Postnatal growth of maxilla & mandible

1. POST NATAL GROWTH
OF
MAXILLA & MANDIBLE
Dr.Ashok kumar A
MDS - I
Dept of orthodontics
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2. Questions related to Growth & development
Essay
• Define Growth and explain Functional matrix theory in detail.(FEB 13 ,19 ,07 )
• Enumerate the various Theories of Growth. Discuss in detail the post natal growth
of Mandible.- (August 13)
• Write the types of growth spurts and significance of each spurt. List the different
methods of assessing skeletal growth status and describe any one method.(Aug-15)
• Write in detail the postnatal growth of the craniofacial complex and mention the
clinical importance of the various growth spurts. (August 09)
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3. • Growth spurt.
• Post natal growth of mandible
• Post natal growth of maxilla
• Direct ossification
• Stress trajectories & Wolfs law
• Safety valve mechanism.
• Functional matrix.
• Drift Vs Displacement.
• Sicher’s theory.
• Prenatal ethiology of malocclusion
• Intramembranous and Endochondral ossification.
• Cartilaginous theory
• Methods of studying growth.
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4. What is Growth & Development?
Growth usually refers to an increase in size and number – Proffit
Development is defined as progression towards maturity – Melvin moss
Prenatal growth : occurring or existing before birth.
Postnatal growth : related to denoting the period after child birth.
Neurocranium
The cranial vault
The cranial base
„Viscerocranium (Face)
The nasomaxillary complex
The mandible
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5. • The growth of the cranium & facial skeleton progress at different rates (Scammon).
• By differential growth, the face literally emerges from beneath the cranium .
Upper face under the influence of
cranial base inclination,
moves upward and forward
Lower face moves downward and
forward on an expanding ‘V’
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6. POST NATAL GROWTH OF MAXILLA
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7. Growth of maxilla with regard to various theories of growth
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8. Translation/Displacement
Primary Translation
• Primary displacement of maxilla in a forward
direction occurs due to the growth of
maxillary tuberosity in a posterior direction.
• Anterior displacement = Posterior lengthening.
Secondary Translation
• Nasomaxillary complex grows by
secondary translation due to growth at
cranial base as it is attached to it
• Occurs during primary dentition period
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9. Growth at Sutures
• Growth occuring at the suture &
surrounding soft tissue cause
opening of suture & brings
downward & forward displacement
of maxilla .
• New bone is formed on either side
cause increasing in overall bone size
of maxilla.
Fronto nasal
Fronto maxillary
Zygomatico maxillary
Zygomatico temporal
Pterygo palantine
Sutures are all
Oblique and more
or less parallel with
each other
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10. Surface Bone Remodeling
• In addition to the specific sites of bone formation, all bony surfaces undergo
selective bone remodeling through deposition and resorption along with
endosteal and periosteal surfaces of bone.
Increase in size
Change in shape of bone
Change in functional relationship
WHY
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11. Orbit, Nasal cavity , Maxillary
sinus
Maxillary Tuberosity Zygoma
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12. Palatal Remodeling –‘V’ principle
Increase in Maxillary Height
Increase in Maxillary Width
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13. Summary of Post natal growth of Maxilla
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14. POST NATAL GROWTH OF MANDIBLE
• In the facial bones, mandible exhibits greatest amount of postnatal growth.
• Mandible grows in a downward and forward direction .
• At birth, the mandible is made of two halves, as it is not united at the midline. The ramus are
short and condylar development is minimal at birth
• By the end of first year, the two halves get united
to form a single mandibular bone.
• Although a single bone, the mandible can be divided
functionally and developmentally into several subunits.
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15. Condylar cartilage –Primary centre
Functional matrix
hypothesis
Sutural dominance &
Cartilaginous theory
Growth of mandible with regard to various theories of growth
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16. Body of the mandible
Ramus
Chin
Ramus &
Coronoid process
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17. Condylar cartilage• The presence of Condylar cartilage is an adatation to
withstand the compression that occurs at the joint .
• 1) Growth occuring at the surface of condylar cartilage by
deposition of bone towards cranial base ,pushes the mandible
forward & downward .
• 2) Carry away phenomenon - Growth of soft tissues including
muscles & connective tissue
carries the mandible forward
away from the the cranial base
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18. Summary of Post natal growth of Mandible
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19. Safety valve mechanism
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20. AGE CHANGES IN MAXILLA
AT BIRTH –Transverse & anterioposterior diameter more
Well marked frontal process
Body consists of little more than alveolar process
Maxillary sinus is a small furrow on the lateral wall of nose
Tooth sockets – close to orbit
IN ADULTS – Vertical Diameter is more due to
1. Developed alveolar process
2. Increased size of maxillary sinus
IN OLD –
1. Infantile condition
2. Resorption of alveolar bone
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21. Age changes of mandible
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23. Dvelopmental anomolies affecting maxilla & mandible
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Agnathia
Mandibular prognathism
Gorlin goltz syndrome
Marfan syndrome
Klinefelter syndrome
Macrognathia

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Treacher Collins Syndrome Pierre Robin Syndrome

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Down syndrome Fetal Alcohol syndrome

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Treatment

27. CONCLUSION
• It is important for the clinician to know the normal and the abnormal
ranges of growth for proper diagnosis, treatment planning and selecting
appropriate clinical procedures.
• Orthodontic treatment irrespective of appliance depends to a great extent
on adaptive capacity of alveolar process, growth and remodelling.
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