Ruby RajPG-First year

Department of Orthodontics

Introduction

Why to study growth

Relevance of growth

Definition of growth and development

Factors affecting growth

Terminologies

Characteristics of bone growth

Theories

Prenatal growth

Post natal

Growth movements

Growth rotations

Conclusion

growth

How

and

where

direction

Environme

nt

0rthodont

ics

remaining

genetics

•skeletal

•malocclusionDisproportionate

growth

•Treatment

•plangrowth

Definition

Growth is an increase in size.

Development is progress towards

maturity .”

TODD

quantitative aspect of biological development

per unit of time

MOYERS

GROWTH

development

growth

differentiation

translocation

all the naturally occuring unidirectional changes in

life of as individual from its existence as a single

cell to its elaboration as a multifunctional unit

terminating in death

MOYERSDEVELOPMENT

Change in any morphological

parameter which is measurable

GROWTH

MOSS

genetic

• genotype

• racial

Environmental factors

• nutrition

• Physical changes like temperature pressure

,hydration

Functional forces

• Extrinsic and intrinsic muscle activities-exercises

• Space occupying organs and cavities

• Growth expansion

F

A

C

T

O

R

S

Growth fields

The outside and inside surface of a bone are

blanketed by mosaic like pattern of soft

tissue , cartilage or osteogenic membrane

called as growth fields .

These when altered are capable of

producing an alteration in the growth of

particular bone.

Growth site:

are growth fields that have a specific

significance in the growth of particular bone

.(location)

eg: Md condyle, Max tuberosity, sutures

between membrane bones of cranium and jaws

.

The growth site may posses an intrinsic

potential to grow.

Growth centre :

special growth site

Control overall bone growth

which has a genetic potential to grow.

Eg: epiphyseal plate, cartilage from speno

occipital synchondrosis.

Remodelling

Differential growth activity involving deposition

and resorption in the inner and outer surfaces of

the bone

ex,-posterior movement of ramus

CHARACTERISTICS OF BONE GROWTH

INTRAMEMBRANOUS

ENDOCHONDRAL

Intramembranous

Rapid apposition without

cartilaginous model

Mesenchymal connective tisssue osseous tisssue

Endochondral

Hyaline cartilage bone

Deeply seated and slowly expanding structures-cartilage

Favours a directed prototype cartilaginous growth

Replaced by bone(indirect bone growth)

GENETIC THEORY

SUTURAL THEORY

CARTILAGINOUS THEORY

FUNCTIONAL MATRIX THEORY

Van LIMBORGH’S THEORY

ENLOW’S EXPANDING ‘V’ PRINCIPLE

ENLOW’S COUNTERPART PRINCIPLE

NEUROTROPHISM IN ORO-FACIAL GROWTH

Genetic

BASED ON THE LOCATION OF GENETIC

CONTROL THERE ARE 3 DETERMINANTS

OF GROWTH

Bone is the primary determinant of its own growth

Cartilage is the primary determinant of skeletal

growth

Soft tissue matrix in which the skeletal elements are

embedded is the primary determinant of growth

SUTURAL THEORY

Sicher and Weinmann 1952

SICHER AND WEINMANN

1952

Proliferation of osteogenictissues

Create space for oppositional growth

points raised against this theory are

1)suture reimplanted

2)growth in cleft cases

SYCHONDROSIS OF CRANIAL

BASE

Spheno-ethmoidal –terminates by 6 yrs

Inter-sphenoidal---disappears at birth

Spheno-occipital---upto adult life

Intra-occipital --closes at 3rd to 5th year of life

CARTILAGINOUS THEORY-JAMES .H.SCOTT

Nasal septal cartilage is the

pacemaker for the

nasomaxillary complex.

Points in favor of this theory

1) in many bones cartilaginous growth

occurs

2) transplantation of epiphyseal plate

3) nasal septal cartilage

FUNCTIONAL MATRIX THEORY

By Melvin Moss(1960)

Of all skeletal tissues and organs are always secondary,compensatory and necessary responses to chronologically and morphologically prior events or processes that occur in specifically related non-skeletal tissues,organs or functional spaces.

maintenance

origin

form

function

growth

Functional cranial component

Functional matrix

Skeletal unit

Tissues,organsand functional spaces

Skeletal tissues

A change in size ,shape,spatial position

and maintanence of all skeletal units is

due to their activity of their respective

functional matrices.

Functional matrix

Periostealmatrix

Capsular matrix

Periosteal matrix

Consist of muscles, blood vessels, nerves,glands etc

Direct action on their skeletal units-leading to bone

deposition and resorption-lead to transformation in size

and shape.

Capsular matrix

Act indirectly and passively-expansion of the

oro-facial capsule(facial bones arise, grow and

maintained)-secondarily compensatory

translation in space.

No deposition and resorption.

Neuro- cranial capsule

Skin and duramater

Protects the neuro cranial capsular functional matrix

Comprises of brain ,leptomeninges and C.S.F

Oro-facial capsule

Skin and mucosa

Protects the orofacial

pharyngeal spaces

Volume and patency of

these spaces influence

the growth of facial

skull

van Limborgh’s theory

1. Intrinsic genetic factor

2. Local epigenic factors

3. General epigenic factors

4. Local environmental factors

5. General environmental factors

ENLOW’S EXPANDING ‘V’ PRINCIPLE

growth and remodeling of the human maxilla.donald h. enlow and seosgbang.Am.J.Orthodontics.volume 51 number 6

ENLOW’S COUNTERPART PRINCIPLE

Growth of any facial or cranial part is related to

their counterparts.

Imbalanced growth occurs if there is change in

amount,time and direction of growth

Nasomaxillary complex-anterior cranial

fossa

Pharyngeal space-middle cranial fossa

Maxilla-mandible

Maxilla-corpus

Maxillary tuberosity –lingual tuberosity

NEUROTROPHISM IN ORO-FACIAL GROWTH

Neutrotrophism is a non impulse transmitting

neural function

involves axoplasmic transport

provides long term interaction between

neurons and innervative tissues that regulates

the morphological,compositional and functional

integrity of those tissues.

SERVO SYSTEM THEORY (Stutzmann and Petrovic )

• Influence of STH

• Gives a cybernetic form of

command

• Proprioceptives in muscle

• Get activated

• Stretching of muscle

• Increase cartilage vascular supply

• Growth

GROWTH

prenatal postnatal

Period of ovum

Period of embryo

Period of fetus

PRENATAL

PERIOD OF OVUM (fertilization-14th day)

PERIOD OF EMBRYO (14-56th day)

presomite

somite

postsomite

PRESOMITE(2-3rd week of IUL)

Formation of amnion and chorion-nutrition-end

of 2nd week

Formation of primary germ layers-3rd

week(gastrulation and neurulation)

Bilaminardisc

During gastrulation

Bilaminar disc – trilaminar disc.

Middle of epiblast layer-primitive streak

Reduces in size

Primitive streak-narrow trough with elevated margins

cranial part-develop to primitive pit surrounded by

primitive node.

14thday-prochordal plate forms-later becomes the

endodermal part of oropharyngeal membrane

3 germ layers

Notochord and Neural tube formation

SOMITE PERIOD

Period of organogenesis.

21-31 day of IUL

Anomalies

Formation of visceral organs from endoderm and

mesoderm

Rapid growth of cranial and caudal part lags behind.

Neural tube

ProchordalPlate

4th week of IUL

Prominent bulge –at ventral aspect of embryo-developing brain

Below bulge-shallow depression-primitive mouth-stomodeum

Floor of stomodeum –buccopharyngeal membrane that

separates stomodeum from the foregut.

Neck elongation of the region between the stomatodeum and

the pericardium

Elongation due to

Appearance of mesodermal

thickenings in the wall of

cranial most part of foregut

called pharyngeal arches

Descend of the

developing heart

FOREGUT

Face-FNP and first pharyngeal arch

Forebrain induces ectoderm

POST SOMITE PERIOD

4-8th week IUL

Maxillary process fuses with MNP and two mandibular process-

narrow the stomodeum

Mouth-continous with oral cavity –due to # of buccopharyngeal

membrane.

Lateral palatal shelves(future secondary palate) –from internal

aspect of maxillary process.

Oral cavity is small and occupied by developing tongue.

6th

week IUL

tongue

Lateral

palatal

shelves

7-8th week of IUL

Head bend over

heart

prominence

Elevation of

face

Growth of

mandible

Increase

volume of oral

cavity

Tongue

descends

Elevation of

palatal shelves

Physical

changes

Blood

flow

Rapid

mitosis

Pressure

changes

Fusion of palatal shelves

1/3rd distance from future incisive

papilla

8-12th week of IUL

Nasal septum and palate fuses

anteriorly

Posteriorly soft palate and uvula

remains free.

primary

secondary

A cleft palate occurs if the palatal shelves fail to fuse

together or may happen if the tongue fails to descent

due to under-development of the mandible

4th ----8 th weekof IUL ------cleft in primary palate

8th ----12th week of IUL -------cleft between hard

and soft palate

CLEFT

Defective growth of palatine shelves

Failure of elevation of shelves

Failure of fusion of shelves

Post fusion rupture of shelves

Micrognathia as in robin complex

REASONS

Palatal elevation

approximation

contact

adherencefusionDisintegrati

on of epithelium

Invasion of mesenchymal cells

Primary intramembraneous ossification centre at 8th

week of IUL at the termination of infra orbital nerve just

above the canine tooth dental lamina

Secondary cartilage ---end of 8th week of IUL in the

region of zygomatic and alveolar process, that fuses with

primary intramembraneous centre .

Premaxillary centre appear anteriorly in each side by 8th

week of IUL fuse with primary maxillary centre

OSSIFICATION

8th

week

4th month(7-18 wks)

Palate undergoes a increase in width than length along

the Mid palatal suture

Median part of upper lip

Position of nasal septum

Nasal septum

DISPLACEMENTGROWTH AT

SUTURES

SURFACE REMODELLING

maxilla

Nasomaxillary complex

Zygomatico-maxillary

Zygomatico-temporal

Zygomatico-frontal

Nasomaxillary

Frontonasal

Intermaxillary

Zygomatic process

Frontal process

Alveolar process

Palatine process

NMC-

Zygomatic bone

Maxilla

Palate

Nasal bone

Orbital roof

•Cortical remodelling

•Selective apposition and

resorption of cortical

surfaces

drift

•Movement of entire

bone

•Primary displacement

•Secondary displacement

displacement

PRIMARY DISPLACEMENT

SECONDARY DISPLACEMENT

ENLOW and BANG

As maxilla grows forward the posterior end is depository to

maintain contact with the adjacent bones but the entire anterior surface of maxilla be

comes resorptive to maintain its shape and configuration

KEY

RIDGE

reversal and remodelling

reversal

deposition resorption

AnteriormaxillaAnterior nasal bone

Pyriform rim

Orbit-medial Orbit-lateral

Sinus-medial Sinus rest surfaces

Tuberosityposteriorlyand laterally

Location of

tuberosity is

marked by the

posterior limit of

ACB

PM plane

Posterior limit of

ACB

tuberosity

Junction of corpus

and ramus

Tooth eruption

Vertical drift

Downward displacement

Downward growth and expansion of palate

deposition resorption

Palate roof,nasalroof

Nasal floor

eruption

Vertical

height of

alveolar bone

Depth of

palate

Width of

bone

laterally

V principle and apposition

at intermaxillary suture

Increase maxillary

width

Anterior and medial

Posterior and lateral

nasalFloor and lateral

sinus

roof

ROTATIONS

growth

Passive

displacement

Active

growth

Extreme variations in

rotational pattern leads to

canting and mislift of the

palate and maxillary arch

Bjork and Skeiller..(1972)

Lateral implants placed on anterior and posterior contour of zygomatic process

rotation

internal

external foward

backward

Internal rotation

External rotation

nasal

deposition

Variations in eruption

internal external

Palatal Plane

FORWARD ROTATION

Excessive I.R

Lack of compensatory E.R

Both

Anteinclination

Psuedo-protrusion

The angle formed between the SpP plane and the Pn plane is called the inclination angle or the “J”angle .Mean-85º

The average value is 85 degrees- straight faces.

5 degrees variation is accepted as normal. If the value decreases below the normal,in

cases where the jaws slant backwards,then it

is considered as retroinclination. If the angle is increased as in cases of the

jaws slanting forward it is termed as

anteinclination.

BACKWARD ROTATION

Retroinclination

Downward and backward tipping of

anterior end of palatal plane and maxillary

base

Jaw bases are translated posteriorly

Upper incisors are lingually tipped

Angle less than 85 degree

Linder –Aronson,Lowe and Woodside

environ

mental

Neuromuscular

dysfunction

Occlusal

forces

nasorespiratory

rotation

CONCLUSION

Inclination of maxilla can be influenced by fixed mechanotherapy

and functional therapy.

Orthopedic treatment measures should be carefully monitored

during active treatment

Degree of maxillary rotation show variations in

direction and intensity each year.

Its smaller than the mandibular rotation

The rotations of both jaws are not always same

Therefore the interactions between the maxillary and the

mandibular rotations play an important role in the vertical

and sagittal relationships of both jaws