HARD TISSUE LESIONS

Dr Norzalina GhazaliBDentSc, BA (Ire), MClinDent (Child Dental Health) (Mal)LecturerFaculty of DentistryUniversiti Sains Islam Malaysia (USIM)20/12/2013

HARD TISSUE OF THE BODY• Bone, cementum, dentin and enamel• Bone, cementum and dentin – similar in their composition &

formation• They are specialized connective tissues and collagen

(principally Type I)

Bone

Inorganic 67%

Hydroxyapatite

Organic 33%

Noncollagenous proteins

5%

Collagen 28%

HARD TISSUE LESIONS• Most diseases arising in the jaws are of odontogenic origin,

but both non-odontogenic and systemic disorders may affect the jaws

Can be:-• Developmental• Inflammatory• Infection• Tumours/ malignancies • Genetic• Metabolic

CYSTS OF THE JAWS• Cysts – is a pathological cavity having fluid or semi-fluid

contents which has not been created by the accumulation of pus, and the majority are lined wholly or in part by epithelium

• Symptoms: (1) Swelling, displacement or loosening of teeth, pain (if

infected)(2) Expansion of bone – may result in an ‘eggshell cracking’

Classification (WHO 1992)

Cysts

Epitelial cysts

Odontogenic

Developmental

Dentigerous, odontogenic keratocyst,

eruption, lateral periodontal cyst,

glandular odontogenic cyst,

gingival cyst

Inflammatory

Radicular (apical and

lateral), residual

cyst, paradental

cyst

Non-odontogenic

Nasopalatine cyst, nasolabial

cyst

Non-epithelial cysts

Solitary bone cyst,

aneurysmal bone cyst

WHO Classification of Tumours (2005)

• OKC is currently designated as a keratocystic odontogenic tumor (KCOT) and is defined as a benign uni-or multicystic, intraosseous tumor of odontogenic origin, with a characteristic lining of parakeratinized stratified squamous epithelium with the potential for aggressive, infiltrative behavior

• Although they are benign, KCOTs are locally aggressive and have a tendency to recur after treatment; reported recurrence rates range from 3% to 60%

Gorlin-goltz syndrome

Cysts in children

In children:• The most common cysts were DC (44%), followed by EC (21%),

TBC (18%), and RC (17%)• The mean ages were 11, 4.3, 14, and 8 years for DC, EC, TBC,

and RC, respectivelyIn adult:• The most common cysts were RC (63%), followed by DC (18%),

OKCT (10%), and non-odontogenic cyst (9%)• The mean age groups were 42, 50, and 46 years for RC, DC,

and OKCT, respectivelyManor E. et al.,

Int J Med Sci 2012; 9(1):20-26

Radiographic findings• Margins – well-defined with peripheral cortication (radio-

opaque margin)• Shape – round/ ovoid radiolucencies because most cysts grow

by hydrostatic mechanisms• Locularity – unilocular or multilocular appearance because of

ridges in the bony wall• Effects on adjacent structures – displacements of a tooth or

the inferior dental canal, roots resorption (rare), bony expansion

• Effect on unerupted teeth – may become enveloped by any cyst

ODONTOGENIC TUMOURS• Are lesions derived from the epithelial and/ or mesenchymal

remnants of the tooth-forming apparatus • Asymptomatic, may cause jaw expansion, movement of teeth,

root resorption, and bone loss

Biologic classificationBenign – no recurrence potential• Adenomatoid odontogenic tumour, squamous odontogenic

tumour, cementoblastoma, periapical cemento-osseous dysplasia, odontoma

Benign – some recurrence potential• Cystic ameloblastoma, calcifying epithelial odontogenic

tumour, central odontogenic fibromaBenign aggressive• Ameloblastoma, odontogenic myxoma, odontogenic ghost cell

tumourMalignant• Malignant ameloblastoma, ameloblastic carcinoma, primary

intra-osseous carcinoma, ameloblastic fibrosarcoma

Odontoma • Are mixed odontogenic tumours – composed of both epithelial

and mesenchymal dental hard tissues• Compound – appear as separate, small, tooth-like structures,

probably produced by localised, multiple budding-off from the dental lamina, found in anterior region, painless swelling

• Complex – appear as amorphous accumulations/ masses of hard tissue (cauliflower-like mass), common in posterior regions

Clinical signs: • Retained deciduous tooth, an impacted tooth, alveolar

swelling, generally no symptoms

Radiographically: • Compound – appear as numerous tiny teeth in a single focus,

typically in a tooth-bearing area• Complex – appear as amorphous opaque masses

Treatment:• Enucleation• No potential of recurrence

Ameloblastoma • Is defined as a benign, locally invasive epithelial odontogenic

neoplasm of putative enamel organ origin WHO, 2005

• Is a lesion of adults, rare in children• In children – usually cystic and appear as odontogenic cysts• Most common – mandibular molar-ramus area

Biologic subtypes:• Solid ameloblastoma• Unicystic ameloblastoma• Peripheral ameloblastoma• Malignant ameloblastoma• Ameloblatic carcinoma

Clinical signs:• As a slow-growing, painless swelling, and causing expansion of

the cortical bone, perforation of the lingual and/or buccal plates and infiltration of soft tissue

• There is often delay in the diagnosis because of its slow-growing nature

Radiographically:• A multilocular radiolucency was the most frequently

encountered. It also presented with root resorption and was associated with unerupted teeth

• May be unilocular• Well-defined and sclerotic margins due to slow growing

Treatment:• Is primarily surgical – range from enucleation, enucleation

followed by application of Carnoy’s solution, marsupialization followed by surgery, and resection

• There was lack of consensus over the most appropriate treatment for ameloblastomas especially in children

• A recurrence rate of 80% for unicystic ameloblastoma treated conservatively

Ghandhi et al. (2006)• Enucleation of unicystic ameloblastoma resulted in the highest

recurrence rate; and the lowest recurrence rate was associated with resection of the tumour

Lau and Samman (2006)

• The conservative management is usually performed due to the benign nature of the ameloblastomas despite reported recurrence rates

• Several factors are taken in to consideration in the treatment of ameloblastoma in children; these include size, location, duration, mural component, psychological impact, control of possible recurrence and scope for follow-up

• A conservative surgical enucleation of unicystic ameloblastoma with careful follow-up rather than partial or complete jaw resection appears to constitute appropriate therapy

• This is to prevent any interruption in growth and development

NON-ODONTOGENIC TUMOURS

Primary – benign• Osteoma• Osteochondroma• Cemento-ossifying fibroma• Central giant cell granuloma• Hemangioma

Primary – malignant• Osteosarcoma• Chondrosarcoma• Langerhans’ cell histiocytosis

Metaststic• Carcinoma

Rare in children

Giant cell granuloma • Commonly seen in young people• Mandible, anterior to the 1st molars• Frequently only a painless swelling, produce a purplish soft

tissue swelling• Radiographically: rounded cyst-like radiolucent area, often

loculated or with a soap-bubble appearance, teeth displacement or occasionally root resorption

Hemangioma of bone• Rare tumours of bone, commonly in the mandible• Clinically, cause progressive painless swelling which when the

overlying bone is resorbed may become pulsatile• Teeth may be loosened• Bleeding from the gingival margins involved by the tumour• Radiographically, there is a rounded or pseudoloculated

radiolucent area with ill-defined margind or a soap-bubble apperance

Osteosarcoma• Highly malignant, the most common primary neoplasm of

bone but overall is rare especially in the jaws• Body of the mandible is a common site, as firm swelling which

grows noticeably in a few months and becomes painful • Teeth may be loosened, may be paraesthesia or loss of

sensation in the mental nerve area• Radiographically, irregular bone destruction noted

Langerhans’ cell histiocytosis• Is a disorder characterized by a proliferation of cells exhibiting

phenotypic characteristics of Langerhans cells• 3 forms are recognised:• Eosinophilic granuloma (chronic localized): Solitary or multiple

bone lesions• Hand-Schuller-Christian (chronic disseminated): Bone lesions,

exophthalmos, diabetes insipidus• Letterer-Siwe (acute disseminated): Bone, skin, internal organs

affected

• Skull, mandible, ribs, vertebrae, and long bones are often involved

• Oral changes – initial presentation• Tenderness, pain & swelling, loosening of teeth, gingival

tissues are often inflamed, hyperplastic & ulcerated• Radiographically, exhibit solitary or multiple radiolucent

lesions which often affect the alveolar bone causing the teeth to appear as if they were floating in space