Growth Pattern Variability (Concepts of Growth & Development) - Orthodontics

PATTERN, VARIABILITY & TIMING

OF GROWTHConcepts of Growth & Development

SARANG SURESH HOTCHANDANI


Concepts of Growth & Development

• The term growth usually refers to an increase in size or number.

• The term development refer to an increase in complexity.• It is increase in specialization with loss of potential.

• Growth is largely an anatomic phenomenon.

• Development is physiologic and behavioral.SARANG SURESH HOTCHANDANI

Growth Pattern

• It is set of complex proportional relationships at a point in time and the also the changes in these proportional relationships over time.

• In other words, Arrangement of body at any one time is a Pattern of Spatially Proportioned Parts. (1st Part of Definition)

•Changes in these Spatial Proportional Parts of Body is called pattern of growth (2nd Part of Definition).


Cephalocaudal Gradient of Growth

•It refers to Growth of Body extending from head towards feet.• means pehle jo head (cephalo) ke near structures honge

wo grow karenge then aahiste aahiste growth outward hoti jayegi.



• During prenatal growth, from conception to 5 months, the head grows more than the body.

• In humans, the head comprises almost 50% of total body length at approximately the 3rd month of intrauterine development.• At this stage Cranium is Large relative to Face

• By the time of birth the head has decreased to approximately 30% of total body length as a result of the limbs and trunk growing faster than the head.

• At birth, legs represent about 1/3rd of total body length while in adult they represent half of total body length.



• So here, pattern of growth is progressive decrease in head and face.

• This trend continues postnatally along an axis of increased growth from the head to the feet.

• Finally, in adults, the head represents approximately 12% of the body length.

• There is more growth of lower limbs than upper limbs in post-natal life

Schematic representation of the changes in overall body proportions during normal growth and development. After the third month of fetal life, the proportion of total body size contributed by the head and face steadily declines. (Redrawn from Robbins WJ, et al. Growth. New Haven: Yale University Press; 1928.)


Differential Growth

Not all the tissues systems of body grow at the same rate because they are present in different various parts of body and that’s why their growth depends on growth of that part of

body…SARANG SURESH HOTCHANDANI

Scammon’s Curve

• Graphic representation for Differential growth which tells us that each tissue grows at different rate.• Growth of the neural tissues is nearly

complete by 6 or 7 years of age.• Growth of general body tissues which

include muscles, bones & viscera show “S shaped curve” have slow rate of growth during childhood and accelerated rate of growth during puberty.


Pattern of Facial Growth

• As in general body, cephalo-caudal growth gradient is also present in Head.

• At birth, the face and jaws are relatively underdeveloped compared with their extent in the adult. As a result, there is much more growth of facial than cranial structures postnatally.


Predictability

•it means Repetition

•Predictability of growth pattern is a specific kind of proportionality that exists at a particular time and progresses towards another, at the next time frame with slight variations.

•Change in growth pattern indicates some alteration in the expected changes in body proportions.


Pattern Also Repeat

• just like ap jaante ho har insan ke jo bones hain similar tareeke se grow karenge means agar ap me maxilla kebaaad ee mandible develope or grow ho raha hai jese ham ooper parh ke aaye hain… wese ee aap predict (means anooman) ker sakti hain ke dusre person me b same tareeke se ee hoga means ke mandible maxilla ke baaddevelop hogi. to is concept ko predictability kehte hainmeans jo Pattern hain growth and development ke wo predict kiye ja sakte hain.


VARIABILITY


Variability

•Generally speaking variability in biology is defined as deviation from normal pattern of growth.•clinically we should able to decide, whether individual is at the extreme end of normal variation or he/she falls outside the normal range before saying he/ she has abnormal growth.


Variability

• Rather than saying growth is normal or abnormal, we should think in terms of deviation from the usual pattern and express this variability (deviation from usual pattern) quantitatively on growth chart.• In this chart child is evaluated relative to its peers.• Normal variability is derived from large scale studies of groups

of children and is shown by solid line on graph for comparing.• If the individual falls along the 50% of peers he/she will be at the mid of

line.• If he/she falls along 90% of peers, he/she will be at the 90% line.


Variability

• It means child is at extremes of normal position if he/she is at least above 97% of peers.

•If he/she falls along less than 90% of peers, he/she will be at 10% of line.

•So, for this reason, child’s growth should plot along same percentage line at all ages to evaluate that child over time.

• If the percentage position line of that person is changed, we should suspect some growth abnormality has occurred.


TIMING


Timing

•Variability in growth occurs in many ways as under;•From normal variation•Influences outside normal experience (serious illness)

•TimingSARANG SURESH HOTCHANDANI

Timing

•As we see in our surroundings that same event of growth happens for different persons at different time.• Some children grow and develop rapidly and mature

early while some children grow & develop slowly and mature late

•So, this occurs because biological clocks of different persons are set differently.


Timing

•Variation in growth and development occurring because of timing are mostly seen in adolescence.

•All children undergo spurt of growth at adolescence but spurt of growth occurs at different times in different individuals.

•Spurt of growth; rapid rise in height & weight.SARANG SURESH HOTCHANDANI

Timing

• In girls, onset of menstruation is excellent indicator of arrival of sexual maturity accompanied by spurt of growth.

•Earlier the adolescence growth spurt occur the more intense appears to be.•Agar 2 baar aahin jara hikre me growth spurt sawer thyo aa be

be khan then jahin me sawer growth spurt thyo aa ooho baardrigho theendo as compared to be je.


Timing

• There are 2 methods of age measurement • Chronological age

• Amount of time since birth or conception.

• Biological age or developmental age• Gaining of various developmental markers or stages.

• Timing variability can be decreased by using biological age.• Pattern is expressed at different time chronologically but not at

different times physiologically.


THE ENDSource: Contemporary Orthodontics (Proffit)

Email: [email protected]: www.twitter.com/fetusdentistaFinal Year BDS @ Bibi Aseefa Dental College, SMBBMU, Larkana, Sindh, Pakistan.


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Growth Pattern Variability (Concepts of Growth & Development) - Orthodontics