 Hello everyone, welcome back to another session in the industry and more. Today we have a growth curve that is Kaman's growth curve in ortho-ondyx. So this growth curve summarizes the postnatal growth of various body tissues. So we have lymphoid, neural, general and genital tissues and this curve summarizes the growth rate that is a postnatal growth rate over the period of 20 years. That is by 20 years from birth by 20 years the growth of most of the body parts or the tissues will be stopped. So on the x-axis we have age that is 0 to 20 years and the y-axis we have size attained as percentage total postnatal growth. So this is 0 percentage and this is the maximum adult percentage that is 100 percentage and some tissues reaching even the double size of adult that is 200 percentage. So ultimately by the 20 year all the tissues reaching to the adult size that is 100 percentage. So we know not all tissues of organs of our body grow at same time and also to same extent. So each tissues have different growth rate and pattern. So different body tissues shows different pattern of growth. So the curve itself seeing the difference between the growth rate of all the four tissues of our body. So now let's see one by one. So we have four body tissues that is lymphoid tissue, general or somatic, neural tissues and the last one is genital tissues. So we are going to study about the scammons growth curve that is the growth of these tissues over the postnatal period. Postnatal growth period that is 20 years. So we have lymphoid tissue. So lymphoid tissue or the lymphoid curve, this is a blue one is a lymphoid curve which includes the thymus, pharyngeal and tonsillar adenoids, lymph nodes and intestinal lymphatic masses. So these lymphoid tissue grow rapidly to reach 200 percentage. So this is 200 percentage of adult size. So this is actual adult size, ultimately it reaches 100 percentage that is adult size. But during the period of 10 to 15 years. So this 10 to 15 years it reaches 200 percentage the lymphoid tissues. Why? Because it is an adaptation to protect the children. That is a younger age group of people from infection. So lymphoid tissue mainly involved with infection control because lymphoid tissues, bile lymphocytes, steel lymphocytes all we know. So all are our body's response mechanisms to infection. So why it is growing up to 200 percentage in this particular period of age? It is to protect the children from infection. After that it drops to 100 percentage that is there will be physiologic involution of the lymphoid tissues slowly by around 20 years it reaches to the normal size. Now next we have the neural curve. So the neural curve is a green one. It is basically includes brain, spinal cord, optic apparatus which is related to the bony parts of skull, upper face and vertebral column. These neural curve which rises strongly during childhood. So there is a exponential phase during the childhood around 0 to 5 years and the brain reaches its full size around 8 years. So by 8 years almost the neural tissues are reaching to its adult size. This is adult size, this is horizontal line because this is 100 percentage. So by 8 years a child is mentally as stable as an adult on a neural level. The mental capability of a child with 8 years is as good as an adult. So that is about neural curve. Now we have the general curve, general curve which is basically a S shaped curve. So S shaped curve it is S shaped curve. General curve is somatic tissues or we can say it is somatic tissues which includes our musculature, bony skeleton, respiratory and digestive organs and also kidneys, liver, spleen and blood volume. So this S shaped growth curve, this growth curve which rises steadily from birth till 5 years. Till 5 years it has a growth phase, okay it is growth phase. After that what happens is 5 to 10 years there will be a flattened phase. So 5 to 10 years there will be flattened phase. So 0 to 5 years there will be exponential growth phase then 5 to 10 years there is a flattened phase again during puberty. So during puberty there will be more acceleration and ultimately it reaches to the adult size by the age of 20. So whereas the last one genital curve is little different, it has the very smaller growth during the early periods because it is associated with the primary sex apparatus, ovary and testis and all secondary sex characters and traits, okay. So it has very small rise in the first year of life then it is almost flatten till the 10 years. After that it goes on increasing and by 20 years it reaches the adult size, okay. So that is the 4 tissues. Now let's come to our oral cavity. So how maxilla and mandible can be related to these tissues. So the maxilla which follows the neural curve because neural we know by 8 years it reaches the adult size. So maxilla also it reaches the complete formation by around 8 years. So if you are doing any treatment on maxilla we need to complete it by 8 years such as face mask it should be given around as early as possible around 6 years or 7 years to promote the growth of maxilla. By 8 years the maxilla formation will be complete, okay. So that is regarding the maxilla whereas the mandible is entirely different it is following a path of our somatic tissues that is the general, general or somatic because it grows till 18 or 20 years. So if you are planning a treatment such as chin cup on mandible we should continue it till 18 or 20 years. So what happens if you are doing a chin cup treatment and if you are stopping by 16 years what happens is the mandible still grows, okay. So the treatment will be a failure because there will be relapse. So we need to wait till the cessation of growth of that particular bone with respect to the treatment. So if maxilla we can stop it by 8 years because by 8 years the growth of maxilla is stopped whereas the mandible is continuously growing till 18 to 20 years. So if you are doing a treatment on mandible we need to wait till 18 to 20 years otherwise there will be relapse. So that is maxilla and mandible which can be related to neural and general curve respectively with regard to the treatment options. So I hope you understood the concept of Scammon's growth curve. So we have 4 tissues lymphoid, general, neural and genital and its growth pattern. The lymphoid is going very high that is 200% and neural is reaching adult size very early around 8 years the rest 2 general and genital is reaching its adult size by 18 to 20 years. So that's all about Scammon's growth curve. I will come up with a new topic in orthodontics. Thank you.