2. CONTENTS
1)Pre Natal development of Maxilla
Embryonic development
Meckel’s cartilage
Development of palate
Mech’ of palate elevation
Palate remodelling
2)Post Natal development of Maxilla
Displacement
Remodelling
Growth at sutures
Growth in height,wifth & length
Key ridges
Maxillary sinus
3. CONTENTS
1) Pre Natal development of Mandible
2) Post Natal development of Mandible
Growth timing
Sites of Growth
Development of ramus,lingual tuberosity,condyle
Growth by counterpart principle
Ramus uprighting
Age changes in Maxilla
Age changes in mandible
Developmental disturbances of face,lip,palate
REFERENCES
5. ANATOMY OF THE MAXILLA
PARTS OF MAXILLA.
1. BODY –large and pyramidal in shape.
2. FOUR PROCESSES.
Frontal
Zygomatic
Alveolar
Palatine
Maxilla houses the largest sinus of the face, the
maxillary sinus
6. DEVELOPMENT OF MAXILLA
Maxilla forms within the maxillary prominences
extending ventrally
from the dorsal aspect of a much
larger mandibular swelling.
Ossification of maxilla begins slightly later than in the
mandible.
7. DEVELOPMENT OF MAXILLA
The primary ossification centre appears for each maxilla
in the 7th week.
The secondary centers are at- zygomatic, nasopalatine
and orbitonasal areas
It lies in the angle formed by the infraorbital nerve and
anterior superior alveolar nerve,above the part of the
dental lamina from which the canine tooth germ
develops.
8. DEVELOPMENT OF MAXILLA
The premaxilla begins to ossify from two centres
in the latter part of the 7th week.
Ossification spreads by:
- Bony trough formed for infraorbital nerve
- Palatine process
Maxillary sinus – 16th week
9. Around the 4th week of intra-uterine life, the
developing brain and the pericardium form two
prominent bulges on the ventral aspect of the
embryo. These bulges are separated by the
primitive oral cavity or stomatodeum.
The floor of stomodeum is formed by the
buccopharyngeal membrane which separates it
from the foregut.
The pharyngeal arches are laid down on lateral
and ventral aspects of the cranial most part of
the foregut which lies in close approximation
with the stomodeum
10. Initially, there are 6 pharyngeal
arches, but the 5th one usually
disappears as soon as it is formed
leaving only five.
They are seperated by 4 branchial
grooves.
The first arch is called
MANDIBULAR ARCH and second
arch is called HYOID ARCH.
11. MECKEL’S CARTILAGE
It is derived from the first
branchial arch around the
41st – 45th day of intra-uterine
life
It extends from the cartilaginous otic capsule to the
midline or symphysis and
provides a template for guiding the growth of the
mandible.
A major portion of this cartilage disappears during
growth and the remaining part develops into following
12. DEVELOPMENT OF PALATE
Palatogenesis begins towards the end of 5th week and is
completed by about 12th week.
The palate develops from two primordia.
Primary palate
Secondary palate
13. PALATE
Primary palate
At the end of 5th wk
Develops from deep part of inter maxillary segment of
the maxilla.
Internal merging of medial nasal prominences.
Represents only a small part of adult hard palate.
14. PALATE
Secondary palate
Primordium of the hard and soft palate posterior to the
incisive foramen.
Begins to develop in the 6th wk, from shelf like
structures called lateral palatine processes.
15. PALATE
The tongue is initially
interposed between the
secondary palatal
shelves.
The palatal shelves
become positioned
above the tongue to allow
for fusion in the midline.
16. PALATE
The processes fuse in the midline and with the nasal
septum and posterior part of primary palate.
begins anteriorly during the 9th wk and is completed
posteriorly by the 12th wk.
17. PALATE
The posterior part of palatal processes remains
unossified, they extend posteriorly beyond the nasal
septum and fuse to form soft palate and uvula.
19. MECHANISM OF PALATE ELEVATION
Elevation of the palate
o Descent of tongue influenced by the growth of the
Meckel’s cartilage and mandible.
o Myoneural activity in the tongue.
o Mouth opening reflexes
20. MECHANISMS OF PALATE ELEVATION
INTRINSIC
Hydration and polymerization of intracellular
substances producing an elastic elevating force.
Differential growth of one side of the palatal shelf.
Triger produced by a build up mucopolysaccharides.
Serotonin release from neural tissue.
21. PALATE
Genesis of cleft palate
o Delay in shelf elevation
o Disturbance in mechanism of shelf elevation
o Failure of shelves to contact due to lack of growth
o Failure to displace the tongue during closure
o [Pierre robin syndrome]
o Failure to fuse after contact as epithelium does not break
down
o Rupture after fusion
o Defective merging
22. The formation of the palate involves the coordinated outgrowth,
elevation and midline fusion of bilateral shelves leading to the
separation of the oral and nasal cavities.
Reciprocal signaling between adjacent fields of epithelial and
mesenchymal cells directs palatal shelf growth and
morphogenesis.
Loss of function mutations in genes encoding FGF ligands and
receptors have demonstrated a critical role for FGF signaling in
mediating these epithelial–mesenchymal interactions.
Hence, deletion that removes the FGF signaling antagonist Spry2
have cleft palate
23. PALATAL REMODELING
External side of the anterior part of the maxillary
arch is resorptive… with bone being added onto
the inside of the arch…..increase in arch
width…..increase in palatal width… V principle.
Growth along mid palatal suture.
As palate descends inferiorly….
- It occupies a different position
24. CLINICAL IMPLICATION
In RME, remodeling of
maxilla follows clinically
induced displacement.
lateral aspect of maxilla
is resorptive.
After fusion of mid
palatal suture, increase
in arch width is due to
remodeling of the
alveolar process.
25. INTER MAXILLARY SEGMENT
It
is composed of
- a labial component : philtrum of upper lip
-upper jaw component : carries four incisor
teeth.
- palatal component : that forms the
triangular primary palate.
The intermaxillary segment is continuous with
the rostral portion of the nasal septum which
is formed by the frontal prominence.
27. DEVELOPMENT OF MAXILLA
Growth occurs by:
Apposition of bone
Surface remodeling
Movement downward & forwards:
Cranial base growth
Growth at sutures
28. POST NATAL GROWTH OF MAXILLA:-
Growth of nasomaxillary complex is produced
by following mechanism:-
Displacement (translation ie acc’ to moss)
:-leads to apposition of bone at sutures
Surface remodeling(transposition)
apposition
resorption
29. DISPLACEMENT
Primary displacement: the process of physical
carry, takes place in conjunction with a bone’s
own enlargement; joint contacts are important in
this process.
Secondary displacement: the movement of bone
and its soft tissues is not directly related to its own
enlargement .It is a fundamental part of the
overall process of craniofacial enlargement
31. It is physical movement of bone.
Causing secondary deposition of bone at sutures
Downward and Forward growth
32. REMODELLING
The functions of remodeling includes:
a) To progressively create the changing size of each
whole bone
b) To sequentially relocate each of the component
regions of the whole bone to allow for overall
enlargement
33.
34. As maxilla grows due to primary displacement its
anterior surface tends to resorb as part of
remodeling.
35. GROWTH AT SUTURE
The maxilla is connected to the
cranium and the cranial base by a
number of sutures.
These sutures include :
Fronto- nasal suture.
Fronto– maxillary suture.
Zygomatico– maxillary suture.
Pterygo– palatine suture.
Zygomatico – temporal suture.
36. POSTNATAL GROWTH OF MAXILLA
Growth in height - vertical
Growth in width - transverse
Growth in length - A -P
37. TRANSVERSE DIMENSION (IN WIDTH)
Growth in midpalatine suture
remodelling at lateral surface of alveolar process
39. VERTICAL DIMENSION (IN HEIGHT)
Eruption of Primary
Patatal
teeth displacement
remodelling
40. SECONDARY DISPLACEMENT OF NMC
Expansion of Middle Cranial fossa has secondary
displacement effect on anterior Cranial floor and
thus on underlying NMC.
Growth occurs in all the 3 dimensions
A-P dimension(in length)
Transverse dimension (in width)
Transverse dimension (in width)
41. SECONDARY DISPLACEMENT
(TRANSVERSE DIMENSION)
Left and right temporal lobes move away from
each other
Increase in transverse width of middle cranial
fossa
Increase in width of maxilla by-
Growth in mid palatine suture
Remodeling at lateral aspect of alveolar process
42. SECONDARY DISPLACEMENT
(A-P DIMENSION)
Ant. & Middle cranial fossa move away from each
other
NMC carried in forward direction
Bone deposited in tuberosity area
Increase in A-P dimension
43. SECONDARY DISPLACEMENT
(VERTICAL DIMENSION)
Middle cranial base is in inclined plane
Increase in dimension of Middle cranial base
causes displacement of NMC in downward
direction
44. NASOMAXILLARY REMODELLING
As clinically and biologically all inside and outside
parts,region and surface participate directly in
growth
So key factors in NMC growth includes
• Lacrimal suture
• Maxillary Tuberosity
• Vertical drift of teeth
• Nasal airway
• Palatal remodelling
• Cheek bone & zygomatic arch
• Orbital remodelling
45. LACRIMAL SUTURE
(KEY GROWTH MEDIATOR)
Diminutive flakes of bony islands surrounded by
many sutures forms perilacrimal sutural system
Without it a developmental ‘gridlock’ will occur
among differentially developing multiple bones
46. It slides maxilla downward along its orbital contacts.This
allows whole maxilla to get displaced inferiorly
The lacrimal bone itself undergoes a remodeling rotation
,because the more medial superior part remains with the
lesser expanding nasal bridge,while the more lateral
inferior part moves markedly outward to keep pace with the
greater expansion of the ethmoidal sinuses.
47. MAXILLARY TUBEROSITY
The horizontal lengthening of the bony maxillary
arch is produced by remodeling at the maxillary
tuberosity
Established by the posterior boundary of anterior
cranial fossa
It is a depository field
the maxillary tuberosity is important in clinical
orthodontics.it is also a major site of maxillary
growth
It lengthens posteriorly
48. MAXILLARY TUBEROSITY
It lengthens posteriorly
A-P
Deposits on buccal surface
width
Deposits on alveolar ridge
height
49. KEY RIDGE
Reversal lines occur at Key Ridge
Anterior to it : Resorption
Posterior to it: Apposition
* Reversal line: Irregular lines
containing concavities directed
away from the bundle bone and
serving as histologic indications
that resorption has taken place up
to that line from the marrow side.
50. THE NASAL AIRWAY
Lining surface of bony wall and floor
Resorptive
Lateral and anterior expansion of nasal
chamber
Downward relocation of palate
The airway functions as a key stone for face
Its obstruction can cause variation in facial
skeleton
51. PALATAL REMODELING
o Anteriorly - labial side is Resorptive
oand palatal side is depository causes
o widening of palate acc to V principle
o As the palate grows inferiorly by the
remodeling process, a nearly complete
exchange of old for new hard and soft
tissue occurs
oGrowth at mid palatal suture plays a
role in the progressive widening of the
palate and alveolar arch
52. MAXILLARY SINUS
All internal surfaces are resorptive except
medial nasal wall
Rapid continous downward growth
Close proximity to buccal maxillary teeth
53. EXPANSION OF MAXILLARY SINUS
At birth - 7 mm length
- 4 mm height
- 4 mm width
Expands at
rate of - 2 mm vertically yearly
- 3mm A-P yearly
Expansion by - bone resorption
- by tooth eruption
(as vacated bone become
pneumatized)
54. THE CHEEK BONE & ZYGOMATIC ARCH
The growth changes of the malar
complex are similar to those of maxilla
itself
The malar region and the anterior part of
the zygoma undergo posterior
remodeling movements.
The inferior edge of the zygoma is
heavily depository
As the malar region grows and becomes
relocated posteriorly, the nasal region is
enlarging in an opposite,anterior
direction,drawing out the nose and
making face deeper,anteroposteriorly
55. ORBITAL GROWTH
Follows ‘V’ principle
Enlarging displacement occurs
Growth at sutures
orbital floor moves
56. VARIATION IN NMC GROWTH
class II ( excessive mid face growth)
class III (decreased midface growth)
It’s common site for single most common
craniofacial anamoly Cleft Palate
59. DEVELOPMENT OF MANDIBLE
2nd bone to ossify
Intramembranous + endochondrial
6th week of intrauterine life
60. 36-38th day mandibular ectomesenchyme interacts with
mandibular epithelium before primary ossification.
Intramembranous bone lies lateral to cartilage.
First ossification centre for each half arises in 6th week in
region of bifurcation of IAN into mental, the ossification
spreads dorsally and ventrally to form ramus and body.
Ossification stops at site where it would be lingula.
Medially it meets its fellow counter part,distally upto
middle ear.
Major cartilage disappears.
61. Secondary accessory cartilages occur bet 10-14th weeks
to form head of condyle, coronoid,mental protuberence
Coronoid cartilage: fuses with expanding
intramembranous ramus before birth
Mental:1-2 small cartilages appear and ossify in 7th
month iu in fibrous symphysial tissue
Condylar cartilage: appear 10th wk.
this is promordium for future condyle.
cartilage differentiate by interstitial n appositional
growth.
62. By 14th wk, 1st evidence of endochondral bone
formtation
Condyle cart is an imp growth centre for ramus.
Condylar growth ia at its peak at puberty.
Occurs12-14 months post natally,2halves fuse into
synostosis
63. Mandible appears as single bone.
Basal bone forms one unit to with alveolar,
condylar, coroniod, angular process and chin is
attached.
They grow by functional matrix theory
Teeth act as functional matrix for development of
alveolar bone
Temporalis influences coroniod process
Masseter n med pterygoid – at angle
Lateral pterygoid – at condyle
65. POST NATAL GROWTH AND
DEVELOPMENT
GROWTH TIMING
Growth of width of mandible is completed first,
then growth in length and finally growth in
height
66. POST NATAL GROWTH AND
DEVELOPMENT
WIDTH OF MANDIBLE
Growth in width is completed before
adolescent growth spurt
Intercanine width does increase after 12 years
Both molar and bicondylar width shows small
increase until growth in length ends
67. POST NATAL GROWTH AND
DEVELOPMENT
GROWTH IN LENGTH
Growth in length continues through puberty
Girls—14-15 years
boys---18-19 years
68. MAIN SITES OF POST NATAL GROWTH
IN THE MANDIBLE
Condylar cartilage
Posterior border of the Rami
Alveolar ridges
69. CONDYLAR CARTILAGE
Secondary cartilage
Dual in function
a) Articular
b)Growth
Not a primary centre for growth ,but
Secondary in evolution
Secondary in embryonic origin
Secondary in adaptive responses to changing
developments
71. Ramus
• It provides an attachment base for masticatory
muscles.
• It positions the lower arch in occlusion with the
upper.
• It is continuously adaptive to the multitude of
changing craniofacial conditions.
72. Moves progressively posterior by
Deposition Posterior part
Resorption Anterior part
73. Superior part of ramus below sigmoid notch
Lingual : deposition
Buccal : Resorption
Lower part of ramus below the Coronoid process
Buccal : depostion
Lingual : Resorption
74.
75. • The mandible as a whole displaces anteriorly
and inferiorly.
76. • The former anterior part of the ramus becomes
the corpus by resorptive and depository
remodeling.
77. THE LINGUAL TUBEROSITY
Major site of mandibular growth and remodeling.
Direct anatomic equivalent of the maxillary
tuberosity.
Effective boundary between the basic structures-
ramus and corpus.
78. Grows posteriorly by deposits on the on its
posterior surface
Its prominence is augmented by the presence of a
resorptive field below it, lingual fossa.
Simultaneuosly the part of the ramus behind the
tuberosity remodels medially
79. RAMUS TO CORPUS CONVERSION
The anterior border of the ramus resorbs relocating
the ramus in a posterior direction.
Development takes place according to the ‘V’
principle.
80. Coronoid process- its lingual surface faces
posteriorly
superiorly
medially all at once.
Deposits of bone on the lingual surface bring
about growth superiorly, posteriorly and medially.
81. • The buccal surface of the coronoid process undergoes
resorption.
• The area of the ramus below the sigmoid notch and
superior portion of the condylar neck…deposition on
lingual and resorption on buccal side.
• Inferior edge of the mandible at the Corpus-Ramus
junction……..resorption…….antegonial notch.
82. Theclinical presence of a deep mandibular
antegonial notch is indicative of a diminished
mandibular growth potential and a vertically
directed mandibular growth pattern.
Singer CP,Mamandras AH,Hunter WS
Gonial region is anatomically variable. The buccal
side can be resorptive or depository depending
on the direction of gonial flares.
83. • Mental foramen is near the lower border at
birth.
• Adult: midway
• Elderly: near the upper border.
84. THE CONDYLE
• Major site of growth with considerable clinical
significance.
• Endochondral growth occurs only at the articular
contact part of the condyle.
• Cartilage is non vascular, hydrophilic and
pressure tolerant.
• This mechanism develops as a response to local
demands.
85. CONDYLE
Lack of mandibular condyle and variable
amounts of ramus…. Lack action of lateral
pterygoid muscle on the same side.
Deviation of mandible on oral opening.
The condylar neck consists of intramembranous
bone.
The lingual and buccal sides of the neck have
resorptive surfaces.
What used to be the condyle becomes the neck
by periosteal resorption and endosteal
deposition..….. ‘V’ principle.
86. Where does the physical force that causes
primary displacement of the mandible come
from….??
• Condylar remodeling acts with displacement as a
co participant but not as the driving force in
response to common activating signals.
• As the mandible is displaced away from its
basicranial articular contact, the condyle and the
ramus secondarily remodel towards it.
88. RAMUS UPRIGHTING
• The ramus normally becomes vertically aligned
during its development.
• A remodeling rotation of the ramus alignment
occurs.
89. CLINICAL IMPLICATION
• It must lengthen vertically
• - to keep in pace with the growth of the
pharynx and middle cranial fossa.
- to accommodate the vertical
nasomaxillary growth.
• Gonial angle
• The vertical growth continues even after
horizontal has ceased to match the
continued vertical growth of the
midface.
90. • Condylar growth now becomes more vertically
directed.
• The direction of resorption and deposition of the
ramus reverses.
91. • Periosteal resorption on the labial bony cortex ,
deposition on the alveolar surface of the labial
cortex, resorption on the alveolar surface of the
lingual cortex, deposition on the lingual side of
the lingual cortex.
92. AGE CHANGES IN MAXILLA
AT BIRTH:
The transverse and anteroposterior
diameters are more than the vertical
diameter.
Frontal process is well marked Inferior surface of maxilla at
birth
Body consists of a little more than the
alveolar process
The tooth sockets reaching to the floor of
orbit
Maxillary sinus is a mere furrow on the
lateral wall of the nose.
Anterior surface of maxilla at
birth
93. IN ADULT:
Vertical diameter is greatest
due to the development of
the alveolar process and
increase in the size of the
sinus.
IN THE OLD:
The bone reverts to infantile
condition.
Its height is a result of
absorption of the alveolar
process.
94. AGE CHANGES IN MANDIBLE
In Infants & Children:
The two halves of mandible fuse during the first year of life.
At birth, the mental foramen,opens below the sockets for the
two decidious molar teeth near the lower border.
This is because the bone is made up of only the alveolar
part with teeth sockets.
The mandibular canal runs near the lower border.
The foramen and canal gradually shift upwards.
Lower jaw of child and adult,
showing the mental foramen.
95. IN ADULTS
The mental foramen opens midway between the
upper and lower borders because the alveolar and
subalveloar parts of the bone equally developed.
The mandibular canal runs parallel with the
mylohyoid line.
The angle reduces to about 110 or 120 degrees
because the ramus becomes almost vertical
96. IN OLD AGE
Teeth fall out and alveolar border is absorbed, so
that the height of the body is markedly reduced.
The mental foramen and the mandibular canal are
close to the alveolar bone.
The angle again becomes obtuse about 140
degrees because the ramus is oblique.
99. DEVELOPMENTAL DISTURBANCES OF
PALATE
1) Cleft palate
During the 7th week, a shift in the blood supply of the
face from the internal carotid to the external
carotid artery occurs as a result of stapedial
artery atrophy.
This is a critical time for mid face development
Deficient blood supply defects of upper lip and
palate.
2) Median cleft face syndrome
100.
101. The depth of the mandibular antegonial notch as an
indicator of mandibular growth potential
Am J Orthod Dentofacial Orthop. 1987 Feb;91(2):117-24.
Singer CP, Mamandras AH, Hunter WS.
A dosage-dependent role for Spry2 in growth and
patterningduring palate development
Ian C. Welsh, Aaron Hagge-Greenberg, Timothy P.
O’Brien*
Mechanisms of Development 124 (2007) 746–761
104. DERIVATIVES OF PHARYNGEAL
ARCHES
ARCHES NERVE MUSCLES SKELETAL ARTERY
I Maxillary arch Trigeminal MOM Mandible, Maxilary
Maxilla,incus,
malleus
II Hyoid Facial Muscles of facial Stapes, styloid Stapedial(embr
expression process,lesser yonic)
cornu & upper Corticotympani
part of body of c(adult)
hyoid,
III Glossopharyng Stylopharyngeu Gr. Cornu & Common
eal s lower part of carotid
body of hyoid
IV & VI Sup laryngeal & Intrinsic Thyroid, IV- rt subclavian
recurrent muscles of cricoid,
laryngeal larynx, pharynx, arytenoid, VI - pulmonary
levetor palatini corniculate,
cuneform
105. AGE CHANGES IN MANDIBLE
• Mandible is relatively
small at birth.
• Eruption of teeth and
development of
alveolar process
contribute to its vertical
growth.
• Assumes a more
forward position.
• With the loss of teeth,
alveolar process
resorbs reducing the
mandibular height.
Editor's Notes
Each of these arches contain: A central cartilage rod that forms the skeleton of the arch. A muscular component called branchiomere. A vascular component. A neural element.
The mental ossicles Incus and malleus Spine of sphenoid bone. Anterior ligament of malleus Spheno - mandibular ligament
Nasal septum- tongue position – palatine shelf fusion the main part of the definitive palate is formed by two shelf like outgrowths from the maxillary prominences. The palatine shelves appear at the 6 th week of development and are directed obliquely at each side of the tongue. At the 7 th week, they attain a horizontal position and fuse to form the secondary palate. The shelves also fuse with the primary palate anteriorly.
Accumulation of hyaluronic acid is the chief component of shelf elevating force. Degree of mesenchymal cell biosynthetic activity at different stages of palatal development .
Micro gnathia Glossoptosis PIERRE ROBIN Upper airway obstruction Cleft palate
Sprouty family of genes Sprouty homolog 2 Fibroblast growth factor A dosage-dependent role for Spry2 in growth and patterning during palate development Ian C. Welsh, Aaron Hagge-Greenberg, Timothy P. O’Brien*
Natural increase in palatal width…… vertical drift of posterior teeth with lateral expansion (v principle).
As a result of medial growth of the maxillary prominences, the medial nasal prominences merge both at the surface and at a deeper level- intermaxillary segment.
Facial growth involves an interrelationship between all componenent parts ,hence no part is independent or selfcontained. Growth works towards an ongoing functional and structural equilibrium
the lowest point of the zygomaticomaxillary ridge. Also called zygomaxillare . Irregular lines containing concavities directed away from the bundle bone and serving as histologic indications that resorption has taken place up to that line from the marrow side
36-38 th day mandibular ectomesenchyme interacts with mandibular epi’ b4 prim ossification. Intramembranous bone lies lateral to cart. 1 ossification centre for each half arises in 6 th week in region of bifurcation of IAN into mental, the ossification spreads dorsally n ventrally to form ramus n body. Ossificatn stops at site whr it wud be lingula. Medially it meets its feloow counter part.distally upto middle ear. Major cart disaapears. Sphenomand lig
Secondary accessory cartilages occur bet 10-14 th weeks to form head of condyle, coronoid,mental protrb Coronoid cart: fuses wit expanding intramemb ramus b4 birth Mentl:1-2 small cartilages appear n ossify in 7 th month iu in fibrous symphysial tissue Condylar cart: appear 10 th wk. this is promordium for future condyle.cart differentiate by interstitial n appositional growth. By 14 th wk, 1 st evidence of endochondral bone formtm Condyle cart imp growth centr for ramus. Condylr growth peak at puberty. 12-14 months post natally,2halves fuse into synostosis
Mand appears as single bone. Basal bone frms one unit to wic alveolar, condylar, coroniod, angular pr n chin is attached. They grow by functoinal matrx theory Teeth act as functional matrix for developmnt of alv bone Temporalis influences coroniod pr Masseter n med pt –angle Lat pt- condylar
Secondary in evolution Secondary in embryonic origin Secondary in adaptive responses to changing developments
This allows for posterior lengthening of the body and the dental arch.
The posterior development of the mandibular bony arch simultaneously proceeds into the region that was previously occupied by the ramus.
Some of the key anatomic parts that participate in the relocation and remodeling process of the ramus and corpus cannot be seen or represented in 2d headfilms . Among these is the lingual tuberosity.
It remodels mostly posteriorly with only a slight lateral shift. Becoz the bicondylar width does not increase as much as mandibular length beyond the early childhood period.
Deposition occurs on the inner side of the v and resorption on the outer surface…..the direction of movement is towards the wide end of the v…
The foramen from childhood maintains a constant position midway between the anterior and posterior borders of the ramus. The depth of the mandibular antegonial notch as an indicator of mandibular growth potential Am J Orthod Dentofacial Orthop. 1987 Feb;91(2):117-24. The depth of the mandibular antegonial notch as an indicator of mandibular growth potential. Singer CP , Mamandras AH , Hunter WS .
GONIAL ANGLE : The angle formed by the junction of the posterior and lower borders of the human lower jaw
The condyle was earlier believed to be responsible for the overall mandibular growth. Endo chon growth occurs here bcoz the pressure levels are beyond the capacity of the bone’s vascular soft tissue membrane.
Lack of mand condyle does cause growth discrepancies but cannot be concluded that it is a growth centre. Although reconstruction of bone can be done to correct the deviation; the absent muscle function cannot be restored.
Enlow’s growth prin’ : Growth of any facial or cranial part relates specificallyto other structural and geometric counterparts
The gonial angle reduces to prevent change in occlusal relationship between maxillary and mandibular arches. At birth: 180 0 Adult: 90 0
C.Gland: swelling and eversion of the lower lip C.Granu: sudden onset and progressive course terminating in chronic enlargement of the lips. [2]:799 Peutz: development of benign hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on the lips and oral mucosa
Busulfan, Chlorambucil, Cyclophosphamide, Mercaptopurine, Methotrexate can cause clcp fetus is most vulnerable to teratogens (substances that cause birth defects) between the 3rd and 8th week after fertilization, when the organs and systems are developing. Certain drugs and other teratogens, however, can harm the fetus at any point during pregnancy. Teratogenic drugs taken before the 20th day following conception often have an all-or-nothing effect, inducing miscarriage or having no effect at all. While drugs taken after the first trimester are less likely to result in serious birth defects, these teratogens can alter the function of organs and systems resulting in more subtle impairments and developmental defect (oshman & milisola ,LLP )