Growth analysis and age estimation /fixed orthodontic courses

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Growth analysis and age estimation /fixed orthodontic courses

  1. 1. Growth Prediction & Age Estimation INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Contents   Growth spurts Skeletal Maturity Indicators 1. Hand wrist Radiographs 2. Cervical Vertebrae 3. Mid-palatal suture 4. Densitometry Method 5. Ante-gonial Notch 6. Symphysis Morphology    Dental Indicators 1. Tooth mineralization 2. 3rd molar development Somatomedian levels Frontal sinus development www.indiandentalacademy.com
  3. 3. dsfsfd    Vdf Jgjbnm nbmbnmvbkjhjhkh www.indiandentalacademy.com
  4. 4. Important concepts in growth and development    Pattern -Differential growth -Predictability Variability -Concept of normality -Age equivalence Timing www.indiandentalacademy.com
  5. 5. Pattern  Pattern represents proportionality-not just proportional relationships at a point in time but change in these relationships over time.  Can be defined as-a set of constraints operating to preserve the integration of parts under varying conditions or through time. www.indiandentalacademy.com
  6. 6. Cephalocaudal gradient of growth www.indiandentalacademy.com
  7. 7.  The accomplishment of normal human proportions is not merely due to a general slowing down. Different tissues grow at different rates at different times.  The overall pattern of growth is a reflection of the growth of the various tissues making up the organism. www.indiandentalacademy.com
  8. 8. Differential growth   Scammon’s curves for growth. Gave a graph for four major tissues of the body. -lymphoid -neural -general -genital www.indiandentalacademy.com
  9. 9. Body Composition Changes with Age STRUCTURE FETUS NEW BORN ADULT Skin & fat 16 % 26 % 25 % Viscera 16 % 16 % 11 % Nervous system 21 % 15 % 03 % Muscle 25 % 25 % 43 % Skeleton 22 % 18 % 18 % www.indiandentalacademy.com
  10. 10. Predictability  Predictability of growth pattern is a specific kind of proportionality that exists at a particular time and progresses towards another, at the next time frame with slight variations.  Any change in growth pattern would indicate some alterations in the expected changes in body proportions. www.indiandentalacademy.com
  11. 11. Variability  No two individuals with the exception of monozygotic twins are alike.  Clinically important to identify if an individual is at the extreme of normal variation or is outside the range.  What is normal? www.indiandentalacademy.com
  12. 12. Normality  Normality refers to that which is usually expected, is ordinarily seen or typical – Moyers  Normality may not necessarily be ideal so rather than categorizing as normal or abnormal one can think of deviations from the normal pattern. www.indiandentalacademy.com
  13. 13.  One way to evaluate normality is using growth charts.  Used to determine if growth is normal in 2 ways- location of the individual relative to the group. - follow a child’s growth to evaluate any unexpected changes. www.indiandentalacademy.com
  14. 14. www.indiandentalacademy.com
  15. 15. Age equivalence  Because of variability all individual at a given chronological age are neither of the same size or same stage of maturation.  It is better to compare biologic development.  “Developmental ages” –skeletal age and dental age are used. www.indiandentalacademy.com
  16. 16. Timing  One of the factors for variability in growth.  Timing variations arise because biologic clock of different individuals is set differently.  Timing-largely genetically controlled. -sex related differences -physical differences -environmental www.indiandentalacademy.com
  17. 17.  Variation in growth and development because of timing are evident in human adolescence.  Plotting change in weight or height shows the pattern of growth.  The distance and velocity graphs can be plotted and compared. www.indiandentalacademy.com
  18. 18.  Growth effects due to timing variation demonstrated using growth velocity curves.  Time variability is reduced if graph plotted using developmental age. www.indiandentalacademy.com
  19. 19. Growth spurts    Periods of sudden acceleration of growth. Due to physiological alteration in hormonal secretion. Timing-sex linked. Normal spurts are  Infantile spurt – at 3 years age  Juvenile spurt – 7-8 years (females); 8-10 years (males)  Pubertal spurt – 10-11 years(females); 15-18 years (males) www.indiandentalacademy.com
  20. 20. www.indiandentalacademy.com
  21. 21.  Pubertal growth spurt:  Important period for orthodontic treatment.  Initiated in the brain-secretion of releasing factors, pituitary gonadotropins.  Sex hormones released-physiological changes occurclassic growth cure pattern.  Timing -2 years earlier in girls.  Affected by genetic and environmental factors. www.indiandentalacademy.com
  22. 22. GIRLS Total development of adolescent growth- 3½yrs Stage 1 Beginning of adolescent growth Stage 2 (12 months later) Peak velocity in height. Stage 3 (12-18 months later) Growth spurt ending. Appearance of breast buds, initial pubic hair Noticeable breast development, axillary hair, dark/more abundant pubic hair. Menses, broadening of hips with adult fat distribution, breasts completed www.indiandentalacademy.com
  23. 23. BOYS Total development of adolescent growth- 5 yrs Stage 1 Beginning of adolescent growth Fat spurt, weight gain, feminine fat distribution Stage 2 (12 months later) Height spurt beginning Redistribution or reduction in fat, pubic hair, growth of penis Stage 3 (8-12 months later) Peak velocity of height. Facial hair appears on upper lip only, axillary hair, muscular growth with, harder/more angular body form Stage 4 (15-24 months later) Growth spurt ending Facial hair on chin and lip, adult distribution/colour of pubic and axillary hair, adult body form. www.indiandentalacademy.com
  24. 24. Velocity curves in for growth at adolescence shows difference in timing between boys and girls. www.indiandentalacademy.com
  25. 25.  Growth of the jaws correlates with physiologic events of puberty –same as height. www.indiandentalacademy.com
  26. 26.    But correlation is not perfect –juvenile acceleration of jaw growth occurs. Sex hormones are produced in adrenals by 6 years‘adrenarche’. More prominent in girls due to greater adrenal component. www.indiandentalacademy.com
  27. 27.  Important clinically-careful assessment of physiologic age-plan orthodontic treatment.  Treatment must begin during  mixed dentition-for girls.  Near completion of permanent dentition-for boysProffit.  But according to Graber, boys have a greater tendency for 3 peaks than girls-very few girls show the mixed dentition growth spurt. www.indiandentalacademy.com
  28. 28. Introduction    Chronological age is often not sufficient for assessing the developmental stage and somatic maturity of the patient. The biological age is determined from the skeletal, dental and morphologic age and the onset of puberty. Due to individual variations in timing, duration and velocity of growth, skeletal age assessment is essential in formulating viable orthodontic treatment plans. www.indiandentalacademy.com
  29. 29. Clinical Importance     To determine the amount of significant facial cranial growth potential left and potential vector of facial development. To decide the onset of treatment timing and type of effective treatment. To evaluate the treatment prognosis. To understand the role of genetics and environment on the skeletal maturation pattern. www.indiandentalacademy.com
  30. 30. Anatomical Region Suitable For Skeletal Maturational Assessment      Head and Neck : Skull Cervical Vertebrae Upper Limb :Shoulder Joint-Scapula Elbow Hand Wrist and Fingers Lower Limb : Femur and Humerus Hip joint Knee Ankle Foot tarsals and Meta tarsals Tooth mineralization as an indicator. Frontal sinus www.indiandentalacademy.com
  31. 31. Hand Wrist Radiographs   Assessment of the skeletal age is often made with the help of a hand radiograph which can be considered the Biological clock. Hand wrist region is made up of numerous small bones. These bone show a predictable and scheduled pattern of appearance, ossification and union from birth to maturity. Hence, this region is one of the most suited to study growth. www.indiandentalacademy.com
  32. 32. Anatomy of Hand-Wrist The hand wrist region is made of four groups of bones 1.Distal ends of long bones of forearm. 2.Carpal 3.Metacarpals 4.Phalanges www.indiandentalacademy.com
  33. 33. Anatomy of skeleton of Hand www.indiandentalacademy.com
  34. 34. Indication Of Hand Wrist Radiographs      In patients who exhibit major discrepancy between dental and chronologic age. Determination of skeletal maturity status prior to treatment of skeletal malocclusion. To assess the skeletal age in a patient whose growth is affected by infections, neoplastic or traumatic conditions. Help to predict future skeletal maturation rate and status. To predict the pubertal growth spurt. www.indiandentalacademy.com
  35. 35. Methods Of Assessing Skeletal Age  Atlas method by Greulich and Pyle  Bjork ,Grave and Brown method  Julian singer’s method  Fishman’s skeletal maturity indicators  Hagg and Taranger method www.indiandentalacademy.com
  36. 36. Greulich and Pyle Method    Greulich and Pyle (1959) published an atlas containing ideal skeletal age pictures of the hand-wrist for different chronological ages and for each sex. Each photograph in the atlas is representative of a particular skeletal age. The patient’s radiograph is matched on an overall basis with one of the photographs in the atlas. www.indiandentalacademy.com
  37. 37. Bjork , Grave And Brown Method      They have divided skeletal development into 9 stages. Each of these stages represents a level of skeletal maturity. Appropriate chronological age for each of the stages was given by Schopf in 1978 This method can differentiate maturation process of hand bones between 9 to 17 years of age. The ossification events are localized in the area of the phalanges, carpal bones, and radius (R) www.indiandentalacademy.com
  38. 38. There are 3 stages of ossification of the phalanges:  First stage: Epiphysis shows the same width as the diaphysis (=)  Second stage: Capping stage (=cap); the epiphysis surrounds the diaphysis like a cap  Third stage: U-stage (=U); bony fusion of epiphysis and diaphysis www.indiandentalacademy.com
  39. 39. First stage: PP2= -stage   The epiphysis of the proximal phalanx of the index finger (PP2) has the same width as the diaphysis. This stage occurs approximately 3 years before the peak of the puberal growth spurt. www.indiandentalacademy.com
  40. 40. Second stage: MP3= -stage  Epiphysis of the middle phalanx of the middle finger (MP3) is of the same width as the diaphysis www.indiandentalacademy.com
  41. 41. Stage three: Pisi-, H1-, and R= - stage   This stage of development can be identified by three distinct ossification areas; these show individual variations but appear at the same time during the process of maturation. Pisi-stage = visible ossification of the pisiforme www.indiandentalacademy.com
  42. 42.  H1-stage = ossification of the hamular process of the hamatum  R = -stage, same width of epiphysis and diaphysis of the radius www.indiandentalacademy.com
  43. 43. Fourth stage: S- and H2-stage    S-stage=first mineralisation of the ulnar sesamoid bone of the metacarpophalangeal joiant of the thumb. H2-stage= progressive ossification of the hamular process of the hamatum The fourth stage is reached shortly before or at the beginning of the puberal growth spurt. www.indiandentalacademy.com
  44. 44. Fifth stage: MP3cap-, PP1cap- and Rcap-stage  During this stage, the diaphysis is covered by the cap-shaped epiphysis  MP3cap-stage, the process begins at the middle phalanx of the third finger www.indiandentalacademy.com
  45. 45.    PP1cap-stage, at the proximal phalanx of the thumb Rcap-stage, at the radius This stage of ossification marks the peak of the puberal growth spurt. www.indiandentalacademy.com
  46. 46. Sixth stage: DP3u-stage   Visible union of epiphysis and diaphysis at the distal phalanx of the middle finger (DP3). This stage of development constitutes the end of puberal growth www.indiandentalacademy.com
  47. 47. Seventh stage: PP3u-stage  Visible union of epiphysis and diaphysis at the proximal phalanx of the little finger (PP3) www.indiandentalacademy.com
  48. 48. Eighth stage: MP3u-stage  Union of epiphysis and diaphysis at the middle phalanx of the middle finger is clearly visible (MP3) www.indiandentalacademy.com
  49. 49. Ninth stage: Ru-stage  Complete union of epiphysis and diaphysis of the radius.  The ossification of all the hand bones is complete and skeletal growth is finished. www.indiandentalacademy.com
  50. 50. Growth period Male Stage1 PP2 = Stage2 MP3 = Stage3 Pisi, H1,R= Female 10.6yr 12.0 8.1 8.1 12.6 9.6 Stage4 S & H2 13.0 Stage5 MP3,RPP 14.0 P1cap 10.6 11.0 Stage6 Stage7 DP3U PP3U 15.0 15.9 13.0 13.3 Stage8 Stage9 MP3U RU 15.9 18.5 13.9 16.0 As a rule, girls reach the various developmental stages 2 years earlier than boys. www.indiandentalacademy.com
  51. 51. Singer’s method of assessment   Julian singer in 1980 proposed a system of hand-wrist radiograph assessment that would enable the clinician to rapidly and with some reliability help determine the maturational status of the patient. To establish baseline for simple clinical reference, six stages of hand-wrist development are described. The stages and characteristics are: www.indiandentalacademy.com
  52. 52. Stage 1 (Early) 1. 2. 3. Absence of the pisiform, Absence of the hook of Hamate and Epiphysis of proximal phalanx of second digit (pp2) narrower than its shaft. www.indiandentalacademy.com
  53. 53. Stage 2 (Prepuberal) 1. 2. 3. Proximal phalanx of second digit and its epiphysis are equal in width (pp2=), Initial ossification of hook of Hamate and Initial ossification of the pisiform www.indiandentalacademy.com
  54. 54. Stage 3 (Puberal onset) 1. 2. 3. Beginning calcification of ulnar sesamoid, Increased width of epiphysis of pp2 and Increased calcification of Hamate hook and pisiform www.indiandentalacademy.com
  55. 55. Stage 4 (Puberal) 1. 2. Calcified ulnar sesamoid and Capping of shaft of the middle phalanx of third digit by its epiphysis (MP3cap) www.indiandentalacademy.com
  56. 56. Stage 5 (Puberal deceleration) 1. 2. 3. 4. Ulnar sesamoid fully calcified and Calcification of epiphysis of distal phalanx of third digit with its shaft (DP3u) All phananges and carpals fully calcified and Epiphysis of radius and ulna not fully calcified with respective shafts. www.indiandentalacademy.com
  57. 57. Stage 6 (Growth completion) 1. No remaining growth sites. www.indiandentalacademy.com
  58. 58. Clinical implication   Stage 2 represents that period prior to the adolescent growth spurt during which significant amounts of mandibular growth are possible. Maxillary orthodontic therapy in conjuction with mandibular growth might aid correction of a class II relationship with considerable speed and ease. Stage 5 represents that period of growth when orthodontic treatment might be completed and the patient is in retention therapy. www.indiandentalacademy.com
  59. 59. Fishman’s Skeletal Maturity Indicators  Proposed by Leonard S Fishman in 1982.  Make use of anatomical sites located on thumb, third finger, fifth finger and Radius . www.indiandentalacademy.com
  60. 60. The Fishman’s system of interpretation Uses four stages of bone maturation  1.Epiphysis equal in width to diaphysis  2.Appearence of adductor sesamoid of thumb  3.Capping of epiphysis.  4.Fusion of epiphysis www.indiandentalacademy.com
  61. 61. Fishman method –Eleven SMIs Width of Epiphysis equal to Diaphysis SMI-1 Third finger-Proximal Phalanx SMI-2 Third finger-Middle Phalanx SMI-3 Fifth finger-Middle Phalanx SMI-4 Appearance of adductor sesamoid of the thumb Capping of Epiphysis SMI-5 Third finger –Distal Phalanx SMI-6 Third finger-Middle Phalanx SMI-7 Fifth finger-Middle Phalanx Fusion of Epiphysis and Diaphysis SMI-8 Third finger-Distal Phalanx SMI-9 Third finger-Proximal Phalanx SMI-10 Third finger-Middle Phalanx SMI-11 Seen in Radius www.indiandentalacademy.com
  62. 62. www.indiandentalacademy.com
  63. 63. Significance     SMI 1,2,3 :- Occur approximately 3 years before the pubertal growth spurt. SMI 4 :- This stage occurs shortly before or at the beginning of pubertal growth spurt. SMI 5,6,7 :- This stage occurs at the peak of the pubertal growth spurt. SMI 8,9,10,11 :- The ossification of all hand bones is completed and skeletal growth is finished. www.indiandentalacademy.com
  64. 64. Maturation Assessment by Hagg and Taranger   Hagg and Taranger in 1980 described 5 stages of MP3 growth , based primarily on epiphyseal changes. Skeletal development in the hand-wrist is analyzed from annual radiographs, taken between the ages of 6 and 18 years, by assessment of the ossification of the ulnar sesamoid of the metacarpophalangeal joint of first finger (S) and Certain specified stages of 3 epiphyseal bones: - Middle and distal phalanges of third finger (MP3 and DP3) - distal epiphysis of Radius (R). www.indiandentalacademy.com
  65. 65. Sesamoid  Sesamoid is usually attained during the acceleration period of the pubertal growth spurt (onset of peak height velocity) www.indiandentalacademy.com
  66. 66. Third Finger Middle Phalanx MP3-F Stage     Start of the curve of pubertal growth spurt . Epiphysis is as wide as metaphysis End of epiphysis are tapered and rounded. Radiolucent gap [cartilageous epiphyseal growth plate] between epiphysis and metaphysis is wide. www.indiandentalacademy.com
  67. 67. MP3-FG Stage      Acceleration of the curve of pubertal growth spurt. Epiphysis is as wide as metaphysis. Distinct medial and lateral border of epiphysis forms line of demarcation at right angle to distal border. Metaphysis begins to show slight undulation. Radiolucent gap between metaphysis and epiphysis is wide. www.indiandentalacademy.com
  68. 68. MP3-G Stage     Maximum point of pubertal growth spurt. Sides of epiphysis have thickened and cap its metaphysis, forming sharp distal edge on one or both the sides. Marked undulations in metaphysis give it “Cupid’s bow’’ appearance. Radiolucent gap is moderate. www.indiandentalacademy.com
  69. 69. MP3-H Stage        Deceleration of the curve of pubertal growth spurt. Fusion of epiphysis and metaphysis begins. Side of epiphysis form obtuse angle to distal border. Epiphysis is beginning to narrow. Slight convexity in metaphysis. Typical Cupid’s bow appearance is absent . Radiolucent gap is narrow. www.indiandentalacademy.com
  70. 70. MP3-HI Stage      Maturation of the curve of pubertal growth spurt. Superior surface of epiphysis shows smooth concavity. Metaphysis shows smooth, convex surface, almost fitting into reciprocal concavity of epiphysis. No undulation present in metaphysis. Radiolucent gap is insignificant. www.indiandentalacademy.com
  71. 71. MP3-I Stage     End of pubertal growth spurt Fusion of epiphysis and metaphysis complete. No radiolucent gap. Dense, radiopaque epiphyseal line forms integral part of proximal portion of middle phalanx. www.indiandentalacademy.com
  72. 72. Third finger distal phalanx  DP3-1:Fusion of Epiphysis and Metaphysis is completed. -This is attained during the deceleration period of pubertal growth spurt ( end of PHV) . www.indiandentalacademy.com
  73. 73. Radius R-I:Fusion of the epiphysis and Metaphysis has began. -This stage is attained 1 year before or at the end of growth spurt.  R-IJ:Fusion is almost completed but there is still a small cap at one or both margin.  R-J:Characterised by fusion of the epiphysis and metaphysis.  These stages were not attained before end of PHV. www.indiandentalacademy.com
  74. 74. Dental age       Chronological and dental age are synchronous in the normal patient. A child is labeled as an early or late developer if there is a difference of +/- 2 years from the average value. If the chronologic age of the patient is younger than the dental age, one can rely on increased growth to a greater degree than when dental age is retarded in relation to the chronologic age ( and possibly biologic age). Dental age can be determined two methods: - Stage of eruption - stage of tooth mineralization on radiograph www.indiandentalacademy.com
  75. 75. Stage of Eruption    Determination of dental age from observation of eruption has been the only method available for a long time In certain cases however, the accuracy of the method is limited. During the quiescent period in eruption, this appoach is inadequate. www.indiandentalacademy.com
  76. 76. www.indiandentalacademy.com
  77. 77. Stage of tooth mineralization on radiograph (Demirjian et al 1973)    When determining dental age radiographically according to the stages of germinations, the degree of the development of individual teeth is compared to a fixed scale. For age determination one does not rely on the last stage of tooth formation but on the entire process of dental mineralization. The procedure can be used for the entire deciduous and mixed dentition period, and is not influnced by early loss of deciduous teeth. www.indiandentalacademy.com
  78. 78.    The calculation is made using a point evaluation system. Each tooth is given a point value according to its state of development. The sum of individual points gives the development value, which can be transferred into the dental age with the aid of standard tables. www.indiandentalacademy.com
  79. 79.    The smaller the sum of points, the younger the dental age; the higher the sum, the older the dental age. Experience shows that the method is sufficiently accurate if the stage of mineralization of teeth 1-7 in the left lower quadrant is examined. The procedure is not valid for patients with several congenitally absent teeth. www.indiandentalacademy.com
  80. 80. www.indiandentalacademy.com
  81. 81. www.indiandentalacademy.com
  82. 82. Lower third molar development in relation to Skeletal Maturity and Chronological Age www.indiandentalacademy.com
  83. 83. Mid Palatal Suture as an Indicator of Maturity   In 1982, Fishman developed the system of skeletal maturation assessment (SMA) which involves the identification of 11 skeletal maturity indicators on H/W radiographs that occur serially from the onset to termination of adolescence. All measurements associated with the growth of the mandible correlate in intensity and timing with growth in stature. The maxilla demonstrates less conformity. www.indiandentalacademy.com
  84. 84.   Therefore knowing more about the development of the maxilla can help a clinician to better time procedures like maxillary expansion. Fishman in 1994 conducted a study to evaluate the ossification pattern of the mid-palatal suture and whether this could be used as a maturity indicator. www.indiandentalacademy.com
  85. 85. Development of human mid palatal suture     Three palatal processes develop that separate the nasal cavity and the mouth. 1) The median palatal process. 2) Two lateral palatine processes. Median palatine process – Primary palate 2 Lateral palatine processes – Secondary palate Embryologically both form b/w 5-12 week of IUL. www.indiandentalacademy.com
  86. 86. The mid palatal suture is formed by 3 parts: 1)Interpremaxillary part 2)Maxillry part 3)Interpalatine part.  A Well established Interpremaxillary suture was formed in 47 day old embryo (primary palate)  The first indication of sutural formation of secondary palate (maxillary and inter palatine part) is at approx. 10 ½ weeks of age.  A definite suture is formed by the 12th week of life.  www.indiandentalacademy.com
  87. 87.   Stages of ossification of midpalatal suture were compared with Fishman’s SMI stages. Certain landmarks were identified on the occlusal films which formed the basis of comparision.  Point A - Most anterior point on premaxilla  Point B – Most posterior point on the posterior wall of the incisive foramen.  Point P – point tangent to a line connecting the posterior walls of greater palatine foramen. www.indiandentalacademy.com
  88. 88.    All measurements were made for – a. Length b. Percentage of development. These were recorded for the following dimensions : A-P - total dimension of the suture of the suture A-B - anterior dimension of the suture B-P - posterior dimension of the suture The results reveled that there is significant correlation b/n maturational development and the beginning of ossification of the mid-palatal suture. www.indiandentalacademy.com
  89. 89. SMI SMI 3 MPS CORRELATION Only about 8% fused Before SMI 4 Very little or no midpalatal approximation exists Before beginning of puberty b/w SMI 4 - 7 An osseous interdigitation is very evident with approximation in some areas Occurs during pubertal growth spurt SMI 9 Increase in rate of approximation (25%) Deceleration of pubertal growth spurt SMI 11 Only 50% approximated End of adolescence (higher %age occurs posteriorly) www.indiandentalacademy.com
  90. 90.   No differences were seen in the pattern of approximation b/w males and females. This study has also verified the fact that midpalatal approximation occurs more posteriorly during the entire adolescent period. Clinical implication :  An ideal time to initiate orthopedic expansion is during the early maturational stage, SMI 1 to 4.  Theoretically less orthopedic force values would be required if treatment is initiated early. www.indiandentalacademy.com
  91. 91. Symphysis morphology as a predictor of the direction of mandibular growth   Nanda et al determined in their study that Symphysis morphology could be used as a predictor of the direction of mandibular growth. The direction of mandibular growth was evaluated with seven cephalometric measurements that included – 1. y – axis 2. SN to mandibular plane 3. Palatal plane to mandibular plane 4. Gonial angle 5. Sum of saddle, articular and gonial angle (Bjork sum) 6. Percentage lower facial height 7. Posterior/Anterior face height (Jaraback ratio) www.indiandentalacademy.com
  92. 92.    The mandibular symphyseal dimensions studied were height, depth, ratio (height/depth), and angle. The Symphysis height was defined as the distance from the superior to the inferior limit on the grid. The Symphysis depth was defined as the distance from the anterior to the posterior limit on the grid www.indiandentalacademy.com
  93. 93.   Symphysis ratio was calculated by dividing Symphysis height by depth. The Symphysis angle was determined by the posteriorsuperior angle formed by the line through menton and point B and the mandibular plane. www.indiandentalacademy.com
  94. 94.  Large Symphysis ratio – receding chin, high mandibular plane, high angle SN-MP, large saddle, articulare & gonial angles,  large anterior facial height, large percentage lower facial height Small Symphysis ratio – large chin low mandibular plane low angle SN-MP low saddle, articular & gonial angles Small anterior facial height www.indiandentalacademy.com Small percentage lower facial height
  95. 95.     The axiom about the chin is that those children who have, will get more with growth, whereas those who do not will not get much growth at the chin. Symphysis ratio was strongly related to the direction of mandibular growth in men. Symphysis with an anterior growth direction of the mandible had a short height, large depth, small ratio, and large angle. In contrast, a Symphysis with a large height, small depth, large ratio, and small angle demonstrated a posterior growth direction. www.indiandentalacademy.com
  96. 96.   Growth changes in Symphysis continued up to adulthood in both female and male subjects, with the female subjects having a smaller and earlier occurring change compared with the male subjects. Symphysis height, depth, and ratio increased while Symphysis angle decreased with age. www.indiandentalacademy.com
  97. 97. Ante gonial Notch – As an indicator of mandibular growth potential    The presence of a prominent mandibular ante gonial notch is a commonly reported finding in subjects with disturbed or arrested growth of the mandibular condyles. In unilateral condylar hypoplasia, marked mandibular notching develops only on the affected side. Bjork’s implant studies have showed that in forward rotating mandibles apposition occurs below the Symphysis and resorption takes place under the angle. Conversely, in backward mandibular rotation apposition beneath the angle is common and resorption underneath the Symphysis is possible. www.indiandentalacademy.com
  98. 98.  The direction of mandibular growth rotation is reflected in the location and degree of remodeling on the inferior surface of the mandible and most pronounced area of remodeling is below the angular region.  Singer and Hunter did a study to compare the craniofacial characteristics and growth potential of orthodontically treated patients with deep mandibular ante gonial notch; with those of a similar group of shallow notch subjects by use of lateral cephalometric radiographs. www.indiandentalacademy.com
  99. 99.    > 3 mm - Very deep mandibular ante gonial notch < 3 mm - Very shallow mandibular ante gonial notch These extremes were examined by them with the hope that any biologic relationship might be more readily apparent in extremes of population. www.indiandentalacademy.com
  100. 100. Concluding remarks were: Deep notch subjects –  more retrusive mandible with short corpus, less ramus height, and a greater gonial angle than did shallow notch subjects.  Mandibular growth direction was more vertically directed  Longer total facial height and longer lower facial height  Smaller saddle angle  Required a longer duration of orthodontic treatment (extractions 3 times the frequency, high-pull and straight-pull head gear, shallow notch subjects – wore low pull head gear exclusively) www.indiandentalacademy.com
  101. 101.  During the average 4-year period examined, the deep notch subjects experienced less mandibular growth as evidenced by1. a smaller increase in total mandibular length. 2. corpus length, and 3. less displacement of the chin in a horizontal direction than did the shallow notch subjects. www.indiandentalacademy.com
  102. 102. Clinical implication  The results of this study suggest that the clinical presence of a deep mandibular ante gonial notch is indicative of a diminished mandibular growth potential and a vertically directed mandibular growth pattern.  An explanation for this could be when the growth of the mandibular condyle fails to contribute to the lowering of the mandible, the masseter and medial pterygoid by their continued growth, cause the bone in the region of the angle to grow downward, producing notching www.indiandentalacademy.com
  103. 103. Frontal Sinus Development as an Indicator for Somatic Maturity at Puberty www.indiandentalacademy.com
  104. 104. Conclusion    Maturational development embodies the biologic progression through life. In the growing years, indicators of the level of maturational development of the individual provide the best means for evaluating biologic age. Maturational development can be assed with the help of all the indicators previously described. However, it must be kept in mind that every child demonstrates a unique sequential pattern of events. No child is the same as the other. www.indiandentalacademy.com
  105. 105.   Skeletal indicators of maturation have been proved to be the most reliable. A combination of skeletal and dental indicators tend to give a very accurate picture of each child’s developmental status. Finally it must be kept in mind that in orthodontic practice it may be more relevant to evaluate the development of the patient in relation to his own growth potential in order to assess whether peak velocity growth is imminent, present or completed. The choice of indicators to be used finally depends upon an orthodontist’s preference. www.indiandentalacademy.com
  106. 106. Bibliography      Hand book of orthodontics – R.E.Moyers, 4th ed Orthodontic Diagnosis - Thomas Rakosi, I Jonas and T M. Graber Contemporary Orthodontics – W.R.Proffit, 3rd ed Facial Growth – D.H.Enlow, 3rd ed Orthodontics – current principles and techniques – T.M.Graber, R.L.Vanarsdall 3rd ed www.indiandentalacademy.com
  107. 107. www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com

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