NEET MDS Lessons
Orthodontics
Growth is the increase in size It may also be defined as the normal change in the amount of living substance. eg. Growth is the quantitative aspect and measures in units of increase per unit of time.
Development
It is the progress towards maturity (Todd). Development may be defined as natural sequential series of events between fertilization of ovum and adult stage.
Maturation
It is a period of stabilization brought by growth and development.
CEPHALOCAUDAL GRADIENT OF GROWTH
This simply means that there is an axis of increased growth extending from the head towards feet. At about 3rd month of intrauterine life the head takes up about 50% of total body length. At this stage cranium is larger relative to face. In contrast the limbs are underdeveloped.
By the time of birth limbs and trunk have grown faster than head and the entire proportion of the body to the head has increased. These processes of growth continue till adult.
SCAMMON’S CURVE
In normal growth pattern all the tissue system of the body do not growth at the same rate. Scammon’s curve for growth shows 4 major tissue system of the body;
• Neural
• Lymphoid
• General: Bone, viscera, muscle.
• Genital
The graph indicates the growth of the neural tissue is complete by 6-7 year of age. General body tissue show an “S” shaped curve with showing of rate during childhood and acceleration at puberty. Lymphoid tissues proliferate to its maximum in late childhood and undergo involution. At the same time growth of the genital tissue accelerate rapidly.