Postnatal growth of maxilla & mandible

Postnatal growth of maxilla & mandible

1. POST NATAL GROWTH OF MAXILLA & MANDIBLE Dr.Ashok kumar A MDS - I Dept of orthodontics 1 Dr.Ashok A

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) 2 Dr.Ashok A

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. Short notes 3 Dr.Ashok A

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 4 Dr.Ashok A

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’ 5

6. POST NATAL GROWTH OF MAXILLA 6 Dr.Ashok A

7. Growth of maxilla with regard to various theories of growth 7 Dr.Ashok A

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 8 Dr.Ashok A

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 9 Dr.Ashok A

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 10 Dr.Ashok A

11. Orbit, Nasal cavity , Maxillary sinus Maxillary Tuberosity Zygoma 11 Dr.Ashok A

12. Palatal Remodeling –‘V’ principle Increase in Maxillary Height Increase in Maxillary Width 12 Dr.Ashok A

13. Summary of Post natal growth of Maxilla 13 Dr.Ashok A

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. 14 Dr.Ashok A

15. Condylar cartilage –Primary centre Functional matrix hypothesis Sutural dominance & Cartilaginous theory Growth of mandible with regard to various theories of growth 15 Dr.Ashok A

16. Body of the mandible Ramus Chin Ramus & Coronoid process 16 Dr.Ashok A

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 17

18. Summary of Post natal growth of Mandible 18 Dr.Ashok A

19. Safety valve mechanism 19 Dr.Ashok A

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 20 Dr.Ashok A

21. Age changes of mandible 21

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23. Dvelopmental anomolies affecting maxilla & mandible Dr.Ashok A 23 Agnathia Mandibular prognathism Gorlin goltz syndrome Marfan syndrome Klinefelter syndrome Macrognathia

24. Dr.Ashok A 24 Treacher Collins Syndrome Pierre Robin Syndrome

25. Dr.Ashok A 25 Down syndrome Fetal Alcohol syndrome

26. Dr.Ashok A 26 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 . Dr.Ashok A 27

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