 Hello everyone, welcome back to another session in dentistry and more we are continuing with our mixed intuition that is we covered first transitional phase so it was divided into first transitional, inter transitional and second transitional period. So the first transitional period where the primate space was utilized by the Molas and it was known as early misal shift. So what is happening in inter transitional phase? So first transitional phase other changes are happening the upper rate of maxillary incisors that is incisor liabilities there and in inter transitional phase it is basically a stable phase and it lasts for around 1.5 years during this time the mouth consists of permanent incisors first permanent Molas that is it includes both central and lateral and primary canines and primary Molas okay so it will be like this 1, 2, C, D, E and 6. So central permanent, lateral permanent, deciduous canine, deciduous first molar, deciduous second molar and permanent first molar. So this period lasts around 1.5 years so and it is quite stable phase with visible changes occurring in the rendition okay. So teeth present are permanent incisors and Molas and primary canines and primary Molas. So the minor changes which is happening during this 1.5 years is the tongue will pushes the mandibular lateral incisor to its final position and also there is a small discrepancy correction by the lips. So the lip movements and tuck movements will correct the alignment minor corrections will be done and there will be mesial drift of mandibular teeth and without any fixed inter cusp relationship still there will be a mesial drift of mandibular teeth okay. So that is inter transitional period. So mixed rendition was divided into first transitional, inter transitional and second transitional. So whereas the second transitional phase where it is characterized by the replacement of primary Molas and canines by the primolas and permanent canines okay. So it was like this 1, 2 then C, D, E, 6 will be 1, 2, 3, 4, 5 and 6. So C, D, E will be replaced by 4, 5 and 3, 3, 4, 5. So during this time the late mesial shift is happening that is using the leeway space. So leeway space is nothing but the distance or the difference in mesodistral diameter of these two teeth that is a primary canine and molas against permanent canine and primolas. So if the space is not available to accommodate the permanent molas the teeth uses leeway space that happens during the second transitional phase. So this space is around 1.8 millimetre in maxilla that is 0.9 in either arch I mean the half of the arch and 3.4 millimetre in mandible right and left side. So the change in exchange of these set of teeth will ultimately removes all the deciduous teeth and now we have only permanent teeth so we are moving to the permanent dentition phase. So there are many features which are getting corrected in second transition phase the main one is the duckling stage. So we have seen the broadband phenomena broadband phenomena or the ugly duckling stage. So ugly duckling stage will be corrected when it will be corrected when the eruption of canine the complete eruption of canine happens. So the canine will push the lateral incisor back to its original position and it will be perfectly aligned okay before it was central incisor is diverged lateral incisor is diverged because the canines pushing the lateral incisor at the root position. So there will be distal movement of the central and lateral incisor. So once the canine completely ribs the force will be transferred to the crown region and it pushes to the mesial side and all teeth will be perfectly arranged. So the correction of broadband phenomena or ugly duckling stage happens during this period that is second transitional period and also this arch which looses the roundness. So we know the gumpads and the deciduous arch are more of a rounded apparent so it loses it roundness and the most common sequence of eruption is 435 and maxilla that is first premolar, canine and second premolar whereas mantable is 345 that is canine, first premolar and second premolar. So this sequence is essential to prevent crowding and utilizing the leeway space okay and the rental arch, length and arch circumference decreases with the mesial force. So that was about the second transitional phase and by second transitional phase all the deciduous teeth are exfoliated and now we have only permanent teeth. So this three phases is very important in exam point of view because you can expect a lot of questions these three phases. The common questions are can expect primate space, primate space then leeway space is another question. Then incisal liability is another question, incisal liability then the ugly deckling stage is another question which is also known as broadband phenomena. So leeway space and the mesial shift is another question, mesial shift that is early mesial shift and late mesial shift. So all these are shot knots and this mixed temptation period could be asked as a short essay also the first inter and second transitional phase you need to write in detail and the first transitional phase I have that the molar relationship the mesial step distal step the end down relationship and flesh terminal plane that also could be a question flesh terminal plane or mesial step could be mesial step end down relationship and distal step all could be shot notes and this mixed temptation could be a long essay or short essay. So I will come up with a new topic in the industry and more thank you.