Diagnostic procedures /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.

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Diagnostic procedures /certified fixed orthodontic courses by Indian dental academy

  1. 1. DIAGNOSTIC PROCEDURES www.indiandentalacademy.com
  2. 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  4. 4.       Examination of postural rest position, TMJ Orofacial dysfunction Radiographic examinations Conventional tomography Computed tomography Ultrasonography           Anthrography FEM Palatography Cineradiography EMG Bone scanning Lazor scanning Videocephalometry Electronic thermography MRI www.indiandentalacademy.com
  5. 5. INTRODUCTION “ The first step towards cure is to know, what the disease is………..” www.indiandentalacademy.com
  7. 7. GOAL To classify malocclusion ,the patient presents with.  Treatment planning.  www.indiandentalacademy.com
  8. 8. MEANING  STRANG: “There is nothing complicated about making a diagnosis in orthodontia, for the moment one has detected a deviation from normal occlusion and so determines that there is malocclusion, the diagnosis is complete.”  ANGLE: Normal occlusion, favorable function& acceptable dentofacial esthetics represented an identity. This process could be called the TRADITIONAL APPROACH. www.indiandentalacademy.com
  9. 9.  CASE,HELLMAN &SIMON: Orthodontic diagnosis required a deeper understanding of the orthodontic problem. The concepts of dental and skeletal problem can be credited to these men. RATIONAL APPROACH  MOORREES & GRON: Dental, skeletal, muscular factors and the somatic and emotional development of an individual. They also considered personal and societal factors. This view is called the OVERALL DIAGNOSIS. www.indiandentalacademy.com
  10. 10. DEFINITION   THOMAS RAKOSI: The recognition and systematic designation of anomalies, the practical synthesis of the findings, permitting therapy to be planned and indication to be determined, thereby enabling the doctor to act. Orthodontic diagnosis requires a broad overview of the patient’s situation. www.indiandentalacademy.com
  12. 12. COMPREHENSIVE DIAGNOSIS   Orthodontic diagnosis should be routinely based on various methods of examination. The COMPREHENSIVE DIAGNOSIS should be a summary of the most important facts and should not take insignificant secondary symptoms into account. www.indiandentalacademy.com
  13. 13. www.indiandentalacademy.com
  14. 14.  Orthodontic diagnosis can be referred to as a diagnostic process. www.indiandentalacademy.com
  15. 15. DIAGNOSIS &TREATMENT PLANNING     Recognize the various characteristics of malocclusion and dentofacial deformity. Define the nature of the problem including the etiology if possible. Design a treatment strategy based on specific needs and desires of the individual. Present the treatment strategy to the patient in such a way that the patient fully understands the ramifications of the treatment. www.indiandentalacademy.com
  16. 16. PROBLEM ORIENTED APPROACHDIAGNOSIS www.indiandentalacademy.com
  17. 17. DIAGNOSTIC AIDS  ESSENTIAL:  Case history Clinical examination Study models RADIOGRAPHS IOPA’S Cephalograms OPG Bitewing Facial Photographs                   www.indiandentalacademy.com NONESSENTIAL Specialized radiographs EMG activity of muscle Hand wrist radiography CT scan MRI Endocrine tests Basal metabolic rate Vitality test Biopsy
  18. 18. www.indiandentalacademy.com
  19. 19. CASE HISTORY  Medical   Dental Family  Patient  Prenatal  Postnatal www.indiandentalacademy.com Patient Birth
  21. 21. PRENATAL PERIOD        MATERNAL Tetracycline stains on teeth Viral infection and cleft formation INTRAUTERINE MOULDING :Pressure during fetal growth distorts the developing face. e.g. PIERRE ROBIN SYNDROMME. Uterine posture Fibroids of the mother Amniotic lesions www.indiandentalacademy.com
  22. 22. TERATOGENS  ASPIRIN  Cleft lip & palate  CIG.SMOKE  Cleft lip & palate  DILANTIN  Cleft lip & palate  ETHYL ALCOHOL  Mid face deficiency  VALIUM  Cleft lip & palate  VIT.D EXCESS  Premature suture closure. www.indiandentalacademy.com
  23. 23.      Maternal diet Metabolic differences: “Cephalometric study of children with various endocrine diseases” A.J.O 59:362-375 1971.These appear to be unlikely causes. (SPEIGER et al) Injury to the mother Drug induced deformities: Thalidomide German measles www.indiandentalacademy.com
  24. 24. BIRTH HISTORY  Forceps deliveries injuries of the TMJ. Pressure Ankylosis Mandibular growth retardation.  BREECH DELIVERY  VOGELGESICHT: Inhibited growth of the mandible due to ankylosis of the T.M.J  Cerebral Palsy  Delivery induced deformation of the upper jaw. www.indiandentalacademy.com
  25. 25. POST NATAL HISTORY    Type of feeding: Breast, Bottle Advantageous: Activates jaw muscle Increases functional loading Moves mandible anteriorly Compensates for the physiologic retruded jaw position at birth. The child's sucking reflex is satisfied. Fewer chances of habits. www.indiandentalacademy.com
  26. 26. CONSISTENCY OF FOOD: SOLID:MASSETER CHEWER       High functional load –strong bony framework. Food-ground Dec. teeth abraded Lower arch displaced forward. 1st molars positioned favorably. Decreased overbite. www.indiandentalacademy.com
  27. 27. NON SOLID:TEMPORALIS CHEWER      Food chewed superficially. Low functional load: incomplete development of framework. Minimal abrasion of teeth. 1st molars unstable Lower arch not displaced anteriorly. www.indiandentalacademy.com
  28. 28.  HABITS: Duration, frequency & intensity. Duration is the most imp.  TRAUMA:# of the condyle.  PRIMARY FAILURE OF ERUPTION: Lead to posterior open bite.  POSTURE: Head: Forward, Chin extended associated with a long face.  Head backward: Short face  Extensive scar formation  MILWAUKEE BRACES www.indiandentalacademy.com
  29. 29. CHIEF COMPLAINT       Recorded in pt’s. Own words. Mention what the pt. feels he/she is suffering from. Pt’s. perception. What is important for the patient. Why has the pt. come? Esthetics or impaired function. www.indiandentalacademy.com
  30. 30. MEDICAL HISTORY          H/O hospitalization :Tonsillectomy & adenoidectomy. Trauma Heart ds., rheumatic fever, murmur Blood transfusion: HIV, hepatitis. Diabetes mellitus Arthritis/osteoporosis Poliomyelitis Muscle dysfunction Hypothyroidism: retained dec. teeth, delayed eruption, abnormal resorption. www.indiandentalacademy.com
  31. 31. DRUG HISTORY     Reveal systemic ds. Epileptic pt. takes dilantin -anticonvulsant drug-gingival hyperplasia-impede tooth movement. Steroids: decreases resistance to infection-difficulty in tolerating orthodontic appliances. Osteoporosis: resorption inhibiting drugs (prostaglandin inhibitors) www.indiandentalacademy.com
  32. 32. ALLERGY Latex sensitivity: gloves, elastics  Nickel sensitivity: wires & brackets. If sensitive titanium brackets or ceramic brackets may be used.  www.indiandentalacademy.com
  33. 33. DENTAL HISTORY     Past dental history will help in assessing the pts. or parents attitude. Indicator of pt’s susceptibility towards Pdl. ds. or caries. H/O traumatic injury to teeth: orthodontic treatment exacerbate periapical symptoms that are already present. Dental health awareness www.indiandentalacademy.com
  34. 34. PSYCHOSOCIAL HISTORY     Social & behavioral history. Difficult to obtain; Parent is reluctant to speak. Emotional problems are suspected when :Thumb sucking, poor progress in school, sleep walking in a young child, enuresis in an older child. www.indiandentalacademy.com
  35. 35. SCHOOL PROGRESS      To know about learning disability. If present modify approach. Pts have short attention span To much of detailed information about treatment can produce anxiety. Reduce responsibility of the patient. www.indiandentalacademy.com
  36. 36. MOTIVATION     EXTERNAL OR INTERNAL External: supplied by pressure by another individual. Internal: comes from within based on his or her own assessment of the situation. A child or an adult who feels that the treatment is being done for him will be a more receptive patient than one who feels that the treatment is being done to him. www.indiandentalacademy.com
  37. 37. EXPECTATION    HIGH, MODERATE, LOW What patient expects from treatment is related to the type of motivation. If the patient expects social adjustment problems to be solved after treatment then he or she is a poor candidate for orthodontic treatment. www.indiandentalacademy.com
  38. 38. COOPERATION     Problem with the child than the adult. Factors important are: The extent to which the child sees the treatment as benefit as opposed to something else he or she is required to undergo. The degree of parental control. A rebellious child with ineffective parents is likely to become a problem. www.indiandentalacademy.com
  39. 39. FAMILY / GENETIC HISTORY      Any siblings of the patient require any orthodontic treatment. Parents ever underwent orthodontic treatment. The tissues primarily affected are: NEUROMUSCULAR SYSTEM TEETH: Size, shape , number, mineralization, path of eruption, position of tooth germ, sequence of eruption. www.indiandentalacademy.com
  40. 40. BONE     SIZE: Hereditary micrognathia or macrognathia. SHAPE: Asymmetries – Crouzon’s disease, cleidocranial dysostosis. LOCATION: Prognathism, retrognathism. Class 2 div.2,Mand.prog.,bimax. protrusion, skeletal open bite, skeletal mand. retrognathism. www.indiandentalacademy.com
  41. 41. SOFT TISSUE Facial clefts  Microstomia  Anomalies of the frena  Ankyloglossia  www.indiandentalacademy.com
  42. 42. CLINICAL EXAMINATION      EXTRAORAL GENERAL PHYSICAL DEVELOPMENT To assess the amt. of growth that has occurred & the potential of future growth that remains. Best results-good growers-amt., rate, direction, pattern that facilitates treatment. Modifiability of a problem & treatment prognosis are strongly influenced by growth. www.indiandentalacademy.com
  43. 43. PHYSICAL GROWTH EVALUATION     Whether the child has recently grown rapidly? Whether there is a change in the size of the clothes? Whether there are signs of sexual maturation? Whether there is a change in the voice? www.indiandentalacademy.com
  44. 44. GENERAL BODY TYPE(PHYSIQUE)    ASTHETIC: Thin physique, possess narrow dental arches. PLETORIC: Obese, have large square dental arches. ATHLETIC: Normally built, being neither thin nor obese. Have normal sized dental arches. www.indiandentalacademy.com
  45. 45. BODY BUILD     SHELDON ECTOMORPHIC: Tall & thin physique. Grow more slowly & reach the pubertal growth spurt later. MESOMORPHIC: Average physique. ENDOMORPHIC: Short & obese. www.indiandentalacademy.com
  46. 46. HEIGHT & WEIGHT Clue to the physical growth www.indiandentalacademy.com
  47. 47. GAIT   It is the way the person walks. Abnormalities of gait are associated with neuromuscular disorders. www.indiandentalacademy.com
  48. 48. POSTURE Poor postural conditions either lead to malocclusion or accentuate it.  A stoop shouldered child with the head hung, chin rests on the chest: Mandibular retrusion.  www.indiandentalacademy.com
  49. 49. CEPHALIC EXAMINATION    The shape of the head is assessed. MARTIN & SALLER (1957): DOLICOCEPHALIC Long & narrow head. Narrow dental arches. www.indiandentalacademy.com
  50. 50. MESOCEPHALIC   Average shape of head. Possess normal dental arches. www.indiandentalacademy.com
  51. 51. BRACHYCEPHALIC   Broad & short head. Broad dental arches. www.indiandentalacademy.com
  52. 52. CEPHALIC INDEX Based on anthropometric determination of the max. width of the head and max. length.  Cephalic index: Max. skull width Max. skull length Dolicocephalic: -75.9 Mesocephalic:76-80.9 Brachycephalic:81-85.4 Hyperbrachycephalic:85.5 www.indiandentalacademy.com
  53. 53. QUADRATE CAPUT  www.indiandentalacademy.com Square deformity of the skull in rickets caused by the protuberances of the frontal and parietal bones.
  54. 54. CRANIOMETRY     Used to study growth. Involves measurement of the skulls found amongst the human skeletal remains. Adv: Precise measurement can be made on dry skulls. Disadv: The growth study is crosssectional. www.indiandentalacademy.com
  55. 55. FACIAL EXAMINATION    “Beauty/esthetics lies in the eyes of the beholder” Goal: Detect disproportion. Done with patient either standing in a relaxed manner or seated in a straight chair. The upright position enables to assume a NHP. www.indiandentalacademy.com
  56. 56. FRONTAL VIEW (FACIAL FORM)    MARTIN & SALLER(1957) EURYPROSOPIC:B road & short face Apical base is wide in trans. dimension. Dental crowding is confined to coronal part, coronal crowding. Trans. expansion indicated. www.indiandentalacademy.com
  57. 57. LEPTOPROSOPIC/HYPERLEPTOPROSO       www.indiandentalacademy.com Long & narrow face. Reduced bizygomatic width. Narrow apical base in trans. dimen. Extraction therapy should be done incase of crowding. Reduced overbite. Steep mand. Plane.
  58. 58. MORPHOLOGIC FACIAL INDEX Morphologic facial height Bizygomatic width Hypereuryprosopic:-78.9 Euryprosopic: 79-83.9 Mesoprosopic:84-87.9 Leptoprosopic:88.0-92.9 Hyperleptoprosopic:93.0  www.indiandentalacademy.com
  59. 59. SYMMETRY  The width of the base of the nose should be approx. same as the inter inner canthal distance, while the width of the mouth should be approx. the distance b/w the irises. www.indiandentalacademy.com
  60. 60. GROSS FACIAL ASYMMETRIES    Congenital defects Hemifacial atrophy/hypertrophy Unilateral condylar ankylosis and hyperplasia. www.indiandentalacademy.com
  61. 61. ANTHROPOMETRY     Enables measurement of skeletal dimensions on living patients. Establishes facial proportion. Various landmarks established in the studies of dry skulls are measured in living individuals by using soft tissue points overlying the bony landmarks. Measurement made with st. or bow calipers. www.indiandentalacademy.com
  62. 62. www.indiandentalacademy.com
  63. 63. ADVANTAGES   Allows to follow the growth of an individual directly, making the same measurement repeatedly at diff. times. Assessment of general pattern of craniofacial growth. DISADVANTAGES  Soft tissue introduces variation. www.indiandentalacademy.com
  64. 64. FARKAS ANTHROPOMETRIC STUDY www.indiandentalacademy.com
  65. 65. MIDLINE DEVIATIONS   Dentoalveolar midline shift in the upper arch. The contat of the upper CI does not coincide with the center of the philtrum. www.indiandentalacademy.com
  66. 66. MIDLINE SHIFT IN THE LOWER ARCH   Dentoalveolar: Results from tooth migration. The mental spine of the mandible coincides with the midsagittal plane of the skull only contact pt. of the incisors is deviated. www.indiandentalacademy.com
  67. 67. SKELETAL DEVIATION OF THE MANDIBULAR MIDLINE  The skeletal midline of the mandible & the contact pt. of the lower incisors is deviated. www.indiandentalacademy.com
  68. 68. LATERAL VIEW-PROFILE      “Poor man’s cephalometric analysis” Goals: To establish whether the jaws are placed proportionately in the anteroposterior plane of space. 2 lines are drawn: one from the bridge of the nose to the base of the upper lip & the 2nd one extending from that pt. downward to the chin. These line segments should form a straight line. Angle: CONVEX PROFILE: Skeletal class2 CONCAVE PROFILE: Skeletal class 3 www.indiandentalacademy.com
  69. 69. www.indiandentalacademy.com
  70. 70. DIVERGENCE OF FACE     MILO HELLMAN Defined as an anterior or posterior inclination of the lower face relative to the forehead. Profile: straight: does not matter whether it slopes anteriorly (anterior divergence) or posteriorly (posterior divergence) Divergence does not indicate facial or dental disproportion whereas profile concavity or convexity does indicate disproportion, but does not by itself indicate which jaw is at fault. www.indiandentalacademy.com
  71. 71. www.indiandentalacademy.com
  72. 72. EVALUATION OF LIP POSTURE &INCISOR PROMINENCE     Teeth protrude: The lips are prominent & everted. The lips are separated at rest by more than 3-4mm. Excessive protrusion: Revealed by prominent lips that are separated when relaxed, so that the pt. must strain to bring the lips together, RETRACTION of the teeth alone tend to improve lip function & facial esthetics. But if the lips are prominent & close over the teeth without strain, the lip posture is largely independent of tooth position. In these individuals retracting the incisors www.indiandentalacademy.com would have little effect on the lip function.
  73. 73.   The lip posture & prominence should be evaluated by viewing the profile with the pts. lip relaxed. The upper lip is related to a true vertical line passing through the soft tissue pt. A & the lower lip is related to a true vertical line passing through the soft tissue pt.B. www.indiandentalacademy.com
  74. 74.    lips fall forward from the line-PROMINENT Lips fall backward from the lineRETRUSIVE Both lips are prominent & incompetentAnterior teeth are protrusive. www.indiandentalacademy.com
  75. 75. EVALUATION OF THE VERTICAL FACIAL PROPORTION & THE MANDIBULAR PLANE ANGLE  A well proportioned face can be divided into vertical thirds. This is called as the LAW OF THIRDS www.indiandentalacademy.com
  76. 76. INCLINATION OF THE MANDIBULAR PLANE    Steep: open bite, long ant. facial ht. Flat: Deep bite, short ant. facial ht. Visualized by placing a finger or a mirror handle along the lower border. www.indiandentalacademy.com
  77. 77. PHOTOGRAPHIC RECORDS  SANDLER & MURRAY “ Clinical photography in orthodontics” J.C.O 97 www.indiandentalacademy.com
  78. 78. EXTRA ORAL VIEWS- FRONTAL   Assesses major disproportions & asymmetries of the face. The camera should be placed perpendicular to the facial midline during exposure. www.indiandentalacademy.com
  79. 79. PHOTOGRAPHIC ANALYSIS-FRONTAL PLANE-ASSESS SYMMETRY     www.indiandentalacademy.com Vertical reference plane: skin nasion to the subnasal pt. Upper horizontal plane: Bipupillary plane. Lower horizontal plane: parallel to the bipupillary plane through the stomion. Mild degree of asymmetry occurs b/w the 2 sides of the face.
  80. 80. FRONTAL DYNAMIC SMILE   Demonstrates the amount of incisor & gingival display while the pt. smiles. Reduction of large overjets or overbites can greatly enhance the pts. smile. www.indiandentalacademy.com
  81. 81. CLOSE UP IMAGE OF POSED SMILE  For the analysis of the smile relationship. www.indiandentalacademy.com
  82. 82. THREE QUARTER EXTRA ORAL VIEW- 45 DEGREE PHOTOGRAPH  Mid face deformities.  Nasal deformities  Assessment of the way the pts. Face is viewed by others. www.indiandentalacademy.com
  83. 83. THE PROFILE    Helpful since the profile of the pt. can change during orthodontic treatment. Left profile-routine diagnosis Rt. profile-facial asymmetry www.indiandentalacademy.com
  84. 84. CLASSIFICATION OF THE FACIAL PROFILE-A.M SCHWARZ-1958    www.indiandentalacademy.com Eye ear plane (Frankfort horizontal plane) Skin Nasion perpendicular Orbital perpendicular according to Simon.
  85. 85.       JAW PROFILE FIELD: Lies b/w both the perpendiculars. Children:13-14mm wide Adults:15-17mm wide Ideal average value face: the subnasal pt. touches the skin nasion perpendicular. The soft tissue chin point: lies in the center of the “jaw profile field”. It is the most ventral point of the soft tissue part of the chin. The skin gnathion (the most inferior chin pt.) lies on the orbital pointer. www.indiandentalacademy.com
  86. 86. NINE POSSIBLE PROFILE VARIANTSA.M SCHWARZ –ST. JAW PROFILE    Average face: The subnasale lying on the skin nasion perpendicular. Anteface: Subnasale lying in front of the skin nasion perpendicular. Retroface: Subnasale lying behind the skin nasion perpendicular. www.indiandentalacademy.com
  87. 87. BACKWARD SLANTING PROFILE     The soft tissue pogonion is displaced too far posteriorly relative to the subnasal point. Backward slanting average face Backward slanting anteface Backward slanting retroface. www.indiandentalacademy.com
  88. 88. FORWARD SLANTING PROFILE     The soft tissue of the chin is too far anterior in relation to the subnasal pt. Forward slanting average face Forward slanting anteface Forward slanting retroface www.indiandentalacademy.com
  89. 89. STEREO PHOTOGRAMMETRY     Use of stereophotogrammetry was first reported by Thalmaan-degen in 1964. It involves photographing a three dimensional object from 2 different coplanar views in order to derive a 3 dimensional reconstruction of an image. The landmarks are identified in 3 dimensions to allow tracking of relative changes in the location of the landmarks as a result of growth, development, mandibular movement, injury, skeletal malformation & treatment. Captures the human face well. www.indiandentalacademy.com
  90. 90.      A 3 dimensional X-ray stereometry is produced from paired coplanar images in order to allow accurate merging of 3 dimensional coordinate data from head films, study casts & facial photographs. Two photographs are taken with 2 semimetric cameras, which form a STEREOPAIR. The cameras are mounted on a frame with a dist. Of 50cm b/w them,& positioned convergently with an angle of 15 degrees. With the use of a analytical plotter & a stereopair a 3 dimensional image of an object is created. ADV.-Noninvasive By combining X-rays with the principles of stereophotogrammetry changes in the bone density can be tracked in 2 dimensions. Gives a good impression of the surface of the object. www.indiandentalacademy.com
  91. 91. ORTHODONTIC APPLICATIONS         “Method for quantifying facial asymmetry in 3 dimensions using stereophotogrammetry” Angle orthod. Vol.65 No.3 1995 Is a 3 dimensional method to quantify facial morphology for the purpose of diagnosis. Detect changes in the facial morphology during growth & development. Detects asymmetries. Assessing facial contour, surface appearance of the face. Evaluation of treatment results. Quantitative data on facial proportions & profile indices. The life like 3D model of the pt. can be rotated enlarged, measured in 3 dimensionswww.indiandentalacademy.com diagnoses. as required for
  92. 92. CONTOUR PHOTOGRAPHY     Uses grid projections during exposure resulting in standardized contour lines on the face. It is a light scanning technique for three dimensional facial measurement, in which telecentric lences are used to eliminate divergence. Suited for smoothly contoured surfaces. Used as an alternative to stereophotogrammetry for three dimensional facial measurement. www.indiandentalacademy.com
  93. 93. USES      DISADVANTAGES Records the shape of the face. Facial symmetry Changes due to growth. To study changes following surgery. Profile   Difficulties are encountered if a surface has sharp features. Great care is needed in positioning the head since small change in the head position produces a large change in the pattern. www.indiandentalacademy.com
  94. 94. SOFT TISSUE EXAMINTION  EXTRA ORAL Forehead  INTRA ORAL Lips & cheek frenal attachments Nose Lips Gingiva Chin Palatal & oral mucosa www.indiandentalacademy.com
  95. 95. EXTRA ORAL-FOREHEAD  The ht. of the forehead (dist. From hairline to glabella) should be 1/3rd of the entire face ht.& is as long as the midthird (dist. of the glabella to the subnasal line)& the lower third (dist. From subnasale to menton. www.indiandentalacademy.com
  96. 96.   Relationship of the forehead is considered to the bizygomatic width. It can be described as Narrow or wide. The lateral forehead contour or the slope of the forehead could be Flat, protruding, steep. The dental bases are more prognathic than incases with a flat forehead. www.indiandentalacademy.com
  97. 97. NOSE Nasal growth & its contribution to profile.  Can be in both vertical & anteroposterior projection. More in vertical.  Males>Females-10-16 yrs. The center of this spurt at the age of 12yrs.  Females-spurt for nasal growth12yrs.  www.indiandentalacademy.com
  98. 98.    Genecov et al “Development of nose & soft tissue profile” Angle orthod 60(8)191,1990 stated that: Nasal projection in females remains virtually constant from age 12.Thus a orthodontist evaluating a pt. of class 2 at this age could expect only a reasonable increase in the nasal projection. There is a sharp peak in the nasal tip projection b/w ages 9&10 Nasal projection in males continued from ages 12-17yrs.Thus any procedure that results in upper lip retraction in combination with anterior nasal growth would produce less than optimal relationship b/w the lips & the nose www.indiandentalacademy.com
  99. 99. SIZE OF THE NOSE    The vertical nasal length measures 1/3rd of the total facial ht. (dist. From hairline to gnathion) The relationship b/w vertical & horizontal length of the nose is 2:1. Microhinic type: The root of the nose is high, short nasal bridge & an elevated tip. www.indiandentalacademy.com
  100. 100. NASAL CONTOUR: Straight, convex, crooked   www.indiandentalacademy.com SHAPE & WIDTH OF NOSTRILS: Should be assessed since they indicate impairment of nasal breathing. Nostrils: oval & bilaterally symmetrical
  101. 101. LIPS   COMPETENT: Slight contact of the lips when the musculature is relaxed. Up to 4mm of lip separation is normal especially in young children. www.indiandentalacademy.com
  102. 102. INCOMPETENT LIPS  Is defined as the inability to seal the lips without excessive strain.  Anatomically short upper lip which do not contact when the musculature is relaxed. Lip seal is achieved after active contraction of orbicularis oris & mentalis muscle  . www.indiandentalacademy.com
  103. 103.  Vig & Cohen “Vertical growth of the lips, A serial cephalometric study” A.J.O 75:405 1979  Both upper & lower lip grew more than the skeletal lower face.  The lower lip grew vertically more than the upper lip.  Most children exhibited lip incompetence at age 6-8 yrs. This is due to incomplete soft tissue growth & should be considered normal. www.indiandentalacademy.com
  104. 104. POTENTIALLY INCOMPETENT EVERTED LIPS  Lip seal is prevented due to protruding max. incisors despite normally developed lips. These are hypertrophied lips with redundant tissue & weak muscular tonicity www.indiandentalacademy.com
  105. 105. VERTICAL LIP RELATIONSHIP  In a balanced face the length of the upper lip measures 1/3rd the lower lip & the chin 2/3rd of the lower face ht. www.indiandentalacademy.com
  106. 106.   The upper incisal edge exposure with the upper lip at rest should be normally 2mm. It is important to distinguish excessive exposure of teeth caused by over eruption of the incisors from that caused by underdevelopment of the upper lip. www.indiandentalacademy.com
  107. 107. LIP STEP-KORKHAUS  Positive lip step: Protrusion of the lower lip in relation to the upper lip. Seen in class 3 malocclusion. www.indiandentalacademy.com
  108. 108. NORMAL LIP PROFILE  Slightly negative lip profile. The lower lip slightly behind the upper lip. www.indiandentalacademy.com
  109. 109. NEGATIVE LIP STEP  Marked retrusion of the lower lip as a symptom of class 2 malocclusion. www.indiandentalacademy.com
  110. 110.     MAMANDRAS “Linear changes of the maxillary & mandibular lips” A.J.O 94:405,1988 Max. lip length in females-14yrs.The mand. vertical lip length growth -16yrs.They attained the max. Lip thickness by age 14 followed by thinning. Males attained max lip length-18yrs,it was not complete. Max lip thickness was attained by 16yrs. Thus the effect of extraction therapy would be more noticeable in females with straight or convex profile than in males. www.indiandentalacademy.com
  111. 111. NASOLABIAL ANGLE-110degree    Formed b/w a tangent to the lower border of the nose & a line joining the subnasale with the tip of the upper lip. (Labrale Superius) Reduces: max. prog., proclined ant. Obtuse: Retrognathic maxilla www.indiandentalacademy.com
  112. 112. CHIN  The bone structure  Thickness & tone of the mentalis muscle  Morphology & craniofacial relation of the mandible.  Recessive, adequate or prominent. www.indiandentalacademy.com
  113. 113. MENTALIS ACTIVITY  The mentalis muscle becomes hyperactive.  Seen in class 2 div 1 cases where puckering of the chin may be seen. www.indiandentalacademy.com
  114. 114. MENTOLABIAL SULCUS  It is the concavity present below the lower lip. www.indiandentalacademy.com
  115. 115. DEEP SULCUS SHALLOW SULCUS www.indiandentalacademy.com
  116. 116. OVER DEVELOPMENT OF THE CHIN HT. (Mentolabial sulcus to menton)    Lip closure is difficult in this type of facial morphology. Hyperactivity of the mentalis muscle Genioplasty required to change the insertion of the mentalis muscle. www.indiandentalacademy.com
  117. 117. CHIN FORMATION & PROFILE CONTOUR   Protruded chin, marked mentolabial sulcus – retruded lip profile. Negative chin, absence of the mentolabial sulcus causing a protruded lip profile. www.indiandentalacademy.com
  118. 118. ASYMMETRY OF THE CHIN:MIDLINE OF THE MANDIBLE   Rotation of the entire mandible to the left side- MANDIBULAR LATEROGNATHY Placement of the chin on to the left side. www.indiandentalacademy.com
  119. 119. TONGUE   Small, Long & broad. Long tongue: Tip of the nose. www.indiandentalacademy.com
  120. 120. TONGUE WIDTH   Class3:Broad ,low lying Imprints of the teeth on the lateral margins of the tongue indicate a discrepancy b/w the width of the dental arch & width of the tongue. Size of the oral cavity should not be decreased further by ortho treat. www.indiandentalacademy.com
  121. 121. LINGUAL FRENUM   Tongue tie-can lead to impaired tongue movements. The tongue lies low. www.indiandentalacademy.com
  122. 122. LIP & CHEEK FRENA   Maxillary labial frenum Heavy: midline diastema www.indiandentalacademy.com
  123. 123. FRENECTOMY Only indicated when the attachment is inserted deeply with the fibre inserted into the interdental papilla.  Done after the eruption incisors.  X ray shows a bony fissure b/w the roots of upper CI.  BLANCH TEST: Upper lip is held away - pull is exerted on the frenum-Area around the incisive papilla becomes blanched.  www.indiandentalacademy.com
  124. 124. MANDIBULAR LABIAL FRENUM  Broad insertion which exerts a strong pull on the FREE & ATTACHED GINGIVA can lead to gingival recession. www.indiandentalacademy.com
  125. 125. GINGIVA  Gingival type: Thick fibrous or thin fragile.  Gingival inflammation  Mucogingival regions www.indiandentalacademy.com
  126. 126. THIN FRAGILE GINGIVA      Alv. Process is narrow Roots can be palpated through the mucosa. Gingival recessions develop around the lower incisors. Visible vascular pattern of mucous membrane Increased tendency of the tissue to produce periodontal damage by labiolingual orthodontic movement www.indiandentalacademy.com
  127. 127. IDIOPATHIC GINGIVAL HYPERPLSIA  Hereditary, hinders dental eruption www.indiandentalacademy.com
  128. 128. OCCLUSAL TRAUMA LINGUAL RECESSIONS  Lead to mucogingival problems   Anomalous relation b/w the tip of the tongue & the lower incisors. Tongue dyskinesia www.indiandentalacademy.com
  129. 129. PALATE    Palatal depth & shape varies in accordance with the facial form. Brachycephalic pt.- have broad & shallow palate. Rugae can be used as a diagnostic criteria for ant. proclination. Third rugae can be seen in line with the canine. www.indiandentalacademy.com
  130. 130. PALATAL MUCOSA & PALATAL VAULT  Palatal swellingDisplaced tooth germs & cysts.  Ulceration  Scar tissue formation www.indiandentalacademy.com
  131. 131. MUCOSAL INDENTATIONS   Traumatic deep bite class2 div 1 Groove in the palatal mucosa caused by the lower anterior teeth due to long standing vertical occlusion. SCAR TISSUE  Scarred palate after surgical closure of an isolated palatal cleft. www.indiandentalacademy.com
  132. 132. DENTAL CHARACTERISTICS  No. of teeth present, unerupted, missing  The counting must include not only the teeth seen but those developing or not developing within the jaws.  Girls develop teeth earlier than boys. www.indiandentalacademy.com
  133. 133. APICAL BASE   Balanced relationship b/w the width of the dental arches & transverse development of the apical bases. Tangents along the outer surfaces of posterior teeth are parallel to each other. www.indiandentalacademy.com
  134. 134. DISHARMONY IN WIDTH OF APICAL BASE & MAX. DENTAL ARCH (APICAL CROWDING)    Upper post. teeth are tilted buccally in comparison to their apical base. Cranially convergent tangents of the posterior buccal tooth surface imply that the basal bone is smaller than the dental arch. Expansion of the dental arch is contraindicated. www.indiandentalacademy.com
  135. 135. BROAD APICAL BASE    The apical base is wider than the dental arch & the posterior teeth are tipped lingually. Discrepancy is indicated by interdental spacing. The tangents of the post. buccal surfaces converge occlusally. Expansion therapy is indicated. www.indiandentalacademy.com
  136. 136. CARIOUS TEETH   Orthodontic treatment is contraindicated when carious teeth are present. There is reduced enamel resistance which is a contraindication for fixed appliance treatment. www.indiandentalacademy.com
  137. 137. WEAR FACETS  Occlusal abrasions are a result of attrition & indicative of parafunctional mandibular movements. www.indiandentalacademy.com
  138. 138. TOOTH FORM & SIZE   Crown size discrepancy: cannot attain proper alignment & intercuspation. Discrepancy b/w tooth size & arch dimension : crowding www.indiandentalacademy.com
  139. 139. INTERARCH DISCREPANCIES   NEUTRO-OCCLUSION The anteroposterior relationship of the maxillary and mandibular molars is correct, with the mesiobuccal cusp of the maxillary 1st molar occluding in the mesiobuccal groove of the mandibular 1st molar. www.indiandentalacademy.com
  140. 140. CLASS - 2   DISTO OCCLUSION The lower dental arch is in a distal relationship to the upper dental arch. The mesiobuccal groove of the mandibular 1st molar contacts the distobuccal cusp of the maxillary 1st molar www.indiandentalacademy.com
  141. 141. CLASS - 3   MESIO-OCCLUSION The mandibular 1st molar is mesial to the maxillary 1st molar and the mandibular incisors are in anterior crossbite. www.indiandentalacademy.com
  142. 142. OVERBITE   The vertical overlap 0f the maxillary incisors over the mandibular incisors is termed as OVERBITE. The maxillary and the mandibular incisors should be in contact in order to prevent supra eruption of the mandibular incisors www.indiandentalacademy.com
  143. 143. VARIATIONS IN THE BITE - DEEP BITE  INVERTED OVERBITE  CROWN LENGTH CLOSED BITE: Due to premature loss of posteriors. www.indiandentalacademy.com
  144. 144. OVERJET- MEAN VALUE-2mm      Is the term used to express the horizontal distance between the most labial surface of the mand. Incisor and the incisal edge of the max. incisor. Equal to the labio lingual thickness of the max. incisor edge. Reflects the anteroposterior relationship Sensitive to abnormal lip and tongue function. Variations are due to abnormal position of either upper or lower incisors. www.indiandentalacademy.com
  145. 145. CURVE OF SPEE   It refers to the anteroposterior curvature of the occlusal surface beginning at the tip of the lower cuspid & following cusp tip of bicuspids & molars continuing as an arc through the condyle. Results in the alignment of teeth to offer max. resistance to functional loading. www.indiandentalacademy.com
  146. 146.    Excessive: restricts the amt. space available for the upper teeth. Normal: Flat Reverse: creates excessive space in the upper jaw. www.indiandentalacademy.com
  147. 147. CROSS BITE    An abnormal relationship of one or more teeth to one or more teeth of the opposite arch ,in the buccolingual or labiolingual direction. Can be dental or skeletal. Can be either unilateral or bilateral. www.indiandentalacademy.com
  149. 149. INTRA ARCH DISCREPANCY       Occlusal view of the orthodontic casts: crowding, spacing & rotation. “Arch width and form” A.J.O 1999:115:305-313 Robert et al: Male arches grow wider than female. Lower intercanine width does not increase after 12yrs. Little changes occur in the premolar arch width after the age of 12. The upper & lower intermolar width increases to a considerable extent b/w ages 7 & 18. www.indiandentalacademy.com
  150. 150.  Expansion can be applicable to a growing child. There is no evidence that appliance can stimulate growth beyond that which would occur normally.  Arch expansion is more stable in the absence of extractions & is most effective in the posterior region. There is unlikely to be stable expansion in the lower intercanine width unless the canines are displaced lingually.  Expansions of the arches posteriorly can be achieved more readily where anteroposterior movement of the arches take place. www.indiandentalacademy.com
  151. 151. VISUAL TREATMENT OBJECTIVE     Can give an excellent clue whether any functional appliance that postures the mandible forward would improve the facial appearance & the profile. The patient is asked to to posture the mandible forward into a correct sagittal relationship. Profile improves-motivates the pt. to achieve a treatment goal. Not improved-other forms of treatment are required. www.indiandentalacademy.com
  152. 152.     Indicated in: Functinal retrusion, deep overbites excessive interocclusal clearances with a normally positioned maxilla. V.T.O: manually or cephalometric tracing Tracing represents the changes expected or desired during treatment. In a child the V.T.O would have to incorporate the expected growth, any growth changes induced during treatment & any repositioning of teeth expected from orthodontic tooth movement. www.indiandentalacademy.com
  153. 153. STUDY MODELS  Replica of the patients oral condition.  Serves as an important reference as the case progresses. www.indiandentalacademy.com
  154. 154. ADVANTAGES        Records dental anatomy. Records intercuspation. Arch form Measures progressAids in pt. motivation Space analysis Permanent record medico legal considerations Inexpensive DISADVANTAGES    Occupy large amt. of space. Liable to damage during storage & transportation. Difficult to discuss a particular case over the phone. www.indiandentalacademy.com
  155. 155. HOLOGRAMS     Holography uses laser light to reproduce a very high quality, three dimensional image of the cast. The recorded image is called a HOLOGRAM. The first hologram was produced by LEITH & UPATNIEKS in 1964. They permit three dimensional model analysis, superimpositions & storage. HOLOGRAPHIC VIEWS: Frontal, occlusal,Rt. buccal & left buccal. www.indiandentalacademy.com
  156. 156. Holograms in orthodontics: A.J.O Oct 1995    SYSTEM: Holocamera, the automatic developer, illumination & measureing system. Holocamera: easy to handle. The model being photographed is placed on glass plate for exposure. The laser beam used in the camera is divergent. www.indiandentalacademy.com
  157. 157. AUTOMATIC DEVELOPER     Developed to expose plates without assistance. Consists of series of trays that contain the various chemicals used, a mechanical engine that controls the movements of the holder in which plates can be placed. 30 plates can be developed simultaneously. The holder carries the plate from tray to tray each having a different function during exposure. www.indiandentalacademy.com
  158. 158. MEASUREMENT SYSTEM   Illumination element: Halogen lamp: to illuminate the hologram. Analysis or measuring element: Plate holder mounted on an x-y-z positioner. The z micropositioner has an optical fiber which is connected to a laser diode that projects a small red spot light used for depth measurement. www.indiandentalacademy.com
  159. 159. ORTHODONTIC APPLICATIONS          Measurement of incisor intrusion. Study the effects of high pull headgear. Tooth position measurements. Study the effect of max. expansion on facial skeleton. Study the effect of class2 elastics on bone displacement. Study the effect of cervical headgear on maxilla. Facial & dental arch symmetry. Determine the centre of rotation produced by orthodontic forces. Lower incisor space analysis. www.indiandentalacademy.com
  160. 160. ADVANTAGES       Convenient, low bulk Resistant to almost all destructive agents apart from fire. These films may be scratched or bent or covered in dust without interfering with the latent image. Superimposition of images is possible, thus detection of any changes & tooth movement are possible. Holographic image can be measured in 3 dimensions. Ease in storage, transportation Cost similar to conventional photography. www.indiandentalacademy.com
  161. 161. DISADVANTAGES    Inability to place the holograms immediately next to the patient’s mouth to make side by side comparisons. Cannot be adjusted once made. Incorrect occlusion of the models when the holograms are being made. www.indiandentalacademy.com
  162. 162. OCCLUSOGRAMS     Involves positive-print 1:1 photographs of dental casts. The tracings of these photographs are called as occlusograms. These are actual size photographs of the occlusal surface of the dental cast. Developed by C.J BURSTONE in 1961. Thus combining occlusograms & cephalometric head films it now possible to make treatment discussions in all three planes of space. TECHNIQUES: Photographic & photocopying www.indiandentalacademy.com
  163. 163. OCCLUSOGRAM SET-UP    4 into 5 inch box camera mounted on a sliding rack so that the distance from the track is adjusted. registration track on the oclusostat for the placement of the cast. The occlusal surfaces of the teeth are flush with the leading edge of the oclusostat which is also the focal length of the camera. www.indiandentalacademy.com
  164. 164.    The recommended focal length of the camera:210mm & can be stopped down to f:45 for the best depth of field. The dist. from the leading edge of the occlusostat to the camera lens & from the camera lens to the film is abt.42cm.At these settings no enlargement is found. Exposure time:5-30 secs. depending on the lighting (incandescent to florescent) & the film can be processed with X-ray developer & fixer. www.indiandentalacademy.com
  165. 165. OCCLUSOGRAM PROCEDURE    The occlusal surfaces of the upper & lower dental casts are photographed in a 1:1 ratio & a tracing is made using the photographs. 4 into 5 inch positive film transparencies are ideal. These transparencies allow the occlusograms to be held one over the other to examine cuspal relations. However for treatment planning purpose tracings are still required. These photographs can be taken either with a 35mm camera & enlarged to a 1: 1 magnification or with a 4 into 5 inch Polaroid camera for 1:1 instant photographic prints. Photographic prints are ideal for tracing purposes. One problem with these positive film traspararencies is the maintenance of the accurate orientation of the dental cast, which needs to be trimmed in the centric relation position www.indiandentalacademy.com
  166. 166.      Impressions are made-casts are poured & trimmed. The posterior borders are trimmed perpendicular to the occlusal plane & the palatal midline. They are in flush with each other when the casts are in C.R. The bases are parallel to the occlusal plane. Wax jaw registration is made with the mandible in most retruded position, recording the occlusal surfaces without perforating the wax. For lateral orientation each cast has an extended registration groove. The casts are then finished & polished. www.indiandentalacademy.com
  167. 167. OCCLUSOGRAM TRACING  For the occlusogram tracing acetate paper with the rough side up is placed over the occlusograms & the max. & mand. teeth are outlined ,showing the gingival tooth contour, incisal edges, buccal cusp ridges, central grooves & cusp tips, the upper & lower registration lines, mid sagittal reference line based on the mid palatal raphe & incisive papilla. “R” & “L” should be marked on the right & left sides to avoid confusion. www.indiandentalacademy.com
  168. 168. TECHNIQUE USING PHOTOCOPYING    The study models are prepared as described earlier. With models in the centric relation & teeth in occlusion three marks on each model are made. i.e. on the rt. & lt. side of the buccal segment & in the midline. The casts are then photocopied on a Xerox machine & the occlusal photocopy is used to obtain a tracing. www.indiandentalacademy.com
  169. 169. ORTHODONTIC APPLICATIONS            Determine arch form & width. Arch length discrepancies (crowding or spacing). To estimate occlusal relationships. To estimate tooth movements in all three planes. Anchorage requirements in each quadrant for extraction cases. The presence & extent of skeletal asymmetries. Presence & extent of tooth mass discrepancies. Determines changes in the cant of occlusal plane. Aid in arch wire construction. Growth changes in the arch can be seen with the help of the tracings. Quantifying treatment progress. www.indiandentalacademy.com
  170. 170. DISADVANTAGES     Not very accurate. Time consuming Possibility of using a occlusogram with a head film produces difference in magnification. To overcome this a user friendly software was developed…………! www.indiandentalacademy.com
  171. 171. 3-D OCCLUSOGRAM SOFTWARE       A.J.O Sept. 1999 The procedure includes : Image scanning & setting. Occlusal view processing Lateral cephalometric processing Occlusogram construction www.indiandentalacademy.com
  172. 172. ADVANTAGES       Combination of lateral cephalometric image with the occlusal views of the upper & lower dental casts complete the 3 dimensional set up of the patient. Demonstrates all the treatment possibilities. All the needed movements of the teeth are clearly visible on the occlusal views in the 3 planes of space allowing the design for the “custom made appliance” & the lateral cephalogram shows the planned displacement for the molars & the incisors. The software can simulate the results of standard surgical procedures. Ease in using Accurate & precise www.indiandentalacademy.com Rapid
  173. 173. e-MODELS-3D Digital dental models using laser technology- J.C.O (2)-2003    Three dimensional digital study model. Methods of producing digital models: Destructive imaging: Removes the part of the cast ,a little at a time ,while it is being imaged. Non destructive imaging: Uses structural light ,laser light or x-rays to image while leaving the original cast intact. www.indiandentalacademy.com
  174. 174.  e - models: are constructed through a laser scanning process that digitally maps the geometry of a patient’s dental anatomy to a high resolution 3D digital image with an accuracy of .+ 01mm.A laser stripe is projected onto the surface of the plaster cast & a digital camera is used to analyze distortions in the stripe. The plaster cast is oriented on all axes to expose all its surfaces for scanning. www.indiandentalacademy.com
  175. 175.   This process produces 3D vertices that are connected into thousands of triangles to form the 3D image. The software then displays the emodel on the computer screen by assigning color shades to each triangle based on its relative orientation to a digital light source. This results in a high-resolution 3D image that can be viewed measured & manipulated on the computer screen as if the cast is in your hand. www.indiandentalacademy.com
  176. 176. ADVANTAGES OF e-model          Measurements can be made in any plane or orientation. Various analysis such as Bolton’s analysis, arch width & length analysis can be done. Cross-sectional tools allow e-models to be sliced in any vertical or horizontal plane to check symmetry, overjet, overbite & complete measurements at any location. Permits analysis of occlusal relationships. Improves accuracy & efficiency of orthodontic diagnosis, treatment planning & bracket placement. Midline analysis (skeletal or dental asymmetries can be evaluated). Mock surgeries & presurgical evaluation can be done. Record keeping Ease in storage www.indiandentalacademy.com
  177. 177. e-plan Latest innovation in 3D treatment planning.  Simulates multiple treatment options to help determine the most effective treatment plan.  Enables the clinician to simulate tooth rotations ,movements & extractions with a click of the mouse.  They allow pts. to watch the movement of their own teeth from a malocclusion view to a post treatment view.  Effective communication tool for pts., their families www.indiandentalacademy.com & referring dentists. 
  178. 178. PHOTOCOPYING        Photocopies of models appear to be valid for: Comparing pre & post treatment arch forms. Checking original tooth rotations For ease in communication Producing occlusograms for demonstration purposes. For maintaining pt. record. Adv: Easy to handle & store www.indiandentalacademy.com
  179. 179. DISADVANTAGES  Less precise for measuring arch length.  Less precise for producing occlusograms for space analysis  Can produce varying degree of distortion since the models are 3 dimensional. The distortion can be limited to 1-2% enlargement. www.indiandentalacademy.com
  180. 180. DIGIGRAPH    Is a synthesis of video imaging, computer technology & three dimensional sonic digitizing. It enables the clinician to perform non invasive & non radiographic cephalometric analysis. Product of DOLPHIN IMAGING SYSTEMS www.indiandentalacademy.com
  181. 181. DIGIGRAPH WORK STATION EQUIPMENT    Measures about 5 feet into 3 feet into 7 feet. The main cabinet contains electronic circuitry & the pt. sits next to the cabinet in an adjustable chair. The head holder is suspended from a boom, supported by a vertical column attached to the cabinet. Two videocameras, permanently armed & focused are mounted on a vertical column. Light emanates from sources inside the boom, thus ensuring all images are properly illuminated. www.indiandentalacademy.com
  182. 182.  This device uses sonic digitizing electronics to record cephalometric landmarks by lightly touching the sonic digitizing probe to the pt. skin. This emits a sound which is then recorded by a microphone as x, y,z coordinates. www.indiandentalacademy.com
  183. 183. OPTIONAL COMPONENTS INCLUDE     A consultation unit that transports information into the operatory, doctors office or consultation area thus allowing viewing & comparison of information & development of visual treatment objectives. 2nd high resolution video camera with a telephoto lens for taking intra oral views Light box for x-rays & a study model holder for video imaging. Camera & video printer for producing copies of video monitor information. www.indiandentalacademy.com
  184. 184. CAPABILITIES OF THE MACHINE    A landmark can be identified as a point in three dimensions. A cephalometric analysis can be made independent of head position. Neither parallelism of the x-ray in the mid sagittal plane nor the symmetry of anatomic morphology b/w left & rt. side is necessary. www.indiandentalacademy.com
  185. 185. ORTHODONTIC APPLICATIONS        Perform cephalometric analysis e.g. Holdaway, Jaraback, Down, Steiner, Burstone, Tweed, Ricketts Superimpositions Monitor patient treatment progress VTO Useful in quantifying facial asymmetries Allows pts. radiograph, photos& models to be stored on a small disk thereby reducing storage requirements. Valuable tool for improving communication among clinician patient & staff. www.indiandentalacademy.com
  186. 186. ADVANTAGES     Non invasive Consistent & reproducible No radiation exposure With practice relatively efficient. www.indiandentalacademy.com
  187. 187. 3 DIMENSIONAL CONE BEAM COMPUTERIZED TOMOGRAPHY IN ORTHODONTICS  Computerized tomography was developed by GODFREY HOUNSFIELD in 1967.  It utilizes conventional x-ray technology & computerized volumetric reconstruction to reproduce a three dimensional image.  The object to be evaluated is captured as the radiation source falls onto a 2 dimensional detector.  Images may be a full head view, skull view or regional components. www.indiandentalacademy.com
  188. 188.   Produces a more focused beam & less scatter radiation as compared to the conventional fan shaped CT devices. Increases x-ray utilization & reduces the Xray tube capacity. www.indiandentalacademy.com
  189. 189. CBCT ACQUISITION SYSTEMS www.indiandentalacademy.com
  190. 190. ORTHODONTIC APPLICATIONS       To locate ectopic cuspids & to design treatment strategies that allow minimally invasive surgery. Location of oral abnormalities (oral cysts, ectopic/ buried teeth & supernumeraries). Airway & volumetric analysis Assessment of bone density, dimensions. quality & alveolar bone height. Implant therapy Imaging TMJ www.indiandentalacademy.com
  191. 191. ADVANTAGES DISADVANTAGES     Radiation exposure is less than conventional CT. It depends upon the settings used- kVp & mA. Effective dose as low as 45uSv to as high as 650uSv. Less expensive & smaller than conventional CT.    Does not map out muscle structures & their attachments. Does not capture color texture of the skin. Long capture time for the full view of the subject:30-40 secs. during which involuntary muscle movements (nostrils & breathing) will lead to inaccuracies in the soft tissue capture. High maintenance www.indiandentalacademy.com
  192. 192. BIBLIOGRAPHY       Orthodontic diagnosis: Thomas Rakosi Graber Vanarsdall: Orthodontics current principles & techniques Athanasios: Orthodontic cephalometry Proffit: Contemporary orthodontics Swain: Orthodontics: Current principles & techniques T.M Graber: Orthodontics principles & practice www.indiandentalacademy.com
  193. 193. “IMPROVING SMILE”USING INNOVATIVE TECHNOLOGY www.indiandentalacademy.com