cystic jaw lesions may be epithelial or non - epithelial , odontogenic or non - odontogenic , developmental , or inflammatory in origin . the distribution of traumatic bone cyst according to diagnosis in a general population has been reported to be 1% . the other names for this lesion are solitary bone cyst , hemorrhagic bone cyst , extravasation cyst , unicameral bone cyst , simple bone cyst and idiopathic bone cyst . the term  cyst  is a misnomer because these intra - bony cavities are not lined by epithelium . they are commonly found in the metaphysis of long bones , but are rare in the jaws . traumatic bone cysts may be classified as unicameral , simple , solitary , hemorrhagic , or idiopathic . although most cases of traumatic bone cysts present in young patients , before 18 years of age , they may be detected at any age . although the posterior region of mandible is more commonly involved , the incisor region is also affected in the young as this area contains more hematopoietic marrow . the majority of posterior lesions are located in the body of mandible , between canine and third molar . clinically , they are usually asymptomatic and are often accidentally discovered on routine radiological examination . the radiographic picture is usually a unilocular radiolucent area with scalloped margins between the roots of teeth . they may be multilocular , associated with unerupted or impacted teeth , and several cysts may be present in the same patient . overlying cortical bone owing to lack of unique clinical and radiographic features , it is important to establish the differential diagnosis between traumatic bone cysts and other bone lesions of the jaws  especially translucent lesions . the definite diagnosis of traumatic cyst can only be determined at surgery . platelet concentrates for surgical use are tools of regenerative medicine designed for the local release of platelet growth factors into a surgical or wounded site . platelet - rich plasma ( prp ) is a blood derivative generated by differential centrifugation in which platelets are concentrated in a small plasma volume . autologous prp is a source for obtaining growth factors especially , platelet - derived growth factor ( pdgf ) and transforming growth factor -  ( tgf -  ) that are essential for bone regeneration . the use of prp can accelerate and enhance body 's natural wound - healing mechanisms . it has the benefit to form a biological gel that may provide containment , clot stability , and function as an adhesive . a 13-year - old boy reported to the department of pedodontics and preventive dentistry with a chief complaint of sensitivity in the lower front teeth . patient gave a history of trauma 3 years ago , following which he fractured his upper front tooth . extraorally there was a swelling in the mandibular anterior region , with intact overlying skin and obliterating the sub - mental contour . on palpation , the swelling was firm and expansion of buccal and lingual cortical bone was appreciable . the lower permanent incisors were tender on percussion and gave a positive response to vitality test . regional lymph nodes were palpable and not tender . both intraoral anterior occlusal and periapical radiographs were taken of the mandibular anterior region [ figures 1 and 2 ] . radiographic examination revealed unilocular , well defined , radiolucent areas , measuring 1.5 cm , 1 cm , and 0.5 cm , respectively . the lesions extended from the mesial root surface of mandibular left canine to the mesial surface of contralateral canine . the involved teeth did not show loss of lamina dura and there was absence of root resorption . anterior occlusal radiograph of mandibular arch showing presence of a cystic lesion intraoral periapical radiograph of mandibular anterior region clinical and radiographic findings indicated the lesion to be a solitary bone cyst . treatment planned was surgical enucleation of the cystic lesion , followed by placement of platelet rich plasma gel into the cystic cavity . under local anesthesia , a round bone cutting surgical bur was used to make an opening along the margins of the cyst . entry into the cystic cavity showed it to be completely empty [ figure 3 ] . a gentle curettage of the bony walls was done in order to induce bleeding . the thin membrane obtained from the bony cavity prior to the surgery , 10 ml of blood was drawn intravenously from the boy and collected in a sterile plastic vaccutube coated with an anticoagulant , sodium citrate . it was then centrifuged at 1300 rpm for 10 minutes , following which layers were obtained : an upper straw - colored fluid , which was platelet - poor plasma ( ppp ) ; a middle buffy coat rich in platelets and ; a lower layer rich in rbcs . the plasma , buffy coat and 1ml of rbc layer was aspirated into another sterile tube without anticoagulant . it was further centrifuged at 2400 rpm for 10 minutes , in order to separate the ppp from the prp . the upper layer of ppp was discarded and prp remained at the bottom of the tube in the form of a red button . for purpose of activation , 6 ml of calcium chloride and thrombin was added and the resultant prp gel was placed inside the bony defect [ figure 4 ] . following soft tissue closure , the patient was prescribed antibiotics and analgesic- anti - inflammatory drugs for a period of 1 week . cystic cavity after placement of plasma - rich - protein post - operative intraoral periapical radiographs were taken immediately , and at monthly intervals . resolution of the lesion was observed ) , followed by regeneration of bone in a relatively short time [ figures 5 and 6 ] . intraoral periapical view at 1 month showing resolution of cystic defect intraoral periapical view at 2 months showing regeneration of bone histological examination showed fibrous connective tissue with occasional chronic inflammatory cells , including lymphocytes , fibrin , hemosiderin , and cementum were observed . prior to the surgery , 10 ml of blood was drawn intravenously from the boy and collected in a sterile plastic vaccutube coated with an anticoagulant , sodium citrate . it was then centrifuged at 1300 rpm for 10 minutes , following which layers were obtained : an upper straw - colored fluid , which was platelet - poor plasma ( ppp ) ; a middle buffy coat rich in platelets and ; a lower layer rich in rbcs . the plasma , buffy coat and 1ml of rbc layer was aspirated into another sterile tube without anticoagulant . it was further centrifuged at 2400 rpm for 10 minutes , in order to separate the ppp from the prp . the upper layer of ppp was discarded and prp remained at the bottom of the tube in the form of a red button . for purpose of activation , 6 ml of calcium chloride and thrombin was added and the resultant prp gel was placed inside the bony defect [ figure 4 ] . following soft tissue closure , the patient was prescribed antibiotics and analgesic- anti - inflammatory drugs for a period of 1 week . cystic cavity after placement of plasma - rich - protein post - operative intraoral periapical radiographs were taken immediately , and at monthly intervals . resolution of the lesion was observed ) , followed by regeneration of bone in a relatively short time [ figures 5 and 6 ] . intraoral periapical view at 1 month showing resolution of cystic defect intraoral periapical view at 2 months showing regeneration of bone histological examination showed fibrous connective tissue with occasional chronic inflammatory cells , including lymphocytes , fibrin , hemosiderin , and cementum were observed . traumatic bone cysts are rare lesions of the jaws . in a pediatric group , with mean age of 14 years , 18% had traumatic bone cysts and the mean diameter of the lesion was 1.7 cm . a higher prevalence in young patients , absence of a history of trauma , and a small number of lesions containing serous fluid with blood reflects the need to discuss the true pathogenesis of traumatic bone cysts . the most accepted version at present is the traumatic - hemorrhagic theory , which suggests that lesions develop if intramedullary clots due to trauma do not undergo lysis or resolution . traumatic bone cysts have a preference for the posterior areas ( body and ramus ) of the mandible ; although the symphysis may also be a site . the mandible has more cortical bone , and repairs itself more slowly compared to the maxilla . this theory explains why traumatic bone cysts occur more often in young individuals , an age at which trauma occurs more often . trauma at the site of lesions and the presence of blood in the cavities are not common . this opens the possibility that micro - trauma of teeth and alveolar ridge are involved in the pathogenesis of traumatic bone cysts . newton and zunt emphasized that endodontic treatment in cases of traumatic bone cyst should be considered before , during or after the surgery . in the present case , pulp of all four mandibular permanent incisors continued to remain vital , and therefore , no endodontic treatment or extraction was done . the treatment of choice for traumatic bone cysts is surgery for curettage of the bone walls , which generally results in short - term healing and recurrence is rare . it was a one - stage surgical treatment followed by placement of prp inside the bony cavity . it has been noted that such content in the bone cavity may represent different stages in the development of traumatic bone cysts . the cavity may contain either a small amount of straw - colored fluid , shreds of necrotic blood clot , fragments of fibrous connective tissue . suei et al . evaluated whether gas was present in the cavity of simple bone cysts . results showed the absence of water / air levels in these cysts on ct examination . this indicated that the operative finding of air in the cavity of simple bone cysts may have been in error at least in some cases . presumptive diagnosis of a traumatic bone cyst was made at the time of surgery ; since the thin connective tissue membrane was scanty for histology . prp works via the degranulation of the alpha granules in platelets , which contain growth factors . the active secretion of these factors is initiated by the clotting process of blood when prp is activated by thrombin . the secreted growth factors immediately bind to their transmembrane receptors on adult mesenchymal stem cells , osteoblasts , fibroblasts , epithelial cells and then cause cellular proliferation , matrix formation , osteoid production , and collagen synthesis through cellular message transforming . prp also contain three proteins in blood known to act as cell adhesion molecules for osteoconduction and as a matrix for bone and connective tissue . prp placed along with bone graft bone appeared to enhance bone regeneration after cyst enucleation in pediatric patients . interestingly , in the present case , placement of prp gel alone resulted in considerable filling of defectwith bone within a short period . on coagulation , the prp preparation assumes a sticky consistency due to its high fibrin content . this  sticky gel  of prp acts as a haemostatic agent , and stabilizes the blood clot . the use of prp increases the vascularity in the first 20 days , with an increase of osteoblast and immature osteoid tissue formation within 3 - 6 weeks , improving the quality and quantity of newly formed bone tissue . histomorphological observations showed that 54% of patients treated with prp achieved 100% bone regeneration within 24 weeks , compared with 38% of the control group . the use of prp in young children could decrease the need for autologous bone grafts collected from extraoral sites , avoiding cutaneous incisions and reducing the extent of mucosal incisions . in the present case , prp resulted in the formation of healthy osteoid tissue within a short period , thus providing stability and support to the permanent teeth . prp could have a potential for routine use in regeneration of cystic bony defects in children . prp is an autogenous preparation , and is inherently safe and free from concerns over transmissible diseases . careful curettage and the use of prp can result in healing with faster favorable bone regeneration , and closure of bony defect .
traumatic bone cyst is an uncommon non - epithelium lined cavity and is seen frequently in young individuals . 
 the lesion occurs more commonly in the mandible , involving the posterior region . 
 it is generally asymptomatic and is diagnosed on routine radiographic examination . 
 the cystic cavity is usually empty and there is scanty material for histological examination . 
 surgical curettage is usually done and recurrence is rare . a case of traumatic bone cyst occurring in the anterior region of mandible in a young boy is presented . following surgical intervention , 
 plasma - rich - protein was placed in the cystic cavity . 
 the lesion showed progressive resolution and bone regeneration of the cystic cavity within a short period of time .