M.L. Chindia School of Dental Sciences UNIVERSITY OF NAIROBI

Presentation Objectives: 1. To provide an appraisal of some common and rare jaw lesions. 2. To provide a review of the existing nomenclature 3. To stimulate some discussion on management approaches

Compound Odontoma Tiny teeth varying in number: Only afew to numerous Do not resemble normal teeth Usually cone-shaped Histologically: Normal arrangement of a centrally placed fibrovascular pulp Tissue surrounded by dentine Crown area covered by enamel Cementum covers the root part.

Complex Odontoma Haphazard arrangement of a usually well, delineated mass of dental hard tissues Bulk of the lesion consists of dentine Enamel plays a minor role Stroma consists of a mature fibrous connective tissue:  Sometimes contains areas identical to the Calcifying Odontogenic cyst  Ghost cells maybe included

Complex Odontoma

Osseous Dysplasia (OD) A pathologic process of unknown aetiology Located in the tooth bearing jaw areas Proliferation of periodontal ligament fibroblasts Bone and cementum deposition Occurs in various clinical forms

Radiographic presentation of OD

Histomorphology of OD Cellular fibrous tissue Trabeculae of woven and lamellar bone Spherules of cementum-like material Lacks encapsulation or demarcation  Merges with cortical or medullary bone

Tissue Variation in OD Reflected in radiographic appearance thus: Predominantly radiolucent Predominantly radiodense Mixed

Subtypes of OD Distinguished by clinical and radiological features: Periapical Osseous Dysplasia Focal Cemento-Osseous Dysplasia occurs in the Posterior jaw quadrant is a limited lesion

Focal OD

Florid Osseous Dysplasia Occurs bilaterally in the mandible or may involve all four quadrants Non-expansile Occurs in middle-aged black females

FOD

Familial Gigantiform Cementoma May involve two or more quadrants Is expansible Occurs at a young age Shows an autosomal dominant inheritance Sporadic cases reported

FGC

Cementoblastoma

Ossifying Fibroma (OF) A well-demacated lesion Composed of: Fibrocellular tissue Mineralized material of varying appearances Most commonly occurs in the 2 nd to 4 th decates Shows a preponderance for females Varied mean age of histological sub-types

Histological Subtypes of OF Juvenile Trabecular Ossifying Fibroma (JTOF) Maxilla the site of predilection Occurs at an older age Mitoses present at histology Less typical features: multinucleated giant cells,pseudocystic stroma degeneration,haemorrhage

Juvenile Psammomatoid Ossifying Fibroma (JPOF) Mainly occurs in the bony walls of the paranasal sinuses Occurs at a much younger age Histology shows small ossicles resembling psammoma bodies Loose and fibrocellular to intensely cellular Minimal intervening collagen Spherical or curved ossicles Differential diagnosis: Intra – cranial meningioma with psammoma bodies.  The psammoma bodies in JPOF are clearly different from the a cellular spherical true psammoma bodies

Clinical appearance of OF

Radiographic appearance of OF

Fibrous Dysplasia A genetically – based sporadic disease of bone May affect a single (monostotic) or multiple (polyostotic) bones FD occuring in multiple adjacent craniofacial bones is regarded as monostotic (craniofacial FD) FD may be part of the Mc Cune – Albright sydrome (MAS).

FD

Radiographic appearance of FD

Ground glass appearance of FD

Radiographic appearance of FD

Epeclemiology of FD The monostotic (MFD) is equally distributed in both genders and ethnic groups The polystotic(PFD) is more frequent in females (F/M ratio;3:1) Both entities are mainly diagnosed in childhood and young adults MAS constitutes 3% of all PFD cases which may manifest at infancy

Aetiology of FD Proliferation and differentiation of preosteoblasts affected by: Mutation in the gene (GNAS1) which encodes for the a- submit a signal transduction G-protein (Gs-alpha) Leads to increased C-AMP production

Clinical Features of FD Occurs more often in the maxilla than in the mandible May involve adjacent bones like the zygoma,sphenoid and temporal plates Base of skull and ribs are the most frequently affected sites in the skeleton Painless swelling leading to facial asymmetry Occasionally café, au lait pigmentation is manifest

Gardener’s Syndrome (GS) Multiple polyposis of the large intestine (premalignant) Osteomas of the bones: long bones, skull and jaws Multiple epidermoid or sebeceous cysts of the skin scalp and back Occasional occurrence of desmoid tumours Impacted supernumerary and permanent teeth

Clinico-radiographic presentation

Aetiology of GS Due to a single phenotypic gene Autosommal pattern of inheritance With complete penetrance and variable expression

Osteoma A benign neoplasm Characterized by the proliferation of either compact or cancellous bone Usually in an endosteal or periosteal location

Clinical Features of Osteoma Is an uncommon oral lesion May occur at any age but more common in the young adult Is slow growing The periosteal form of the disease manifests as a sclerotic, circumscribed mass At histology it is composed either of extremely dense compact bone or course cancellous bone.

Clinico-radiographic presentation

Ameloblastic Fibroma (AF) Displays soft tissues similar to those found in an immature tooth germ Lacks a hard tissue component Epithelial strands lie in a myxoid cell-rich mesenchyme Mitotic figures are extremely rare May contain granular cells: Granula cell AF or Granular Cell Odontogenic fibroma Epithelial component closely resembles that of ameloblastoma The stromal component is, however, different Stroma in AF: immature,embryonic,cell rich myxoid tissue

Clinico-radiologic Features of AF Painless swelling Centrally placed: a radiolucent lesion Peripherally located: swelling in the gingivae Bone saucerization in peripheral location

Clinical presentation

Intra-operative appearance

Surgical defect

Hyperplasia of the Mandibular Condyle (HPMC) A rare unilateral enlargement of the condyle Should not be confused with neoplasia May superficially resemble osteoma or chondroma Aetiology remains obscure Mild chronic inflammation has been suggested:  Proliferative osteomyelitis Unilateral occurrence suggests a local phenomenon

Clinical Features of HPMC Unilateral slowly progressive elongation of the face Deviation of the chin away from the affected side Enlarged condyle may be clinically evident Striking radiographic features in all views Affected condyle may be painful or not A severe malocclusion is the sequela

Clinico- radiographic presentation

Treatment of HPMC Resection