GROWTH AND DEVELOPMENT OF FACE

CONTENTSINTRODUCTION

PRENATAL GROWTH

POSTNATAL GROWTH

DEVELOPMENTAL ANOMALIES

MYOFUNCTIONAL THERAPY

CONCLUSION

REFERENCES

Growth and development of an individual can be divided into prenatal and the post natal periods

The prenatal 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 three fold increase during postnatal period.

INTRODUCTION

Weight also increases by 6.5 billion times prenatally where postnatally 20 fold.

Post natal growth is characterized by much differentiation than rate.

• PRENATAL GROWTH

• POSTNATAL GROWTH

• MATURITY

• OLD AGE

GROWTH

OVUM

EMBRYO

FETUS

PRENATAL GROWTH

PERIOD OF OVUM/ PRE-IMPLANTATION PERIOD

SPERMATOGENESIS

OOGENESIS

36HRS

48HRS

11-12 DAYS

FERTILIZATION

CLEAVAGE FORMATION

DAY 7-10

BLASTOCYST FORMATION

structure

IMPLANTATION

Occurs when there is an error in cell division following meiosis or mitosis.

CHROMOSOMAL ABNORMALITIES

numerical

structural

TRISOMY

DOWN SYNDROME( TRISOMY 21)

Individual have three copies of chromosome 21 rather than two

NUMERICAL ANOMALY

FACIAL CLEFTS

SHORT UPPER LIP

SHORTENED PALATE

PROTRUDING AND FISSURED TONGUE

DELAYED ERUPTION OF TEETH

Features

MENTAL RETARDATION

FLAT BACK OF HEAD

ABNORMAL EARS

BROAD FLAT FACE

SHORT NOSE

MONOSOMY

TURNERS SYNDROME

Individual is born with only one sex chromosome ; an X

KLINEFELTER’S SYNDROME

Additional X genetic material in males

Total of 47 chromosomes found in males

47XXY

CLINICAL FEATURES

Frontal baldness is absent

Poor beard growth

Fewer chest hairs

Narrow shoulders

Hypogonadism

sterility

DELETION DUPLICATION TRANSLOCATION

INVERSIONS INSERTIONS

STRUCTURAL ANOMALY

END OF FIRST WEEK TO 8TH

WEEK

FORMATIVE PERIOD OF ORGANS

MORPHOGENESIS

PERIOD OF GREATEST SENSITIVITY

PERIOD OF EMBRYO

PRESOMITE PERIOD

SOMITE PERIOD

POSTSOMITE PERIOD

8 – 21 DAYS

trophoblast cells Blastocyst embryoblasts epiblast Embryoblast hypoblast [two layered germ disc(8 days)]

PRESOMITE PERIOD

FORMATION OF TWO LAYERED EMBRYO

ECTODERM

ENDODERM

PRE/PROCHORDAL PLATE

DEVELOPMENT OF PRIMITIVE STREAK WHICH FORMS THE MESODERM (3 WEEKS)

(HENSON’S NODE)

FORMATION OF THREE LAYERED EMBRYO:GASTRULATION(3RD WEEK)

NOTOCHORDAL PROCESS

PRIMITIVE GROOVE

PRIMARY GERM LAYERS

ECTODERM epithelium covering the outside of the body

epithelial lining of oral cavity, nasal cavity & sinuses.

MESODERM Skeletal system , muscles, blood, lymph cells, vessels, kidneys internal organs

ENDODERM Epithelial lining of the

pharynx, stomach, lungs, vagina urethra.

21 – 31 days

Ectodermal layer at the head end of embryo forms the neural plate

Major organs and tissues differentiate during this period thus making it susceptible to environmental influences.

SOMITE PERIOD

FORMATION OF NEURAL TUBE AND NEURAL GROOVE

Neural tube undergoes massive expansion to form the forebrain , midbrain and hindbrain

Neural crest cells leave neuroectoderm and enters mesoderm.

The proper migration of neural crest cells is

essential for development of face and teeth.

Full facial development does not occur

Neural crest cells fail to migrate properly to the facial region.

TREACHER COLLIN SYNDROME

Article: Mandibulofacial dysostosisMarie M Tolarova, march 9 2012

o Treacher collin syndrome is an inherited developmental disorder

o Prevalence: 1 in 70000 of live births

o Syndrome was named after Edward treacher collin (1862-1932) who described the essential features.

o Growth of craniofacial structures derived from the first and second arch , groove and pouch is diminished symmetrically and bilaterally

Deficiency of midline tissues of the neural plate with higher blood ethanol level.

Usually occur in chronic alcoholics

FETAL ALCOHOL SYNDROME

when head end of the neural tube fails to close

between 23rd-26th day of conception.

Results in absence of major portion of the brain, skull and scalp

ANENCEPHALY

32 – 56 DAYS

Characterized by formation of external features and branchial arches.

Facial features become recognizable

Embryo is now called fetus

POST SOMITE PERIOD

MESENCHYME

Cartilage - meckel’s cartilage

Skeletal components: incus and malleus of middle ear

Nerve of arch – mandibular

Muscles – Muscles of mastication , mylohyoid, anterior belly of digastric , tensor tympani and tensor veli palatini

FIRST ARCH

LIGAMENTS : anterior ligament of malleus , sphenomandibular ligament.

External acoustic meatus from first ectodermal cleft

FIRST ENDODERMAL POUCH : endoderm lines the future middle ear, mastoid antrum auditory tube , inner layer of tympanic membrane

Cartilage – REICHERT’S CARTILAGE

skeletal structures: stapes, styloid process and lesser cornu and upper part of body of hyoid bone.

Stylohyoid ligament sheath

Nerve- facial nerve

SECOND ARCH

Muscles – muscles of face, stylohyoid, posterior belly of digastric, stapedius

SECOND POUCH : Middle ear and palatine tonsils

Skeletal component : Greater cornua of hyoid bone and Lower part of body of hyoid bone

Nerve – glossopharyngeal

Muscle – stylopharyngeus

Inferior parathyroid gland and thymus from the third pouch

THIRD ARCH

Gives rise to cartilages of larynx

Superior thyroid gland is derived from fourth pouch.

Nerves – superior laryngeal and recurrent laryngeal

Muscles – muscles of larynx and pharynx

FOURTH AND SIXTH ARCH

9TH WEEK TILL BIRTH

PERIOD OF FUNCTIONAL MATURATION

Growth in length is particularly striking in 3rd 4th & 5th months

Increase in weight mainly occurs in last 2 mnts

PERIOD OF FETUS

Development of face

SAGITTAL SECTION

Buccopharyngeal membrane ruptures at 24 to 26 days

Article : Head and Neck embryology: An overview of development , growth and defect in the human fetus

-Allison Baylis, may 2009

• Occurrence 1 in 1000 birth• Common in males• Varies from small notch in lip to complete

division of lip and alveolar part of maxilla

CLEFT LIP

Bilateral cleft : bottom portion of nose and a portion of upper lip are hanging free

Cleft lip correction surgery often done very shortly after birth

Experience dental abnormality and are candidates for orthodontic treatment

fusion of mandibular and maxillary processes

reduction of stomatodeum size

forming the cheeks

DEVELOPMENT OF CHEEKS

lens placode

Sinks below to separate from surface ectoderm

Appear as twin bulging directed laterally and lying between maxillary and lateral nasal process

DEVELOPMENT OF EYE

Come forward by narrowing of frontonasal process

Eyelids : folds of ectoderm formed above and below the eyes

mesoderm enclosed within the folds

rare autosomal dominant disorder

lower eyelid ectropion

upper eyelid distichiasis,

euryblepharon,

bilateral cleft lip and palate,

conical teeth.

BLEPHAROCHEILODONTIC SYNDROME

Formed around the dorsal part of first ectodermal cleft

Series of mesodermal thickenings appear on 1st and 2nd arch

Pinna is formed by fusion of these thickenings

DEVELOPMENT OF EXTERNAL EAR

Oculo-Auriculo-Vertebral(OAV) syndrome

GOLDENHAR SYNDROME

Associated with anomalous development of first and second branchial arch

Asymmetric involvment of craniofacial structures

Complete aplasia to dysplastic pinnae Bilateral and asymmetric ear involvement Ear tags Mandibular hypoplasia on the affected side

AORTIC VASCULATURE DEVELOPMENT

Muscle cells in the first arch become

apparent during the 5thweek and begin to

spread within the mandibular arch into each

muscle site’s origin in the 6th and 7th week.

These form the muscles of mastication

MUSCULAR DEVELOPMENT

Develops in conjunction with the developing muscle fibres.

sensory fibres to mandible C5 motor fibres to muscles of mastication

C7 – follows migration of facial muscle mass from neck onto the face

NEURAL DEVELOPMENT

First 20 years of growth after birth

Characterized by increased maturation of tissue.

POSTNATAL GROWTH

Soft

tissue growth

Hard

tissue growth

Postnatal growth

27O bones Calvarium: face=8:1(birth); 2.5:1(adult female) 2:1(adult male) Skull bones= 45[adult:22] 2 halves of frontal bone-fuse 2 yrs 2 parietal bones 4 pieces of occipital bone-fuses at 3-4 yrs 3 parts of sphenoids bone-fuses during first

yr

NEONATAL SKELETON

3 pieces of ethmoid bone- fuses at 5th or 6th yr

4 parts of temporal bone-fuses by puberty Mastoid process absent in neonate

Endochondral and intramembraneous Occipital bone Temporal bone Sphenoid bone

Ethmoid bone: endochondral ossification

Made up of duramater, primitive periosteum, aponeurosis

FONTANELLES

Anterior fontanelle

Posterior fontanelle

(sphenoidal)

(Mastoid)

Bands of cartilage remains at the junction of bone

Important growth sites of cranial base

CRANIAL SYNCHONDROSES

Spheno occipital:

Principal growth cartilage of cranial base during childhood. Active upto 12-15yrs closes by 17-20yrs Direction of growth is upwards Carries anterior part of cranium bodily

forwards

Sphenoethmoidal : closed by 2-4yrs

Mid sphenoid : closes shortly after birth

Intra occipital: closes by 3-5 yrs of age

Suture is a type of fibrous joint which only occurs in the skull

Tiny amount of movement is permitted which contributes to compliance and elasticity of skull

These joints are synarthroses

Growth at sutures

TMJ only nonsutured joint in skull

Suture joints undergo changes throughout childhood and into early childhood

SUTURES OF CRANIUM

Fusion of skull bones at birth is craniosynostosis

Joint that has ossified over time is called synostosis

FACE

Round and flat face

Growth of lip mostly during growth spurt

Nasal bone growth complete by 10 years more prominent during adolescence

Article: Three dimensional facial growth studied by optical surface scanning

-Spencer J Nute et al, J of orthodontics/vol 27/2000/31-38

Aim : study 3-D growth of face and examine the hypothesis that there are 3-D differences b/w faces of boys and girls

132 british caucasians b/w 5-10yrs

Result :

Greatest difference b/w facial heights and least in mid facial dimensions

Face height of both sexes increased by an avg of 3-4mm annually

Nose height and prominence and alar base width increased by 2mm per year on average

Prominence and width of lower face increased more

Neuromuscular re education or re patterning of oral and facial muscles

Facial and tongue exercises

Behavior modification techniques to promote proper tongue position, improved breathing, chewing and swallowing

In a growing patient

MYOFUNCTIONAL THERAPY

Moss’ functional matrix theory

Functional matrix theory proposes that functional matrices, tissues like muscles and glands influence skeletal units such as jaw bones and ultimately control their growth

Orthodontic functional appliances may be active or passive

◦PASSIVE APPLIANCES ACT BY REPOSITIONING THE MUSCULATURE ASSOCIATED WITH MANDIBLE

FRANKEL APPLIANCE

◦ACTIVE APPLIANCES REPOSITION THE MANDIBLE

HERBST APPLIANCE

BIONATOR

TWIN BLOCK APPLIANCE

Functional appliance treatment should be started before the pubertal growth spurt

(mandible may exhibit increased growth which may be influenced)

worn for at least 10-12 hours a day nighttime as this is when growth takes

place

DURATION AND TIMING OF WEAR

CONCLUSION STOMATODAEUM IS A DEPRESSION BOUNDED

CRANIALLY BY BULGING PRODUCED BY BRAIN AND CAUDALLY BY PERICARDIAL CAVITYMANDIBULAR PROCESS GIVE RISE TO LOWER LIP AND MANDIBLEUPPER LIP BY FRONTONASAL PROCESS WITH RT AND LT MAXILLARY PROCESS, FAILURE CAUSES VARIOUS FORMS OF HARELIPCHEEKS FORMED BY POSTERIOR PART OF MAXILLARY AND MANDIBULAR PROCESS

NOSE IS DERIVED FROM FRONTONASAL PROCESSCHANGES IN FACIAL FEATURES CONTINUES THROUGHOUT LIFE

HUMAN ANATOMY B.D CHAURASIA FOURTH EDITION. CHAPTER 1

DEVELOPMENT OF FACE,NOSE AND PALATE INDERBIR SINGH , HUMAN EMBROLOGY 7TH EDITION, CHAPTER 11 MACMILLAN PUBLICATIONS

PRENATAL AND POSTNATAL DEVELOPMENT OF FACE NIKHIL MARWA,TEXTBOOK OF PEDIATRIC DENTISTRY 2ND EDITION, SECTION 3 JAYPEE PUBLICATIONS

REFERENCES

ARTICLE : HEAD AND NECK EMBRYOLOGY: AN OVERVIEW OF DEVELOPMENT , GROWTH AND DEFECT IN THE HUMAN FETUS

-ALLISON BAYLIS, MAY 2009

TEXTBOOK OF PEDODONTICS , SHOBHA TANDON, 2ND EDITION

CRANIOFACIAL COMPLEX, RAY E STEWART AND ROBERT N MOORE

MANDIBULOFACIAL DYSOSTOSIS , MARLE M TOLAROVA MARCH 9, 2012

EMBRYOLOGY OF HEAD , FACE AND ORAL CAVITY, TEN CATES , ORAL HISTOLOGY 6TH EDITION

TEXTBOOK OF ORTHODONTICS- S. GOWRI SANKAR

ARTICLE: THREE DIMENSIONAL FACIAL GROWTH STUDIED BY OPTICAL SURFACE SCANNING

-SPENCER J NUTE ET AL, J OF ORTHODONTICS/VOL 27/2000/31-38

MODULE – INTRODUCTION TO JOINTS MEDICAL GROSS ANATOMY