The mandible develops through both intramembranous and endochondral ossification. Ossification begins at 6 weeks in utero in the body and ramus via intramembranous ossification. Condylar ossification begins at 14 weeks via endochondral ossification in the condylar head. Coronoid and symphysis ossification also occur via endochondral ossification, beginning at 4 and 6 months in utero, respectively. Mandibular growth occurs through condylar cartilage growth, alveolar process development, and subperiosteal bone deposition and resorption. Growth of the condyle ceases between 20-25 years of age while the lower border of the

1. MANDIBLE
‫حسن‬ ‫شريف‬ ‫د‬ 1

2. ORIGIN OF THE MANDIBLE
First Branchial Arch
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3. TYPES OF OSSIFICATION
1-
INTRAMEMBRANOUS
2-
ENDOCHONDRAL
FLAT BONES LONG BONES
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5. * Starts at : 6 WIU
* Develops: Intramembranous ossification
* Site of ossification center of the mandible:
At branching of mental and incisive from inferior alveolar nerve.
•Gives rise to:
1. Body of the mandible.
2. Ramus of the mandible under the inferior alveolar canal.
Development Of Body Of The Mandible
Ossification Center
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DEVELOPMENT OF CONDYLE
Time of origin: 14 WIU.
❑ Site:
Condylar head.
❑ Life span:
Continue until 20 years of age.
❑ Type of ossification:
Endochondral type.
❑ Gives rise to:
1- Head and neck of condyle.
2- Posterior part of ramus above mandibular foramen.

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DEVELOPMENT OF CORONOID
Time of origin: 4 MIU.
❑ Site:
Anterior border of Coronoid.
❑ Life span:
Continue until first years of age.
❑ Type of ossification:
Endochondral type.
❑ Gives rise to:
1- Coronoid process.
2- Anterior part of ramus above mandibular foramen.

8. DEVELOPMENT OF SYMPHYSIS
❑Site:
At the midline of the mandible.
❑Life span:
Continue until first year of age.
❑Type of ossification:
Endochondral type.
❑Gives rise to:
1- Symphysis menti.
2- Increase the width of the mandible.
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9. ❑ Condylar growth leads to:
1- Increase Ramus Height.
2- Increase Mandible’s Length.
3- Increase Inter-condylar Distance.
* Growth of the mandible is obtained by the following:
1.Growth by condylar cartilage.
2.Development of alveolar process and tooth eruption.
3.Subperiosteal bone deposition and resorption
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10. ❑ Growth of Alveolar Process:
1. Increase height Of Alveolar Process.
2.Increase height Of The Body of mandible.
❑ Growth by Subperiosteal Bone
Deposition and Resorption:
1. Increase The Body Length and Height.
2. Widening Of The Mandible.
3. Increase The Distance Between Mandibular
Canal And Roots.
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11. ** IMPORTANT NOTE **
Growth Of Condyle ceased At :
20-25 Years Of Age.
Growth Of Lower Border Of Mandible Stopped At :
7 Years Of Age.
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12. AGE CHANGES OF
THE MANDIBLE
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13. AGE CHANGES OF THE MANDIBLE
Stages of growth:
1. At birth.
2. Child.
3. Adult.
4. Old age after teeth extraction.
Study point:
1. Angle of the mandible.
2. Condyloid and coronoid processes.
3. Mental foramen level.
4. Tooth number.
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14. AT BIRTH:
1. Angle of the mandible: 165o
2. Coronoid process: at higher
level in relation to condyle.
3. Mental foramen: at lower level
4. Deciduous teeth: no teeth.
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15. CHILD:
1. Angle of the mandible: 140o
2. Coronoid process: at higher level in
relation to condyle.
3. Mental foramen: at higher level than in
infant but not reach to the middle of the
vertical height
4. Deciduous teeth: fully erupted
5. The condyle: contain cartilage for growth.
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16. ADULT:
1. Angle of the mandible: 110o
2. Coronoid process: at lower level in
relation to condyle.
3. Mental foramen: above the level of
middle of the vertical height
4. Permanent teeth: fully erupted and
alveolar bone are fully developed.
5. The condyle: contain cartilage for
growth until the second decade ( 20 year).
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17. OLD AGE:
1. Angle of the mandible: 140o
2. Coronoid process: at higher
level in relation to condyle.
3. Mental foramen: become near
the upper border of the mandible.
4. Permanent teeth: are extracted
with alveolar bone degeneration.
5. The condyle: not contain
cartilage.
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18. THANK YOU
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