detailed description of craniofacial development of maxilla & mandible

1. DR. SWATI SAHU
MDS FELLOW
DEPT. OF ORAL & MAXILLOFACIAL SURGERY
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3. MAXILLA
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4. Introduction
Growth
Development
Prenatal growth & development of maxilla
 Prenatal growth & development of palate
Postnatal growth & development of maxilla
CONTENTS
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5. Development of Tongue
• Formation of Anterior 2/3rd of the Tongue
• Formation of Posterior 1/3rd of the Tongue
• Developmental defect of Tongue
Developmental defect of maxilla
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6. Growth and development of an individual can be divided into pre-natal and the post-
natal periods. Pre-natal period of development is a dynamic phase in the development
of a human being.
INTRODUCTION
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7. • Stewart – It may be defined as a developmental increase in mass. In other
words it is a process that leads to an increase in the physical size of cells, tissues,
organs or organisms as a whole.
• Proffit – an increase in size or number.
• Pinkham – an increase, expansion or extension of a given tissue.
GROWTH
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8. DEVELOPMENT
• Moyers – all the naturally occurring unidirectional changes in the life of an
individual from its existence as a single cell to its elaboration as a multifunctional unit
terminating in death.
• Todd – development means progress towards maturity.
• Proffit – development is in complexity.
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9.  Indicator of general health.
 Identify unusual growth patterns at an early stage.
 Etiology and development of malocclusion.
 Identify abnormal occlusion – early stage.
 Poorly timed eruptions - malocclusion
 Growth - effects stability of occlusion.
 Use of growth spurts.
IMPORTANCE OF GROWTH
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10.  Growth and development of an individual can be divided into PRENATAL & the
POSTNATAL periods.
 The pre-natal period of development is a dynamic phase in the development of a
human being.
 During this period, the height increases by almost 5000 times as compared to only a
threefold increase during the post-natal period.
 The pre-natal life can be arbitrarily divided into three periods.
1. Period of the Ovum
2. Period of the Embryo
3. Period of the Fetus
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11.  This period extends for a period of approximately two weeks from the time of
fertilization.
 During this period the cleavage of the ovum and the attachment of the ovum to
the intra-uterine wall occurs.
PERIOD OF OVUM -
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12. PERIOD OF EMBRYO -
 This period extends from the fourteenth day to the fifty sixth day of intra-uterine life.
 During this period the major part of the development of the facial & the cranial
region occurs.
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13. PERIOD OF FETUS -
 This phase extends between the fifty sixth day of intra-uterine life till birth.
 In this period ,accelerated growth of the cranio-facial structures occurs
resulting in an increase in their size.
 In addition, a change in proportion between the various structures also occurs
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14. PRENATAL DEVELOPMENT OF MAXILLA
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15. • Around fourth week of intra uterine life a prominent bulge appears on ventral aspect of
the embryo corresponding to the developing brain.
• Below the bulge the shallow depression , which corresponds to the primitive mouth
appears called stomatodaeum .
• Floor of stomatodaeum is formed by buccopharyngeal membrane, which separates it
from foregut.
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16. Pharyngeal arch
• During 4th week, lateral plate mesoderm of ventral foregut, segments to form
5 bilateral mesenchyme swellings– pharyngeal arches
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17. Each PHARYNGEAL ARCH consists of
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1. A central cartilage rod that form
the skeleton of the arch.
1. A muscular component termed as bronchomere
2. A vascular component.
3. A neural element.

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19. • Mesoderm covering the developing forebrain proliferates, and forms a downward
projection that overlaps the upper part of the stomatodeum this downward projection
is called the frontonasal process
• The first branchial arch is called the mandibular arch and plays an important role in the
development of the naso maxillary region.
• The stomodeum is overlapped superiorly by frontonasal process & laterally by
mandibular arches of both sides.
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• The ectoderm overlying the Fronto-nasal Process shows bilateral localized thickenings
above the stomatodeum. These are called the Nasal Placodes.
• These Placodes soon sink and form the Nasal Pits.

21. • Formation of nasal pits divides frontonasal process into 2 parts :
- The medial nasal process
- The lateral nasal process
• The mandibular arch gives off a bud from its
dorsal end called the maxillary process which
grows ventro-medio-cranial to the mandibular
process.
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22 • At this stage the stomodeum is overlapped from above by the frontal process, below by
the mandibular process & on either side by the maxillary process.
• The two mandibular processes grow medially & fuse to form the lower lip & the lower
jaw.

23. • Maxillary process undergoes growth, frontonasal process becomes narrower so that 2 nasal
pits come closer.
• Line of fusion of maxillary process & the medial nasal process corresponds to the
nasolacrimal duct.
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• Each maxillary process now grows medially and fuses , first with the lateral nasal
process and then with the medial nasal process .
• Medial and lateral process also fuse with each other in this way the nasal pit(external
nares) are cut off from the stomatodeum .
• As the Maxillary Process undergoes growth the Fronto-nasal process becomes narrow
so that the two Nasal Pits come closer.
• Mesodermal basis of the median part of the lip(called philtrum)is formed from the
frontonasal process.

25. DEVELOPMENT OF NASAL CAVITY
• Nasal cavity are formed by extension of nasal pits .
• Soon the medial and lateral processes fuse , and form a partition between the pit and the
stomatodeum this is called primitive palate and is derived from the frontonasal process.
• The nasal pits now deepen to form the nasal sac .
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• The dorsal part of this sac is , at first , separated from the stomatodeum by thin
membrane called the bucconasal membrane or nasal fin this soon breaks down.
• Nasal sac now has a ventral orifice that opens on the face (anterior or external nares) and
dorsal orifice that open into stomatodeum (primitive posterior nasal aperture) .

27. • Frontonasal process becomes progressively narrower .
• This narrowing of the frontonasal process and the enlargement of the nasal cavities
themselves being closer together the intervening tissue becomes much thinned to form the
nasal septum ventrally attached to below the primitive palate and dorsally bucconasal
membrane.
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28. PRENATAL DEVELOPMENT OF PALATE
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29. • The palate is formed by contributions of the-
I. Maxillary process
II. Palatal shelves given off by the maxillary process
III. Fronto nasal process
• The frontonasal process gives rise to the premaxillary region while the palatal shelves grows
medially , their union is prevented by the presence of the tongue, thus initially the developing
palatal shelves grow vertically downward the floor of the mouth
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30. PRIMARY PALATE
• By the fusion of the maxillary and nasal
processes in the roof of the stomodeum, the
primitive palate (or primary palate) is
formed, and the olfactory pits extend
backward above it.
• It consists of the maxillary
process and medial nasal process.
• The lip and primary palate close during
the 4th to 7th weeks of gestation
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31. Primitive palate of a human embryo of thirty-seven to thirty-eight days.
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32. SECONDARY PALATE
• The development of the secondary
palate commences in the sixth week
of human embryological
development.
• It is characterised by the formation of
two palatal shelves on the maxillary
prominences
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33. • As the palatal shelves grow medially their, their union is prevented by the presence of
tongue
• Initially the developing palatal shelves grow vertically toward the floor of mouth
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34. • During 7th week of intrauterine life, a transformation in the position of the palatine shelf
occurs
• They change from a vertical to a horizontal position
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35. Various reasons are given to explain how this transformation occurs. They are:
• Alteration in biochemical and physical consistency of the connective tissue of the
palatal shelves
• Alteration in vasculature and blood supply to the palatal shelves
• Apperance of an interensic shelf force
• Rapid differential mitotic activity
• Muscular movements
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36. • The 2 palatal shelves, by 8 ½ weeks of intra uterine life are in close approximation to each
other
• Initially the 2 palatal shelves are covered by an epithelial lining. As they join the epithelial cells
degenerate
• The connective tissue of the palatal shelves intermingle with each other resulting in their
fusion
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37. • The entire palate doesnot contact and fuse at the same time. Initially the contact occurs in
the central region of the secondary palate posterior to the premaxilla
• From this point, closure occurs both anteriorly and posteriorly
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38. 8th week IUL
Stomodeum enlarge
Tongue drops
Vertically inclined palatal shelves -horizontal
Shelves contact each other in midline
By 12th week, fusion of palatal processes is complete
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41. Elevation of palate
Histological section
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42. Theories of palatal shelf elevation
EXTRINSIC FORCES
 Descent of tongue
 Myoneural activity with in tongue
 Shelves pushed up by tongue
 Mouth opening reflexes
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43. INTRINSIC FORCES
Hydration and polymerisation of intercellular substance
Differential growth on one side of palatal shelf
Turgor produced by build up of HYALURONIC ACID
SEROTONIN release from neural tissue.
Mesenchymal cell biosynthetic activity
Changing amounts of GLYCOSAMINOGLYCANS(GAG)
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44. Palatal fusion
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45. FUSION OF PALATAL SHELVES
 9-10 Week.
 Epethlium Thickens And Contacts.
 Role Of Glycoproteins And Desmosomes
 Degeneration Of Epithelium.
 Conective Tissue Penetration And Intermingling.
 Entire Palate Does Not Fuse At Same Time, Intial Contact ,Central Region Of
Secondary Palate, Then Closure Continues Both Anterior And Posteriorly.
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46. OSSIFICATION OF PALATE
• Ossification of the palate occurs from the 8th week of intra- uterine life.
•This is an intramembranous type of ossification
• The palate ossifies from a single centre derived from the maxilla
• The most posterior part of the palate does not ossify. This forms the soft palate
• The mid palatal suture ossifies by 12-14 yrs
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47. APPLIED ANATOMY
Cleft lip (cheiloschisis) and cleft palate (palatoschisis), which can also occur together
as cleft lip and palate, are variations of a type of clefting congenital deformity caused by
abnormal facial development during gestation.
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48. CLEFT PALATE
• Cleft palate is a condition in which the two plates of the skull that form the hard
palate (roof of the mouth) are not completely joined
• Palate cleft can occur as complete or incomplete (a 'hole' in the roof of the mouth,
usually as a cleft soft palate). When cleft palate occurs, the uvula is usually split. It occurs
due to the failure of fusion of the lateral palatine processes, the nasal septum, and/or the
median palatine processes (formation of the secondary palate
Incomplete cleft palate Unilateral complete lip and palate Bilateral complete lip and palate
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49. COMPLICATIONS
• Cleft may cause problems with feeding,
ear disease, speech and socialization.
• An infant with a cleft palate will have
greater success feeding in a more upright
position.
• Gravity will help prevent milk from
coming through the baby's nose if he/she
has cleft palate.
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50. TREATMENT
STAGE ONE
• Often a cleft palate is temporarily closed, the cleft isn't closed, but it is
covered by a palatal obturator.
• Cleft palate can also be corrected by surgery, usually performed between 6
and 12 months.
• If the cleft extends into the maxillary alveolar ridge, the gap is usually
corrected by filling the gap with bone tissue. The bone tissue can be acquired
from the patients own chin, rib or hip.
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51. STAGE TWO
• Carried out from 18th month to 5th year of life, generally corresponds to primary dentition
phase
STAGE THREE
• Spans from 6th to 11th year of life, generally corresponds to mixed dentition phase
STAGE FOUR
• Include the treatment done during the permanent dentition stage, 12-18 yrs of age
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52. POSTNATAL DEVELOPMENT OF
MAXILLA
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53. Postnatal growth of maxilla is a multifactorial process
According to Moss-
• Translation (displacement)
• Transposition (surface remodeling)
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54. Translation / dislocation
Dislocation comprises of movement of the whole bone as it
simultaneously expands
Displacement can be
Primary
Secondary
SCHOOLS OF THOUGHT
• Sutural theory
• Nasal septal theory
• Functional matrix
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55. Sutural theory
Sicher believed that craniofacial growth occurs at sutures.
Maxilla is attached to the cranium by frontomaxillary,
zygomaticomaxillary, zygomaticotemporal and pterygopalatine
suture, which are more-or-less oblique and parallel to each
other
Thus growth in these areas will push the maxilla downward and
forward
But???
• Suture is a tension adapted tissue
• Suture doesn’t grow when transplanted
• Growth takes place in untreated cases of cleft palate
Enlow’s; Essentials of Facial Growth, 4th Edition
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56. Nasal septum theory
James Scott
He viewed cartilaginous sites throughout the skull as primary centres
of growth
cartilage is a pressure-adapted tissue
Pressure (of the growing brain) accommodating growth of the nasal
septum provides a source of physical force that displaces the whole
maxilla anteriorly and inferiorly. This sets up field of tension for the
sutures, at which bone deposition may now take place.
But???
Experiments are not decisive
Enlow’s; Essentials of Facial Growth, 4th Edition
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57. Functional matrix theory
Melvin moss
Researches suggest that if there is no primordium for the eye, the orbit does not develop
Acc to him, the functional soft tissue matrix is the epigenic governing determinant of skeletal
growth process and all skeletal growth is secondary, compensatory and mechanically obligatory to
it.
In achondroplastic dwarfs, the midface shows marked concavity and retardation owing to deficient
cartilage growth
Enlow’s; Essentials of Facial Growth, 4th Edition
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58. Transposition / remodelling
If you see in the picture, The area previously occupied by the
ramus has now been converted into mandibular body of the adult
This is REMODELLING
It is a sequence of differential deposition and resorption that
results in reshaping and resizing of bone into its adult form
The surface that faces the direction of movement is depository
and that away from it is always resorptive
Enlow’s; Essentials of Facial Growth, 4th Edition
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59. Lacrimal suture
Lacrimal bone is a flake of bony island with its entire
perimeter surrounded by sutures, separating it from many
bones
The lacrimal bone acts a key traffic control, providing for
slippage of multiple bones along its perimeter
In itself, the lacrimal bone undergoes remodelling rotation
Enlow’s; Essentials of Facial Growth, 4th Edition
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60. Maxillary tuberosity and key
ridge
Maxillary arch grows in 3 directions
• Posteriorly deposition on posterior surface of maxillary tuberosity
• Laterally- deposition on buccal surface of tuberosity
• Downward- deposition along alveolar ridge
Endosteal surface is resorptive for growth of maxillary sinus
Reversal occurs at key ridge, where most of the external surface
becomes resorptive
Enlow’s; Essentials of Facial Growth, 4th Edition
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61. Zygomatic arch
Resorption at anterior surface and deposition at
the lateral and posterior surfaces
As a result the zygomatic arches move posteriorly
and bilaterally outwards
Enlow’s; Essentials of Facial Growth, 4th Edition
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62. Orbital growth
To compensate for resorption in the endocranial side
To compensate for the downward growth of nasomaxillary
complex
To make the supraorbital rim more prominent
V PRINCIPLE= Anterior – lateral- superior relocation
of orbit
Enlow’s; Essentials of Facial Growth, 4th Edition
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63. POSTNATAL DEVELOPMENT OF
PALATE
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64. Enlow’s; Essentials of Facial Growth, 4th Edition
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65. • In early pre natal life the palate is relatively long but from the 4th month it widens as a result of
mid palatal suture growth and appositional growth along the lateral alveolar margins.
• Growth of the mid palatal suture occurs between 1 and 2 years of age.it is large in its posterior than in
its anterior part, so that the posterior part of the nasal cavity widens more than the anterior part.
• Lateral appositional growth continues until 7 years of age by this time the palate achieves its maximum
anterior width. Posterior appositional growth continues after the lateral growth has ceased, so that the
palate becomes longer and wider during late childhood.
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66. • The appositional growth of the alveolar processes contributes to deepening as well as widening
of the vault of the bony palate at the same time adding to the height and breadth of maxilla
• Ossification does not occur in the posterior part of the palate, giving rise to the region of soft
palate. Myogenic mesenchymal tissues of the I, II and IV branchial arch migrates into this facial
region supplying the musculature of facial and palate.
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67. DEVELOPMENTAL ANOMALIES AFFECTING
MAXILLA
• Cleft palate.
• Agnathia
• Micrognathia.
• Macrognathia.
• Treacher collins syndrome (first arch
syndrome)
• Cleidocranial dyplasia
• Craniofacial dysostosis
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AGNATHIA
• Synonyms – otocephaly, holoprosencephaly agnathia
• Lethal anomaly characterised by hypoplasia or absence of mandible
with abnormally positioned ears having an autosomal recessive mode of
Inheritance.
• Due to failure of migration of neural crest mesenchyme into the maxillary
Prominence at fourth to fifth week of gestation.

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MICROGNATHIA
• Small jaw
• Either maxilla / mandible may be affected.
• Two types – true / Pseudo
• Congenital /acquired
• Occasionally follows hereditary pattern
• Occurs due to deficiency in premaxillary area
and patient with this deformity appear to have
the middle third of the face retracted.

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MACROGNATHIA
• Condition of abnormally large jaws
• May be associated with certain other conditions
 Pagets disease of bone
 Acromegaly
 Leontiasis ossea , a form of fibrous dysplasia

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TREACHER COLLINS – FRANCESCHETTI SYNDROME
• Synonym - Mandibulofacial dysostosis
• Autosomal dominant
• The gene of treacher Collin was mapped to chromosome 5q32-q33.1
• Clinical manifestations –
 Antimangoloid palpebral fissure with a coloboma of outer portion
of lower eyelids
 Hypoplasia of facial bones especially malar and mandible
 Malformation of external ear
 Macrostomia, high palate
 Blind fistulas between the angles of ear and angle
of mouth
 Atypical hair growth
 Facial clefts
 Bird like or fish like face

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CLEIDOCRANIAL DYSPLASIA
• Synonyms – Marie and sainton’s disease,
scheuthauer- marie- sainton syndrome,
mutational dysostosis
• A congenital disorder of bone formation manifestated with
clavicular hypoplasia with a norrow thorax, which allows
approximation of shoulders in front of the chest.
• Delayed ossification of skull, excessively large fontanels
and delayed closing of sutures are prominent features
• Arnold head – characteristic skull abnormalities
• Etiology – mutation in core binding factor alpha – 1
(CBFA-1) gene, located on chromosome 6p21

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CRANIOFACIAL DYSOSTOSIS (CROUZONS SYNDROME)
• Caused by premature obliteration and ossification of two or more sutures,
More often coronal and sagittal sutures
• Etiology – mutation of fibroblast growth factor receptor (FGFR-2) gene
• The mutation in transmembrane region of FGFR3
• Clinical features –
 Obliteration of coronal and sagittal sutures
 Flattening of acromium, growing only at vertical axis
 Forehead is wide and high
 Wide face
 Hypoplastic maxilla (pseudoprognathism)
 Deviation of nasal septum
 Narrowed or obliterated anterior nares
 Wide beaked nose
 Hypertelorism
 Divergent squint
 Antimongoloid eyelids
 Upper eyelid mimicking “frog face”
 Malocclusion, malposed teeth and dysphasia

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75. DEVELOPMENT OF TONGUE
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76. What is Tongue?
Largest single muscular organ inside the oral cavity, which lies relatively free.
develops in relation to the pharyngeal arches.
It develops from two parts, they are
•formation of anterior 2/3rd of the tongue
•formation of posterior 1/3rd of the tongue
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77. Formation of anterior 2/3rd of the tongue:
• Tuberculum Impar: first a swelling arises in the
midline of the mandibular process. And is flanked
by two other swellings
• Lingual Swelling: The lateral part of the
mandibular process mesenchymal thickening
develops to form two lingual swellings.
•Develops from mesenchyme of 1st pharyangeal
arch .
(text book of Inderbir Singh ,8th edition,G P Pal,HUMAN EMBRYOLOGY)
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78. •These lateral swelling quickly enlarge and merge
with each other and the tuberculum impar to form
a large mass from which mucous membrane of the
anterior 2/3rd of the tongue is formed.
(text book of Inderbir Singh ,8th edition,G P Pal,HUMAN EMBRYOLOGY)
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79. Formation of posterior 1/3rd of the tongue:
Root of the tongue arises from large
midline swelling develops from
mesenchyme of 2nd,3rd and 4th arches.
Consist of ,
1. Copula (associated with 2nd arch)
2. A large hypobranchial eminence
(associated by 3rd and 4th arch)
(text book of Inderbir Singh,8th edition, G P Pal, HUMAN EMBRYOLOGY)
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80. • Hypobranchial eminence overgrows the
copula
• The tongue separates from the floor of
the mouth by a down-growth of
ectoderm around its periphery, which
degenerates to form lingual sulcus and
gives the tongue mobility.
(text book of Maji Jose,1st edition, ORAL BIOLOGY) 4/14/2018
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81. Muscle of the tongue have a different origin, they arises
from the occipital somites, which have migrated forward
in to the tongue area, carrying with them their nerve
supply hypoglossal nerve
(text book of Ten Cate’s,7th edition,ORAL HISTOLOGY) 4/14/2018
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NERVE SUPPLY OF TONGUE

83. Papillae:
Small hair-like structure on the upper surface of the tongue that give the tongue its
characteristics rough texture.
Types:
• Fungiform Papillae
• Filliform Papillae
• Foliate Papillae
• Circumvallate Papillae
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84.  Fungiform Papillae:
• Anterior portion of the tongue (look like fungi)
• Scattered between the numerous filifom papillae at the tip of the tongue
• Smooth, round structure appears red(because of highly vascular connective tissue
core, visible through a thin, non keratinized covering epithellium)
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85. Filiform Papillae:
• covers entire anterior part of the tongue
• Cone shaped structures each with a core of
connective tissue covered by a thick
keratinized epithelium
• Together form a tough abrasive surface that
is involving in compressing and breaking
when tongue is opposed to the hard palate
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86.  Foliate papillae:
• Sometimes present on the lateral margins of the posterior part of the tongue
• Pink,consist of 4 to 11 parallel ridges that alternate with deep grooves in the
mucosa and few taste buds are present in the epithelium of the lateral walls of
ridges
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87. Cirumvallate Papillae:
• Adjacent and anterior to the sulcus
terminalis are 8 to 12 papillae
• Large structure, each surrounded by
a deep, circular groove in to which
open the duct of minor salivary
• Have connective tissue core that
covered on the superior surface by a
keratinized epithelium
• The epithelium covering lateral walls
is non-keratinized and contains taste
buds
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88. Taste Bud –
• A specialized receptor that occurs only in the oral cavity and pharynx is called taste
bud.
• Most of them found in fungiform papilla, foliate and circumvallate papilla.
• Barrel shaped structure composed of 30 to 80 spindle shaped cells
• Communicate with surface through a small opening called taste pore
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90. DEVELOPMENTAL DEFECTS
OF TONGUE
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1. Aglossia
2. Microglossia
3. Macroglossia
4. Ankyloglossia
5. Cleft tongue
6. Fissured tongue
7. Median rhomboid glossitis
8. Benign migratory glossitis
9. Hairy tongue
10. Lingual varices
11. Lingual thyroid nodule

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AGLOSSIA -
Complete absence of tongue at birth-very rare
MICROGLOSSIA -
• A rare congenital anomaly -presence of small or
rudimentary tongue
• Aglossia-microglossia with extreme glossoptosis
• Etiology-fetal cell traumatism in the first few weeks of
gestation

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MACROGLOSSIA -
An enlarged tongue
TYPES:- 1. Congenital/ primary 2. Secondary
Congenital macroglossia:- Due to overdevelopment of musculature which may or may not be associated with
generalized muscular hypertrophy
Secondary macroglossia: - May occur as a result of tumor of tongue such as, diffuse lymphangioma or
haemangioma.
CLINICAL FEATURES –
• Displacement of teeth / malocclusion.
• Crenation and scalloping of the lateral border of tongue
• Tips of the crenation fitting into the interproximal
spaces between the teeth.
ASSOCIATED SYNDROMES:-
Beckwith’s Wiedemann syndrome & Down syndrome
Beckwith’s Weidemann syndrome includes -Neonatal hypoglycemia , Mild micro cephaly , Umbilical hernia ,
Fetal visceromegaly
TREATMENT - No particular treatment
Removal of cause
Surgical trimming

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ANKYLOGLOSSIA -
CLASSIFIED AS -
Partial
Complete
Partial ankyloglossia/ Tongue tie: - results of a short lingual frenum/ one which is attached near
to the tip of the tongue.
Complete ankyloglossia:- Fusion between the tongue and the floor of the mouth
CLINICAL FEATURES - difficulty during speech
TREATMENT- frenectomy

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CLEFT TONGUE / BIFID TONGUE -
• Complete & Partial
 Complete cleft / bifid tongue - A rare condition Is due
to lack of merging of the lateral lingual swelling of
this organ
 Partially cleft tongue - Common condition Is due to incomplete merging and failure of
groove obliteration by underlying mesenchymal proliferation.
• Manifest as deep groove in the midline of dorsal surface.
Associated syndrome –
 Oro facial digital syndrome-
Thick fibrous band in the lower anterior mucobuccal fold eliminating the sulcus & with clefting
of the hyperplastic mandibular alveolar process.
Clinical considerations - Microorganisms &food debris may collect in the base of the cleft &
cause irritation.

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FISSURED TONGUE / SCROTAL TONGUE -
• Manifests as small furrows or grooves 2-6mm in depth on the dorsal surface often radiating
from central groove on the midline of the tongue
• Associated with chronic trauma or vitamin deficiency/hereditary
• Painless except in cases when food debris tends to collect in the grooves & produce irritation.
• Associated with Melkersson-Rosenthal
syndrome (traid of recurring facial paralysis,
cheilits granulomatosis and fissured tongue )

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MEDIAN RHOMBOID GLOSSITIS -
• Congenital anomaly which is due to failure of the tuberculum impar to retract or withdraw
before fusion of the lateral halves of the tongue
• Etiological agent - candida albicans
• CLINICAL FEATURES - it appears as an ovoid ,diamond, rhomboid shaped reddish patch or
plaque on the dorsal surface of the tongue, immediately anterior to circumvallate papillae

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BENIGN MIGRATORY GLOSSITIS -
Geographic tongue, wandering rash of tongue ,glossitis areata exfoliative
• Areas of desquamation of the filiform papillae in an irregular circinate pattern
• Central portion – inflamed white with borders may be outlined by a thin, yellowish white line
or band.
• Fungiform papillae persist &appear as elevated dots.
• The area of desquamation remain for a short time in one location & then heal & appear in
another location i.e ; migration
• TREATMENT - Empirical since its etiology is not known.
Reassurance to the patient.

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HAIRY TONGUE -
Hypertrophy of the filiform papillae of the tongue with lack of normal desquamation which
may be extensive and form a thick matted layer on the dorsal surface.
Color of the papillae varies, yellowish white to brown or even black.
Etiology - Candida albicans
TREATMENT - Brush the tongue to promote
desquamation and remove the debris.

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LINGUAL VARICES -
Lingual or sublingual varicosities
• Varix - is a dilated , tortuous vein, most
commonly a vein.
• Mostly involved -sublingual varix
• Common in older adults
• Red or purple elevated blebs of vessels on the ventral surface and lateral borders of the
tongue as well as floor of the mouth.
• No treatment needed

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LINGUAL THYROID NODULE -
In this anomalus condition, the follicle of thyroid tissue are found in the substance of the tongue,
possibly arising from thyroid that failed to migrate to its original position/ from enlarge remnants
that became detached and were left behind.
ETIOLOGY - functional insufficiency of the chief thyroid gland in the neck.
CLINICAL FEATURES - nodular mass in or near the base of the tongue.
Dysphagia, dysphonia, dyspnoea, hemorrhage with pain or feeling of tightness or fullness in the
throat.
TREATMENT -Careful physical examination to demonstrate the thyroid gland location.

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MANDIBLE

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• Introduction
• Anatomy of mandible
• Prenatal development of mandible
• Postnatal development of mandible
• Development of mandible in relation to various theory of growth
• Age changes
• Developmental anomalies
CONTENTS

103. 103
MANDIBLE
Largest and
strongest bone of
the face
1st pharyngeal
arch
Articulation with
skull
shape and
Function
14 April 2018
INTRODUCTION

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ANATOMY OF MANDIBLE
It has horseshoe shaped body which lodges the teeth, and pair of rami which project upwards
from the posterior ends of the body and provide attachment to muscle.

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PRENATAL DEVELOPMENT OF MANDIBLE
• Start abouth 4th week of intra- uterine life.
• Developing brain and the pericardium form two
prominent bulges on the ventral aspect of the embryo.
• These bulges are separated by primitive oral cavity or
stomodaeum .
• The floor of the stomodaeum is formed by the bucco-
pharyngeal membrane, which separates it from the
foregut.

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• Mesoderm of foregut comes to arranged in the form of six bars that run
dorsoventrally in the side wall of the foregut.
• These are called pharyngeal arches.

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• First Branchial arch called MANDIBULAR ARCH.
• Mandibular arch gives off a bud from its dorsal end called maxillary process.
• It grows ventro-medially cranial to main part of the arch which is called mandibular
process.

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• Mandibular process of each side grow towards each other.
• fuse in midline - give rise to mandible.
• First structure develop in lower jaw :
- Mandibular division of Trigeminal nerve.
Neurotrophic factor produced by nerve induce osteogenesis.

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MECKEL'S CARTILAGE
• It is the cartilage of the first arch
• In human beings the Meckel's
cartilage has a close positional
relationship to the developing
mandible but makes no
contribution to it.
• At 6 weeks of development this
cartilage extends as a solid hyaline
cartilaginous rod, surrounded by a
fibrocellular capsule, from the
developing ear region to the
midline of the fused mandibular
processes.

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• The Mandibular branch of trigeminal nerve has close relationship to Meckel’s cartilage

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• On lateral aspect of Meckel’s cartilage, during the 6th week of embryonic development,
a condensation of mesenchyme occurs in the angle formed by the division of the
inferior alveolar nerve and its incisor and mental branches.

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Centre of ossification
Intramembraneous Ossification starts at the division of mental and incisive branch of
inferior alveolar nerve lateral to meckel’s cartilage around
7th week IUL.

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• From center of ossification bone formation spreads:
 Anteriorly - midline
 Posteriorly - where mandibular nerve divided into lingual and inferior alveolar branch.
• Bone formation spreads rapidly and surrounds the inferior alveolar nerve to form
mandibular canal.
• Intra-membranous ossification spreads in anterior and posterior direction forms the Body &
Ramus of the mandible.
Gray’s Anatomy – Fortieth edition

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• Anteriorly bone extends towards midline and comes in approximation with similar bone
forming on opposite side.
• These two bones remain separated by fibrous tissue mental symphysis untill shortly after
birth.
• Continued bone formation increases size of mandible with development of alveolar process
to surround the developing tooth germ.

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• Ossification spread posteriorly to form ramus of mandible, turning away from
meckel’s cartilage.
• This point of divergence is marked by lingula in adult mandible.
Thus by 10 weeks the rudimentary mandible is formed almost entirely by membranous
ossification with little direct involvement of Meckel’s cartilage

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NOW….. What is the
fate of the Meckel’s
cartilage?
• Incus and malleus
• Spine of sphenoid bone
• Anterior ligament of malleus
• Spheno-mandibular ligament

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SECONDARY CARTILAGES IN MANDIBULAR
DEVELOPMENT
Further growth until birth influenced by appearance of secondary cartilage
 Condylar cartilage
 Coronoid cartilage
 Symphyseal cartilage

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CONDYLAR CARTILAGE
• Appear during 12th week of IUL
• Rapidly form cone shape mass which is converted quickly to bone by endochondral
ossification.
• At the end of 20th week only a thin layer remains on the condylar head ,persist until the end
of the second decade of life ,providing a further growth .
(Ten Cate’s Oral Histology – Sixth Edition)

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• Cartilage fuses with mandibular ramus around 4th month.
(Contemporary orthodontics Williams R. proffit fifth edition)

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CORONOID CARTILAGE
• Appears at about 4 month of
development.
• Coronoid cartilage is transient growth
cartilage and disappears long before
birth.
• Cartilage grow as a response of
developing temporalis muscle.
• Coronoid cartilage become
incorporated into expanding intra-
membranous bone of ramus.
(Ten Cate’s Oral Histology – Sixth Edition)

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• Two in number
• Appear in between the two end of Meckel’s cartilage.
• They are obliterated within the first year after birth.
SYMPHYSEAL CARTILAGE
(Ten Cate’s Oral Histology – Sixth Edition)

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POSTNATAL DEVELOPMENT OF MANDIBLE
• Right & left mandibular body fuses at midline symphysis one year after birth.
• Mandible appears as single bone.
(Contemporary orthodontics Williams R. proffit fifth edition)

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• According to MOSS while mandible appears in the adult as a single bone, it
is divisible into several skeleton subunits
 Condylar process
 Coronoid process
 Angular process
 Ramus
 Body of mandible
 Alveolar process
 chin.
(Facial Growth – Donald H. Enlow third edition)

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MANDIBULAR CONDYLE
• It is a major site of growth
• Historically, the condyle has been
regarded as a kind of cornucopia
from which the whole mandible
itself pours forth.
• The condyle functions as regional
field of growth that provides an
adaptation for its own localized
growth circumstances

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• The condylar growth mechanism itself is a clear-cut process.
• Cartilage is a special non-vascular tissue and is involved because of variable levels of
compression
• An endochondral growth mechanism is required for this part of the mandible.
• Endochondral growth occurs only at the articular contact part of the condyle
• In Figure the endochondral bone tissue (b) formed in association with the condylar cartilage (a)
The enclosing bony cortices (c) are produced by periosteal-endosteal osteogenic activity

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• The lingual and buccal sides of neck characteristically have a resorptive surface.
• This is because condyle is quite broad and neck is narrow
• The neck is progressively relocated into areas previously held by the much wider
condyle
• What used to be condyle in turn becomes the neck as one is remodeled from the
other .
• This is done by periosteal resorption combined with endosteal deposition.

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• Explained another way, the endosteal surface of the neck actually faces the growth
direction; the periosteal side points away from the course of growth.
• This is another example of the V principle, with the V-shaped cone of the condylar
neck growing toward its wide end.

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ROLE OF CONDYLE
• It is directly involved as a unique, regional growth site.
• It provides an indispensable latitude for adaptive growth.
• It provides movable articulation.
• It is pressure tolerant and provides a means for bone growth (endochondral) in a situation
in which ordinary periosteal (intramembranous) growth would not be possible .
• It can also, all too frequently, become involved in TMJ pathology and distress.

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CLINICAL IMPLICATION
• Condylar cartilage dose have some measure of intrinsic, genetic programming,
• This , however, appears to be restricted to capacity for continued cellular proliferation .
• Cartilage cells are coded and geared to divide and continue to divide by extra condylar
biomechanical forces.
• So overall mandibular length be clinically increase or decrease for class II and class III individuals if
this were done during the period of active condylar growth.
(Facial Growth – Donald H. Enlow third edition)

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AGE CHANGES IN THE MANDIBLE
AT BIRTH
• At the birth the mental foramen, opens below the sockets for the two deciduous molar
teeth near the lower border.
• The mandibular canal runs near the lower border.
• The angle is obtuse. It is 175.

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AT CHILDHOOD
• The two halves of the mandible fuse during the first year of the life.
• The body becomes elongated in its whole length, but more especially behind the mental
foramen, to provide space for the three additional teeth developed in this part.
• Mandibular foramen slightly above the occlusal plane
• The angle becomes less obtuse around 140.

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IN ADULT
• The mental foramen opens midway between the upper and lower borders.
• The mandibular canal runs parallel with the mylohyoid line.
• Mandibular foramen 7 mm above the occlusal plane
• The angle reduces about 110 or 120 degrees.

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IN OLD AGE
• Alveolar border is absorbed, so that height of the body is markedly reduced.
• The mental foramen and mandibular canal are close to the alveolar border.
• The angle again becomes obtuse about 140 degrees .

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DEVELOPMENTAL DEFECTS
OF THE MANDIBLE
• Agnathia
• Micrognathia
• Macrognathia
• Coronoid hyperplasia
• Condylar hyperplasia
• Condylar hypoplasia
• Bifid condyle
• Torus mandibularis

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CORONOID HYPERPLASIA
• Rare developmental anomaly
• Result in limited mandibular movement
• Unknown etiology.
• M:F ratio 5:1
• May be unilateral or bilateral
• Bilateral is more common
(Oral and maxillofacial Pathology- Neville third edition)

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CONDYLAR HYPERPLASIA
• Excessive growth of one of the condyles
• Cause is unknown, but local circulating
problems, endocrine disturbances, and trauma
have been suggested as possible etiologic
factors.
(Oral and maxillofacial Pathology- Neville third edition)

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CONDYLAR HYPOPLASIA
• Congenital or acquired
• congenital:
mandibulofacial dysostosis
goldenhar syndrome
hemifecial microsomia
• Acquired:
disturbances of the growth center of the condyle.
(Oral and maxillofacial Pathology- Neville third edition)

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BIFID CONDYLE
• Rare
• Most of have medial and lateral head divided by an
antero posterior grooves.
• Some condyles may be divided into an anterior and
posterior head
• Cause is uncertain
• Antero-posterior may be traumatic origin.

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TORUS MANDIBULARIS
• Develops along the lingual aspect of the mandible.
• Probably multifactorial, including both genetics and
environmental influences.
(Oral and maxillofacial Pathology- Neville third edition)

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TMJ ANKYLOSIS
Ankylosis of the Temporomandibular joint, an arthrogenic disorder of the TMJ, refers to restricted
mandibular movements (hypomobility) with deviation to the affected side on opening of the mouth.

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145. CLINICAL FEATURES -
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• Obvious facial deformity
• Deviation of chin towards affected side
• Inability to open the jaws, absent condylar movements
on affected side
• In unilateral ankylosis, the lower jaws shifts
towards the affected side on opening of the mouth
• Flatness or fullness on affected side
• Cross bite on ipsilateral side
• Class II malocclusion on affected side
TREATMENT
• Surgical
• Non-surgical

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• Ten Cate’s Oral Histology – Sixth Edition
• Human embryology- Inderbir Sing Eight edition
• Contemporary orthodontics Williams R. proffit fifth edition
• Facial Growth – Donald H. Enlow third edition
• Gray’s Anatomy – Fortieth edition
• Human anatomy-BD Chaurasia Forth Edition
• Shafer’sTextbook of Oral pathology sixth edition
• Oral and maxillofacial Pathology- Neville third edition
REFERENCES

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THANK YOU