GROWTH AND DEVELOPMENT

Some Concepts Of Growth

1. Concept of Normailty
• Normal refers to which is usually expected / ordinary / typical.
• Craniofacial growth changes with Age.
• Thus, what is normally seen in one age group may be not be necessarily normal for different age group.
2. Rhythm of Growth: According to Hooton

Growth is not steady & uniform, wherein all body parts enlarge at same rate, & increment of 1 year equal to proceeding or succeding year.

3. GROWTH SPURTS

Period when sudden acceleration of Growth. This sudden increase in growth, termed 'Growth Spurt'

Cause of accentuated growth : Physiological alteration in hormonal secretion.

Timings Of Growth Spurts

1. Just before birth
2. 1 year after birth
3. Mixed Dentition growth spurt
• Boys : 8 - 11 years
• Girls : 7 - 9 years
4. Pre Pubertal growth spurt
• Boys : 14 - 16 years
• Girls : 11 - 13 years

→ Growth modification by Myofunctional appliance gives better results during growth phase.

→ Surgical Correction : done only after Cessation of Growth.

4. Differential Growth

   Human body doesn't grow at Same Rate Throughout Life.
   Different organs grow at different rate, to different amount, at different times.

   1. Scammon's Growth Curve
   2. Cephalo caudal Gradient of Growth

Scammon's Growth Curve

Body tissues broadly classified into 4 types:

• Lymphoid Tissues : grows rapidly in Late childhood & reaches almost 200 % of adult size.
  This is adaption to infection in children as they are more prone.
  But, till 18 years age, it involutes to reach adult size.
• Neural Tissue : Very rapidly & reaches adult size by 6 - 7 years age. Very little growth occur after it.
  This facilitates intake of further knowledge.
• General Tissues or Visceral Tissues : Bone, Muscle & other organs.
  S- Shaped Curve : Rapid growth upto 2 - 3 years,
  followed by Slow Phase between 3 - 10 years.
  After 10th year Rapid Phase terminating by 18 - 20 years age.
• Genital Tissues : Negligible growth until puberty, Rapid growth at puberty.


Cephalo caudal Gradient of Growth

Axis of increasing growth extending from Head towards Feet.

Post Natal growth is more in body parts away from Hypophysis Cerebri.

1. 3 Months I.U.L. :
   • Head = 50 %
   • Lower limbs = Rudimentry
2. BIRTH :
   • Head = 30 %
3. ADULT :
   • Head = 12 %
   • Lower limbs = 50 %