Fibro osseous lesions of jaws/ dental implant courses by Indian dental academy by indiandentalacademy

GITAM DENTAL COLLEGE & HOSPITAL

DEPARTMENT OF ORAL & MAXILLOFACIAL SURGERY

SEMINAR ON FIBRO-OSSEOUS LESIONS OF THE JAWS & ITS SURGICAL MANAGEMENT

Presented By: Dr. Sambhav K Vora II MDS

CONTENTS Introduction  Classification  Fibrous dysplasia  Cemento-osseous dysplasia  Periapical cemento-osseous dysplasia  Focal cemento-osseous dysplasia  Florid cemento-osseous dysplasia  Familial gigantiform cementoma  Ossifying fibroma  Juvenile ossifying fibroma  Osteoblastoma & osteoid osteoma  Cementoblastoma  Differential diagnosis  Controversies  Conclusion  References

FIBRO-OSSEOUS LESIONS OF THE JAWS

INTRODUCTION:. The term FibroOsseous lesions (FOL) has been used for many years as a general description for a group of tumors and proliferative disorders, which affect the jaws .They comprise a number of specific clinical entities in which clinical, radiological and histological features often overlap causing confusion to both pathologist and clinicians in diagnosis and therapy A bewildering variety of names have been given to lesions within the FOL group. These include fibrous dysplasia, osteitis fibrosa cystica, fibrous osteoma, osseous dysplasia, osteofibrosis, periapical cementoma, and osteoid osteoma. This multiplicity of names, frequently applied to the same pathological condition has created confusion with regard to diagnostic criteria and misunderstanding of individual biological behavior. Fibro osseous lesions (FOL) refer to a diverse process in which the normal bone architecture is replaced by fibroblast and collagen fibers containing variable amounts of mineralized material1. Fibro osseous lesions of the jaws as a generic term used to describe a number of apparently different pathologic entities that commonly affect the maxilla, mandible and other facial bones1. FOL is a generic designation given to a group of disorders (ranging from inflammatory to neoplastic) that microscopically exhibit, a connective tissue matrix and islands / trabeculae of bone. Although the histological appearance and frequently the clinical and radiological features may be similar for many of these lesions, they demonstrate a wide range of biological behaviour1.

The characteristics used to separate the clinical entities are the symptoms and the radiographic appearance, both of which are extremely varied. Lesions vary from small, localized, asymptomatic areas discovered on radiographs to welldefined lesions that cause expansion of the single bone to a functionally disturbing or cosmetically deforming enlargement of one or many bones. The radiographic appearance varies from a large, diffuse, dense ground glass pattern with indistinct boundaries, to localized cyst like radiolucent lesion to welldefined solitary or multiple radiolucencies with varying foci of radiopaque areas 1

This presentation is aimed at reviewing the current knowledge and literature of clinical, radiological, histological features, differential diagnosis, treatment of fibro-osseous lesions and controversies related to varios lesions and its management.. CLASSIFICATION FIBRO OSSEOUS LESIONS OF JAWS I.

Fibrous Dysplasia

II.

Cemento-Osseous Dysplasia. a) Focal Cemento osseous Dysplasia b) Periapical Cemento osseous Dysplasia c) Florid Cemento osseous Dysplasia

III.

Familial Gigantiform Cementoma

IV.

Ossifying fibroma.

Juvenile ossifying fibroma

III.

Miscellaneous

Osteoblastoma,OsteoidOsteoma.Cementoblastoma,

Charles Waldronâ&#x20AC;&#x2122;s classification: I.

Fibrous Dysplasia

Monostotic Polyostotic

II. Fibro Osseous (Cemental) lesions presumbly arising in periodontal ligament.

Periapical Cemental Dysplasia Localised Fibro Osseous Cemental Lesions (Probably reactive in

nature)

Florid Cemento osseous Dysplasia (Gigantiform Cementoma) Ossifying fibroma and cementifying fibroma.

III.

Fibro- Osseous Neoplasm of Uncertain or Debatable Relationship to

those arising in the periodontal ligament.

Cementoblastoma, Osteoblastoma, Osteoid Osteoma. Juvenile

active

ossifying

fibroma

and

aggressive

active

cementifying/ossifyingfibromas

Brannon and Fowler classification9

1.Fibrous dysplasia A. Monostotic B. Craniofacial C. Polyostotic D. McCune-Albright syndrome 2. Ossifying fibroma and juvenile ossifying fibroma 3. Osseous dysplasia A. Periapical B. Focal C. Florid D. Familial gigantiform cementoma

CLASSIFICATION OF RADIOLOGICAL PATTERNS OF THE FIBROOSSEOUS LESIONS OF THE JAWS3

Divided into 3 groups-

i. Tumour ii. Dysplasia iii. Inflammation

These 3 groups were again divided into 5 types based on their radiographic patterns-

A. Focal B. Target C. Radiolucent D. Calcification E. Multiconfluent

The importance of radiology to the diagnosis of FOL: Maxillofacial FOLs are of particular interest to the radiologist because they emphasize the central role of the radiologist in the diagnostic process. This role arises because the pathology for all FOLs is identical, although they range widely in behaviour, from dysplasia, hamatoma to benign neoplasia with occasional recurrence. The late Charles Waldron wrote “In absence of good clinical and radiologic information a pathologist can only state that a given biopsy is consistent with a FOL. With adequate clinical and radiologic information most lesions can be assigned with reasonable certainty into one of several categories” Conversely in the absence of such information Eisenberg and Eisenbud stated that “pathologists today will often rightly decline to render a definitive diagnosis, Instead, the pathologist will resort to the noncommittal designation of benign fibro-osseous lesions [their italics]. This is the only acceptable approach considering the potential for inappropriate treatment otherwise.” Therefore the identification of the majority of FOLs is made upon clinical and radiological features Radiological assessment of the anatomical location of a bone tumour, its shape and size, the pattern of its matrix and its destruction, the definition of its margins and concomitant softtissue abnormalities generally correlate with its behaviour (aggressive or benign). “Periosteal reaction” an important feature considered by skeletal radiologists “is not a feature of benign fibro-osseous lesions”. Many FOLs, particularly COD, are symptomless and require no surgery. Therefore diagnosis of the lesions on clinical and radiological features alone may obviate the need for an otherwise unnecessary invasive procedure. This avoidance of surgery could benefit the patient, because exaggerated growth of FD may be stimulated by surgery in young patients.7 8

Radiological evaluation can be carried out with plain radiography ( P.A view, lateral view, oblique view or waters projection), OPG, Intra oral periapical radiograp and Occlusal radiograph. Bitewing radiograph can be useful only in visualization of supracrestal bone formation, which if present is suggestive of malignancy such as osteosarcoma or chondrosarcoma. C. T scans are also excellent for demonstrating many subtle lesions especially for the evaluation of expansile and destructive processes and also for the visualization of cortical breakthrough and extraosseous extensions. I.V contrast administration enhances the soft tissues. Dentascans can also be useful in diagnosing fibro-osseous lesions. M.R.I can be useful in differentiating solid from non-solid masses, for exfibrous dysplasia complicated by the presence of Aneurysmal bone cyst. C.T scan has advantage over MRI In its ability to show the matrix of lesion and whether it contains fibrous, cartilaginous or calcified tissues. Such information is helpful in the formulation of clinical differential diagnosis.

FIBROUS DYSPLASIA: W.H.O (1992), defined Fibrous dysplasia (FD) as a benign lesion, presumably developmental in nature, characterized by a presence of fibrous connective tissue with a characteristic whorled pattern and containing trabeculae of immature bone. It is a condition in which normal medullary bone is gradually replaced by an abnormal fibrous tissue proliferation. The mesenchymal tissue contains variable amounts of an osseous matrix that presumably arises through metaplasia and consists of only woven bone. THIS DISEASE PRODUCES SOLITARY or multifocal lesions in which there is arrest of bone development in the woven 9

bone stage with failure to lamellar bone. The resultant fibro osseous tissue is poorly formed and structurally in adequate. The precise etiology remains unknown, although various theories have been proposed. Many authorities accept the premise that fibrous dysplasia represents a non neoplastic hamartomatous growth resulting from altered mesenchymal cell activity or defect in the control of cell activity. Marx and Stern (2003) stated that although the clinical development of FD becomes apparent between 5 to 15 years of age , it begins in the embryo with the spontaneous gene mutation or deletion of an intra cytoplasmic transducer protein responsible for bone maturation .all the daughter cells of the original aberrant cell will produce immature bone, therefore the earlier this occurs in embryonic development, the more the widespread will be the FD.

CLINICAL FORMS OF FIBROUS DYSPLASIA /TYPES Philip et al (1997) – classified FD in to MONOSTOTIC and POLYOSTOTIC types, where Monstotic type of FD is further divided in to three subtypes: • Juvenile • Juvenile, aggressive • Adult Philip et al(1997) Polyostotic type of FD is divided in to three subtypes: • Craniofacial FD – in which only the bones of craniofacial complex are affected including the mandible and maxilla.

• Lichlenstein and jaffe type of FD – in which bones of the skeleton with café au lait pigmentation. • Albright syndrome type of FD- has a traid of severe polyostotic FD, café au lait pigmentation and various endocrinopathies.

MONOSTOTIC FIBROUS DYSPLASIA Monostotic fibrous dysplasia (MFD) is a type of Fibrous Dysplasia, which involves only one bone.MFD is the most common type of regional deformity. Waldron et al 8 (1992) classified Monostotic type of FD in to three subtypes: • Juvenile • Juvenile, aggressive • Adult JUVENILE FIBROUS DYSPLASIA Philip (1997) In the head and neck area, monostotic juvenile fibrous dysplasia is the most common type of regional deformity. It is slow growing regional distortion that enlarges proportionately with the affected bone. The regional over growth continuous until general body growth ceases in the late teens or early twenties. An uncommon form known as aggressive juvenile fibrous dysplasia grows at an ever faster rate producing major, often grotesque deformity that results in loss of function of the affected bone Clinical Features: Seen in 1st and 2nd decades of life Has equal sex predilection

Maxilla is effected more than mandible. Wood N.K and Goaz P.W (1975) stated that the expansion is smooth and covered with normal appearing mucosa or skin. Ulceration overlying the bony enlargement is uncommon but may be seen when the mass disrupts the occlusion or is traumatized during eating. The first sign of disease is a gradually increasing painless swelling, which is not well circumscribed and causes a gradually increasing facial asymmetry. The enlargement is usually smooth, often fusiform in outline and is more pronounced buccaly than lingually or palatally. When maxilla is involved there is usually increased prominence of the cheek and buccal expansion distal to canine, which may extend to involve the tuberosity. Maxillary lesions commonly extend locally to involve the sinus, Zygomatic process, floor of orbit and orbital contents are displaced in some cases. Where the growth is rapid and extensive there may be marked swelling of the cheek with exopthalmus and proptosis. Mandibular lesions occur most frequently in the molar and premolar regions and if the lower border is involved there may be an obvious protuberance and increased depth of the jaws. Radiological features: It varies with the stage of maturity of the lesion, in early stages the lesion may be radiolucent becoming radiopaque as more bone is formed. The mature lesion retains none of the normal architecture of trabecular bone, having replaced it with abnormal bone that produces a “ground glass” or “orange peel” pattern on radiographs. There is no line of demarcation because the lesion blends with surrounding bone. Expansion of the cortical plates and displacement of tooth roots is common. The laminadura is usually obscured and cortical plates are thinned. 12

Treatment: Treatment is pursued only when lesions are cosmetically unacceptable or interfere with sight, mastication and speech, most lesions of the normal form of juvenile fibrous Dysplasia do not require treatment until the patient has reached adulthood. Lesions should not be treated by radiotherapy in an attempt to halt growth because of the risk malignancy in later life.

ADULT FIBROUS DYSPLASIA: It is a rare form that occurs spontaneously in adults. It resembles ossifying fibroma in many ways and must be separated from it because the treatment is very difficult. Clinical features: Are similar to mature juvenile FD. The affected area presents as an asymptomatic diffuse expansion of the cortices. Some movement of teeth with in the area may occur. Radiological features: Philip (1997) less homogenous than juvenile FD, exhibits a mixed radiolucent and radiopaque “cotton – ball” pattern. As with other forms of disease, individual lesions blend with the surrounding bone .expansion and thinning of the cortical plates is usually evident. . Treatment: Philip (1997) treatment aspect is different from juvenile FD because it is not self-limiting. In adults, attempts are made to completely remove

smaller lesions and halt the progression of larger ones with continuous conservative treatment.

POLYOSTOTIC FIBROUS DYSPLASIA

Philip (1997) polyostotic type of FD is divided in to three subtypes: • Craniofacial FD – in which only the bones of craniofacial complex are affected including the mandible and maxilla. • Lichlenstein and jaffe type of FD – in which multiple bones of the skeleton with café au lait pigmentation. • Albright syndrome type of FD – has a traid of severe polyostotic FD, café au lait pigmentation and various endocrinopathies.

Clinical featuresSeen in patients under 40 yrs of age Females are commomly affected than males Maxilla is commonly affected than mandible. In the jaws, pain or fracture is rarely present. The most common complaint is swelling, often toward the buccal side. On examination, the tissue overlying the swelling is of normal color. The teeth usually are not mobile, although in severe cases may be displaced. With involvement of maxilla, the nose may be appear displaced and may have nasal obstruction and exophthalmia. In most severe cases of craniofacial involvement, the patients face may appear significantly

asymmetric. The serum laboratory values in FD are usually within normal limits Radiographic features: Radiographic appearance of Fibrous Dysplasia is variable, ranging from a RADIOLUCENT lesion to a densely radio opaque lesion.

The classic

presentation has been described as a homogenous radioopacity with the numerous trabecular of woven bone imparting “GROUND GLASS” appearance. A 2nd possible pattern is a radiolucent lesion with patchy, irregular opacities resulting in a mottled radiographic appearance similar in Pagets disease. An important distinguishing feature of Fibrous Dysplasia is POORLY DEFINED clinical & radiographic margins of the lesion. FD commonly displays an abnormal opacification, which ranges from the very numerous, small and diffusely distributed opacities [“groundglass” and “peau d’orange” to sclerosis , classically described as “cotton–wool”. Different patterns may not only be present in different parts of the same lesion, but may also depend on whether the film used is “direct exposure” or “fluorescent screen film”.7 The expansion of FD of the mandible is classically spindle (or fusiform)-shaped when viewed on a true (axial) occlusal film) or on a posterioanterior projection of the mandible. Differential diagnosisOssifying fibroma: FD is well established at the age of 20 years but ossifying fibroma is seen at an older age. Radiographically OF are well demarcated, spherical or egg shaped, heterogeneous from the normal bone, also shows expanded or thinned residual uninvolved cortex and displacement of the inferior alveolar canal, whereas FD are not 15

demarcated, fusifiorm in shape an homogenous. The radiographs and scans support the concept advanced by Worth that OF is a disease with in the bone while FD is a disease of the bone . Chronic sclerosing osteomyelitis :resembles FD in its diffuse and poorly demarcated radiographic appearance. It too may occur in teenagers and preteens, but it is more in adults. However, unlike FD, Chronic sclerosing osteomyelitis is usually severely and constantly painful: there is frequently a history of an abscessed tooth, or some other infection and appro[priate cultures may yield actinomyces and eikenella corrodens Pagets disease :can be distinguished by its onset on individuals older than 40 years and its incrases alkaline phosphate levels. Osteosarcoma: may be difficult to distinguish from FD radiographically. In general osteosarcomas do not remodel but resorb the cortex and expand outward from the destroyed cortex.

TREATMENT and PROGNOSIS: Once a jaw lesion is determined to represent fibrous dysplasia, the extent of skeletal involvement should be investigated lesions of F.D. characteristically exhibit a period of slowly progressive, persistent growth stabilization or considerable showing of growth after the onset of puberty often follows. Lesions that result in functional or cosmetic disability may be treated by osseous recontouring via a transoral approach. This procedure is generally initiated following the active growth stage and during the period of stabilization of disease process. For large lesions involving the midface Weber- Fergussion approach is good alternative for surgical recontouring procedures. 16

The incidence of Malignant transformation of existing F.D. is regarded as rare < 1%.

Some investigators have suggested that the change of developing a

malignancy is greater in pts. With polyostotic form of the disease, some Patients who have developed malignancy had received Radiation therapy, suggesting that radiation had a sole in the transformation process. Rapid enlargement of a lesion or onset of pain suggests the possibility of malignant degeneration. Most SARCOMAS arising in Pre existing lesions of F.D. are high grade lesions with Poor Prognosis.

These have included Osteosarcomas, fibrosarcomas,

chondrosarcomas, malignant fibrous histiocytomas

CEMENTO â&#x20AC;&#x201C; OSSEIOUS DYSPLASIAS: These disease process defined by specific clinical and pathologic features have been classified as

CEMENTO OSSEOUS DYSSLASIAS: -

Periapical cement osseous dysplasia

Focal cemento osseous dysplasia.

Florid cement osseous Dysplasia.

The precise etiology of these lesions is not known. Most investigators suggest that the C.O.D are the result of disorders in the metabolism of cells normally involved in the production of bone and cementum matrices.

The aberrant 17

activity of these tissues may be the result of an unusual response to undefined local factors.

PERIAPICAL CEMENTO OSSEOUS DYSPLASIA: This peculiar condition characteristically involves the periapical bone at the apices of teeth with vital, noninflammed pulps. The process involves multiple teeth, usually the mandibular anterior teeth. Periapical cemental dysplasia most commonly affects middle aged black women. Clinical features: Age:

Most patients are between 30-50 years.

Site and Location:

Mandible is the commonly affected site and anterior

mandible is the frequently affected location. Waldron9 (1993) lesions are mostly asymptomatic, discovered when radiographs are taken for other purposes. Solitary lesions may occur, but multiple foci are present most frequently Teeth associated with the lesions are almost invariably vital and seldom have restorations, Bone expansion is absent and pain is not a feature. Teeth are vital, a feature, which distinguishes this condition from apical, cystic and inflammatory process. Radiological feature: The lesions are usually detected incidentally on routine radiographic examinations, as the disease is almost invariably asymptomatic

Lesions of this type typically have three distinct stages of development. (1) Osteolytic (2) Cementoblastic (3) Mature

Osteolytic stage: The osteolytic stage is characterized by a circular area of rarefaction at the apex of the vital tooth. The lamina dura is usually absent in the apical region of the adjacent tooth. The radiolucent area is well demarcated from the surrounding alveolar bone and a sclerotic ring may be present,which is thicker ,more irregular,and more diffuse than the margin of a cystic lesion. The average lesion is approximately 0.5 to 1cm in diameter during this stage in rare instances,the lesion may be larger than 1cm, in which case it is most likely that multiple teeth will be involved. The lesion is usually round when it is smaller than 1cm;it spreads laterally when it enlarges,eventually losing its circular configuration. Cementoblastic stage: The cementoblastic stage is characterized by the appearance of a radiodense cemental mass towards the centre of the lesion. Initially, a single mass which develops may be very faint. The radiolucent component remains prominent. An outer rim of sclerotic bone may be present,especially if active lysis of host bone is in progress. The radiolucent zone between the central mass of sclerotic rim is divided into three radiologically distinct bands. The outer band is the region in which calcific spherules of cementum-like material are formed. In the intermediate band, one can see individual calcific spherules coalescing with each other form calcific massules. In the inner band, Which is adjacent to the central mass, invidual massules are seen that coalesce with the central mass. 19

Mature Stage: In the mature stage a single central mass develops. In some instances the mass develops from the apex of the involved tooth, causing it to have a crescent shape. The periphery of the mass tends to have a smooth surface, although it may be irregular or even lobulated as a result of coalesced massules. During periods of dormancy, the cemental mass is in direct apposition with the adjacent bone and may be mistaken easily for idiopathic osteosclerosis. During active periods, an outer radiolucent fibrocemento osseous band and radiopaque margin of reactive bone reappear. The radiolucent band is usually millimeters wide; however, it may be as thin as a normal periodontal ligament space or as wide as 0.5 cm. in some instances, especially on panoramic radiographs, the lingual aspect of the radiolucent outer rim may appear to extend up on to the root of a tooth; however, this may represent a projection artifact. The cemental mass may grow on either side of the root, but it usually does not attach to the root apex. The outer rim of sclerotic bone is a variable feature.

Histopathology: These lesions are usually diagnosed on clinical and radiographic features. When biopsied, they usually consist of multiple fragments of moderately cellular, collagenous tissue investing variable amounts of bone and cementum matrix.

The relative amount and degree of mineralization of the matrix

components are variable, largely dependent on the length of time the lesions have been present and therefore the stage of prognosis. The calcified tissue is associated with osteoblasts and cementoblasts along the surface and is deposited in variety of configurations, including trabecular, spherules or relatively irregular masses. 20

Treatment and Prognosis: Requires no definitive treatment following diagnosis only periodic observation is necessary during which time one would expect to see the radiographic changes association with maturation of the lesions.

FOCAL CEMENTO â&#x20AC;&#x201C; OSSEOUS DYSPLASIA: It is a recently described entity that is thought to fall between P.C.D. and florid osseous dysplasia in the biologic spectrum of C.O.D. Clinical features: (1) Most common in females and a higher incidence in whites. (2) Lesions are typically solitary involving the bone in POSTERIOR MANDIBLE. (3) Characteristically asymptomatic and frequently discovered during routine radiographic examination. (4) Most lesions are MIXED radiolucent â&#x20AC;&#x201C; radio opaque areas, although the radiographic appearance may very from well defined radiolucent lesion to a densely radio opaque area. (5) Most of lesions < 1.5 cm in size (6) Many cases involve bone adjacent to the roots of asymptomatic vital teeth. (7)

Some cases of F.C.O.D. have been associated with development of

idiopathic bone cavities.

Histopathology: 21

(1) Characteristic feature of F.O.D. is consistency of tissue removed during biopsy. The tissue is often difficult to correct from the lesion and is removed as multiple fragments of gritty tissue this feature is especially helpful in distinction of Ossifying fibroma which can be removed / separated easily from adjacent normal bone. (2) These fragments are associated with surgical hemorrhage. (3) Soft tissue consists of cellular proliferation of fusiform, spindled cells in a collagenous stroma. (4) Small blood vessels observed. (5) Connective tissue consists of small, irregular trabecular of woven bone and globular deposits of cementum like matrix. Treatment and Prognosis: As lesions exhibits only limited potential for progressive growth, most lesions require no additional treatment.

FLORID CEMENTO OSSEOUS DYSPLASIA: This disease process represents the most clinically extreme end of the spectrum of disorders classified as cemento â&#x20AC;&#x201C; osseous dysplasias. Clinicalfeatures: Most patients who develop F.O.D. are adult, black women. The disease process characteristically alters he normal bone pattern in a generalized, bilateral faction. FOD typically produces mottled, mixed radiolucent radioopaque lesions adjacent to the teeth through out the affected portions of the jaws. As the 22

lesions mature over time, they may consist predominantly of irregular, diffuse, sclerotic masses. Uncomplicated lesions of FOD may produce mild cortical expansion but are otherwise complicated.

However, the altered bone is

susceptible to the development of Osteomyelitis following traumatic episodes such as extractions or biopsies or from mucosal ulcerations such as those resulting from ill fitting removable prosthesis. Treatment and Prognosis: It is a non-neoplastic, self limited process that requires no treatment following diagnosis. In fact, owing to the significant alterations in the affected bone any form of trauma, including a biopsy procedure is best avoided.

FAMILIAL GIGANTIFORM CEMENTOMA: • This is a disorder of jaw bones that ultimately leads to the formation of massive sclerotic masses of disorganized mineralized material. • In the past it was a synonym for florid COD. • It is an uncommon hereditary disorder that demonstrates high penetrance & variable expressivity. • It is different from conventional cemento osseous dysplasia.

Clinical features 23

• Commonly seen in caucasians and african blacks, no sex predilection. • The osseous pathosis appears to be limited to the jaws but multifocal involving both maxilla and mandible. • Rapid and expansile growth pattern of jaws in adolescence results in facial deformity, impaction, malposition, and malocclusion of the involved dentition. • Anemia, multifocal polypoidal adenomas of the uterus may be present – gynocologic consultation is required. • The osseous enlargement ceases during fifth decade.

Radiographic features • Resemble cemento osseous dysplasias. • Initially they appear as multiple radiolucencies in the periapical regions. • The affected sites expand and develop mixed radiolucent and radiopaque pattern. • With further maturation, they become predominantly radiopaque with a thin radiolucent rim. Histopathologic features • It shows same spectrum of changes seen in the florid cemento oseeous dysplasia, the two cannot be distinguished radiographically.

Treatment and Prognosis

• Shave down surgical procedures at the earlier stage to improve aesthetics are not successful due regrowth. • At the later stage (radiopaque) partial removal of affected bone will result in sequestration of the remaining affectd bone. • Extensive resection and reconstruction of the lesion is recommended at a later stage if they are causing significant functional & esthetic deformity. • The extent of surgical procedures is greater at a later stage.

OSSIFYING FIBROMA: It is considered by most to represent a benign neoplasm arising from undifferentiated cells of periodontal ligament tissue. This lesions has been referred to as osteofibroma, fibro-osteoma and benign fibro-osseous lesion of Periodontal ligament origin. In 1972, the World HealthOrganization (WHO) considered ossifying fibroma to be a tumor of bone origin This lesion shares identical clinical radiographic and histopathologic features of with cementifying fibroma. Neoplastic etiology for ossifying fibroma includes persistent, locally aggressive growth characteristic

and finding of recurrence is seen. Some

investigators regard the lesion as example of localized dysplastic process in which bone metabolism has been altered. Clinical features: It is typically a slow growing, expansible lesions that replaces normal bone as it enlarges.

Most lesions are asymptomatic when detected with rare exceptions, lesions arise in tooth bearing regions of jaws, with the body of mandible being the most common site. Most affected patients are adults with peak incidence between 20 and 40 years. A definite female predominance (5:1). When lesions remains undetected for a period of time, the lesion exhibits slow but persistent progression, in gradual expansion and possible thinning of buccal and lingual cortical plates. Firbromas occur as solitary lesions. In contrast to fibrous dysplasia, the most important distinguishing feature is well circumscribed sharply defined border between lesion and adjacent bone. Early lesions present as unilocular or multilocular radiolucencies. It progresses gradually to a mixed radiolucent radiopaque stage and matrix material is deposited and mineralized in the lesion. Fully mature, long standing lesions appear as dense, radiopaque masses surrounded by a thin, well defined regular, radiolucent rim. As lesions enlarge, they may displace adjacent teeth and less commonly cause resorption of tooth roots. Histopathology: The tumor consists of a collagenous stroma containing variable number of uniform spindled or stellate cells. Collagen fibers are often arranged haphazardly. The degree of vascularity is variable some are relatively avascular and fibrotic, whereas others exhibit a well vascular stoma.

Irregular partially interconnecting trabecular of woven bone are noted. Presence of OSTEOBLASTS along the surface of bone deposits. Basophitic spherical calcifications and anastamosing trabecular of cementum like material are also frequently present. Differential diagnosis1. Fibrous dysplasiaS.No

Fibrous dysplasia

Ossifying fibroma

Site- common in maxilla

Common in mandible

Seen at 1st and 2nd decade

3rd and 4th decade

Equal sex predilection

Females

are

commonly

affected 4.

Radiologically

line

of Line of demarcation seen

demarcation between normal bone and immature bone 5.

Fusiform

elongation

( encapsulated neoplasm)

or Round or oval expansion

expansion 6.

Histologically

only

bone will be seen

woven Lamellar bone will also be seen.

2. Osteoid osteoma and osteogenic sarcoma- gives an ill defined aggressive appearance with radiographic signs of malignancy. 3. Condensing osteitis and focal sclerosing osteomyelitis- lacks the surrounding radiolucent capsule seen in ossifying fibroma and thus easily differentiated.

4. Ameloblastoma – multilocualated, bubbly appearance, clear line of demarcation present, root resorption may be present. Sometimes even associated with unerupted tooth. 5. Adenomatoid odontogenic tumourTreatment & Prognosis: An intraoral approach for the surgical excision of tumor by enucleation is the preferred method of management adjacent normal structures including teeth, neurovascular elements and bone should be preferred whenever possible when large lesions are excised and potential risk for postoperative fracture, IMF should be considered during initial healing stages. In extensive lesions surgical resection and bone grafting is indicated. Cryotherapy is also indicated in treating ossifying fibroma for conditions which are lying adjacent to the bone or lying within the bone.1

JUVENILE OSSIFYING FIBROMA: • Synonyms: juvenile aggressive ossifying fibroma, juvenile active ossifying fibroma and aggressive psammomatoid ossifying fibroma. • The term active juvenile ossifying fibroma is considered when the lesion behaves in the more aggressive manner & the patient is under the age of 15 years. Recurrences rates of around 30 to 50 % are encountered in this type of lesion.2 • This uncommon lesion is distinguished from standard OF based on – its more clinicaly aggressive biologic behaviour, 28

– occurrence in younger age group, – and tendency to occur in different anatomic sites.

Clinical features • Most cases reported before the age of 15 yrs. • The most frequent sites of occurrence include the orbital ,frontal and ethmoid bones, the paranasal sinuses, and the maxilla. • In contrast to standard OF mandible is less frequently involved. • Common clinical presentation are proptosis, exophthalmos, visual disturbances, nasal obstruction and facial asymmetry. • Many tumors exhibit rapid and progressive enlargement. • Some lesions produce expansion and thinning of cortices; others may erode the bone and adjacent soft tissue spaces. • Intra cranial extension through cribriform plate leading to elevation of frontal lobe and pneumococcal meningitis is also reported.

Radiographic features • Most tumors present as destructive, expansile lesion, often with fairly well demarcated, even corticated, borders. • Frequently the lesion exhibits a primarily radiolucent quality with varying amounts of internal radiopacity, reflecting the degree of mineralization.

Histopathologic features • Microscopic findings of this lesion are controversial. • The tumor stroma consists of a highly cellular proliferation of spindled to stellate cells with minimal intervening collagen. • The cellular stroma invests thin strands and cords of osteoid, which contain many osteocyte like cells. • It also contains woven bone trabeculae with osteoblastic rimming. • Some lesions contain numerous unoiform, round often laminateds tructures described as ossicles or psammoma like bodies. • Other features include –multinucleated

goiant cells, myxoid stromal

altterations with areas of degenration, and pseudocyst formation.

Treatment and Prognosis • The approach to surgical treatment is continually evolving. • Complete surgical excision is the goal, taking into consideration the size, location, and extent of the tumor. • Small accessible lesions may be amenable to surgical excision with enucleation alone or with peripheral ostectomy. • Reported recurrence rates for this tumor is between 30% and 58% but no evidence of metastasis. • Larger, recurrent lesions may necessitate segmental resections and reconstruction with bone grafts.

OSTEOBLASTOMA AND OSTEOID OSTEOMA: Osteoblastoma and Osteiod Osteoma are recognized neoplasms in the extragnathic skeleton and have been occasionally been reported in the jaws. There is wide agreement that Osteoblastoma and Osteoid Osteoma are closely related lesions and are separated only on the basis of their clinical and radiologic characteristics. Some authorities prefer the term Osteoblastoma for both lesions. The radiographic findings in Osteoblastoma of the jaws and the remainder of the skeleton are quite inconsistent and showing varying combinations of radiolucency and calcification that sometimes are indistinguishable from typical ossifying/ cementifying fibromas. Histologically, osteoblastomas can show a range of features, but most typically they have a highly vascularised stroma containing irregular, frequently anastomosing trabecular of Osteoid and immature bones with varying decrease of calcification. The osteoid trabecular are surrounded by prominent, plump osteoblasts and similar osteoblast like cells are conspicuos in the inter trabecular spaces. Varying number of multinucleated giant cells may also be present. Although the histologic findings in the usual osteoblastoma are fairly distinctive, they have enough overlapping features with some ossifying fibromas so that the designation of a given lesion as an Osteoblastoma or an ossifying fibroma may be constroversial.

CEMENTOBLASTOMA: Clinical and Radiographic features: â&#x20AC;˘ It is a odontogenic neoplasm of cementoblasts

• And also known as true cementoma. • These are rare, less than 1 % of all odontogenic tumors. • The most common site is posterior mandible that too first molar area (50%). • No sex predilection, rarely affects deciduous teeth. • The common age group is 10-30 yrs. • Pain and swelling may be present. • Radiogrphically it appears as a radiopaque mass that is fused to one or more tooth roots and is surrounded by a thin radiolucent rim. • The outline of the roots of involved tooth is usually obscured as a result of root resorption and fusion of tumor with the tooth.

Histopathologic features • It resembles osteoblastoma and only difference is fusion of the tumor with the root. • It consists of sheets and thick trabeculae of mineralized material with irregularly placed lacunae and prominent basophilic reversal lines. • Cellular fibrovascular tissue surrounds the trabeculae, and giant cells are often present. • The periphery of the lesion corresponding to the radiolucent zone seen on the radiograph, is composed of uncalcified matrix, which often is arranged in radiating columns.

Treatment and Prognosis • Surgical extraction of the tooth together with the attached calcified mass. • Surgical excision of mass with root amputation and endodontic treatment of the involved tooth may also be considered. • The prognosis is excellent, tumor does not recur after removal. • Progressive growth of the tumor after extraction of the tooth and incomplete removal of the mass has been documented.

According to Eversole et al, the histopathological features of the benign fibroosseous process, and radiographic findings, such as evidence of bone cortical expansion and well-defined margins, suggest the diagnosis of non-aggressive OF, type B. However, the radiographic features seem to make a modest contribution to the diagnosis of hybrid lesions, as indicated by the small number of cases reported in the literature. In addition, Central giant cell granuloma fundamentally presents radiolucent images, especially in lesions with huge dimensions. It is recognized that CGCG may produce calcified material. We emphasize that the CT images revealed the localization, nature and extent of the lesion. The last feature seems to be present in all the cases reported. The images led to a diagnosis of OF, and the anatomopathological examination confirmed an association of CGCG and a fibro-osseous lesion.

Differential diagnosis of fibro-osseous lesions – 33

Radiolucent lesionsa. Unicystic radiolucency with sclerotic margin1. Cyst- radiolucency will be smooth, thin and sharply defined. Tooth will be vital and aspiration shows positive response. b. Unilocular radiolucency without sclerotic margin with ill defined margins should be differentiated with malignancies. Root resorption will also be seen in all malignant lesions. c. Multilocular radiolucent lesionLocules of trabeculae might be few in number and of poor density like central giant cell granuloma or it may be coarse and thick resembling like ameloblastoma. Chronic osteomyelitis should also be considered as differential diagnosis.

Mixed radiolucent and radioopaque lesions1. Periapical cement osseous dysplasia- radiolucent lesion surrounds the apex of the tooth, with either sclerotic margin or opaque masses within the lucent lesion. Tooth will be vital, absence of pain, no expansion of cortices. 2. Malignant metaststic lesions like osteogenic sarcoma and osteoblastic carcinoma appears as mixed radiolucent â&#x20AC;&#x201C; radioopaque lesions but they are usually irregular and ill defined along with root resorption which is not seen in fibro-osseous lesions.

3. Odontoma- it is usually located above the crown of an unerupted tooth and seldom it is found in the apical region . these are more radioopaque compared to fibroosseous lesions. 4. Fibrous dysplasia- common in maxilla, seen in 1st and 2nd decade of life. Has equal predilection for both male and female. Jaw expansion is seen which is of fusiform type. there is noline of demarcation between normal bone and defective bone. 5. Condensing osteitis- clinically pain, inflammation, drainage, tenderness on palpation and regional lymphadenitis will be present. 6. Cement-ossifying fibroma- predilection for premolars and molars. Seen under 30 years .

Attains size of 2 to 4 cm, produces discernible

expansion. Mixed radiolucencies and radioopacities not necessarily contacting teeth1. Fibrous dysplasia 2. Chronic osteomyelitis 3. Cement-ossifying fibroma 4. Pagets disease 5. Chondrosarcoma

Radio-opaque lesions1. Fibrous dysplasia 2. Focal sclerosing osteomyelitis 35

3. Diffuse sclerosing osteomyelitis 4. Focal cement-osseous dysplasia.

CONTROVERSIES • Despite the many years of dedicated study by numerous investigators, the concepts and parameters of fibro-ossoeus diseases are still in flux. Among the new theories and contentions, there is now essential agreement that the osseous dysplasias represent a single disease process, while the so-called juvenile active ossifying fibroma and other aggressive, active, psammomatoid ossifying/cementifying fibromas remain controversial2

• Are fibro-osseous lesions malformations, hamartomas, or neoplasms? • It is strange that fibrous dysplasia, cemento-ossifying fibromas are considered as fibro-osseous lesions not neoplasms and Osteoid osteoma

and osteoblastoma are considered as neoplasms and not fibro-osseous lesions. The major controversies are: 1. Distinguishing various fibro-osseous lesions among themselves and also with other neoplastic lesions. 2. Surgical management of this lesions also remain controversial as to treat such lesions aggressively initially only or should wait for its transformation into malignancy then en bloc resections should be planned. Some lesions can only be treated by curetting and enucleating. 3. Identifying and predicting aggressive lesions histologically

The debate as to tissue of origin is of little clinical significance, as long as one differentiates ossifying fibromas from fibrous dysplasia. Hamner et al advocated the periodontal origin of ossifying fibroma. The periodontal ligament has been shown to be capable of producing cementum and osteoid, both of which are characteristically found in ossifying fibromas. Krausen et al and Spjut et al, however, postulated that primitive mesenchymal cells in areas such as the ethmoid bone and long bones may produce cementum at sites distant from odontogenic tissue. They discredited the notion that these tumors arise from ectopic periodontal tissue in these locations. .

CONCLUSION • FOLs are diverse group of processes and benign in nature. • Diagnosis involves all aspects of the disease like clinical, radiographic, and histopathological features. • Histopathology of FOLs is similar, and confusing. • Treatment largely depends on extent of esthetic and functional deformity.

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