GOOD MORNING

Seminar on

Mixed radiopaque – radiolucent lesions

- By Samarth johari

DefinitionsRadiolucent : It refers to that portion of a

processed radiograph which appears as dark / black. It is caused due to the passage of maximum photons through the objects.

Radiopaque : It refers to that portion of processed radiograph which appears as light / white. It is caused due to the presence of dense objects in path of photons that are strong absorbers.

Why Mixed????

Some normal anatomic structures and disease states can produce mixed radiolucent and radiopaque images on radiographs.

Some pathology may be present as an osteolytic lesion, which appears as radiolucency in radiograph.

During it’s development, foci of calcified material may form within the osteolytic area.

When these foci become large and mineralized, they become radiographically apparent.

Thus, mixed radiolucent & radiopaque condition frequently represents an intermediate stage in development of lesion.

Mixed Radiolucent – Radiopaque Lesions

1. Cementoma2. Calcifying epithelial odontogenic cyst3. Calcifying epithelial odontogenic tumor4. Adenomatoid odontogenic tumor

1. CEMENTOMA :Also known as – • Periapical cemental dysplasia• Fibrocementoma• Sclerosing cementum• Periapical osteofibrosis• Periapical fibrosarcoma• Periapical fibrous dyplasia• Periapical fibro – osteoma

Defined as – a reactive fibro–osseous lesion derived from the odontogenic cells in the periodontal ligament.Located at – apex of tooth.

Clinical features –• More common in females, blacks & in middle age.• Age group : middle age.• Common in mandibular anterior region.• Asymptomatic & involved tooth is vital.• Usually diagnosed during routine checkup.• Small in size ( <1cm in diameter) but may become quite

large causing expansion of alveolar process.• Early phase – resorption of normal bone ( radiolucent

phase )• Developing phase – abnormal bone manufactured within

lesion (mixed radiopaque & radiolucent phase)• Late / mature phase – internal structure dominated by

abnormal bone.

Radiographic features -• Location :–Epicenter lies at apex of tooth.–Mostly lesion is multiple & bilateral.

• Periphery & shape :–Well defined periphery.–Radiolucent border of varying width, surrounded by

varying width of sclerotic bone.–May be irregular in shape or round or oval shaped

centered over apex of tooth.• Internal structure :–Stage 1 – osteolytic stage :» Radiolucency ( 1cm in diameter ) in periapical region»More than 1 tooth may be involved.

–Stage 2 – cementoblastic stage :» small areas of calcification develops within

radiolucency.

–Stage 3 - Mature stage:» Individual calcified mass increase in size»Masses unite with adjacent lesions to form

single large radiopaque mass with thin radiolucent line in periphery

• Effects on surrounding structures :–Adjacent teeth are not displaced–No root resorption of adjacent teeth are seen–Adjacent teeth are vital, with intact PDL space,

lamina dura may be discontinuous–No expansion of jaw is seen

Differential diagnosis –• Periapical rarefying osteitis – in early stages,

PCD can not be ruled out radiographically alone. Thus, final diagnosis is based on vitality of involved tooth.

• Benign cementoblastoma & odontoma – –Cementoblastoma : solitary, attached to surface of

root which may be partly resorbed.better defined peripheral soft tissue capsule

–Odontoma : starts occlusal to a toothprevents eruptionresembles tooth like structuremore uniform in width & better defined

than the periphery of PCD

Management -• Periodic radiographic evaluation (watchful

neglect)• Surgical enucleation indicated in cases of

expansion of cortical plates.

2. CALCIFYING EPITHELIAL ODONTOGENIC CYST :Also known as – Calcifying odontogenic cystGorlin’s cystDefined as –an unusual lesion with features suggestive of a cyst & characteristics of a solid neoplasm.Clinical features –• females > males• 3/4th of the lesion occurs centrally, 75% occuring

anterior to the 1st molar.• Affects both jaws equally.• Slow growing, asymptomatic.• May cause expansion or destruction of cortical plates.

• Adjacent teeth may be displaced.• May be associated with an odontoma & may have

calcified material identified as dysplastic dentine.• Aspiration yields a viscous,granular, yellow fluid.

Radiographic features –• Location :–Anterior to 1st molar–Associated with cuspids& incisors, where it may manifest as pericoronal radiolucency

• periphery & shape :–Vary from well defined & corticated with curved, cyst

like shape to ill defined & irregular.

• Internal structure :–may be completely radiolucent or may show

evidence of small foci of calcified material that appear as white flecks or small smooth pebbles.–Multilocular in rare cases.

• Effect on surrounding structures :–Most commonly associated with cuspid–Displacement of teeth may be seen–Root resorption is present–Perforation of cortical plates in enlarged lesions

• It may resorb roots of adjacent teeth.• Radiolucency may containsmall foci of calcified material seen as whiteflecks or smooth pebbles ( radiopacities ). At times the entire lesion may be occupied by the calcific body & thus appear radiopaque.

Differential diagnosis –• Fibrous dysplasia – appears as mottled or has a smoky

defined borders, more common in maxilla.

• Odontoma – surrounded by a capsule.

• AOT – in the intermediate stage of development, AOT appears like a CEOC.

• Cementoblastoma – well defined radiographic image attached to the root of the tooth.

Management –• Enucleation with curettage• Regular follow - up

3. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR :Also known as –Pindborg’s tumorAmeloblastoma of unusual type with calcificationDefined as –rare tumor of distinctive microscopic appearance that appears to arise from the reduced enamel epithelium or dental epithelium.Clinical features –• Accounts for 1% odontogenic tumor.• Males > females• Age range : 8-92 yrs.• Mandible > maxilla• Common in premolar – molar region• Rarely may have extraosseous location.

• Usually asymptomatic.• May be associated with paresthesia.• Associated with unerupted teeth.• Cortical expansion is common.• Palpation indicates hard swelling with well defined or diffused

border.• Simulates ameloblastoma, less aggressive but locally invasive.• Rate of recurrence is high.

Radiographic features –• Location :

– Mandible > maxilla– More common inpremolar – molar area

• Periphery :– Well defined cyst like cortex– Irregular & ill defined border

• Internal structure :– May be unilocular or multi locular ( HONEYCOMB PATTERN )– Numerous scattered, radiopaque foci of varying size & density

are seen.– Small thin, opaque trabaculae cross radiolucency in many

direction ( DRIVEN SNOW APPEARANCE )• Effects on surrounding :

–May displace developingTooth & prevent eruption– Expansion of jaw withmaintenance of cortical boundary may occur

Differential diagnosis –• AOT – more common in anterior maxilla as comparedto CEOT, which is common inthe mandibular premolar – molarregion.• Calcifying odontogenic cyst –aspiration yields vicous, granular,yellow fluid.• Odontoma – has a capsule.

Management – Conservative treatment with local ressection with limited margins.

4. ADENOMATOID ODONTOGENIC TUMOR :Also known as –• Adenoameloblastoma• Ameloblastic adenomatoid tumor

Defined as –an uncommon, non aggressive tumor of odontogenic epithelium, with a duct like structure & varying degree of inductive changes in connective tissue.Classified as –• Peripheral adenomatoid odontogenic tumor• Central adenomatoid odontogenic tumor –a. follicular typeb. extra follicular type

a. follicular type – associated with embedded tooth

b. extrafollicular type – not associated with embedded tooth.

Clinical features –• Females > males• Age range : 5-50yrs• Maxilla > mandible• More common in anterior cuspid region• Asymptomatic• Slow growing swelling• Associated with unerupted tooth• Expands cortices but is non - invasive

Radiographic featurers – • Location :–More common in incisor – canine – premolar

region–May have follicular relationship with impacted

tooth–Does not attach at CEJ–Surrounds greater part of tooth

• Periphery :–Well defined corticated, sclerotic border

• Internal structure :–Completely radiolucent or may contain faint radiopaque foci–Occasionally, small calcifications with well defined borders,

like cluster of small pebbles• Effects on surrounding structures :–Displacement of adjacent Teeth–Root resorption is rare–Prevents eruption–Expansion of jaw mayAppear but outer cortex ismaintained

Differential diagnosis –• CEOC – occurs in older age group, usually in

premolar region.

• CEOT – more common in posterior mandibular region.

• Ameloblastic fibro – odontoma – more common in posterior mandible region, is multilocular & radiopacities of enamel & dentine are seen inside the radiolucency. Whereas, in AOT snow flecks are seen in periphery.

• Odontogenic fibroma or myxoma –TENNIS RACKET appearanceis seen.

Management –• Conservative surgical excision with curettage.