeth are normal in size03Correct anteroposterior position of incisors Three assumptions Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis Mix Dentition Estim

9、ating of Unerupted Permanent Teeth Estimating of Unerupted Permanent TeethRadiograghicPrediction table methodsCombinationUndistorted radiographic image Compensate for enlargementPeriapical radiographsPanoramic radiographs.Measurement of the teeth on radiographs True width of primary molarApparent wi

10、dth of primary molarMeasurement of the teeth on radiographs True width of unerupted PremolarApparent width of unerupted premolar= Accuracy is fair to good depending on the quality of the radiographs and their position in the arch. The technique can be used in maxillary and mandibular arches for all

11、ethnic groups.Measurement of the teeth on radiographs Estimating of Unerupted Permanent Teeth RadiograghicPrediction table methodsCombinationMoyers prediction Estimation from proportionality tablesMeasuring the mesiodistal width of the lower incisors Prediction the size of both the lower and upper u

12、nerupted canines and premolars Estimation from proportionality tablesNorthern European white childrenNo radiographs are required , used for the upper or lower arch. Estimation from proportionality tables Estimation from proportionality tables Estimating of Unerupted Permanent TeethRadiograghicPredic

13、tion table methodsCombinationCombination of radiographic and prediction tableIt depends!Comparison1Radiograghic2Most practicalNorthern European white childrenNo radiograghsNo reference table3MoyersTakana & JohnstonNorthern European white childrenNo radiographsDepending on the quality of the radiogra

14、phs and their position in the archFor all ethnic groups. Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis Although the natural teeth match very well in most individuals, approximately 5% of the population have some degree of disproportion among

15、the sizes of individual teeth. - Tooth Size Discrepancy(TSD)Tooth Size AnalysisTooth Size AnalysisBolton RatioTooth Size Analysis(78.8 1.72)%(91.5 1.51)% A quick check for . Anterior tooth size discrepancy : 2 2 Posterior tooth size discrepancy： 5 = 5 A tooth size discrepancy of less than 1.5mm is r

16、arely significant.Tooth Size Analysis Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysisAnalysis of Diagnostic RecordsTwo partsCephalometric analysis of dentofacial relationshipsDental cast analysisto evaluate space excess or deficiency and symmet

17、ry within the dental arches The introduction of radiographic cephalometrics is in 1934 by Hofrath in Germany and Broadbent in USA.Cephalometric analysis Function Original purpose Evaluating dentofacial proportions and clarify the anatomic basis for a malocclusion Observing pathologic changes (Someti

18、mes) Researching on growth patterns in the craniofacial complex.This patient has fusion of the 1st and 2nd cervical vertebrae ,with the odontoid process extending into the margin of foramen. Function Function Original purpose Evaluating dentofacial proportions and clarify the anatomic basis for a ma

19、locclusion Observing pathologic changes (Sometimes) Recognizing and evaluating changes brought about by orthodontic treatment. Researching on growth patterns in the craniofacial complex. Function The goal of cephalometric analysis is to evaluate the relationships, both horizontally and vertically, o

20、f the five major functional components of the face .Cephalometric analysisCephalometric analysisCranial Base S，N，Po，Ba, Bo Maxilla Or，Ptm，ANS，PNS，A， UI Mandibular Co，Go，B，LI， Pog，Me，GnCephalometric Landmarks S.sella N.nasion Po.porion Ba.basion BoSNPoBaBoCephalometric Landmarks Or. orbitale Ptm. ANS

21、. Anterior nasal spine PNS Posterior nasal spine A. subspinale UI. Upper IncisorOrANSUIAPtmPNSCephalometric Landmarks Co. condylion Go. gonion Pog. pogonion Me. menton Gn. gnathion B.supramental LI. lower incisor CoGoBLIPog/Gn/MeCephalometric LandmarksTwo methodsContemporary measurement approachCeph

22、alometric analysis via direct comparison with reference templateCephalometric analysisContemporary measurement approach Choice of a Horizontal (Cranial) Reference Line. Steiner Analysis Sassouni Analysis Wits AnalysisChoice of a Horizontal Reference LineAn international congress was held in Frankfor

23、t, Germany in 1882.with the choice of a horizontal reference line for orientation of skulls“Machine porion :The upper surface of the ear rod of the cephalometric Anatomic porion”: The upper surface of the shadow of the auditory canal .Choice of a Horizontal Reference LineNHP (natural head position):

24、 Relaxed individuals look at a distant obiect or into their own eyes in a mirror and incline their heads up and down in increasingly smaller movements until they feel comfortably positioned.Choice of a Horizontal Reference LineChoice of a Horizontal (Cranial) Reference Line.Steiner AnalysisSassouni

25、AnalysisWits AnalysisContemporary measurement approachSteiner Analysis SNA : Maxilla to the cranial base 82 2 SNB： Mandible to the CB 78 2 ANB: skeletal jaw discrepancy. SN-MP( mandiblar plane): Vertical position of the mandible.ANB angle is influenced by two factors :Vertical height of the face. An

26、teroposterior position of nasion.Steiner AnalysisSteiner Analysis U1-NA （mm ) U1-NA L1- NB（mm) L1-NB Holdaway Ratio: The balance between the prominence of the chin and the prominence of the lower incisor : the more prominent the chin, the more prominent the incisor can be。Steiner AnalysisSteiner AnalysisSteiner AnalysisChoice of a Horizontal (Cranial) Reference Line.Steiner Anal