hello everyone welcome to dentalmed today in this video we'll be talking about fibrous dysplasia let's get started [Music] so fibrous dysplasia it is a disease of bone now why is it called fibrous dysplasia because it is characterized by fibers and dysplasia is there is abnormal growth and differentiation so what is fibrous dysplasia it is an uncommon non-heridatory developmental tumor-like condition non-hereditary developmental tumor-like condition which is characterized by it is characterized by replacement of normal bone so here see this is a non hereditary condition Presence by birth it is it forms a tumor like growth it is characterized by replacement of the normal bone by an excessive proliferation of cellular fibrous connective tissue now this connective tissue is intermixed with irregular bony trabeculae okay so with this definition we can we have a like idea of what are the features that would be seen in fibrous dysplasia it is a tumor-like condition Developmental and non-hereditary uncommon okay what happens is there is replacement of normal bone now what all things replaces the normal bones excessive proliferation of cellular fibrous connective tissue now this fibrous connective tissue it is mixed with irregular bony trabeculae now how does this occur what is the etopathogenesis of fibrous dysplasia so what happens is we have a gene which is situated in the long arm of chromosome number 20. this Gene is known as gnas1 this the full form is guanine nucleotide binding protein Alpha stimulating activity polypeptide 1. okay this is known as the gnas1 gene which is situated in the long arm of chromosome number 20. this is the guanine nucleotide binding protein Alpha stimulating activity polypeptide 1. now there occurs so this Gene basically encodes for the G protein okay now there occurs post zygotic missense mutation in this Gene okay and because of which there is excessive or increased production of the G protein so there is basically what happens there is a post zygotic missense mutation in the gnas1 gene which is situated in the long arm of chromosome number 20 which encodes for G protein because of this mutation there is excessive or increased production of the G protein now these DNA changes they are acquired from the zygote stage onwards throughout the lifespan okay due to this due to the increased activation of the G protein there is overproduction of cyclic amp now this overproduction or over produced cyclic amp it hops in the body what does it do there is hyper function of the affected endocrine glands along with that there is effect on the differentiation of the orontoblasts and there is proliferation of the melanocytes so what is the etopathogenesis of fibrous dysplasia there occurs a post zygotic missense mutation in the gnas1 gene which is situated in the long arm of chromosome number 20 which encodes for G protein because of this Miss sense for zygotic mutation there occurs increased activation of the G protein leading to overproduction of the cyclic amp this cyclic amp hops over the body what does it do it leads to hyper function of the affected endocrine gland there it also leads to the uh it also affects the differentiation of the odontoblast and it also leads to excessive proliferation of the melanocytes okay now next if we talk about the clinical features of fibrous dysplasia clinically it could be divided into three types that is monostartic fibrous dysplasia polyostotic fibrous dysplasia and the last one is craniofacial fibrous dysplasia the monostartic fibrous is mono means single one and ostatic means bone formation so the monostotic means condition which is involving single type of method which is affecting one bone formation any one polyar static means when the bone formation of two or more bones are affected and the third type is the craniofacial fibrous dysplasia first of all we'll be discussing about the monostatic fibrous dysplasia here the disease is limited to the single bone the bones involved could be rib femur tibia craniofacial bones or humerus okay now this is more common it has no gender predilections it uh it could be like it is seen in the same amount or in the same percentage as seen in males and females it is more common in the second decade of life that is 10 to 19 years and there is a painless swelling on the affected area which is seen so this is the monostotic fibrous dysplasia after that if we talk about the polyastotic fibrous dysplasia in the polyastatic fibers dysplasia there is involvement of two or more bones along with that what are the sites that could be seen it is femur tibia pelvis ribs skull and facial bones upper extremities lumbar spine clavicle and cervical spine it could be unilateral or bilateral affecting any one side on both the sides of the body now here the skeletal manifestations are seen what is the skeletal manifestation there is a Shepherd crook deformity so this is the shepherd Crook and this kind of deformity is seen in the polyastotic fibrous dysplasia so what happens is there is convature of the femoral neck and the proximal shaft this is a pathogonomic feature or the diagnosing feature of fibrous dysplasia the disc curvature of the femoral neck and the proximal shaft leading to the shepherd crook deformity it also has certain extraskeletal manifestations see this is the shepherd crook deformity scene in fibrous dysplasia now this also has certain extraskeletal manifestations which is so that was the skeletal manifestation that we have seen which was uh found in the fibrous dysplasia it also has a extra skeletal manifestation which is the cutaneous pigmentation which is seen see see we have seen that the overproduced cyclic amped hops in the body from P it was production of melanocytes so this correlates with another [Music] um presentation of polystartic fibrous dysplasia which is cutaneous pigmentation here there are pigmented macules that are present okay these are known as Cafe OLED spots why are they called as Cafe Olivet they represent coffee with milk see something of this kind therefore they are known as Cafe OLED spots now these caffeolid spots if you remember they are seen also in neurofibromatosis okay so how would we differentiate whether how would we differentiate just looking on the extraskeletal manifestation whether it is a fibrous dysplasia or neurofibromatosis see what happens is in fibrous dysplasia there are the margins of the cafe Olive spots these margins of the kephalic spots they are Jagged okay all round they are Jagged means they are irregular okay the margins in the cafe cafelet spot of fibrous dysplasia are jacked or irregular whereas the regular margins are present in the Catholic spots of neurofibromatosis along with that these irregular margins of the fibrous dysplasia they are seamed or they are called to resemble the coastline of Main okay see Jagged borders so these Capulet spots of fibrous dysplasia are some are known to remember the coastline of main they are compared to the coastline of main along with that these lines they never cross the midline they would be present ipsilateral only on one side they would never cross midline but the uh carefully spots which are seen in the neurofibromatosis they have round edges they are present they cross the midline present on both the sides along with that they are like the coast of California okay smooth with smooth borders so they are compared to the coast of California for neurofibromatosis coast of California and for fibrous dysplasia they are known they are compared with Coastline of Main okay now next the fibrous dysplasia it can have a it can be seen associated with the Triad of wound effect okay what are the Triad fibrous dysplasia along with kefalid spots along with certain endocrine distance disturbances which is precautious puberty hyperthyroidism adrenal disorders diabetes hyperpituitarism and hyper calcium okay so fibrous dysplasia associated with the Triad of bone bone defects that is fibrous dysplasia along with caffeolid spots and certain endocrine disturbances which would include precautious puberty hyperthyroidism adrenal disorders diabetes hyper pituitarism and hypercalcemia these are known as this this forms the mercuna Albright syndrome now these Triad that is fibrous dysplasia kephalit spot and endocrine disturbances such as precautious puberty hyperthyroidism adrenal disorders diabetes hypothetism and hypercalcemia are known as the Albright triode now next is the fibrous dysplasia along with the caffeine spot okay if fibrous dysplasia is present and only careful with pots are seen this is known as jaffe's type of fibrous dysplasia okay sometimes fibrous dysplasia is seen associated with intramuscular myxoma so this forms the massabrat syndrome we have three mycunia Albright syndrome the Japanese type of fibrous dysplasia and mesoprod syndrome so if fibrous dysplasia associated with only kefallots Cafe spots jeffy's type fibrous dysplasia Cafe alert spot and the endocrine disturbances mercuna Albright syndrome fibrous dysplasia with intramuscular myxoma no keflute spots then it is the it is known as the Mesa broad syndrome next is the craniofacial fibrous dysplasia which we have seen is a third type of clinical manifestation so this could be either monoaustotic or polyester dick it more it is the mostly affected bones are maxilla frontal bone zygomasphenoid and the ethymoidal bone and when the maxilla and the associated bones are affected it gives a lion type of appearance or the leonine appearance therefore it is known as leontiosis OSH ostia so if the maxilla and the associated bones that is frontal zygomosphenoid ethanoidal they are affected this gives an appearance of a leon it it gives a leonine appearance so this type of fibrous dysplasia is known as leontiosis leonty asses ostia so what are the clinical features there is painless jaw swelling the lips are incompetent along with that see these are the oral manifestations basically which are seen in fibrous dysplasia okay so there is a jaw swelling painless or painless spelling or the bulging of the joyous seen along with that the lips are incompetent then it is more severe in maxilla and in children most commonly seen in maxilla and in children so along with that there is frequent buccal cortical plate expansion with intact gingiva so but a buccal cortical plate expands with an intact overlying gingiva okay now next if we talk about the radiographic features of fibrous dysplasia then a radiolucent lesion is seen in the bone which is affected along with that there is a destructive lesion in the diaphysis and the metaphysis which is seen okay there is a so the normal trabecular pattern is completely lost here resulting in the scalloping of the Endo osteal bone okay and there is Extreme thickening of the cortex so this thickened sclerotic border with a radiolucent lesion so this thickens sclerotic border is known as Rin design okay what is rinseine thickens chlorotic border with a radulucent lesion seen in fibrous dysplasia is known as rinse signs see here it is more clearly appreciable okay now how how does this disease progress see in the early lesion there is uniform unilocular radiolucency which is seen uniform radio unilocular radulucency and the normal bony trabecular pattern is seen in the early lesions after that there are small multi new multilocular radiolucent lesions with well-defined border and fine bony trabecule along with that there is an increase in the trabeculation with more radio opaque lesions okay so now we have more number of radio opaque lesions and increased number of tuberculations because of these increased trabeculations ground glass cotton wool or the orange peel appearances seen see this is the Cotton wool appearance can we see this is because of the radio opacity that is overgrowth of the bone so ground glass this could be regarded as ground glass cotton wool or the orange peel appearance along with that there is expansion of the buccal cortical plate which can be seen see next if we talk about the histopathological features which are seen in the fibrous dysplasia so first of all there are irregular shaped trabeculae with immature or woven bone in the cellular in a cellular Loosely arranged fibrous dysplasia see these are the irregular shaped woven bony trabeculae and there is this low cellular fibrous stroma which is present these tobacco is irregular and woven that is immature they are dispersed in these loose cellular fibrous trauma these tuberculates they are not connected to each other and they assume a curvilinear shape therefore they are known as the Chinese latter letter letter pattern so the Chinese letter pattern is a classic histopathological feature which is seen in fibrous dysplasia foreign they are arising by metaplasia and they are like not surrounded by the plump of oppositional osteoblasts like the normal bony trabacular okay some certain in histopathological feature along with these certain calcified ferules can also be seen there is no capsule or line demarcation between the normal and the lesional bone and there could be intervening fibrous connective tissue with the mononuclear cells okay next if we talk about the treatment of fibrous dysplasia so it is a self-limiting disease and it ceases to grow when the patient reaches puberty for the monostartic type of fibrous dysplasia cosmotic surgeries cosmetic surgeries can be opted for such as Optical Canal decompression if the surgery is contra indicated then vitamin D and bisphosphonate therapy can be given to the patient along with that the polyastatic fibrous dysplasia it requires a multidisciplinary approach next if you talk about the malignancy potential it is 0.4 percent for monostotic four percent around four percent for the polyastortic type and the malignancies which are reported subsequent to the fibrous dysplasia could be osteosarcoma fibrosarcoma chondrosarcoma malignant fibrous histiocytoma so if we revise what all what all things we have studied or the classic features which are present in fibrous dysplasia see this is a self-limiting non-hereditary disorder first of all what happens is the gene which is affected in fibrous dysplasia it is present in the long arm of chromosome number 20. this Gene is a gnas1 gene this gene causes the production of G protein and G protein leads to the it stimulates the production of cyclic amp because of the over cyclic amp this overproduced cyclic amp it hops in the body what is the full form of hop so there is hyper function of the affected endocrine glands there is the osteoblasts differentiate differentiation is affected and there is over proliferation of the melanocytes the clinical features we have three forms monostotic five polyestotic and craniofacial see um we have seen what are the what are the what all bones are affected in the polyester type a special feature is seen that is the shepherd crook deformity what is Shepherd's group deformity why does it occur it resembles the shepherd crook it occurs because there is a curvature of femoral neck and the proximal shaft a curvature is seen in the femoral neck and the proximal shaft leading to the shepherd group deformity along with that Cafe OLED spots are seen that is coffee dispersed within the milk Cafe Olive spots are also seen neurofibromatosis but in fibrous dysplasia unilateral not crossing the midline resembling the coast of Maine in neurofibromatosis it is bilateral ipsilant it is bilateral it is present all over the body it crosses the midline and resembling the coast of California why coast of California because it has smooth borders why coast of Maine because it has ragged or Jagged borders okay after that it can have three types it can be associated with if the fibrous dysplasia is associated with only careful it spots it is known as the Japanese type fibrous dysplasia kephalit spots and endocrine disturbances water disturbances like hyperthyroidism hyper pituitarism hypercalcemia precautious puberty adrenal disorders and diabetes Etc could be seen it is known as the mercuna Albright syndrome and this triode that is fibrous dysplasia kefirate spots and the endocrine is disturbances is known as the Albright triode along with that if fibrous dysplasia is present with a scene with multiple intramuscular myxoma which is more common in women then this is known as the mesobot syndrome next if we talk about the radiographic feature then a classical ring rent sign is seen what is render sign it is the Lucian Lucent lesion which has a thickened sclerotic border Lucent lesion with thickensclerotic border it is a classical sign of fibrous dysplasia along with that cotton wool ground glass or orange peel appearance can also be seen oral manifestations we have seen there is bulging there is uh expansion of the buccal plate incompetent lips mother line teeth can be there in histopathological features a classical feature that is seen as Chinese letter pattern while Chinese letter pattern is seen because the because of the irregularly shaped bony trabeculae of the immature bone there is no oppositional oppositional osteoblasts which are seen here okay uh treatment if we look about it is self-limiting and it seizes once the person has achieved puberty this is it about fibrous dysplasia do not forget to like share and subscribe to my channel do hit the Bell icon if you don't want to miss any latest updates also let me know in the comment section below if this video has helped in any ways as this would boast me to make videos of even better versions for you all stay tuned keep watching thank you