 Welcome back to a new video on dentistry and more. So today's topic is about theories of growth. So there are various theories of growth of head and face region in orthodontics. The theories are genetic theory, sutural theory, cartilaginous theory and functional matrix theory. One of the first theory is genetic theory. So it was given by Alan G. Broglie in 1950s. According to this theory, the growth is controlled by genes. As the name suggests, the control of growth is on genes. So it is more of an assumed theory than a proven one. There is no proof for this theory. It is more of an assumption. So according to this theory, head and face grew from growth centers. So we know growth centers. So the head and face grows from growth centers. The point is under strict genetic control. So there is a strict genetic control upon the growth of head and face. So primarily, genetic control determines the initial features. Later, the secondly, the local feedback and inner communication happens between cells and tissues. That is the process of growth. Primarily, the genetic control determines the basic initial features than the local feedback and inner communication. That is the further growth that is happening between cells and tissues. So this theory is not accepted at all because this theory can't explain the role of epigenetic and environmental factors. So this theory is later replaced by many theory. This is one of the first theory because of this genes involvement. A part of this was correct, but it cannot prove or it cannot explain the entire growth of head and face region because it is not considering the epigenetic and environmental factors of growth which has significant roles in the growth and development of head and face. Because genetics control only certain features, no complete influence on the head and face region. Suppose if genetic theory is true, we could predict the feature of a children from the syphilogram of parents. If this is to be true, we can easily predict what happens or what would happen for children from the syphilograms of parents, but this is not at all possible. To an extent, we can say that this might happen, but there is no complete assurance that this would happen because there is always involvement of epigenetic and other environmental factors and other growth factors. There is a slight favoring side, the significance of development of malocclusion because mostly the occlusion similarities we can see which runs in families. Malocclusion will be of little significance under genetic theory. So genetic theories, most of the things are against genetic theory, so only few things like malocclusion, some similarities which can be caused by the genetics because genetics is there definitely, genetics has a role, but we cannot explain the entire growth of head and face by the genetic theory. So a part of genetic theory can be accepted, but not completely. So this is the first theory that is genetic theory given by Alan Gibrodi, complete control of genes. Remember it has initial control on basic features and there is cells and tissues, inner communication and local feedback, there is no emphasizing on epigenetic and environmental factors, so it rejected a little influence on the malocclusion because there is occlusion similarities in the family. So now let's move on to the future theory. Dentistry and more. So today's topic is future theory. So last class we have finished genetic theory. So let's continue our future theory that is theory of growth and orthodontics. So various theories were there to explain the concept of growth and development in the head and face region. So the second theory is future theory that is given by Wienman and Cichl in 1952. So as per this theory all bond forming elements are growth centers that is cartilage, suture and periostein and the craniofacial growth occurs at suture. This is the key point. The craniofacial growth occurs at sutures. So we can see few sutures over here. This is frontomaxillary suture, zygomaticomaxillary suture, terigomaxillary suture and zygomatic temporal suture. So this red section is a complex which is known as nasomaxillary complex. The nasomaxillary complex will grow downward and forward as a result of this suture proliferation. So that is the theory of suture theory that is a theory that the concept behind sutural theory the nasomaxillary complex of this maxillary complex it grows forward. So this forward and downward so this grows forward and downward along with the mantible. So it needs to be balanced with the growth of the mantible. So it grows forward and downward along with mantible. So there will be parallel sutures that is paired sutures. All these sutures are present on the both side. So this parallel sutures pushes this nasomaxillary complex downward and forward. So this is the concept of sutural theory. According to Cissure what he believed was the proliferation of connective tissue between two bones which causes growth and functional maintenance of bone that is it is happening at the sutures. And all bone forming elements like cartilage, sutures and periosteum are growth centers which are actually responsible for facial growth and assumed all were under tight intrinsic genetic control. So it is also emphasizing the role of genetics but is stressing upon the sutures. But just like genetic theory the sutural theory also is not accepted well because there is lot of things going against this. When transplantation of suture occurred there is no growth. So when scientifically transplanted the sutures it cannot produce the growth. So this is rejected. This sutural theory cannot explain the microcephaly and hydrocephaly conditions and also the cleft palate if the growth occurs at these areas the microcephaly and cleft palate will not be happen or will not happen these conditions. So microcephaly or hydrocephaly and also the cleft palate is not explained by the sutural theory. And one more thing is the remodeling of bone that is the periosteum remodeling of bone is influenced strongly by the environmental factors not it is it is very unlikely to be under the intrinsic hereditary control. So it also did not emphasizing on the environmental factors of bone remodeling or bone growth. So that is why this theory is not well accepted just like genetics theory. So that is all about sutural theory the other name is sutural dominant theory given by Veenman and Cicero in 1952 the nasomaxillary complex with paired sutures. So it pushes the nasomaxillary complex forward and downward it is not accepted because it could not explain microcephaly cleft palate or hydrocephaly condition and when it is transplanted there is no growth. So that is a summary of sutural theory next we will move on to the cartilaginous theory on dentistry and more. So today's topic is cartilaginous theory. So in theories of growth we have covered genetic theory and sutural theory. So where the growth and development the theory emphasizing on genetics and sutures this particular theory which is concentrating on cartilages. So this was given by Scott it is also known as Scott's hypothesis so the theory emphasizing on the role of cartilage in growth and development of head and face region. So that is the cartilaginous part act as a primary growth centers in maxill and mantibul. So in maxillum the cartilaginous part is nasal septum or nasal septal cartilage and in mantibul it is quantilar cartilage. So these cartilages act as intrinsic factors on cartilaginous there is intrinsic factors in growth and development. So these factors are present in cartilage on periosteum whereas sutures act as secondary because they just responds to the response due to seeing controsis proliferation and local environmental factors. But in sutural theory they were highlighting the sutures but this is opposite. So intrinsic growth controlling factors are present in cartilage and periosteum whereas sutures are secondary and dependent on the extra sutural influences. So we need to recognize the skull as a primary center of growth with nasal septum being the major contribution in the maxillary growth. But whereas mantibul we can say that the contiles the contila cartilage. Being evidences are the epiphyseal plate when transplanted to another site the growth continues. So it was not there in the sutural theory when sutures were transplanted the growth did not occur. But the epiphyseal plate when transplanted the growth continues. And nasal septal cartilage also when it is transplanted it also shows growth and when it is removed the nasal septal cartilage is removed it was found that there is a midfacial deformity. So thereby they can emphasizing on the potential of cartilage in growth and development of nasal maxillary complex and mantibul. But the problem with this mantibular contila cartilage it did not develop into or it did not create a new growth at a different site or the contila cartilage could not continue the growth at a different site when transplanted. So it is actually a growth center not a site of growth. So that was one of the shortcoming but still mantibular contile is act as a growth site. So this is basically the theory is stressing upon the cartilage. So every theory has one key point this is genetics this is suture and this is cartilage. So the two key cartilage in the head or the face is maxillary nasal septal cartilage and in mantibular it is contila cartilage and this cartilage creates or it produces the intrinsic factors for the growth and causes the growth and development of nasal maxillary complex and mantibul. So that is how the cartilagin theory explains the growth and development of head and face region. So now let us move on to the functional matrix theory. Thank you. The nasal septal cartilage which forwardly and downwardly displaces nasal maxillary complexes as a part of the growth. So when growth happens the nasal maxillary complex so nasal maxillary complex the same complex we have seen in sutural theory but the sutures are creating the potential for growth but here it is a cartilage that is a nasal septal cartilage which creates the potential and moves the nasal maxillary complex forward and downward. At the same place the contils contila cartilage it need to be considered as a long bone with cartilage is present at the both ends. So it act as a growth centers and it produces growth. So the growth of mantibul is explained by the contila cartilage. So all the cartilages throughout the skull are primary centers of growth and the growth of maxilla is attributed to the growth of nasal septal cartilage which causing the forward and downward growth of nasal maxillary complex and nasal septal cartilage is a pacemaker of a growth of nasal maxillary complex and as I told mantibul it is like a diaphysis of long bone bent with epiphyzyl cartilage at both ends. So we know that the shape of mantibul so if we bend it it looks like a diaphysis of a long bone with epiphyzyl cartilage at both the ends. So that's how scot explained the growth of maxilla and mantibul. Hello everyone welcome back to a new video on dentistry and more. So today's topic is functional matrix theory. So that is a fourth theory in theories of growth where covered genetic theory, sutural theory and cartilaginous theory. We have seen what causes growth and development in each theory the genetical involvement the sutural involvement and the cartilaginous involvement. Now let's move on to a different concept that is functional matrix theory. In functional matrix theory it is all about a functional cranial component. Now let's see what is functional matrix hypothesis are also known as Mohs functional matrix theory it was given by Melvin Mohs. Functional matrix theory it claims that the origin, growth, form, position and maintenance of all skeletal tissues and organs are always secondary, compensatory and obligatory responses to temporally and operationally prior events that occur in specifically related non-skeletal tissues organs or functioning spaces are also known as functional matrices. So actually the main thing happens the structures which are related to these bonds the non-skeletal tissues organs or functioning spaces are actually creating the growth. So that is the concept of functional matrix theory. The theory itself suggests that the organs the skeletal tissues are always secondary and compensatory responses happening because of the events occur in the functional matrices which are non-skeletal tissues it is a very different concept put forward by Melvin Mohs actually it was a work of van der klo and later Melvin Mohs modified this. So this space or also known as functional matrices actually has two unit that is functional matrix and skeletal unit. So in functional matrix it is again we can divide this into capsular matrix and periostyle matrix. So functional matrix is about a one function then cranial component this matrix and skeletal unit. So periostyle and capsular matrices. The periostyle matrices actually it is influences bone directly it influences bone. So this might be surrounding a bone and it directly influences that particular bone through periosteum and causing bone deposition and resorption. So actually it is known as microskeletal units. So bone growth is occurs by transformation that is deposition and resorption. So what are the periostyle matrices we can say that it could be a temporalis muscle it could be a blood vessel it could be a gland which causing deposition and resorption of that particular bone and causing transformation growth changes. This is known as microskeletal units. So bone formation is by direct influences of this periostyle matrix. So it could be temporalis muscle, blood vessels or gland anything which surrounds a particular bone and the next thing is capsular matrix. Capsular matrix is nothing but which is a capsule surrounding a mass or space. So it is a thing which is covering a mass just like the duramatter and scalp which covers the neural mass and orbit which covering the orbital tissues. So these are known as capsular matrices. So capsular matrix which is a covering unit which actually forms a epigenetic growth factors which has epigenic growth factors which causes the growth and it creates a translational growth or it creates translational or volumetric changes and it is known as macroskeletal unit. So macroskeletal unit the capsular matrices act upon the macroskeletal unit and causing translation. The periostyle matrix which is acting upon the macroskeletal unit which is causing transformation by bone deposition and resorption. So transformation and translation which ultimately results in growth. So this is the basic concept of functional matrix theory. So basically the totality of soft tissues associated with a single function is termed as functional matrix. So basically two distinct types of functional matrices that is periostyle and capsular matrices periostyle matrices I already mentioned before that functional cranial component. Functional cranial component is nothing but the function we were talking about it has two components that is functional matrix which is actually perform the functional duty of a bone and the skeletal unit which provides a biomechanical role of protection and support to this functional matrix. So the cranial component functional matrix is actually act as a matrix and the skeletal unit which provides support through a biomechanical role. So functional matrix are basically two types capsular matrix and periostyle matrices. So periostyle matrices influence bone through periosteum by direct deposition and resorption. It can be temporalis muscle, teeth, blood vessels, nerves and glands. So periostyle matrices form the local environmental factors which affect the growth. And the influence of periostyle matrices restricted to just a part of bone that is it affects the micro skeletal units whereas the capsular matrix which includes the capsule that surrounds the masses and spaces just like neural mass is containing the scalp and durameter and also orbital mass which is supporting tissues of eye or oronasal pharyngeal spaces. Spaces are surrounded by various tissues that form capsule. Neuro cranial capsular matrix is many matrices are there so these matrices cause growth of a whole bone not just a part of bone the entire whole bone through a volumetric expansion of capsular matrix. It is creating a spatial translation of whole bone or macroskeletal unit. So whole bone formation or volumetric expansion occurs by the effect of capsular matrices. Now let's see what is a skeletal unit. Now let's see what is micro skeletal and macroskeletal unit. Already we have seen what is micro skeletal and macroskeletal. Just for a comparison micro skeletal is just a part of bone that is forming by the action of periosteal matrix. So functional matrix the periosteal matrix is at the bone the small part of bone by transformation that is by formation or the resorption and deposition that transformation is happening by micro skeletal units and it affects the size and shape affects the size and shape okay that is micro skeletal unit but the macroskeletal unit it is not just a part of bone it is a core of bone and by the action of capsular matrix okay this capsular matrix at the bone macroskeletal unit it is by the process of translation that is volumetric expansion is happening and it is the not just size and shape it is the position so positional changes happening with the macroskeletal unit. So these two compare to happen the growth of that particular bone. So let's see some example and it's corresponding micro skeletal unit that is periosteal matrix if this temporalis it is associated with cornoi process tooth the alveolar bone the medial and lateral teregoid muscle associated with angloframus which are the micro skeletal unit which is a part of a bone and the capsular matrix is such as nasal mass eye mass and orofacial capsule nasal mass it the macroskeletal unit is cranium then eye mass it's orbit and the orofacial capsule the core of mandible and maxilla. So that is the basic idea of periosteal matrix and micro skeletal unit and also the capsular matrix and macroskeletal unit. So according to this theory the growth potential actually lies outside the bone that is a functional space or a functional matrix where the things are happening rather than the bone itself so that is the most accepted theory that is functional matrix theory the functional cranial component it's functional matrix and its skeletal units and the capsular matrixes and periosteal matrices it's micro skeletal and macroskeletal units. So what are the clinical implications of this functional matrix theory because orthodontic corrections of malocclusion is done either by intraoral or extraoral appliances so force application by these appliances tend to alter the functional matrix. So we are applying this concept in orthodontic appliances so alteration of periosteal functional matrices produces changes in micro skeletal unit that is micro skeletal unit and alteration in the capsular functional matrixes produces macroskeletal unit changes in the macroskeletal unit. So what happens the periosteal matrix that is a tooth this is a periosteal matrix tooth the movement orthodontic after the orthodontic treatment there is change in alveolar bone and capsular matrix such as dendrofacial orthopedics like dendrofacial complex there is macroskeletal unit that is joe's okay joe movement or joe changes will happen that is the capsular matrices. So that's all about the theories the major theories of growth we have covered the theories genetic theories ritual theory cartilaginous theory and functional matrix theory. So these are the four important theories which commonly as for the university exam the functional matrix theory is little complicated but it is just the two parts and if you have this flow chart in your mind it will be easy. So I'll come up with a new session if you have any particular chapter or particular subject would like to have glasses on do mention in the comment box. So I'll come up with a new topic and dentistry and more thank you.