The mandible develops from the first pharyngeal arch. In humans, Meckel's cartilage contributes to early development but does not form the mandible itself. Ossification of the mandible begins around 6 weeks gestation laterally to Meckel's cartilage, spreading anteriorly and posteriorly. The mandible's growth is further influenced by three secondary cartilages - the condylar, coronoid, and symphyseal cartilages - which facilitate endochondral ossification of the condyle and remodeling of other regions. By birth, the mandible has largely formed through intramembranous ossification guided by these cartilages.

1. DEVELOPMENT OF
MANDIBLE Presented By:
Muaviya Khan

2. DEVELOPMENT OF
MANDIBLE
• Forms from the 1st arch within the mandibular process.
• Meckel’s cartilage (cartilage of 1st arch) forms lower jaw in primitive
vertebrates.
• In humans, it has a close relation to the developing mandible but makes
no direct contribution to it.

3. Meckel’s Cartilage
• Forms at 6th week of development.
• It is a solid hyaline cartilage surrounded by a
fibro-cellular capsule.
-Extends from joint capsule to the midline of
the fused mandibular processes.

4. MECKEL’S CARTILAGE
CONT’D
• Formation of the mandibular division of trigeminal nerve begins two- thirds
along the length of the cartilage.
• It divides into two branches at this point:
 Lingual nerve
 Inferior alveolar nerve (IAN)
Lingual nerve runs along the medial aspect of the cartilage.
inferior alveolar nerve runs along the lateral aspect of the cartilage
Inferiorly, IAN divides to form mental and incisive branches.

5. PRIMARY OSSIFICATION
CENTRE• Condensation of mesenchyme occurs lateral to
Meckel’s cartilage in the 6th week gestation.
• This condensation begins at the angle formed
by division of the IAN into incisive and mental
branches.
• Intra-membranous ossification begins in this
condensation during the 7th week.
• Ossification begins in the membrane
covering the outer surface of Meckel’s
cartilage.
• from this centre, bone formation spreads
rapidly, anteriorly to the midline,
• nearly to the point of division of the inferior
alveolar nerve into lingual nerve

6. Development of ramus and body
RAMUS OF MANDIBLE
• Ossification spreads posteriorly into mesenchyme of the 1st
arch.
• Spreads away from Meckel’s cartilage and this point of
divergence is marked by lingula in adult mandible
• By 10th week, primitive mandible is formed almost entirely
by membranous ossification.

7. BODY OF MANDIBLE
-At 7 weeks of development, intramembraneous ossification
Begins in this condensation, forming 1st bone of mandible
-From the center of ossification, bone formation spreads rapidly
anteriorly to midline and posteriorly toward the point where the
Mandibular nerve divides into its lingual and inferior alveolar
branches
-The trough is converted to a canal as bone forms over the nerve, by
joining the lateral and medial plates.
(Trough is like a channel which further produces bony canal)

8. SECONDARY GROWTH
CARTILAGES
• Further growth of mandible till birth is influenced by formation of three
• secondary cartilages.
Secondary Cartilages
Condyla
r
Coronoi
d
Symphyse
al

9. Secondary Growth Cartilages Cont’d
CONDYLAR CARTILAGE CORONOID CARTILAGE SYMPHYSEAL CARTILAGE
• Appears during 12th week.
• Rapidly forms cone/carrot
shaped mass occupying most of
ramus area.
• Converted to bone by
endochondral ossification. By
20th week
• only a thin layer of cartilage
remains in the condylar heads
• Appears at about 4th
month of development.
• Forms near anterior
border and top of the
coronoid process.
• It is a transient cartilage.
• Disappears long before
birth.
• Two in number.
• Appear in the connective
tissue between two ends of
the Meckel’s cartilage.
• Get obliterated within the
first year of birth.

10. •Thank you for your attention!