Cephalometric points /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
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Cephalometric points /certified fixed orthodontic courses by Indian dental academy

  1. 1. www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. INTRODUCTIONINTRODUCTION HISTORYHISTORY TRACING AND ITS EQUIPMENTSTRACING AND ITS EQUIPMENTS REFERENCE POINTSREFERENCE POINTS -PROPERTIES-PROPERTIES -DEFINITIONS-DEFINITIONS SIGNIFICANCE OF LINEAR ANDSIGNIFICANCE OF LINEAR AND ANGULAR MEASUREMENTSANGULAR MEASUREMENTS CONCLUSIONCONCLUSION www.indiandentalacademy.comwww.indiandentalacademy.com
  3. 3. INTRODUCTIONINTRODUCTION The assessment of cranio-facial dimensionThe assessment of cranio-facial dimension is not a new skill in orthodontics.Theis not a new skill in orthodontics.The earliest method used was to assessearliest method used was to assess facial proportions from an artistic point of viewfrom an artistic point of view with beauty and harmony as the guidingwith beauty and harmony as the guiding principles.principles. www.indiandentalacademy.comwww.indiandentalacademy.com
  4. 4. Cephalometric radiography was introducedCephalometric radiography was introduced in to orthodontics during 1930’s ,but thein to orthodontics during 1930’s ,but the method gained wider range of acceptancemethod gained wider range of acceptance only in the last twenty yearsonly in the last twenty years www.indiandentalacademy.comwww.indiandentalacademy.com
  5. 5. HISTORICAL PREVIEWHISTORICAL PREVIEW The evolution of cephalometry in 20The evolution of cephalometry in 20thth century is universally linked tocentury is universally linked to Edward Angle’s publication of his classification of malocclusion The scheme used the relationship b/wThe scheme used the relationship b/w maxillary and mandibular dental archesmaxillary and mandibular dental arches www.indiandentalacademy.comwww.indiandentalacademy.com
  6. 6.  VANLOON-1915 For meaningful diagnosis & treatmentFor meaningful diagnosis & treatment planning, a three dimensional systemplanning, a three dimensional system was required to determine the relation ofwas required to determine the relation of dentition to the facedentition to the face  BROADBENT & HOFRATH-1931 Published methods to obtainPublished methods to obtain standardized head radiographs in thestandardized head radiographs in the Angle orthodontistAngle orthodontist www.indiandentalacademy.comwww.indiandentalacademy.com
  7. 7. TRACING TECHNIQUESTRACING TECHNIQUES  Familiarise with gross anatomy of head-the bonyFamiliarise with gross anatomy of head-the bony components of cranium and facecomponents of cranium and face  A two dimensional cephalogram represents aA two dimensional cephalogram represents a three dimensional object & bilateral structuresthree dimensional object & bilateral structures will be projected on to the film.These bilateralwill be projected on to the film.These bilateral structures should be distinguished and tracedstructures should be distinguished and traced www.indiandentalacademy.comwww.indiandentalacademy.com
  8. 8. EQUIPMENTSEQUIPMENTS -LATERAL CEPHALOGRAM (8X10 INCHES)-LATERAL CEPHALOGRAM (8X10 INCHES) -ACETATE MATTE TRACING PAPER-ACETATE MATTE TRACING PAPER -3H DRAWING PENCIL-3H DRAWING PENCIL -MASKING TAPE-MASKING TAPE -SHEETS OF CARDBOARD (6X12 INCHES)-SHEETS OF CARDBOARD (6X12 INCHES) -A PROTRACTOR-A PROTRACTOR -DENTAL CASTS TRIMMED TO MAXIMUM-DENTAL CASTS TRIMMED TO MAXIMUM INTER CUSPIDATION OF TEETH IN OCC:INTER CUSPIDATION OF TEETH IN OCC: -VIEW BOX-VIEW BOX www.indiandentalacademy.comwww.indiandentalacademy.com
  9. 9. REFERENCE POINTSREFERENCE POINTS The effective evaluation of radiographsThe effective evaluation of radiographs depends on accurate definitions anddepends on accurate definitions and localisation of landmarks,which provideslocalisation of landmarks,which provides the basis for all further workthe basis for all further work Distinction is made b/w anatomical andDistinction is made b/w anatomical and anthropological points which are locatedanthropological points which are located on or within skeletal structureson or within skeletal structures www.indiandentalacademy.comwww.indiandentalacademy.com
  10. 10. PROPERTIESPROPERTIES Ease of locationEase of location Constancy of contoursConstancy of contours www.indiandentalacademy.comwww.indiandentalacademy.com
  11. 11. 1.EASE OF LOCATION:1.EASE OF LOCATION: According to MOYERS (1973) thisAccording to MOYERS (1973) this depends on the following factorsdepends on the following factors -Quality of radiographs-Quality of radiographs -Overlapping anatomical contours-Overlapping anatomical contours -Observer experience-Observer experience www.indiandentalacademy.comwww.indiandentalacademy.com
  12. 12. A. QUALITY OF RADIOGRAPHSA. QUALITY OF RADIOGRAPHS  The quality of radiographs is often marred byThe quality of radiographs is often marred by magnification or distortionmagnification or distortion -Magnification is due to divergence of x-rays .-Magnification is due to divergence of x-rays . The smaller the focus film distance andThe smaller the focus film distance and greater the object image distance, greater is thegreater the object image distance, greater is the magnificationmagnification -Distortion arises from two dimensional-Distortion arises from two dimensional representation of three dimensional objectrepresentation of three dimensional object www.indiandentalacademy.comwww.indiandentalacademy.com
  13. 13. B. OVERLAPPING ANATOMICALB. OVERLAPPING ANATOMICAL CONTOURSCONTOURS Facial structures overlap a great deal,soFacial structures overlap a great deal,so that location of certain landmarks maythat location of certain landmarks may present problemspresent problems www.indiandentalacademy.comwww.indiandentalacademy.com
  14. 14. C. OBSERVERC. OBSERVER EXPERIENCEEXPERIENCE Observer’s experience and practice play aObserver’s experience and practice play a major role in the interpretation ofmajor role in the interpretation of radiographs ,with knowledge of anatomyradiographs ,with knowledge of anatomy and x-ray anatomy as the key factorand x-ray anatomy as the key factor www.indiandentalacademy.comwww.indiandentalacademy.com
  15. 15. 2. CONSTANCY OF CONTOURS2. CONSTANCY OF CONTOURS The structures of skull show dependenceThe structures of skull show dependence on a number of factors such as sex ,on a number of factors such as sex , growth , race etc…growth , race etc… The constancy of contours is therefore notThe constancy of contours is therefore not entirely reliable in contra-distinction toentirely reliable in contra-distinction to points located close to the base of skullpoints located close to the base of skull where variation due to growth is minimalwhere variation due to growth is minimal www.indiandentalacademy.comwww.indiandentalacademy.com
  16. 16. Reference pointsReference points UnilateralUnilateral BilateralBilateral www.indiandentalacademy.comwww.indiandentalacademy.com
  17. 17. www.indiandentalacademy.comwww.indiandentalacademy.com
  18. 18. Nasion Most anterior point of naso-frontal suture in the median planewww.indiandentalacademy.comwww.indiandentalacademy.com
  19. 19. Nasion’ The point of maximum concavity b/w nose and foreheadwww.indiandentalacademy.comwww.indiandentalacademy.com
  20. 20. Sella Midpoint of hypophysial fossa www.indiandentalacademy.comwww.indiandentalacademy.com
  21. 21. Midpoint of entrance to sella The midpoint of line connecting the posterior Clinoid process and the anterior opening of Sella turcica www.indiandentalacademy.comwww.indiandentalacademy.com
  22. 22. Condylion Most superior point on the head of the condyle www.indiandentalacademy.comwww.indiandentalacademy.com
  23. 23. Basion The lowest point on the anterior margin of the Foramen magnum in the median planewww.indiandentalacademy.comwww.indiandentalacademy.com
  24. 24. Gonion The intersection of line tangent to the posterior margin of the ascending ramus and the mandibular base www.indiandentalacademy.comwww.indiandentalacademy.com
  25. 25. Menton The most inferior point of the outline Of symphysis in the mid-sagittal plane www.indiandentalacademy.comwww.indiandentalacademy.com
  26. 26. Gnathion The most anterior and inferior point of bony chinwww.indiandentalacademy.comwww.indiandentalacademy.com
  27. 27. Point B,Supramentale The most posterior point in the outer contour of mandibular alveolar process,in the median plane www.indiandentalacademy.comwww.indiandentalacademy.com
  28. 28. Prosthion The lowest,most anterior point on the alveolar portion of the premaxilla b/w the upper centrals www.indiandentalacademy.comwww.indiandentalacademy.com
  29. 29. Point A,Subspinale The deepest midline point b/w the anterior nasal spine and the prosthionwww.indiandentalacademy.comwww.indiandentalacademy.com
  30. 30. Anterior Nasal Spine The tip of bony anterior nasal spine , In the median plane www.indiandentalacademy.comwww.indiandentalacademy.com
  31. 31. Posterior Nasal Spine The intersection b/w pterygopalatine fossa and the floor of the nose. www.indiandentalacademy.comwww.indiandentalacademy.com
  32. 32. Orbitale Lowermost point of the orbit in the radiograph www.indiandentalacademy.comwww.indiandentalacademy.com
  33. 33. Tip of nose The most anterior point of soft-tissue nose www.indiandentalacademy.comwww.indiandentalacademy.com
  34. 34. Subnasale The point at which nasal septum merges mesially with the integument of upper lipwww.indiandentalacademy.comwww.indiandentalacademy.com
  35. 35. Inferior labial Sulcus The point at which labrale inferius meets soft tissue pogonionwww.indiandentalacademy.comwww.indiandentalacademy.com
  36. 36. Labrale Superius Edge of upper lip www.indiandentalacademy.comwww.indiandentalacademy.com
  37. 37. Soft tissue pogonion The most anterior point of soft tissue chin www.indiandentalacademy.comwww.indiandentalacademy.com
  38. 38. pterygomaxillare The posterior superior point of pterugomaxillary fissure www.indiandentalacademy.comwww.indiandentalacademy.com
  39. 39. Porion The most superiorly positioned point of external auditory meatus www.indiandentalacademy.comwww.indiandentalacademy.com
  40. 40. Articulare The point of intersection of posterior Border of condylar process of mand And inferior border of basilar part of Occipital bone www.indiandentalacademy.comwww.indiandentalacademy.com
  41. 41. www.indiandentalacademy.comwww.indiandentalacademy.com
  42. 42.  Dento-skeletal analysis –carried out in 3 stages.Dento-skeletal analysis –carried out in 3 stages. 1.Analysis of facial skeleton 2.Analysis of maxillary and mandibular bases 3. Dento alveolar analysis www.indiandentalacademy.comwww.indiandentalacademy.com
  43. 43. ANALYSIS OF FACIAL SKELETONANALYSIS OF FACIAL SKELETON DeterminesDetermines Saddle, Articular and Gonial angles and the extent of cranial base &angles and the extent of cranial base & facial heightfacial height www.indiandentalacademy.comwww.indiandentalacademy.com
  44. 44. SADDLE ANGLE TheThe NS-ar angle is the angle b/w anteriorangle is the angle b/w anterior and posterior cranial baseand posterior cranial base Within the posterior cranial base lies theWithin the posterior cranial base lies the sagittal growth centre, the sphenooccipitalsagittal growth centre, the sphenooccipital synchondrosissynchondrosis The position of the fossa is determined byThe position of the fossa is determined by growth changes in this areagrowth changes in this area www.indiandentalacademy.comwww.indiandentalacademy.com
  45. 45. www.indiandentalacademy.comwww.indiandentalacademy.com
  46. 46. A large saddle angle indicates a posteriorA large saddle angle indicates a posterior position and a small saddle angle indicates anposition and a small saddle angle indicates an anterior position of the fossaanterior position of the fossa If this deviation is not compensated by lengthIf this deviation is not compensated by length of the ascending ramus –prognathic orof the ascending ramus –prognathic or retrognathicretrognathic Mean valueMean value 123o + 5o www.indiandentalacademy.comwww.indiandentalacademy.com
  47. 47. ARTICULAR ANGLE If the bite is opened by extrusion ofIf the bite is opened by extrusion of posterior teeth the angle increases whileposterior teeth the angle increases while mesial movement makes it smallermesial movement makes it smaller A large articular angle imposesA large articular angle imposes retrognathic changes on the profile &retrognathic changes on the profile & small angle , the prognathic changessmall angle , the prognathic changes Mean value is 143Mean value is 143O + 6O www.indiandentalacademy.comwww.indiandentalacademy.com
  48. 48. GONIAL ANGLEGONIAL ANGLE A large angle –posterior rotation of theA large angle –posterior rotation of the mandible with condylar growth directedmandible with condylar growth directed posteriorlyposteriorly A small gonial angle-anterior rotation withA small gonial angle-anterior rotation with vertical growth of the condylevertical growth of the condyle Mean value is 128Mean value is 128OO ++ 77OO www.indiandentalacademy.comwww.indiandentalacademy.com
  49. 49. www.indiandentalacademy.comwww.indiandentalacademy.com
  50. 50. Upper and Lower gonial angles-JarabakUpper and Lower gonial angles-Jarabak Divided by a line drawn from nasion toDivided by a line drawn from nasion to goniongonion The upper angle is formed by ascendingThe upper angle is formed by ascending ramus and the line joining nasion andramus and the line joining nasion and goniongonion Large upper angle –horizontalLarge upper angle –horizontal Large lower angle-vertical growthLarge lower angle-vertical growth Small upper angle-caudalSmall upper angle-caudal Small lower angle-sagittal growthSmall lower angle-sagittal growthwww.indiandentalacademy.comwww.indiandentalacademy.com
  51. 51. www.indiandentalacademy.comwww.indiandentalacademy.com
  52. 52. 1.The increased gonial angle is due to1.The increased gonial angle is due to adaptation to greater anterior faceadaptation to greater anterior face height.Adaptation may also occur in theheight.Adaptation may also occur in the posterior part of facial skeleton due toposterior part of facial skeleton due to posterior rotation in the TMJ,with theposterior rotation in the TMJ,with the gonial angle unchanged ;the basal anglegonial angle unchanged ;the basal angle will be increased however.will be increased however. 2. The height of the alveolar process adapts2. The height of the alveolar process adapts to a large gonial angle ,resulting into a large gonial angle ,resulting in increased anterior face heightincreased anterior face height www.indiandentalacademy.comwww.indiandentalacademy.com
  53. 53. www.indiandentalacademy.comwww.indiandentalacademy.com
  54. 54. Posterior gonial anglePosterior gonial angle Two types of gonial angles can beTwo types of gonial angles can be distinguisheddistinguished -A gonial angle opening out-A gonial angle opening out posteriorly,with Go1 relatively largeposteriorly,with Go1 relatively large -A gonial angle opening out anteriorly ,-A gonial angle opening out anteriorly , with Go 1 relatively smallwith Go 1 relatively small www.indiandentalacademy.comwww.indiandentalacademy.com
  55. 55. www.indiandentalacademy.comwww.indiandentalacademy.com
  56. 56. Anterior gonial angleAnterior gonial angle The anterior gonial angle was checked forThe anterior gonial angle was checked for correlation with the basal plane angle.correlation with the basal plane angle. -Basal plane angle becoming smaller in-Basal plane angle becoming smaller in relation to gonial angle due to posteriorrelation to gonial angle due to posterior rotation of mandiblerotation of mandible -A relative increase in basal plane angle-A relative increase in basal plane angle due to anterior rotation of mandibledue to anterior rotation of mandible www.indiandentalacademy.comwww.indiandentalacademy.com
  57. 57. Sum of posterior anglesSum of posterior angles The sum of all the three angles isThe sum of all the three angles is 396396OO ++ 66OO  If it is greater than 396If it is greater than 396OO , the direction of, the direction of growth is likely to be vertical;if it is smallergrowth is likely to be vertical;if it is smaller then growth may be expected to bethen growth may be expected to be horizontalhorizontal www.indiandentalacademy.comwww.indiandentalacademy.com
  58. 58. www.indiandentalacademy.comwww.indiandentalacademy.com
  59. 59. ANALYSIS OF MAXILLARY ANDANALYSIS OF MAXILLARY AND MANDIBULAR BASESMANDIBULAR BASES www.indiandentalacademy.comwww.indiandentalacademy.com
  60. 60. SNA AngleSNA Angle It defines the anteroposterior position ofIt defines the anteroposterior position of point A relative to anterior cranial basepoint A relative to anterior cranial base with a mean value of 81with a mean value of 81OO as normalas normal A large SNA Angle (greater than 84A large SNA Angle (greater than 84OO )) makes the antero-posterior position ofmakes the antero-posterior position of maxilla prognathicmaxilla prognathic A small angle (less than 78A small angle (less than 78OO ) makes it) makes it retrognathicretrognathic www.indiandentalacademy.comwww.indiandentalacademy.com
  61. 61. www.indiandentalacademy.comwww.indiandentalacademy.com
  62. 62. www.indiandentalacademy.comwww.indiandentalacademy.com
  63. 63. SNB AngleSNB Angle It defines the antero-posterior position ofIt defines the antero-posterior position of mandible in relation to the anterior cranialmandible in relation to the anterior cranial base with a mean value of 79base with a mean value of 79OO as normalas normal A large SNB Angle (greater than 82A large SNB Angle (greater than 82OO )) makes it prognathicmakes it prognathic A small SNB Angle (less than 79A small SNB Angle (less than 79OO ) makes) makes it retrognathicit retrognathic www.indiandentalacademy.comwww.indiandentalacademy.com
  64. 64. www.indiandentalacademy.comwww.indiandentalacademy.com
  65. 65. MORPHOLOGY OF THE MANDIBLEMORPHOLOGY OF THE MANDIBLE -- orthognathicorthognathic - prognathic- prognathic - retrognathic- retrognathic www.indiandentalacademy.comwww.indiandentalacademy.com
  66. 66. Orthognathic typeOrthognathic type Ramus and the body are fully developedRamus and the body are fully developed with the width of the ascending ramuswith the width of the ascending ramus equal to the height of body of the mandibleequal to the height of body of the mandible The occlusal surface runs parallel to planeThe occlusal surface runs parallel to plane of the mandible with condylar andof the mandible with condylar and coronoid process almost on the samecoronoid process almost on the same planeplane The lower incisors almost at right angle toThe lower incisors almost at right angle to plane of the mandibleplane of the mandible www.indiandentalacademy.comwww.indiandentalacademy.com
  67. 67. www.indiandentalacademy.comwww.indiandentalacademy.com
  68. 68. Retrognathic typeRetrognathic type The ascending ramus is narrow,as is theThe ascending ramus is narrow,as is the condyle in the antero-posterior directioncondyle in the antero-posterior direction The coronoid process is shorter than theThe coronoid process is shorter than the condylar process and the mandibularcondylar process and the mandibular angle is largeangle is large The angle b/w the axis of lower incisorsThe angle b/w the axis of lower incisors and the mandibular plane is greater thanand the mandibular plane is greater than 9090OO .. www.indiandentalacademy.comwww.indiandentalacademy.com
  69. 69. Prognathic typePrognathic type The ascending ramus and the body areThe ascending ramus and the body are wide with small mandibular anglewide with small mandibular angle The symphysis is well developedThe symphysis is well developed The angle b/w the axis of lower incisorsThe angle b/w the axis of lower incisors and the mandibular plane is less than 90and the mandibular plane is less than 90OO www.indiandentalacademy.comwww.indiandentalacademy.com
  70. 70. ANB AngleANB Angle The ANB Angle is positive if point A liesThe ANB Angle is positive if point A lies anterior to NB and negative if point A liesanterior to NB and negative if point A lies posterior to NBposterior to NB If NA and NB coincide the angle will beIf NA and NB coincide the angle will be zerozero On average the angle is 2On average the angle is 2OO High positives-class II ,and negatives inHigh positives-class II ,and negatives in skeletal class IIIskeletal class III www.indiandentalacademy.comwww.indiandentalacademy.com
  71. 71. www.indiandentalacademy.comwww.indiandentalacademy.com
  72. 72. The Wit’s MethodThe Wit’s Method A measure of the extent to which jaws areA measure of the extent to which jaws are related to each other antero-posteriorlyrelated to each other antero-posteriorly The perpendiculars are drawn on a lateralThe perpendiculars are drawn on a lateral cephalometric head filmtracing from pointcephalometric head filmtracing from point A and point B on maxilla and mandible onA and point B on maxilla and mandible on to the occlusal plane which is drawn thruto the occlusal plane which is drawn thru the region of maximal cuspalthe region of maximal cuspal interdigitationinterdigitation www.indiandentalacademy.comwww.indiandentalacademy.com
  73. 73. The points of contacts on the occlusalThe points of contacts on the occlusal plane are labelled as AO and BOplane are labelled as AO and BO It was found that with normal occlusion,It was found that with normal occlusion, point BO was approx 1mm anterior topoint BO was approx 1mm anterior to point AOpoint AO In skeletal Class II jaw dysplasias ,pointIn skeletal Class II jaw dysplasias ,point BO will be located well behind point AOBO will be located well behind point AO and viceversa in skeletal Class IIIand viceversa in skeletal Class III www.indiandentalacademy.comwww.indiandentalacademy.com
  74. 74. www.indiandentalacademy.comwww.indiandentalacademy.com
  75. 75. HORIZONTAL LINESHORIZONTAL LINES Inter-relations are assessed to determineInter-relations are assessed to determine the vertical position of the maxillary andthe vertical position of the maxillary and mandibular basesmandibular bases The most important lines are the SNThe most important lines are the SN plane,FH plane,Palatal plane,occlusalplane,FH plane,Palatal plane,occlusal plane and the mandibular planeplane and the mandibular plane www.indiandentalacademy.comwww.indiandentalacademy.com
  76. 76. www.indiandentalacademy.comwww.indiandentalacademy.com
  77. 77. Basal plane angleBasal plane angle It defines the inclination of the mandible toIt defines the inclination of the mandible to the maxillary base ,therefore also servesthe maxillary base ,therefore also serves to determine the rotation of the mandibleto determine the rotation of the mandible If the basal plane angle is large then theIf the basal plane angle is large then the mandible is usually rotated backwards andmandible is usually rotated backwards and if it is small then the mandible is rotatedif it is small then the mandible is rotated forwardsforwards www.indiandentalacademy.comwww.indiandentalacademy.com
  78. 78. With the retro-inclination of the maxillaryWith the retro-inclination of the maxillary base , the basal angle will be relativelybase , the basal angle will be relatively smaller,with ante-inclination, relativelysmaller,with ante-inclination, relatively largerlarger The mean basal angle is 25The mean basal angle is 25OO www.indiandentalacademy.comwww.indiandentalacademy.com
  79. 79. www.indiandentalacademy.comwww.indiandentalacademy.com
  80. 80. N-S-Gn AngleN-S-Gn Angle This angle determines the relative positionThis angle determines the relative position of mandible to cranial base as anof mandible to cranial base as an additional checkadditional check It has a mean value of 66It has a mean value of 66oo A greater value –mandible in a posteriorA greater value –mandible in a posterior position with a vertical growth patternposition with a vertical growth pattern If the angle is less than the mean valueIf the angle is less than the mean value mandible is in an anterior positionmandible is in an anterior position www.indiandentalacademy.comwww.indiandentalacademy.com
  81. 81. DENTO-ALVEOLAR ANALYSISDENTO-ALVEOLAR ANALYSIS www.indiandentalacademy.comwww.indiandentalacademy.com
  82. 82. Angulation of upper incisorsAngulation of upper incisors Two measurements are considered;firstlyTwo measurements are considered;firstly its long axis considered in relation to SNits long axis considered in relation to SN and secondly to palatal planeand secondly to palatal plane For the first measurement , the long axisFor the first measurement , the long axis of upper incisors is extended to intersectof upper incisors is extended to intersect the SN line and the posterior angle isthe SN line and the posterior angle is measuredmeasured www.indiandentalacademy.comwww.indiandentalacademy.com
  83. 83. The mean value is 102The mean value is 102oo ++ 2200 Up to the 7Up to the 7thth year , it is only 94-100year , it is only 94-100OO onon average ,with 102average ,with 102OO achieved only 1 or 2achieved only 1 or 2 years after eruptionyears after eruption Larger angles indicate maxillary incisorLarger angles indicate maxillary incisor protrusion and smaller angles very uprightprotrusion and smaller angles very upright incisorsincisors www.indiandentalacademy.comwww.indiandentalacademy.com
  84. 84. In the second measurement the anteriorIn the second measurement the anterior angle b/w the long axis of incisor and theangle b/w the long axis of incisor and the palatal plane is measuredpalatal plane is measured The mean value from 8The mean value from 8thth year onward isyear onward is 7070OO ++ 55OO An enlarged angle signifies very uprightAn enlarged angle signifies very upright incisors ,a smaller than average oneincisors ,a smaller than average one incisor protrusionincisor protrusion www.indiandentalacademy.comwww.indiandentalacademy.com
  85. 85. www.indiandentalacademy.comwww.indiandentalacademy.com
  86. 86. Angulation of Lower IncisorsAngulation of Lower Incisors The posterior angle b/w the long axis ofThe posterior angle b/w the long axis of the incisor and the mandibular plane isthe incisor and the mandibular plane is determineddetermined The mean value is 90The mean value is 90OO ++ 33OO From the 6From the 6thth to the 12to the 12thth year ,the angleyear ,the angle increases from 88increases from 88OO – 94– 94OO www.indiandentalacademy.comwww.indiandentalacademy.com
  87. 87. A wide angle indicates protrusion ofA wide angle indicates protrusion of mandibular incisors , a smaller thanmandibular incisors , a smaller than normal angle , a very upright incisorsnormal angle , a very upright incisors www.indiandentalacademy.comwww.indiandentalacademy.com
  88. 88. Assessment of Incisor positionAssessment of Incisor position The distance of incisal edges from theThe distance of incisal edges from the NPog line is determinedNPog line is determined The average distance is 4The average distance is 4 ++ 2 mm for2 mm for mawillary incisors and for lower incisors itmawillary incisors and for lower incisors it is -2 to +2mmis -2 to +2mm www.indiandentalacademy.comwww.indiandentalacademy.com
  89. 89. This particular measurement is a keyThis particular measurement is a key factor-factor- -whether the extraction is indicated-whether the extraction is indicated -whether the lower incisors can be-whether the lower incisors can be moved forwardmoved forward -whether the anchorage is critical-whether the anchorage is critical www.indiandentalacademy.comwww.indiandentalacademy.com
  90. 90. www.indiandentalacademy.comwww.indiandentalacademy.com
  91. 91. www.indiandentalacademy.comwww.indiandentalacademy.com
  92. 92. CONCLUSIONCONCLUSION Among the many miracles of life is theAmong the many miracles of life is the uniqueness of human face.No part of ouruniqueness of human face.No part of our anatomy provides more information;anatomy provides more information; indeed,no part of our anatomy is moreindeed,no part of our anatomy is more vital to our success and existence.vital to our success and existence. In this era of burgeoning biotechnologyIn this era of burgeoning biotechnology orthodontic profession has entered aorthodontic profession has entered a pivotal period –the one that will continue topivotal period –the one that will continue to change the practice of orthodontics.change the practice of orthodontics. www.indiandentalacademy.comwww.indiandentalacademy.com
  93. 93. For more details please visitFor more details please visit www.indiandentalacademy.comwww.indiandentalacademy.com www.indiandentalacademy.comwww.indiandentalacademy.com

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