Clinical implications of growth and development /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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Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy

  1. 1. www.indiandentalacademy.com
  2. 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  3. 3. CONTENTS       Introduction Growth:pattern ,variability ,timing Growth modification Growth prediction Assessment of growth direction Assessment of growth potential www.indiandentalacademy.com
  4. 4. INTRODUCTION www.indiandentalacademy.com
  5. 5. GROWTH   TODD: GROWTH IS INCREASING IN SIZE. PROFITT: GROWTH IS INCREASE IN SIZE OR NUMBER.  Growth is a dynamic process with a stable pattern of changes resulting in the increase in physical size and mass during it’s course of development.  Thus, growth is a three-fold process “SELFMULTIPLICATION,DIFFERENTIATION,ORGAN IZATION” each according to it’s own kind.A fourth dimension is TIME. www.indiandentalacademy.com
  6. 6. DEFINITIONS OF DEVELOPMENT:  Todd: “Development is progress towards maturity”.  Moyers : “Development refers to all the naturally occurring unidirectional changes in the life of an individual from its existence as a single cell to its elaboration as a multifunctional unit terminating in death. Thus, it encompasses the normal sequential events between fertilization and death” www.indiandentalacademy.com
  7. 7. GROWTH: PATTERN , VARIABILITY AND TIMING PATTERN VARIABILITY TIMING www.indiandentalacademy.com
  8. 8.  The first important feature of growth corresponds to Pattern It reflects proportionality  The physical arrangement of the body at any one time is a pattern of spatially proportional parts.  There is higher level pattern of growth which refers to changes in these spatial proportions over time.  www.indiandentalacademy.com
  9. 9. NORMAL GROWTH PATTERN: Not all tissue systems of the body grow at the same rate.Muscular and skeletal elements grow faster than the brain and CNS. PREDICTABILITY: The proportional relationships can be specified mathematically and the difference between a growth pattern is the addition of a time dimension. VARIABILITY : Variability in growth and development can be expressed quantitatively to categorize people as normal or abnormal. It is usually assessed with peer group of children. www.indiandentalacademy.com
  10. 10. TIMING Its final major concept in physical growth & development  Variation in timing arises because the same event happens for different individuals at different TIME  The biologic clocks of different individuals are set differently. www.indiandentalacademy.com
  11. 11. Cephalocaudal Gradient of Growth    Fetal head size - 50% of total body length. Head&face size - 30% Adult head size - 12% www.indiandentalacademy.com
  12. 12. Ceph – head  Caudal-feet  this simply means increase in growth from head to feet  www.indiandentalacademy.com
  13. 13.  Changes in head and face during growth www.indiandentalacademy.com
  14. 14. SCAMMONS GROWTH CURVE 200 Lymphoid Percent of Adult size Neural 100 General Genital 0 Birth 10 years 20 years www.indiandentalacademy.com
  15. 15. RHYTHM AND GROWTH SPURTS  The rate of growth is most rapid at beginning of cellular differentiation which increases until birth and decreases thereafter*  Postnatally growth does not occur in a steady manner. There are periods of sudden rapid increases which are termed as growth spurts. www.indiandentalacademy.com
  16. 16.  Three types of growth spurts Name of Spurt 1. Infantile / childhood growth spurt Female 3 years Male 3 years 2. Mixed dentition /Juvenile growth 6-7 years spurt 7-9 years 3. Prepubertal / adolescent growth spurt 14-15 years 11-12 years www.indiandentalacademy.com
  17. 17. CLINICAL SIGNIFICANCE OF GROWTH SPURTS 1. 2. 3. Differentiate growth changes are normal or pathologic Treatment of skeletal discrepancies is more advantages in mixed dentition period Pubertal growth spurt offers the best time in cases like predictability, treatment direction, time and management. www.indiandentalacademy.com
  18. 18. 4. Arch expansion is carried out during the maximum growth period. 5. Orthognathic surgery should be carried after growth ceases. www.indiandentalacademy.com
  19. 19. GROWTH MODIFICATION TREATMENT  It is procedure of INTERCEPTIVE ORTHODONTICS Definition: “It has been defined as that phase of the science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions of the developing dento-facial complex”. www.indiandentalacademy.com
  20. 20. Diagnostic Procedures  Clinical Examinations :  The physical status or the build, height & weight are measured and accordingly the body types can be divided into Ectomorphic –tall and thin physique Endomorphic –average physique  Mesomorphic –short and obese physique  Extra oral Examination:      Size and shape of Head Dolicocephalic-long and narrow head Mesocephalic-average head shape Brachycephalic-broad and short head shape www.indiandentalacademy.com
  21. 21. 2. The form of face :    Mesoprosopic-average or normal facial form Euryprosopic-broad and normal facial form Leptoprosopic-long and narrow facial form Facial profile and divergence :  To establish this the patient has to be placed in a natural head position.  Convex profile – Skeletal class II malocclusion.  Concave profile – Skeletal class III malocclusion. www.indiandentalacademy.com
  22. 22.  Divergence: “Divergence of the face is defined as an anterior or posterior inclination of the lower face in relation to forehead” • 3 types of facial divergence  It is purely influenced by ethnic or racial background www.indiandentalacademy.com
  23. 23. VISUAL TREATMENT OBJECTIVE THE VISUAL TREATMENT OBJECTIVE {VTO} REPRESENTS A “CEPHALOMETRIC SETUP” WHICH INCLUDES THE EXPECTED GROWTH AND TREATMENT CHANGES AS PROJECTED FROM THE ORIGINAL MALOCCLUSION AND FACIAL MORPHOLOGY.  This treatment forecast was developed by Ricketts and named by Holdaway.  VTO is a treatment design procedure that 1.Changes the areas due to normal growth,the cranial base, chin and maxilla. 2.Changes the areas affected by orthopaedic alteration. 3.Visualises the orthodontic movement of the teeth within the jaws to a more normal relationship. www.indiandentalacademy.com
  24. 24.    Treatment for a growing patient must be planned and directed to the face and structure that can be anticipated in the future. The VTO forecast is valuable for orthodontists self improvement, in that it permits him to set his goals in advance. Identification of discrepancies between goals and results provide him with objective picture through which his treatment could be improved. www.indiandentalacademy.com
  25. 25. Class II div I with full occlusion 6mm of cuspal advancement into class I relation www.indiandentalacademy.com After VTO
  26. 26. FUNCATIONAL ANALYSIS Postural rest position  In order to determine the postural rest position the patients orofacial musculature must be relaxed.  Muscle exercises like the tapping test can be  1. 2. used to relax the mandible* The moment of the mandible from the rest position to full articulation is analysed in 3 planes of space ,this closing movement of the mandible can be divided into 2 phases. Free phase. Articular phase* www.indiandentalacademy.com
  27. 27. www.indiandentalacademy.com
  28. 28.  a. b. c. For complete functional examination the following condition should be differentiated Pure rotation. Rotation movement with anterior sliding component. Rotation movement with posterior sliding component. www.indiandentalacademy.com
  29. 29.     For example: A class II Malocclusion can manifest in 3 ways. Firstly when the mandible moves from rest to occlusion without any deviation. It means that neuromuscular and morphologic relationship correspond to each other. As there is no functional disturbances it is a true class II Malocclusion. Secondly when there is a anterior gliding component. It means that the mandible slides forward into habitual occlusion hence class II Mal relationship is actually more severe than what you see. Thirdly: Where there is a posterior gliding component. The mandible glides backwards into a class II occlusion and it is not true class II malocclusion. www.indiandentalacademy.com
  30. 30.  Vertical Relationship: 1. True Deep over bite 2. Pseudo deep over bite *  Transverse relationship: 1. This analysis is particularly relevant for differential diagnosis of cases with unilateral posterior cross bite. Depending on the functional analysis, two types of skeletal mandibular deviations can be differentiated. Laterognathy 2. Laterocclusion   * www.indiandentalacademy.com
  31. 31. www.indiandentalacademy.com
  32. 32. RADIOGRAPHIC AND CEPHALOMETRIC EVALUATIONS 1.OPG (Orthopantomograph):   It gives valuable information like unerupted supernumery, unusual crown and root forms, congenital missing and details of 3rd molars can be obtained. It gives valuable information like stages of Germination, the degree of development of teeth is compared to fixed scale. www.indiandentalacademy.com
  33. 33. 2. CEPHALOMETRICS:  The introduction of radiographic cephalometrics in 1931, was to be used originally for research in craniofacial growth pattern and as clinical tool for the study of malocclusion and underlying problems. www.indiandentalacademy.com skeletal
  34. 34. 3. Hand Radiograph:  Chronological age is not sufficient for assessing the developmental stage and somatic maturity of the patient, so that the biologic age has to be determined.  Assessment of the skeletal age in often made with the help of hand radiograph  Analysis of skeletal maturity up to 9 years, the stages of mineralization of the carpal bones must be determined thereafter metacarpal bones & phalanges should be evaluated  Various indicators for development and maturity are established which occur regularly in a definite sequence during skeletal development. www.indiandentalacademy.com
  35. 35. Growth Related Problems MALOCCLUSIONS: I. Skeletal Malocclusions:  The skeletal malocclusion three planes of space namely 1. Sagittal plane: * Prognathism * Retrognathism 2. Transverse plane: * Crossbite 3. Vertical plane: * Open bite * Deep bite www.indiandentalacademy.com
  36. 36. DENTOALVEOLAR MALOCCLUSION Malposition of individual teeth Sagittal plane Malposition of groups of teeth Transverse plane Malocclusion Vertical plane www.indiandentalacademy.com
  37. 37. SAGITTAL DENTOALVEOLAR MALOCCLUSION* Class I Malocclusion  Class II Malocclusion  Class II Div 1 Malocclusion  Class II Div 2 Malocclusion    Class II, Subdivision Class III Malocclusion    True Class III Pseudo Class III Class III subdivision www.indiandentalacademy.com
  38. 38. CLASS II MALOCCLUSION DIVISION I DIVISION II www.indiandentalacademy.com
  39. 39. Cephalometric Characteristics of Class II Division 1 Malocclusion #    The relationship of maxilla to cranial base showed no significant differences The mandible was significantly retrusive with the chin located further posteriorly resulting in a larger angle of facial convexity Maj & co-workers suggested: In some cases the inclination of anterior teeth either exaggerates or camouflages the differences between the bony bases. They concluded that skeletal differences not due to abnormal development in size of any specific part but rather were result of abnormal relationship between the parts in the direction of discrepancy #(Seminar in ortho, Vol12, No.1 (Mar)06) www.indiandentalacademy.com
  40. 40. Cephalometric Characteristics of Class II Division 2 Malocclusion #     According to wallis class II division2 had posterior cranial base larger than division1 He noted in a typical division2 cases relatively more acute gonial and mandibular plane angles, shorter lower anterior face height and excessive overbite. Hedges noted a larger angle of convexity in division 2 cases Hedges concluded only consistent cephalometric finding was the lingual axial inclination of the maxillary central incisors. # (Seminar in ortho, Vol12, No.1 (Mar)06) www.indiandentalacademy.com
  41. 41. CLASS III MALOCCULSION www.indiandentalacademy.com
  42. 42. Malocclusions Occuring in Vertical Plane 1. 2. Open Bite Deep Bite 1. Open Bite “Open bite is a Malocclusion that occurs in the vertical plane, characterised by lack of vertical overlap between the maxillary and mandibular dentition”. www.indiandentalacademy.com
  43. 43. DEEP BITE Definition: “Deep bite is defined as a condition of excessive overbite where the vertical measurement between the maxillary and mandibular incisal margins is excessive when the mandible is brought into habitual or centric occlusion”. – Graber. www.indiandentalacademy.com
  44. 44. MALOCCLUSION IN TRANSVERSE PLANE  Cross Bites “Cross Bite is defined as a condition where one or more teeth may be abnormally malposed buccally or lingually or labially with reference to the opposing tooth or teeth”. – Graber www.indiandentalacademy.com
  45. 45. GROWTH MODIFICATIONS  Concepts and principles of functional jaw therapy:  Norman Kingsley –(1879)  Pierre Robin –(1902)  Alfred Rogers –(1918)  Viggo Andresen – (1936,1939) www.indiandentalacademy.com
  46. 46.     Norman kingsley was first to use forward positioning of mandible in orthodontics Jumping of bite was very popular method in those times pierre robin designed an appliance monobloc alfred p rogers showed importance of muscles in growth and development www.indiandentalacademy.com
  47. 47.  Viggo andresen came up with retention activator  Andresen’s activator was a milestone for removable appliances  Myotonic – muscle mass  Myodynamic-muscle activity www.indiandentalacademy.com
  48. 48.  Principles :    In 1883 roux hypothesis forces , function and form His working hypothesis became background for general orthopedic and functional appliances Treatment principles:  Force applicaton  Force elimination www.indiandentalacademy.com showed natural
  49. 49.  Neuromuscular response :  Success of functional appliance depends on this response  Functional appliance considered as biologic because of force elimination and growth guidance functions www.indiandentalacademy.com
  50. 50. FUNCTIONAL APPLIANCES  DEFINITION: “A REMOVABLE OR FIXED APPLIANCE THAT ALTERS THE POSTURE OF MANDIBLE AND TRANSMITS THE FORCES CREATED BY THE RESULTING STRETCH OF THE MUSCLES AND SOFTTISSUES AND BY THE CHANGE OF THE NEUROMUSCULAR ENVIRONMENT TO THE DENTAL AND SKELETAL TISSUES TO PRODUCE MOVEMENT OF TEETH AND MODIFICATIONS OF GROWTH“- ORTHODONTIC TERMS ) www.indiandentalacademy.com ( GLOSSARY OF
  51. 51.  CLASSIFICATON:  TOOTH BORNE ACTIVE APPLIANCES EX : BIONATOR, MODIFIED ACTIVATOR WITH EXPANSION SCREWS  TOOTH BORNE PASSIVE APPLIANCES EX:ACTIVATOR ,BIONATOR ,HERBST APPLIANCE  TISSUE BORNE PASSIVE APPLIANCES EX:FUNCTIONAL REGULATOR OF FRANKEL  MYOTONIC APPLIANCES MYODYNAMIC APPLIANCES www.indiandentalacademy.com
  52. 52.  REMOVABLE FIXED APPLIANCES EX : ACTIVATOR ,BIONATOR FIXED FUNCTIONAL APPLIANCES o Group 1 appliances ex:oralscreen,inclined plane o Group 2 appliances ex:activator,bionator o Group 3 appliances ex:frankel appliance, vestibular screen www.indiandentalacademy.com
  53. 53. Activator    Andresen developed a mobile loose fitting appliance which was progenitor of kingsley appliance. “Biomechanic working retainer “ Andresen and haupl teamed up to create appliance called Activator. www.indiandentalacademy.com
  54. 54. Philosophy of treatment  Individual optimum :   The basis of treatment was to stimulate condylar changes by relocating the mandible anteriorly thus achieving desired occlusion Efficacy of activator: According to Andresen and haupl(1955) concept myotatic reflex activity and isometric contractions induce musculoskeletal adaptation by introducing new mandibular closing pattern. A fundamental requirement for condylar growth is stimulation of lateral pterygoid muscle www.indiandentalacademy.com
  55. 55.  Skeletal and dentoalveolar effects of activator:  Third level of articulation (moffet)  Construction bite  Depends on growth potential  Condylar growth translates mandible downward and forward direction .  Effective during tooth eruption and alveolar bone apposition. www.indiandentalacademy.com
  56. 56. o Force analysis : Static forces  Dynamic forces  Rhythmic forces o  Modifications:  Bow activator a m schwarz  Wunderers modifications  Cybernatic of schmuth or reduced activator  The propulsor www.indiandentalacademy.com
  57. 57.  Cutout or palate free activator  The karwetzky modification Herrens activator .  www.indiandentalacademy.com
  58. 58. Bionator  Development and Principles:  Balters developed Bionator 1950  Balters hypothesis states : The equilibrium between the tongue and circumoral muscles is responsible for shape of the dental arches and intercuspation. www.indiandentalacademy.com
  59. 59.  Balters hypothesis supports the early function and form concept of Vander Klaaw and functional matrix theory of moss  Principle of treatment is to modulate the muscle activity www.indiandentalacademy.com
  60. 60.  Efficacy:   Allows to wear day and night   Reduced size Constant influence on tongue and perioral muscles Skeletal and dentoalveolar effects : Limited effectiveness in case of skeletal disturbances  Distortion of appliance due less acrylic support  www.indiandentalacademy.com
  61. 61. Bionator types :  Standard appliance  Openbite appliance  Class III or Reversed bionator www.indiandentalacademy.com
  62. 62. FRANKEL FUNCTION REGULATOR  FRANKEL PHILOSOPHY : BUCCAL SHIELDS AND LIP PADS HOLD the buccal and labial musculature away from the teeth and investing tissues, eliminating any possible restrictive influence from this functional matrix . Frankel conceives his vestibular restrictions as artificial “ought to be “ matrix . www.indiandentalacademy.com
  63. 63. Functional matrix concept of Melvin Moss:  Buccal shields of frankel directly alter the soft tissue configuration, increasing the oral volume, that is the capsular matrix that allows the muscle to exercise and adapt and improve.  The impact of the space increase on the basal development of mandible has been suggested.  The term translative growth gives a new credence to the theoretic and therapeutic aspect of orthopedic treatment with frankel. www.indiandentalacademy.com
  64. 64.  Frankel has stressed another theoretic action Tissue tension created by shields and pads exerts contiguous periosteal tissue pull leading to increased bone activity . www.indiandentalacademy.com
  65. 65. TYPES OF FRANKEL APPLIANCE: TYPES USES 1)FR 1 ---A) FR1a ---- CL 1 AND CL 2 DIV 1 MALOCCLUSION. CL 1 MALOCCLUSION WITH MINOR CROWDING CL I WITH DEEP BITE. B) FRI b ---- CL 2 DIV 1 MALOCCLUSION WITH OVERJET LESS THAN 5 mm. C) FRI c ---- CL2 DIV 2 MALOCCLUSION WITH OVERJET MORE THAN 7mm. 2) FR 2 ---- CL 2 DIV 1 AND DIV 2 MALOCCLUSIONS. 3) FR3 ---- CL 3 MALOCCLUSIONS. 4) FR4 ---- OPEN BITE AND BIMAXILLARY PROTRUSION. 5) FR 5 ---- HIGH MANDIBULAR PLANE & VERTICAL MAXILLARY EXCESS www.indiandentalacademy.com
  66. 66. TWIN BLOCK  Development of twin block : WILLIAM J CLARK in 1977  Goal was to produce a technique to maximize growth response  Designed for full time wear to take advantage of all functional forces applied to the dentition . www.indiandentalacademy.com
  67. 67. Proprioceptive stimulus to growth :  Inclined plane important role . mechanism  Occlusal forces provide constant proprioceptive stimulus influencing growth rate and trabecular structure of supporting bone . www.indiandentalacademy.com plays an
  68. 68. CLINICAL RESPONSE TO TREATMENT ACCORDING TO MCNAMARA (1980) : “THE PLACEMENT OF APPLIANCES RESULTS IN AN IMMEDIATE CHANGE IN THE NEUROMUSCULAR PROPRIOCEPTIVE RESPONSE PROVIED ALL PHASIC AND TONIC MUSCLE ACTIVITY IS AFFECTED ,RESULTING MUSCULAR CHANGES ARE VERY RAPID AND CAN BE MEASURED IN TERMS OF MIN,HOURS & DAYS STRUCTURAL ALTERATIONS ARE MORE GRADUAL & ARE MEASURED IN MONTHS,WHERE BY THE DENTOSKELETAL STRUCTURES ADAPT TO RESTORE A FUNCTIONAL EQUILIBRIUM TO SUPPORT THE ALTERED POSITION OF MUSCLE BALANCE” www.indiandentalacademy.com
  69. 69. www.indiandentalacademy.com
  70. 70. INDICATIONS :  The primary indication for twin block is early mixed dentition of class II division 1 malocclusion .   ↓ overjet and correct distal occlusion improve arch form by transverse or sagittal development . www.indiandentalacademy.com
  71. 71. Pre Treatment www.indiandentalacademy.com
  72. 72. Post Treatment www.indiandentalacademy.com
  73. 73. Studies of functional appliance therapy 13 studies were conducted to know the concepts influencing the functional appliance therapy. First study (woodside 1975): To know the effectiveness of activator treatment during day and night on mandibular length. www.indiandentalacademy.com
  74. 74.  Second study and third study (altuna,woodside 1977;1985): These studies attempted to clarify the experimental conditions to achieve increased mandibular length . www.indiandentalacademy.com
  75. 75.  The fourth study (woodside et al 1975): It tested the effectiveness of activator with wide opening in the construction bite (8mm beyond the rest ). o The fifth study (shapera 1974): This study demonstrated a recovery from midface restriction within 5years of treatment in sample of patients. www.indiandentalacademy.com
  76. 76.  The sixth investigation study (woodside 1985): It was conducted to compare differences in electromyographic (emg) activity generated in the lateral pterygoid muscle by frankel function regulator and activator . To test hypothesis on activity of muscle on proliferration of condylar tissue. www.indiandentalacademy.com
  77. 77.  The seventh study (sessle et al): A sample of six juvenile monkeys (macaca fasicularis) was studied to test the longitudinal effect of functional appliances on jaw muscle activity . www.indiandentalacademy.com
  78. 78. www.indiandentalacademy.com
  79. 79.  The eighth and ninth study(sectakof1992 ;yamin1991 ) : These studies tested functional activity in the muscles of mastication after insertion of functional appliance. www.indiandentalacademy.com
  80. 80.  The tenth study (organ 1979): Tested the hypothesis on extention of buccal shield into the soft tissues of the oral vestibule www.indiandentalacademy.com
  81. 81. The eleventh study (woodside et al 1987): A sample of juvenile monkeys was studied to assess the remodelling changes in condyle and gleniod fossa . www.indiandentalacademy.com
  82. 82.  o The twelfth study (voudouris,1988): found similar changes in mixed dentition animals . The thirteenth study (angelopoulos1988): showed glenoid fossa relocation helps correcting class II dysplasia. www.indiandentalacademy.com
  83. 83.  Conclusion of studies : Part time use of appliance do not produce any effect on mandibular length  Large or moderate vertical opening of construction bite redirects the maxillary growth direction.  The function regulator does not increase bone formation at apical base but rather at alveolar crest.  www.indiandentalacademy.com
  84. 84.  Functional regulator & activator create similar increased amount of LMP activity at appliance insertion.  Chronic condylar unloading produces rapid downward and forward relocation of glenoid fossa. www.indiandentalacademy.com
  85. 85. A new parameter for estimating condylar growth direction :  Effects of STH and TESTOSTERONE: According to Petrovic et al, stutzmann,gasson et al    supplementary lengthening of mandible compared to maxilla increased stimulation of lateral pterygoid muscle shows more posterior location of mitosis in condylar cartilage decreased stimulation shows mitosis less posterior location www.indiandentalacademy.com
  86. 86.  If sth or testosterone level rises beyond certain level (STH3 &STH4) jumping of bite ↓ new suboptimal occlusal adjustment ↓ increased lpm activity ↓ increased number of dividing cells in condylar cartilage ↓ more posterior growth direction www.indiandentalacademy.com
  87. 87. www.indiandentalacademy.com
  88. 88. Growth rotation and alveolar bone turnover of the mandible  Anterior mandibular growth rotation rate of alveolar bone formation at first mandibular Ist premolar is greater than posterior growth rotation  Mitotic index in ramus is higher in anterior growth rotation than posterior growth rotation www.indiandentalacademy.com
  89. 89.  Conclusion: 1>better understanding of biologic phenomena in mandibular growth rotation . 2> diagnosis and projection of treatment effectiveness in dentofacial orthopaedics www.indiandentalacademy.com
  90. 90. Servosystem concept and its tentative causal interpretation in method of operation of functional appliances Two categories : 1>postural hyperpropulsor ,activator ,class II  elastics ,frankel appliance ,clark twinblock ,baltors bionator ↓ effect movement of mandible ↓ stimulates condylar cartilage www.indiandentalacademy.com
  91. 91. 2>herren & lsu activator ,harvold &hamilton activator extraoral forward traction on the mandible ↓ effects sagittal repositioning of mandible www.indiandentalacademy.com
  92. 92. Glenoid Fossa functional appliances ↓ ↑se contractile activity of lpm ↓ intensified activity of retrodiscal pad ↓ growth stimulating factor ●enhancement of local mediators ● ↓se local regulators ↓ change in condylar trabecular orientation ●additional growth of condylar cartilage ↓ lengthening of mandible www.indiandentalacademy.com
  93. 93. Importance of masticatory muscle function in dentofacial growth *    Elevator muscles influence transverse and vertical facial dimensions . Increased loading of the jaws associated with masticatory muscle function shows increased sutural growth and bone apposition. strong masticatory muscles have homogenous facial morphology in contrast to individuals with weak masticatory muscles * Sem in ortho ,vol12 no2(june)2006 www.indiandentalacademy.com
  94. 94. According to animal studies :  Altering consistency of diet shows changes in biting force level, masticatory activity and behaviour .  The influence of tension created by masticatory muscles apply to craniofacial skeleton there by altering its growth . www.indiandentalacademy.com
  95. 95.  Research studies shows that masticatory muscles are able to influence craniofacial growth of man provided tension they apply to facial bone structures is above a certain threshold ie mild overload window (frost) .  Epigenetic influences of masticatory muscles force on craniofacial growth may apply only in presence of increased muscle activity . www.indiandentalacademy.com
  96. 96. GROWTH PREDICTION “GROWTH PREDICTION IS THE FORECASTING OF THE DIRECTION AND AMOUNT OF GROWTH OF THE MAXILLA AND MANDIBLE {HORIZONTAL AND VERTICAL GROWTH TRENDS} AS WELL AS THE TIMING OF THE ADOLESCENT GROWTH PERIOD.” WHAT IS THE NEED FOR IT???? • HELPS THE CLINICIAN DEALING WITH INTERCEPTION AND /OR CORRECTION OF DENTOFACIAL MALOCCLUSIONS. • DECISIONS CAN BE MADE ABOUT THE NEED FOR TREATMENT. • DECISIONS COULD BE MADE ABOUT THE TIMING, TYPE AND LENGTH OF TREATMENT. www.indiandentalacademy.com
  97. 97.  d’Arcy thomson analysed growth of seashells and classified them according to patterns of enlargement and developing equations to fit the process . www.indiandentalacademy.com
  98. 98.  According to aristotle “ The process of growth where upon the addition of a figure or body leaves the resultant figure or body similar to original is called gnomonic growth “ www.indiandentalacademy.com
  99. 99.  Second characteristic of nautilus : Gnomonic growth can be described by particular kind of curve logarithmic or equiangular spiral. www.indiandentalacademy.com
  100. 100.  According to thompson : “Any plane curve proceeding from a fixed point or pole and such that the vectorial area of any sector is always a gnomon to the whole preceding figure is called an equiangular or logarithmic spiral if such relationship could be discovered in the face ,then prediction about its growth would be feasible as in the nautilus” www.indiandentalacademy.com
  101. 101. Gnomonic growth of human head  Growth of craniofacial spaces : according moss study indicate that orofacial capsular matrices particularly the oropharyngeal functioning spaces manifest gnomonic growth . www.indiandentalacademy.com
  102. 102.  Fig nasal f sp Nasal functioning spaces of human fetuses of various crown-rump lengths (Left). The oral functioning spaces of the same fetuses (right) www.indiandentalacademy.com
  103. 103. www.indiandentalacademy.com
  104. 104.  Fig v1 v2 v3 www.indiandentalacademy.com
  105. 105. Neurotrophism  According to moss :  Great extend of messages necessary for controlling growth derived from the nerves that innervate  Pathway of inferior alveolar nerve is considered a logarithmic spiral DNA dominates craniofacial growth where messages are carried to distant organs by axoplasmic flow  www.indiandentalacademy.com
  106. 106. Logarithmic growth of human mandible www.indiandentalacademy.com
  107. 107. www.indiandentalacademy.com
  108. 108. www.indiandentalacademy.com
  109. 109. Arcial growth of human mandible www.indiandentalacademy.com
  110. 110. www.indiandentalacademy.com
  111. 111.  Methods of predicting facial growth changes * 1. longitudinal method 2. metric method 3. structural method 4. computerised method * (angle orthodontist vol 70 no6 2000) www.indiandentalacademy.com
  112. 112. Computerized prediction method  Tool of analysis and not method of analysis. ADVANTAGE: facilitates testing and applying more complex formulas to growth prediction. www.indiandentalacademy.com
  113. 113. CLINICAL IMPLICATIONS www.indiandentalacademy.com
  114. 114. ASSESSMANT OF GROWTH DIRECTION  Rotation of jaws during growth Terminology: Condition Bjork Shudy Anterior growth greater than posterior Forward rotation Clockwise rotation Posterior growth greater than anterior Backward rotation Counter Clockwise rotation www.indiandentalacademy.com
  115. 115. Condition Bjork Solow, Houston Profitt Rotation of mandibular Core relative to cranial base Total rotation True rotation Internal rotation Rotation of mandibular plane relative to cranial base Matrix rotation Apparent rotation Total rotation Rotation of mandibular plane relative to core of mandible Intramatrix rotation Angular remodelling of lower border External rotation www.indiandentalacademy.com
  116. 116. ROTATION OF MANDIBLE www.indiandentalacademy.com
  117. 117. www.indiandentalacademy.com
  118. 118. SIGNIFICANCE OF MANDIBULAR ROTATION     Major factor in development of malocclusion Posterior rotation – retrogenia. Anterior rotation - progenia. Plays important role in treatment planning. www.indiandentalacademy.com
  119. 119. Growth related rotation of mandible www.indiandentalacademy.com
  120. 120. Clinical implication of growth rotation       Aetiological assessment. Determine nature of anamoly Prognostic evaluation Determining possible forms of treatment and indications Choosing principle of treatment Assess stability of treatment results www.indiandentalacademy.com
  121. 121. Assessment of growth potential According to ricketts  magnitude .  direction .  timing .  www.indiandentalacademy.com
  122. 122. Growth assessment parameters  Krogman defines five ages of childhood 1.chronological age 2. biologic age morphological age skeletal age dental age circumpubertal age www.indiandentalacademy.com
  123. 123. 3.behavioural age . 4. mental age . 5. self concept age . www.indiandentalacademy.com
  124. 124. 1> chronologic age :“It is defined as age measured by years lived since birth “ helps to categorise early maturity average maturity  late maturity www.indiandentalacademy.com
  125. 125.  Biologic age :1 somatotypic age 2 height and weight age www.indiandentalacademy.com
  126. 126.  Somatotypic age : according to sheldon ectomorph mesomorph endomorph www.indiandentalacademy.com
  127. 127.  Height and weight age :  Convenient determinant of developmental age . It is compared on standard growth curve of certain child to characterise a childs height compared to that children of same chronological age .  www.indiandentalacademy.com
  128. 128. Girls Boys www.indiandentalacademy.com
  129. 129. Skeletal age :  anatomical regions small to restrict radiation exposure and expense . Many ossification centres which ossify at separate times Easily accessible  www.indiandentalacademy.com
  130. 130.  Regions normally used for age assessment head and neck :skull cervical vertebrae upper limb : shoulder joint –scapula elbow hand wrist and fingers www.indiandentalacademy.com
  131. 131.  Lower limb – femur and humerus hip joint knee ankle foot tarsals metatarsals phalanges www.indiandentalacademy.com
  132. 132.  Hand wrist radiograph : It is one of the region which is most suitable to study growth . ANATOMY : 4 GROUPS OF BONES 1.DISTAL ENDS OF LONG BONES OF FOREARM 2.CARPALS 3.METACARPALS 4.PHALANGES www.indiandentalacademy.com
  133. 133. Anatomy of Hand Wrist Radiograph Distal phalanx Middle phalanx  FIG Proximal phalanx Metacarpal [5 ] Scaphoid Lunate Pisiform, Triquetral, Trapezium, Trapezoid, Capitate, Hamate Carpal [ 8 ] Radius Distal ends of www.indiandentalacademy.com Ulna long bones
  134. 134. RADIOLOGICAL ASSESSMENT OF PREDICTION OF SKELETAL GROWTH  1 GREULICH AND PYLE METHOD  2 BJORK GRACE AND BROWN METHOD  3 FISHMANS SKELETAL MATURITY INDICATOR  4 MATURATION ASSESSMENT BY HAGG AND TARANGER AND KR  5 SINGERS METHOD OF ASSESSMENT www.indiandentalacademy.com
  135. 135.  Skeletal maturation evaluation using cervical vertebrae : According to hassell & farman   Shapes of cervical vertebrae differ at each level of skeletal development. To determine existence of potential growth. www.indiandentalacademy.com
  136. 136. www.indiandentalacademy.com
  137. 137. Tooth mineralization as an indicator of skeletal maturity :  Entire deciduous and mixed dentition period .  Calculating is made using a point evaluation system (demirjian et al1973, schopf 1970) .  www.indiandentalacademy.com
  138. 138.  Pubertal /sexual age : According to Hagg and taranger  Girls if the menarche has occurred ,peak height velocity attained deaccelerating → growth rate is  Boys with prepubertal voice change spurt  Boys with male voice → pubertal → growth rate is deaccelerating www.indiandentalacademy.com
  139. 139.  NEURAL AGE : developmental landmarks year age(months) 2 4 6 8 10 Characteristic features Follows moving objects with eyes Can sit for short time. Grasps objects May unaided Creeps tries to help with feeding www.indiandentalacademy.com
  140. 140. Year 1 1.5 2 word 3 4 5 6 age cruises holding onto rail of cot 18 walks , runs awkwardly and stiffly 24 runs without falling ,uses three sentences walks erect , stand on one foot draws ,copies ,prints letter can tie shoe lases ,can read well reads and write well. www.indiandentalacademy.com
  141. 141.  mental age : determines outlook of patient towards treatment .  determines standard capacity of child to read  Intelligent quotient (IQ) : It is mental age expressed as a percentage of the chronological age www.indiandentalacademy.com
  142. 142. www.indiandentalacademy.com

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