Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Post natal growth and development of mandible and maxilla /certified fixed orthodontic courses by Indian dental academy


Published on

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,
Dental implants courses.for details pls visit ,or call

Published in: Education
  • Be the first to comment

Post natal growth and development of mandible and maxilla /certified fixed orthodontic courses by Indian dental academy

  2. 2. Post Natal Growth and Development INDIAN DENTAL ACADEMY Leader in continuing dental education
  3. 3. Contents Introduction Terminologies Concepts of growth Osteogenesis Regional development Cranium Nasomaxillary complex Mandible
  4. 4. Contents Clinical implications Conclusion References
  5. 5. What is post natal growth?? Post natal growth is the first 20 years of growth after birth. It compressed of 3periods; How does it defer from prenatal growth?? Prenatal growth is characterized by a rapid increase in cell numbers and fast growth rates Postnatal growth is characterized by declining growth rates and increasing maturation of tissues.
  6. 6. Terminologies Primary cartilage Secondary cartilage Growth centre – location at which independent growth occurs Growth site – mere location at which growth occurs
  7. 7. Terminologies Deposition – addition of new bone to the bony surface by osteoblastic activity Resorption – removal of bone due to osteoclastic activity
  8. 8. Terminologies Cortical drift – relocation of bone by simultaneous deposition and resorption processes on the opposing periosteal and endosteal surfaces Displacement – movement away from a certain position or place Primary displacement- occurring in conjunction with bone’s own growth Secondary displacement – caused by enlargement of adjacent or remote bones or soft tissues; but not of the bone itself
  9. 9. Remodeling – reshaping of the outline of the bone by selective resorption of bone in some areas and deposition in other areas Relocation – relative movement in space of a bony structure, due to bone deposition on one side and resorption on the other side
  10. 10. Concepts of growth Enlow’s growth concepts Concept 0ne facial growth and development is a morphogenic process In-depth understanding of facial morphogenesis Normal Vs range of abnormal Biologic reasons for these variations Diagnosis, treatment planning appropriate procedures and selection of Biologic factors underlying the problems of retention, rebound and relapse
  11. 11. Concept two Bones grow by adding new bone tissue Surface facing towards direction of growth– deposition Surface facing away--- resorption
  12. 12. Concept three Mosaic-like pattern of growth fields Example- outer periosteal has resorptive field then the corresponding endosteal is depository and vice versa These combinations produce characteristic growth
  13. 13. Concept four Periosteal bone covers 50% of the cortical bone Endosteal bone the remaining.
  14. 14. Concept five Operation of growth fields – carried out by osteogenic membrane and other surrounding tissues Growth not programmed within the calcified part of bone itself, rather the blue print lies in the surrounding soft tissues
  15. 15. Concept six All various depository and resorptive growth fields do not have same rate of the growth activity Fields with special significance play crucial role in the growth process--- growth sites
  16. 16. Example:- mandibular condyle During remodeling resorption bone deposition exceeds
  17. 17. Concept seven Remodeling is the basic part of bone growth process Why the bone must remodel ??? Its regional parts are moved from one location to another as the bone enlarges Example: ramus progressively moves posteriorly by a combination of deposition and resorption.
  18. 18. Progressive, sequential movement of components as a bone enlarges--- relocation Relocation is the basis for remodeling If we consider the previous example, ramus as a whole relocates posteriorly and the posterior part of the corpus by lengthening also gets relocated and occupies the same area, once the ramus occupied earlier. Growth and remodeling are in effect, inseparable parts of the same actual process
  19. 19. Palate grows downwards by periosteal resorption on nasal side and deposition on oral side
  20. 20. Why about half of any given bone can and must have a resorptive external surface as the bone increases in overall size??? Bone does not enlarge symmetrically by uniform deposition of new bone. Rather each regional part becomes relocated in a sequential manner. Some outside surfaces are thus necessarily resorptive
  21. 21. To summarize, The process of growth remodeling accelerated by the composite of soft tissue are to Progressively enlarge each whole bone Sequentially relocate each of the component parts of the whole bone to allow for overall enlargement Shape the bone to accommodate its various functions in accordance with the physiologic actions exerted on that bone Provide progressive fine-tune fitting of all the separate bones to each other and to their contiguous, growing, functioning soft tissues
  22. 22. Carry out continuous regional structural adjustments of all parts Note Bones remodel throught out life Rebound and relapse is a normal expression of the same remodeling functions
  23. 23. Concept eight As bone enlarges, simultaneously carried away from other bones in direct contact with it. The space, thus created is utilized for the bony enlargement and the process--- primary displacement / translation.
  24. 24. Example 1: Nasomaxillary complex is in contact with the floor of the cranium. Whole maxillary region displaced, downward and forward in toto away from cranium by expansive growth of the soft tissues in the mid-facial region
  25. 25. Example 2 The whole mandible is displaced away from its articulation in each glenoid fossa Condyle and ramus, grow upward and backward
  26. 26. Note The ramus remodels and becomes wider longer The increasing mass of masticatory muscles Enlarged breadth of pharyngeal space Vertical lengthening of the nasomaxillary part of the growing face
  27. 27. Concept nine Secondary displacement Example : increase in the size of middle cranial fossa result in a marked displacement movement of the whole maxillary complex anteriorly and inferiorly. This is quite independent of the enlargement of maxilla itself. growth and
  28. 28. To summarize, Overall skeletal growth process has two functions: Positioning each bone Designing and constructing each bone and all of its regional parts so that they can carry out that bone’s multifunctional role The functional input to the osteogenic tissues of bone from the soft tissues------bone develop into its definitive morphologic structure and to occupy the location it does.
  29. 29. Concept ten Facial growth: Requires intimate morphogenic interrelationship among all of its component growing, changing and functioning soft and hard tissue parts. No part is developmentally independent and selfcontained Growth process works towards an ongoing state of composite functional and structural equilibrium.
  30. 30. Other concepts Cephalocaudal growth Scammon’s growth curve Enlow’s counterpart principle
  31. 31. Cephalocaudal gradient of growth
  32. 32. Cephalocaudal gradient It represents the changes in overall body proportion during normal growth and development In third month of IUD head takes almost 50%of total body length. At birth;head -39%of total body length In adults;head-12%of total body length. Trunk and limbs grow faster than head and face
  33. 33. Differential growth[scammon’s growth curve]
  34. 34. scammon’s growth curve Different tissue in body grow at different times and different rates. Neural tissues-complete 90% of growth at 6years and 98% by 10 years of age. Lymphoid tissues-proliferates rapidly in late childhood and reaches allmost 200%of adult about 18 years of age the tissues undergoes involution to reach adult size. General tissues-it has muscle bone an organ exhibit a S shaped curve with rapid growth upto 2-3 years of age follows by slow phase of growth between 3-10years .after 10 years a rapid phase of growth occurs terminating by 18-20 years. Genital tissue;grow rapidly at puberty leading adult size after which growth ceases.
  35. 35. Enlow’s counterpart principle Growth of any given facial or cranial part relates specially to other structural and geometric counterparts in the face or cranium Regional relationships exist ---craniofacial region Balanced growth = Regional and corresponding counterparts enlarge to same extent Imbalance in differences in regional relationship Amount of growth Direction is due to
  36. 36. Different parts and their counterparts Part Counterpart Palate Anterior cranial fossa Middle cranial fossa Ramus of the mandible Maxillary arch Mandibular arch Maxillary tubeosity Lingual tuberosity Bony maxilla Corpus of the mandible
  37. 37. Osteogenesis Mechanism of bone formation Endochondral Intramembranous
  38. 38. Five steps to Endochondral bone formation Hypertrophy of chondrocytes and matrix calcifies Invasion of blood vessels and the connective tissue Osteoblasts differentiate and produce osteoid tissue Osteoid tissue calcifies Membrane covers bone and is essential
  39. 39. Five steps to Intramembranous bone formation Osteoblasts produce osteoid tissue Cells and blood vessles are encased Osteoid tissue is produced by membrane cells Osteoid calcifies Essential membrane covers the bone
  40. 40. Comparison of selected physiologic properties of bone and primary cartilage important during growth Characteristic Cartilage s Calcification Non-calcified Bone Vascularity Non-vascular Vascular Surface membrane Rigidity Non-essential Essential Flexible Inflexible Pressure resistance Tolerant to Sensitive to pressure pressure Calcified
  41. 41. Regional development Functions Growth Mechanisms and sites Timing Compensatory mechanisms Theoretical and Clinical issues
  42. 42. Cranium Cranial vault Basicranium
  43. 43. Cranial vault Functions: protection of brain- primary function Growth 1)Mechanisms and sites Cranium grows ---as brain grows Accelerated during infancy, 90% of it is complete by 5th year
  44. 44. As brain expands, bones of calvaria are displaced correspondingly outwards Primary displacement causes tension in the sutural membranes – immediate response– sutural edges At same time new bone is also formed on the flat surfaces– both, ecto- &endo- cranial
  45. 45. Arc of curvature of the whole bone decreases and the bone becomes flatter and remodeling not extensive. Note: Endosteal surface is in contact with the dura, that functions as periosteum, is not a resorptive surface. This is an error in the older literature, sometime still encountered.
  46. 46. To summarise, Increase in cranial width Primarily through “fill-in” ossification of proliferating connective tissue in coronal.lamboidal.interparital.paritosphenoidal paritotemporal sutures. the and Increase in cranial length Growth of the cranial base– active response at the coronal suture Increase in cranial height Activity of parietal sutures along with occipital, temporal
  47. 47. According to Davenport Length of brain case at different ages is as follows: Age Growth in % Birth 63 6 months 76 1 year 82 2 year 87 3 years 89 5 years 91 10 years 95 15 years 98
  48. 48. Growth of the braincase in width (no. of mm/year) Age Cranial width First 9 months (prenatal) 6 months (postnatal) 6-12 100 mm 1-2 years +9mm 2-3 years +1.5mm +50mm +20mm
  49. 49. Timing Growth under the influence of the expansion of the enclosed brain Brain growth largely completed by early childhood Cranial vault --- one of the first regions to attain full size Compensatory mechanisms Sutural system provide extensive adaptive capabilities in pathological conditions like hydrocephalus Cultural like head binding
  50. 50. Theoretical and clinical issues General agreement on the mechanism of growth Little understading about control of cessation of sutural growth Clinical issues ---- abnormal and anomalous growth Hydrocephalus, cranial stenosis Surgical intervention is the treatment of choice
  51. 51. Basicranium Functions Adapted to upright the body posture Development of large cerebral hemispheres Articulates the skull with vertebral column, mandible and maxillary region Buffer zone between brain, face and pharyngeal region Template for facial growth
  52. 52. The neural side of cranial floor different from calvaria The endocranial surface of basicranium is resorptive in most areas Further, fossa enlargement is accomplished by direct remodeling involving on the outside with resorption inside. Various cranial fossae Anterior Middle Posterior
  53. 53. Middle and posterior fossae divided by the petrous elevation Olfactory fossae separated by crista galli The right and left middle cranial longitudinal midline sphenoidal elevation fossae--- Right and left anterior and posterior cranial fossae---longitudinal midline bony ridge Note all these elevations depository in nature
  54. 54. Mechanism and Sites Elongation at synchondroses Cortical drift and remodeling Sutural growth This combination provides Differential growth enlargement between the cranial floor and calvaria Expansion of confined contours in the various endo cranial fossae Maintenance of passages and housing for vessels and nerves
  55. 55. Midventral segment of cranial floor grows much slowly than the floor of the laterally located fossae. Expansion of hemispheres--- sutural growth and cortical drift
  56. 56. Midline part ---- synchondroses Retention left chondrocranium from primary cartilges of
  57. 57. Synchondroses Spheno-ethmoidal Cartilaginous band between the sphenoid and ethmoid bones. Ossifies by 5-25 years Intersphenoidal Cartilaginous band between 2 parts of sphenoid; ossifies by birth
  58. 58. Intra-occipital Ossifies by 3-5 years Spheno-occipital Principal growth cartilage during childhood period Provides a pressure adapted bone growth mechanism
  59. 59. Bone remodeling seen in cranial base 1- resorption on the anterior wall of middle cranial fossa 2- deposition on the orbital face of sphenoid 3-anterior displacement of ant. cranial fossa 4-Elevation of petrous temporal bone Lowering of the foramen magnum Perimeter of the foramen enlarges
  60. 60. Timing Show reduced rate of remodeling with the completion of brain growth Cranial synchondroses are paced differently Compensatory mechanism Basicranium considered one of the most stable sturctures of craniofacial skeleton Hence diplays less compensatory growth copmared to other structures
  61. 61. Theoretical and clinical issues Various hypotheses proposed but the concept is still not clear How much of the basicranial changes are under the influence of functioning growth fields?? How much of it due to inherent growth potential of the cartilages??? Skeletal base dysplasia--affects the growth of craniofacial structures Neither surgical nor orthodontic means of treatment are successful in eliminating the underlying defect Treatment rendered is only compensatory --- growth of maxilla and mandible altered
  62. 62.
  63. 63. Nasomaxillary complex Functions Important role in mastication (attachments of teeth and muscles) Provides significant portion of airway Houses olfactory nerve endings Encloses eyes Adds resonance to the voice through the sinuses contained within the region
  64. 64. Nasomaxillary complex Mechanisms and Sites Growth observed at Sutures Nasal septum Periosteal and endosteal surface Alveolar process According to Mills “maxilla increases in size by subperiosteal activity postnatally
  65. 65. Maxilla The growth mechanism is produced by Displacement Growth at sutures Surface remodelling
  66. 66. Primary displacement Active, downward and forward Maxillary tuberosity lengthening posteriorly Secondary displacementPassive, downward and forward direction Cranial base– middle cranial fossa grows anteriorly Important during primary dentition periods
  67. 67. Which is the biomechanical force underlying the maxillary displacement?? Primary displacement- anterior and inferior as it grows and lengthens posteriorly Nature of this displacement--- reviewed historically
  68. 68. Controversies regarding maxillary displacement Maxillary tuberosity
  69. 69. Bone growth within the various maxillary sutures produces pushing-apart of the bones, with resultant thrust of whole maxilla being displaced anteriorly and inferiorly as well.
  70. 70. Nasal septum theory – Scott Pressure accomodating expansion of nasal septal cartilage– source of physical force Drawbacks Source of displacement is multifactorial Experimental studies– surgical deletion affected the growth process; not that they control growth process
  71. 71. Functional matrix concept Facial bones grow in a sub-ordinate growth control relationship with all surrounding, pace-making soft tissues Note Concept five Operation of growth fields – carried out by osteogenic membrane and other surrounding tissues
  72. 72. Growth at sutures Fronto-nasal Fronto- maxillary Zygomatic-temporal Zygomatico-maxillary Pterygo-palatine All are oblique; more or less parallel to each other Downward and forward growth
  73. 73. Surface remodelling Increase in size Change in shape Change in functional relationship
  74. 74. Resorption occurs on the lateral surface of orbital rim leading to lateral movement of the eye ball Floor of orbit-deposition in superior, lateral and anterior direction
  75. 75. Bone deposition along posterior margin of maxillary tuberosity Bone resorption occurs on lateral wall of nose
  76. 76. Also on the floor of the nasal cavity Increase in height of maxilla
  77. 77. Face enlarges by width As teeth upright alveolar height increases Except mesial wall others resorb – increase in size of maxillary sinus
  78. 78. Zygomatic bone moves in posterior direction. Anterior nasal spine prominence increases due to bone deposition
  79. 79. Maxillary height Sutural growth toward the frontal and zygomatic bones Appositional growth towards the alveolar process Maxillary width Growth in median sutures Vertical drift of posterior teeth with lateral expansion---- alveolar divergence Mutual transverse rotations of maxillae--- separation of the halves more posteriorly than anteriorlyMaxillary length Apposition on the maxillary tuberosity Sutural growth towards the palatine bone
  80. 80. Compensatory mechanisms Well designed for adaptive and compensatory growth Most of it seen in alveolar process In narrow palate , alveolar process compensates in height and width Skeletal class II still we find Angle’s Class I molar relation
  81. 81. Mandible Mandible undergoes the largest amount of growth post-natally and also exhibits the largest variability The functional parts includeRamus Corpus Angle of mandible Lingual tuberosity The alveolar process The chin
  82. 82. Functions Mastication Maintenance of airway Speech Facial expression
  83. 83. Ramus Function Provides an attachment base for masticatory muscles Plays key role in placing the corpus and dental arch into ever-changing fit with the growing maxilla and the limitless structural variations of face
  84. 84. Mechanisms and sites Moves posteriorly ; combination of resorption and deposition Resorption –anterior ramus while deposition posteriorly---drift posteriorly Functions of remodel— Accommodate the increasing mass of masticatory Enlarged breadth of pharyngeal space Lengthening of corpus
  85. 85. Corpus As anterior border of ramus resorbs – posterior drift Conversion of earlier ramus into posterior part of the body. Thus body of the mandible lengthens
  86. 86. Ramus to corpus remodeling conversion Ramus relocated in a posterior direction; Bony arch length increased Resorption of anterior border of ramus---- making room for the last molar This is evident from tiny mandible of fetus till attainment of adult size Bicondylar dimension established much earlier in childhood; bilateral growth separation between condyles is minimal beyond early childhood years
  87. 87. Coronoid process Follows V principle Lingual surface faces- 3 directions—posterior, superior and medial Lengthens vertically- V oriented vertically
  88. 88. Deposition occurs on lingual surface Also posterior movement seen – V oriented horizontally
  89. 89. Angle of the mandible Lingual side- resorption antero-inferiorly while deposition postero-superiorly Buccal side vice versa This results in flaring of mandible
  90. 90. The lingual tuberosity Direct equivalent of maxillary tuberosity Boundary between ramus and body Yet not included in the basic vocabulary of cephalometrics Moves posteriorly by deposition on its posteriorly facing surface Ideally max. tuberosity closely overlies lingual tuberosity
  91. 91. Protrudes noticeably in a lingual direction A large resorption field below it– lingual fossa Tuberosity relocates posteriorly with only relatively slight lateral shift At the same time that part of the ramus just behind remodels medially----- becomes part of corpus, thereby lenghtening it.
  92. 92. Alveolar process Develops in response to tooth buds As teeth erupt the alveolar process erupt Adds height and thickness to body of mandible
  93. 93. Chin A specific human characteristic; recent man only As age advances the growth of chin becomes significant Sexual and genetic factors
  94. 94. Condyle Anatomic part of special significance Evolutionary changes Earlier thought to be the master center; now a regional field of gowth– regional adaptive growth
  95. 95. Mechanism Cartilage is special non-vascular tissue Secondary type of cartilage Endochondral mechanism of bone formation—due to variable levels of compression Proliferative process – upward and backward growth of condyle
  96. 96. Height Ramus height increases correlate with corpus length Anterior mandibular height is related to dental development and overall downward and forward growth of mandible Width Bigonial and bicondylar diameter increase– divergence of mandible Most width increases as it grows longer (Enlow’s V principle)
  97. 97. Length By combination of resorption and deposition at the ramus-corpus interface
  98. 98. Clinical implications
  99. 99. Facial form and anatomic basis for malocclusions Dolicocephalic facial form Brain inhorizontally long and relatively narrow Basicranium more flat and horizontally longer Nasomaxillary complex in a protrusive position relative to mandible Mandible – downward and backward rotation of entire mandible Occlusal plane rotated to a downward-inclined plane Retrognathic profile--- Class II molar relation
  100. 100. Brachycephalic Brain – rounder and wider Basicranium more upright and short Nasomaxillary complex is short horizontally Retrusive maxilla and a more relatively prognathic mandible Prognathic profile, Class III molar relarionship
  101. 101. Interrelationship among brain form, facial profile & occlusal type predisposes --- facial form and malocclusion Examples Caucasian groups-dolichocephalic headform, Class II malocclusions and retrognathic profile Far-eastern population- brachycephalic headform, Class III malocclusion and prognathic profile
  102. 102. Clinical implications of growth in 3 dimensions Sequence of growth cessation Growth in width --- transverse plane Growth in length ---- antero-posterior plane Growth in height----- vertical plane
  103. 103. Transverse plane Growth completed before adolescent growth spurt Minimally affected by adolescent growth changes Example 1: 13 year old girl with cross bite; transverse growth ceased. Interceptive procedures ruled out. Role of midpalatal suture in lateral displacement of palatal shelves is minimal Maxillary expansion even after suture closure should be possible
  104. 104. Antero-posterior plane, Jaws to continue throughout puberty For example, 13 yearold girl- orthognathic maxilla and retrognathic mandible; myofunctional appliances can be given In case of retrognathic maxilla, protraction of maxilla not indicated beyond 14 years
  105. 105. Vertical plane Growth occurs upto 18-19 years Most common discrepancies Open bite--- Skeletal / Dental Deep bite--- Skeletal / Dental Discrepancy Skeletal Dental Open bite FMP angle >250 Deep bite <250 Infra erupted incisors, supra erupted molars Vice versa
  106. 106. Conclusion
  107. 107. CONCLUSION It is important before understanding the abnormal to have a clear idea of the way the face and its component part develop.since the dentist and orthodontist are heavily involved in the development of not just the dentition but the entire dentofacial complex,practitioner may able to manipulate the facial growth for the benefit of the patient, We do not fully understand the factors which control the amount and direction of growth.
  108. 108. References Craniofacial Development ------ Sperber Contemporary Orthodontics---- Proffit Essentials of facial growth --- Enlow- Hans Facial growth---- Enlow – Poston Glossary of Orthodontic terms----John Daskalogiannakis Orthodontics Practice and Principles– TM Graber Scientific foundations of Dentistry----Cohen Text book of Orthodontics---- Bishara Text book of Orthodontics---- Moyers
  109. 109. Thank you For more details please visit