fibro - osseous lesions ( fol ) are a poorly defined group of lesions affecting the jaws and craniofacial bones .
all are characterized by the replacement of bone by cellular fibrous tissue containing foci of mineralization that vary in amount and appearance .
recent world health organization classification ( 2005 ) for fibro - osseous lesions was considered while sub - dividing these into various groups [ table 1 ] .
so proper categorization requires good correlation of the history , clinical findings , radiographic characteristics , operative findings , and histologic appearance .
the aim of this study was to analyze various clinico - pathological and radiological features in the benign fol reported and to compare the features between fibrous dysplasia ( fd ) and cemento - ossifying fibroma ( cof ) .
these patients were treated for fol , reported to the hospital between 1989 and 2009 .
the clinical parameters included were age , sex , location , duration , family history , associated symptoms , and behavior of the lesion .
the radiographic appearance , histologic features , treatment , and follow - up data were also recorded .
basic clinical parameters such as age , sex , duration of lesion , family history , history of trauma , associated symptoms , palpatory findings , status of associated / involved teeth , associated pigmentation , site of the lesion , treatment , and recurrence details were retrospectively analyzed .
regarding site distribution , the maxilla was divided into two anatomic regions as anterior ( midline to distal surface of canine ) and posterior ( mesial surface of first premolar distally ) .
the mandible was divided into four anatomic regions such as anterior ( midline to distal surface of canine ) , posterior ( mesial surface of first premolar distally ) , angle ( from distal of third molar to the inferior portion of ramus ) , and ramus ( upper portion of the ramus beyond the occlusal plane ) .
radiological features were assessed for radiolucency , radiopacity , margin of the lesion , cortical - plate expansion , involvement of antrum , displacement , and resorption of teeth .
histopathologically , parameters such as type of bone ( mature / immature ) , cellularity , presence of cementum - like material , and nature of stroma were assessed .
a total of 80 cases of benign fols were recorded over the 20 years . among these , cof ( all variants ) was the most frequent tumor found in 60 patients with 63 lesions ( 73.2% ) and fd was found in 20 patients ( 24.4% ) . in general for fol ,
the age ranged from 3 years to 65 years with a mean age of 23.3 years ; the majority of cofs and fds were seen in the second decade ( 38.3% and 65% respectively ) .
the male - female ratio for these 80 patients was 1:1 with slight female predilection ( 27 men and 33 women i.e. , 1:1.2 ) , whereas fd showed definite male predilection ( 13 men and 7 women , i.e. , 1.8:1 ) .
however , there was no significant correlation between the lesions and the sex with p > 0.05 [ figure 1 ] .
the sex distribution of 80 patients with fibro - osseous lesions most of the time , fol patients complained of a slow - growing swelling of the jaws and facial asymmetry ( 75 patients = 93.7% ) whereas in four patients ( 5% ) , it was an incidental finding ; all these four cases were later diagnosed to be cof . in one case of fd ,
a biopsy was done because of a non - healing extraction socket . in case of cof ,
the associated signs and symptoms involved pus discharge , tenderness , egg shell crackling , tender lymph nodes , ulceration of the overlying mucosa , numbness of lip and proptosis .
none of family history and past medical history data collected were contributory to our study except few which are listed below .
there were four cof patients recorded with history of extraction ( 2 patients ) , surgery for osteosarcoma ( 1 patient ) , and history of trauma ( 1 patient ) at the site of current presentation . when fol as a whole was taken , no specific jaw / side predilection was evident .
the cof showed slight mandibular predilection ( 1.37:1 ) unlike that of fd which showed definitive maxillary predilection ( 2.3:1 ) .
moreover , cof were often recorded in mandibular posterior region ( 51.2% ) , whereas at the time of presentation fd was recorded unilaterally in maxilla as a whole bone .
there were three cases of cof noted at the midline either in maxilla ( 1 patient ) or in mandible ( 2 patients ) and three other cases of cof crossed midline with an extensive presentation in the mandible .
the most posterior presentation of cof was noted in two of our cases in the ramus and angle of the mandible [ table 1 ]
. extensive involvement of facial bones like ethmoidal and frontal bone was seen in fd ( 2 patients ) , in four cases of cof { juvenile ossifying fibroma ( jof ) variant } , and in two patients with aggressive form of ossifying fibroma ( of ) ( which can not be classified as jof ) .
when the data was subjected for chi - square test , significant association was found between the fol and the site ( maxilla and mandible ) with p < 0.05 [ figure 2 ] .
the site distribution of 80 patients with fibro - osseous lesions mobility of teeth was seen in 13 patients which included 11 cases of cof and two cases of fds . in one case of cof ,
the lesion was associated with displacement of teeth , whereas one cof showed impacted tooth .
radiographically , 23 ( 38.3% ) cofs showed mixed opaque and lucent areas , 19 ( 31.6% ) cases showed only radiolucent areas and 18 ( 30% ) cases showed only radiopacity . among these ,
55 ( 91.6% ) had a well - defined border whereas 5 ( 8.3% ) cases were having diffuse outline .
a total of eight cofs , showed involvement of antrum , displacement and resorption of the teeth . among fds
, most of them showed mixed opaque and lucent areas ( 75% ) , diffuse borders ( 60% ) with only four cases ( 20% ) showing expansion of cortical plates , and five cases showing expansion of antrum .
only one case showed resorption of the associated teeth . in case of cof , on 34 ( 56% )
occasions it was provisionally diagnosed as cof and fd was considered in four cases . among 20 fds , 15 ( 75% ) times fd was considered as a provisional diagnosis and only in two occasions , it was thought in terms of cof .
other provisional diagnosis considered were adenomatoid odontogenic tumor , ameloblastoma , aneurysmal bone cyst , odontoma , calcifying epithelial odontogenic tumor , odontogenic myxoma , central giant cell granuloma , and odontogenic keratocyst for cof and osteoma for fd .
the cof on the post - operative histologic findings was seen as a well - demarcated lesion that was separated from the overlying cortical bone by a thin zone of fibrous tissue .
the stroma was fibro - cellular ( 42 cases ) and fibrous ( 18 cases ) with irregular thin trabeculae of woven bone ( 43 patients ) or lamellar bone ( 11 patients ) rimmed by osteoblasts .
basophilic , ovoid , cementum - like material was evident in 21 cofs : among these four were considered as jof  psammamatoid type . other features evident with regular histopathology
were the presence of giant cells ( 5 cof ) , myxoid areas ( 1 jof ) , and endothelial proliferation ( 1 cof ) .
fd showed merging of lesional bone with the normal along with highly fibrous stroma ( 8 cases ) consisting of immature trabeculae of woven bone ( 18 lesions ) giving a 
comparison of histopathological features between cemento - ossifying fibroma and fibrous dysplasia the treatment procedures rendered in these cases has been summarized in the table 3 .
eight patients of cof showed recurrences within a period ranging from 2 months to 4 years .
one case of jof showed three recurrences every year . among three patients with fds , two patients had recurrences after 2 and 4 years respectively , with last one showing multiple ( 3 times ) recurrences almost after 3 years each time .
a total of 80 cases of benign fols were recorded over the 20 years . among these , cof ( all variants ) was the most frequent tumor found in 60 patients with 63 lesions ( 73.2% ) and fd was found in 20 patients ( 24.4% ) . in general for fol ,
the age ranged from 3 years to 65 years with a mean age of 23.3 years ; the majority of cofs and fds were seen in the second decade ( 38.3% and 65% respectively ) .
the male - female ratio for these 80 patients was 1:1 with slight female predilection ( 27 men and 33 women i.e. , 1:1.2 ) , whereas fd showed definite male predilection ( 13 men and 7 women , i.e. , 1.8:1 ) .
however , there was no significant correlation between the lesions and the sex with p > 0.05 [ figure 1 ] .
the sex distribution of 80 patients with fibro - osseous lesions most of the time , fol patients complained of a slow - growing swelling of the jaws and facial asymmetry ( 75 patients = 93.7% ) whereas in four patients ( 5% ) , it was an incidental finding ; all these four cases were later diagnosed to be cof . in one case of fd ,
a biopsy was done because of a non - healing extraction socket . in case of cof ,
the associated signs and symptoms involved pus discharge , tenderness , egg shell crackling , tender lymph nodes , ulceration of the overlying mucosa , numbness of lip and proptosis .
none of family history and past medical history data collected were contributory to our study except few which are listed below .
there were four cof patients recorded with history of extraction ( 2 patients ) , surgery for osteosarcoma ( 1 patient ) , and history of trauma ( 1 patient ) at the site of current presentation . when fol as a whole was taken , no specific jaw / side predilection was evident .
the cof showed slight mandibular predilection ( 1.37:1 ) unlike that of fd which showed definitive maxillary predilection ( 2.3:1 ) .
moreover , cof were often recorded in mandibular posterior region ( 51.2% ) , whereas at the time of presentation fd was recorded unilaterally in maxilla as a whole bone .
there were three cases of cof noted at the midline either in maxilla ( 1 patient ) or in mandible ( 2 patients ) and three other cases of cof crossed midline with an extensive presentation in the mandible .
the most posterior presentation of cof was noted in two of our cases in the ramus and angle of the mandible [ table 1 ]
. extensive involvement of facial bones like ethmoidal and frontal bone was seen in fd ( 2 patients ) , in four cases of cof { juvenile ossifying fibroma ( jof ) variant } , and in two patients with aggressive form of ossifying fibroma ( of ) ( which can not be classified as jof ) .
when the data was subjected for chi - square test , significant association was found between the fol and the site ( maxilla and mandible ) with p < 0.05 [ figure 2 ] .
the site distribution of 80 patients with fibro - osseous lesions mobility of teeth was seen in 13 patients which included 11 cases of cof and two cases of fds . in one case of cof ,
the lesion was associated with displacement of teeth , whereas one cof showed impacted tooth .
radiographically , 23 ( 38.3% ) cofs showed mixed opaque and lucent areas , 19 ( 31.6% ) cases showed only radiolucent areas and 18 ( 30% ) cases showed only radiopacity . among these ,
55 ( 91.6% ) had a well - defined border whereas 5 ( 8.3% ) cases were having diffuse outline .
a total of eight cofs , showed involvement of antrum , displacement and resorption of the teeth . among fds
, most of them showed mixed opaque and lucent areas ( 75% ) , diffuse borders ( 60% ) with only four cases ( 20% ) showing expansion of cortical plates , and five cases showing expansion of antrum .
in case of cof , on 34 ( 56% ) occasions it was provisionally diagnosed as cof and fd was considered in four cases . among 20 fds , 15 ( 75% ) times fd was considered as a provisional diagnosis and only in two occasions , it was thought in terms of cof .
other provisional diagnosis considered were adenomatoid odontogenic tumor , ameloblastoma , aneurysmal bone cyst , odontoma , calcifying epithelial odontogenic tumor , odontogenic myxoma , central giant cell granuloma , and odontogenic keratocyst for cof and osteoma for fd .
the cof on the post - operative histologic findings was seen as a well - demarcated lesion that was separated from the overlying cortical bone by a thin zone of fibrous tissue .
the stroma was fibro - cellular ( 42 cases ) and fibrous ( 18 cases ) with irregular thin trabeculae of woven bone ( 43 patients ) or lamellar bone ( 11 patients ) rimmed by osteoblasts .
basophilic , ovoid , cementum - like material was evident in 21 cofs : among these four were considered as jof  psammamatoid type .
other features evident with regular histopathology were the presence of giant cells ( 5 cof ) , myxoid areas ( 1 jof ) , and endothelial proliferation ( 1 cof ) .
fd showed merging of lesional bone with the normal along with highly fibrous stroma ( 8 cases ) consisting of immature trabeculae of woven bone ( 18 lesions ) giving a  chinese letter 
eight patients of cof showed recurrences within a period ranging from 2 months to 4 years .
one case of jof showed three recurrences every year . among three patients with fds , two patients had recurrences after 2 and 4 years respectively , with last one showing multiple ( 3 times ) recurrences almost after 3 years each time .
the fol of the jaws comprise a diverse , interesting , and challenging group of conditions that pose difficulties in classification and treatment .
common to all is the replacement of normal bone by a tissue composed of collagen fibers and fibroblasts that contain varying amounts of mineralized substance , which may be bony or cementum - like in appearance .
langdon et al . , suggested that certain fols of the jaw may represent different stages in the evolution of a single disease process .
although the first case report of fibro - osseous lesion was reported 60 years ago , there are only few retrospective studies regarding their clinic - pathological correlation . among them , the four important studies were carried out by alsharif et al . , on chinese population , ogunsalu et al . , on jamican population , langdon et al .
comparison of clinical parameters with previous studies however , although fol are one of the common lesions occurring in india , such a retrospective study is not reported in the english language literature .
we also tried to compare the features between cofs and fds , which are the only two groups of entities reported in this region .
aggressive variants seen in young adults are called as jof ( who 1992 ) . according to recent who classification of fols ,
of is a well - demarcated lesion composed of fibrocellular tissue and mineralized material of varying appearances .
juvenile trabecular of and juvenile psammamatoid of are two histologic variants of of . due to the presence of cementum - like material of have been called as cementifying fibroma ( cf ) or cof if they have both cementum and bone - like material .
previous studies considered cementoid lesions as separate groups which included cemento - osseous dysplasia , gigantiform cementoma , and cementoblastoma .
however , alsharif et al . , has considered cof as cementoid lesions containing cementum - like material , since he has considered of as a separate entity . however , in 1992 the who grouped such lesions under the common denomination of cof on the grounds that they represented histologic variants of the same type of lesion . in this study , of and
cof are combined and no cementoid lesions were reported till today to our hospital . in our data ,
24 cases were diagnosed as of , 21 as cof , 11 as cf , and 4 as jof .
however , we considered all 60 cases as a single entity ( cof ) in contrast to the study on chinese population where cof and of are assessed separately .
none of these cases showed any familial history as we know there are two case reports of familial cof .
the term fd was given by lichtenstein in 1938 , which was earlier described as osteitis fibrosa disseminate .
it is a genetically based sporadic disease of bone that may affect single or multiple bones ( monostotic or polyostotic ) or if it is occurring in multiple adjacent craniofacial bones , it is regarded as craniofacial fd .
fd may be part of jaffe - lichenstein 's , macunae albright 's , or mazabraud 's syndrome . in over 80% of cases
it is monostotic , whereas all 20 cases in our data showed a solitary lesion in the jaws , although few of maxillary lesions extending up to infra - orbital margin affect vision .
, was 27 years and 34 years , contrasting to what we got as 21 years for the present study .
early lesions may be radiolucent , but they become increasingly radiopaque and typically show a diffuse radiopacity or  ground glass appearance  . in the present study , 75% of the lesions showed mixed opacity and lucency , whereas two cases were completely radiolucent and three cases with complete radiopaque picture .
the key histologic features of fd are delicate trabeculae of immature bone with no osteoblastic rimming , enmeshed within a fibrous stroma giving a 
mature bone was seen in one of our case and osteoblastic rimming was evident in few areas of five cases and stroma was mostly fibrocellular , although few showed a completely fibrous or vascular background . compared with previous studies,[468 ] both cof and fd were predominantly seen in younger population ( 25.5 years and 21 years respectively ) .
however , in our data , there was a definite male predilection ( 1.8:1 ) for fd which was contrasting to the previous studies.[468 ] when compared with fd , many of cof presented with associated symptoms like pus discharge , egg shell crackling , tenderness , ulceration of the overlying mucosa , numbness of lip , and proptosis which is unusual for these groups of lesions ( this involvement was seen in four patients diagnosed as jof ) .
other than jof , there are no previous reports of conventional cof showing highly aggressive behavior . only few fds presented with aggressive symptoms .
the involvement of other facial bones ( frontal , ethmoidal , antrum ) was a frequent finding in cof when compared with fd .
both cof and fd showed multiple recurrences . since few of our cof cases showed history of trauma and association with osteosarcoma , a careful detailing of these in the history
is emphasized although its correlation with the occurrence of the lesion can not be established through this study . as aggressive behavior and recurrence
was a frequent finding in few patients with cof , a long follow - up was advised .
juvenile ossifying fibroma was of predominantly psammamatoid type and finally , not a single cementoid lesion was reported for last 20 years .
 background : fibro - osseous lesions ( fols ) are one of the commonest entities reported in the head and neck region . 
 however , studies on these groups of lesions on indian population were not carried out before . 
 so this motivated us to analyze the clinico - pathologic correlation of fibro - osseous lesions reported at our hospital.materials and methods : a retrospective review was made of all the lesions surgically treated in our hospital . 
 a total of 6,175 biopsies were performed during the study period . 
 all the cases which were histopathologically diagnosed as fols were included in the study . 
 the demographic data , radiographic features , and histopathologic findings were analyzed and compared with similar studies on other races.results and conclusion : we could find 80 cases diagnosed as fibro - osseous lesions and information about them was documented . 
 the most common fol reported in the region was cemento - ossifying fibroma ( cof ) ( 75% ) than fibrous dysplasia ( fd ) ( 25% ) . 
 these were commonly occurring in 2nd decade without any sex or site predilection . 
 however , cof was showing a slight female predominance and fd with a definite male predominance . 
 cof was commonly seen in mandible ( posterior region ) whereas fd mainly confined to the maxilla ( as a whole bone ) . 
 radiographically , most of cof showed well - defined mixed opaque and lucent areas whereas fd showed diffuse borders . 
 cortical plate expansion and resorption of associated teeth was a frequent finding in cof when compared with fd . 
 histopathologically , stroma was fibrocellular in many cases of cof , whereas most fds showed fibrous stroma , interspersed with mainly woven bone . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
Clinical findings
Radiological findings
Provisional diagnosis
Pathologic findings
Treatment and recurrence
DISCUSSION
CONCLUSION