Surgical embryology in relation to common cranio facial /certified fixed orthodontic courses by Indian dental academy

Surgical embryology in relation to
common craniofacial anomalies
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


•
•
•
•
•
•
•

Cleft lip/ cleft palate
CRANIOSYNOSTOSIS SYNDROMES
Treacher collins Syndrome
Hemi facial microsmia
Vascular malformation
Hemangioma
Down s syndrome

BRANCHIAL ARCHES
• Rod like thickening of mesoderm
• 4 arches are well developed by 4th week of
gestation
• 5th and 6th arches are still rudimentary
• Development takes place over weeks 4 to 7
• Contribute mostly to neck development but
the first arch contributes to facial
development

Each arch contains:
• A cartilagenous component
• A muscular component
• An aortic arch (artery)
• A nerve


First Branchial Arch
• Divides early into 2 portions
• Maxillary process dorsally (maxilla, zygoma,
squamous ,temporal bone)
• Mandibular process ventrally


First Branchial Arch
• Cartilage (Meckel’s Cartilage)
• Dorsal end becomes the malleus and incus
• Intermediate portion regresses, but the
perichondrium
• forms:
• Anterior ligament of the malleus
• Sphenomandibular ligament
• Ventral portion forms the mandible

• First Branchial Arch
• Muscular component
Muscles of mastication
(temporalis, masseter, med & lateral
pterygoids) Accessorymuscles of mastication
(mylohyoid, ant belly ofdigastric)
Tensor tympani
Tensor veli palatini

• Second Branchial Arch
• Cartilage (Reichert’s Cartilage)
• – Dorsal end becomes stapes (except footplate) and
styloid
• process
• – Intermediate portion regresses and perichondrium
forms
• the stylohyoid ligament
• – Ventral end forms the lesser cornu of the hyoid and
the
• upper half of the hyoid bone

• Muscular Component
• – Migrates over superficial face to form the muscles of
facial
• expression
• – Stapedius muscle
• – Stylohyoid muscle
• – Posterior belly of digastric
• Aortic Arch
• – Hyoid artery
• – Stapedial artery

• Nerve-Facial Nerve (CN VII)


DEVELOPMENT OF FACE
• The face derives from five prominences that
surround a central depression, stomodeum,
which constitutes the future mouth.
• The prominences are the
single median frontonasal &
paired maxillary and mandibular prominences
• All of these prominences and arches arise
from neural crest

FNP

MAN

FG


MAX

ST

• Union of the facial prominences occurs by
either of two developmental events at
different locations:
• merging of the frontonasal, maxillary, and
mandibular prominences or
• fusion of the central maxillonasal
components.


ANOMALIES OF DEVELOPMENT
• Defects of facial development are the result of a
multiplicity of etiologic factors, some genetic, most
unknown. The study of these anomalies constitutes
TERATOLOGY.
• Defective development is categorized into
– malformations that are generally genetically determined,
– deformations that are environmentally influenced, and
– disruptions that are of metabolic, vascular, and/or
teratogenic origin.

• Malformation develop predominantly in the
embryonic period and are not selfcorrecting

• Deformations and Disruptions occur in the fetal period
and may correct themselves.

Cleft lip
• Failure of the facial prominences to merge or
fuse results in abnormal developmental clefts.
• These clefts are due to the disruption of the
many integrated processes of induction, cell
migration, local growth, and mesenchymal
merging


• UPPER-When maxillary process do
not fuse with Medial nasal
process.(unilateral/Bilateral)
• Unilateral cleft lip, more common
on the leftside, is a relatively
common congenital defect (1 in
800 births) that has a strong
familial tendency, suggesting a
genetic background

• oblique facial cleft - persistence
of the groove between the
maxillary prominence and the
lateral nasal prominence running
from the medial canthus of the
eye to the ala of the nose
• Midline mandibular cleft Persistence of the furrow
between the two mandibular
prominences produces the rare

• Median cleft lip (the true “hare
lip”)is due to the incomplete
merging of the two medial nasal
prominences, therefore leading in
most cases (with deep midline
grooving of the nose) to various
forms of bifid nose.


• Macrostmia – Inadequate fusion of
mandibular & maxillary process with each
other .
• If unilateral – Lateral facial cleft.


• The three elements that make up the secondary definitive
palate—the two lateral maxillary palatal shelves and the
primary palate of the frontonasal prominence
• Initially widely separated due to the vertical orientation of
the lateral shelves on either side of the tongue .
• During the 8th week post conception, a remarkable
transformation in the position of the lateral shelves takes
place.

• They change from vertical to horizontal as a prelude to
their fusion and to partitioning of the oronasal chamber

• Successful fusion of the three embryonic
components of the palate involves complicated
synchronization of shelf movements with growth
and withdrawal ofthe tongue and with growth of
the mandible and head.
• The mis-timing of any of these critical events, due
to environmental agents or to genetic
predisposition,
• results in the failure of fusion, leading to clefts of
the palate.

CRANIOSYNOSTOSIS SYNDROMES
• CRANIOSYNOSTOSIS -Pathological condition
that results from premature fusion of one or
more sutures in the cranial vault;

Common syndromes:
• Aperts
• Crouzon


Growth at sutures
• Sutures allow growth perpendicular to them
• Growth at suture lines related to brain growth
Early closure causes growth parallel to suture


• Fibroblast growth factor and fibroblast growth
factor receptor (FGFR) regulate fetal osteogenic
growth expressed in cranial sutures in early fetal
life.
• Mutations in FGFR2 →Apert’s syndrome and
Crouzon’s disease
• Mutation leads to increase in number of
precursor cells that enter osteogenic pathway
• Which leads to increased subperiosteal bone
matrix formation & premature calvaria
ossification during fetal development

CROUZONS Clinical findings
•
•
•
•
•

Brachycephaly,
significant hypertelorism,
proptosis, maxillary
hypoplasia, beaked nose
Intracranial anomalies
Hydrocephalus
• Normal intellect
• • Normal extremities

APERT s


Timing of surgery
• Early operation(3-6 months)
Rapid brain growth reshape bone
• Better compliance of brain dura and scalp
• Calvarium in an infant aged 3-9 months is much more
malleable, easier to shape and providing a better outcome.
• forehead advancement first
• • facial advancement later, to avoid the risk of frontal
• journal of pediatric neurosciences
• REVIEW ARTICLE Year : 2009 | Volume : 4 | Issue : 2 | Page : 86-99
Pediatric craniofacial surgery for craniosynostosis: YN Anantheswar1, NK
Venkataramana2


Treacher collins Syndrome
• Mandibulofacial dysostosis involves structures
derived from the first and second pharyngeal
arch
• This syndrome is thought to result from
retardation or failure of differentiation of
maxillary mesoderm at & after 50 mm stage of
embryo


– Malar and supraorbital hypoplasia
– Non-fused zygomatic arches
– Cleft palate in 35%
– Hypoplastic paranasal sinuses
– Downward slanting palpebral fissures
– Mandibular hypoplasia with increased angulation
– Coloboma of lower eyelid with absent cilia
– Malformed pinna
– Normal intelligence


HEMI FACIAL MICROSMIA
• hemifacial microsomia was defined as a
condition affecting primarily aural, oral, and
mandibular development.
• The disorder variesfrom mild to severe, and
involvement is limited to one side in many
cases,
• Goldenhar syndrome is considered a variant of
this complex, characterized additionally by
vertebral anomalies and epibulbar dermoids

HEMANGIOMA
A type of birth mark ,
• The cause of hemangioma is currently
unknown; however, several studies have
suggested the importance of estrogen
signaling in hemangioma proliferation.
• maternal placenta embolizes to the fetal
dermis during gestation resulting in
hemangiomagenesis

Thank you
For more details please visit


Surgical embryology in relation to common cranio facial /certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (19)

Similar to Surgical embryology in relation to common cranio facial /certified fixed orthodontic courses by Indian dental academy

Similar to Surgical embryology in relation to common cranio facial /certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Surgical embryology in relation to common cranio facial /certified fixed orthodontic courses by Indian dental academy

Editor's Notes