正畸治疗前的模型分析和投影测量分析(课件)

1、Orthodontic diagnosis: The development of a Problem ListOperator : Zhou LingSupervisor: Prof. Li Date: 2013.6.61Orthodontic diagnosis: 1534Development of a Problem List The Problem-Oriented approachClinical EvaluationAnalysis of Diagnostic RecordsOrthodontic ClassificationChapter outline221534Develo

2、pment of a Problem LAnalysis of Diagnostic RecordsTwo partsCephalometric analysis of dentofacial relationshipsDental cast analysisto evaluate space excess or deficiency and symmetry within the dental arches3Analysis of Diagnostic Records Symmetry Space analysis Estimating of unerupted permanent teet

3、h Tooth size analysisDental cast analysis4 SymmetryDental cast analysis4Symmetry Transparent ruled grid placed over dental cast Oriented to the midpalatal raphe Spot asymmetries in arch form , and tooth position5Symmetry Transparent ruled gri Lateral drift of incisors (Crowding, C lost 3 blocked out

4、)SymmetryDrift of posterior teeth（Early loss of E)6 Lateral dPendulum7Pendulum7 Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis8 SymmetryDental cast analysis8Alignment (Crowding): Space Analysis9Alignment (Crowding): 9Dental cast Computer algor

5、ithmSpace Analysis10Dental cast Computer algorith 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片段法铜丝法11 Measuring arch perimeter fStep two: Calculation of re

6、quired spaceMeasure the mesiodistal width of each erupted tooth from contact point to contact point.12Step two: Calculation of requiSpace Analysis13Space Analysis13 01 The space available will not change because of growth.02All the teeth are normal in size03Correct anteroposterior position of inciso

7、rs Three assumptions14 01 02All the teeth ar InteractionProtrusionRetrusionCrowding15 InteractionPro 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

8、 of the two.161617171818191901 The space available will not change because of growth.02All the teeth are normal in size03Correct anteroposterior position of incisors Three assumptions2001 02All the teeth are normal In a child with a well-proportioned face, there is little or no tendency for the dent

9、ition to be displaced relative to the jaw during growth.But the teeth often shift anteriorly or posteriorly in a child with a jaw discrepancy. 21 In a child with a well-propor222201 The space available will not change because of growth.02All the teeth are normal in size03Correct anteroposterior posi

10、tion of incisors Three assumptions2301 02All the teeth are normal Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis24 SymmetryDental cast analysis2 Mix Dentition Estimating of Unerupted Permanent Teeth25 Mix Estimating of Unerupted Permanent Teet

11、hRadiograghicPrediction table methodsCombination26 Estimating of Unerupted PeUndistorted radiographic image Compensate for enlargementMeasurement of the teeth on radiographs27Undistorted radiographic image True width of primary molarApparent width of primary molarMeasurement of the teeth on radiogra

12、phs True width of unerupted PremolarApparent width of unerupted premolar=28 True width of primary mola 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 ethnic groups.Measurement o

13、f the teeth on radiographs29 Accuracy is fair to good depe Estimating of Unerupted Permanent Teeth RadiograghicPrediction table methodsCombination30 Estimating of Unerupted PeMoyers prediction Estimation from proportionality tablesMeasuring the mesiodistal width of the lower incisors Prediction the

14、size of both the lower and upper unerupted canines and premolars31Moyers prediction Estimatio Estimation from proportionality tables32 Estimation from proportionaNorthern European white childrenNo radiographs are required , used for the upper or lower arch. Estimation from proportionality tables33 E

15、stimation from proportion Estimation from proportionality tables34 Estimation from proportiona Estimating of Unerupted Permanent TeethRadiograghicPrediction table methodsCombination35 Estimating of Unerupted PeCombination of radiographic and prediction tableIt depends!36Combination of radiographic a

16、nComparison1Radiograghic2Most practicalNorthern European white childrenNo radiograghsNo reference table3MoyersTakana & JohnstonNorthern European white childrenNo radiographsDepending on the quality of the radiographs and their position in the archFor all ethnic groups.37Comparison1Radiograghic23Moye

17、r Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis38 SymmetryDental cast analysis3 Although the natural teeth match very well in most individuals, approximately 5% of the population have some degree of disproportion among the sizes of individual

18、 teeth. - Tooth Size Discrepancy(TSD)Tooth Size Analysis39 Although the natural teeth maTooth Size Analysis40Tooth Size Analysis40Bolton RatioTooth Size Analysis(78.8 1.72)%(91.5 1.51)%41Bolton RatioTooth Size Analysi A quick check for . Anterior tooth size discrepancy : 2 2 Posterior tooth size dis

19、crepancy： 5 = 5 A tooth size discrepancy of less than 1.5mm is rarely significant.Tooth Size Analysis42 Tooth Size Analysis42 Symmetry Space analysis Estimating of unerupted permanent teeth Tooth size analysisDental cast analysis43 SymmetryDental cast analysis4Analysis of Diagnostic RecordsTwo parts

20、Cephalometric analysis of dentofacial relationshipsDental cast analysisto evaluate space excess or deficiency and symmetry within the dental arches44Analysis of Diagnostic Records The introduction of radiographic cephalometrics is in 1934 by Hofrath in Germany and Broadbent in USA.Cephalometric anal

21、ysis45 The introduction of radiogra Function Original purpose Evaluating dentofacial proportions and clarify the anatomic basis for a malocclusion Observing pathologic changes (Sometimes) Researching on growth patterns in the craniofacial complex.46 Function Original purpose 46This patient has fusio

22、n of the 1st and 2nd cervical vertebrae ,with the odontoid process extending into the margin of foramen. Function 47This patient has fusion of the Function Original purpose Evaluating dentofacial proportions and clarify the anatomic basis for a malocclusion Observing pathologic changes (Sometimes) R

23、ecognizing and evaluating changes brought about by orthodontic treatment. Researching on growth patterns in the craniofacial complex.48 Function Original purpose 48 Function 49 Function 49 The goal of cephalometric analysis is to evaluate the relationships, both horizontally and vertically, of the f

24、ive major functional components of the face .Cephalometric analysis50 The goal of cephalometric aCephalometric analysis51Cephalometric analysis51Cranial Base S，N，Po，Ba, Bo Maxilla Or，Ptm，ANS，PNS，A， UI Mandibular Co，Go，B，LI， Pog，Me，GnCephalometric Landmarks52Cranial BaseCephalometric Land S.sella N.n

25、asion Po.porion Ba.basion BoSNPoBaBoCephalometric Landmarks53SNPoBaBoCephalometric Landmark Or. orbitale Ptm. ANS. Anterior nasal spine PNS Posterior nasal spine A. subspinale UI. Upper IncisorOrANSUIAPtmPNSCephalometric Landmarks54 Or. orbitale OrANSUIAPtmPNSC Co. condylion Go. gonion Pog. pogonion

26、 Me. menton Gn. gnathion B.supramental LI. lower incisor CoGoBLIPog/Gn/MeCephalometric Landmarks55 Co. condylionCoGoBLIPog/Gn/Me5656Two methodsContemporary measurement approachCephalometric analysis via direct comparison with reference templateCephalometric analysis57Two methodsContemporary measurCo

27、ntemporary measurement approach Choice of a Horizontal (Cranial) Reference Line. Steiner Analysis Sassouni Analysis Wits Analysis58Contemporary measurement approChoice of a Horizontal Reference LineAn international congress was held in Frankfort, Germany in 1882.with the choice of a horizontal refer

28、ence line for orientation of skulls59Choice of a Horizontal Referen“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 Line60“Machine porion :Choice of a6161NHP (natural head

29、position): 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 Line62NHP (natural head position): CChoice of a Horizontal (Cranial

30、) Reference Line.Steiner AnalysisSassouni AnalysisWits AnalysisContemporary measurement approach63Choice of a Horizontal (CraniaSteiner 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 mandib

31、le.64Steiner Analysis SNA : MaxillaANB angle is influenced by two factors :Vertical height of the face. Anteroposterior position of nasion.Steiner Analysis65ANB angle is influenced by two6666Steiner Analysis U1-NA （mm ) U1-NA L1- NB（mm) L1-NB67Steiner Analysis U1-NA （mm )6 Holdaway Ratio: The balanc

32、e 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 Analysis68 Holdaway Ratio: Steiner Analysis69Steiner Analysis697070Steiner Analysis71Steiner Analysis71Choice of a Horizontal (Cranial) Reference Line.Steiner AnalysisSassouni AnalysisWits AnalysisContemporary measurement approach72Choice of a Horizontal (Craniaskeletal open bite SN FH PP OP MP Sassouni Analysis73skeletal open bite SN FH PP 7474Choice of a Horizontal (Cranial) Reference Line