ORAL PATHOLOGY – PATHOLOGY OF JAWS

VII. practical training

3rd year Dentistry

Odontogenic cyst 1. Radicular Inflammatory Around apex of non-vital tooth frequent adults (20-60 years), 3× more common in the maxila than in the mandibula Clin: slow progression, may be asymptomatic, when infammed – pain+ edema RTG: bone resorption, size cca 1 cm Histology: cavity with squamous cell epithelium (Malassez rest), dense

chronic or mixed inflammatory infiltrace, cholesterol crystals

Radicular cyst

Odontogenic cyst

2. Follicular (dentigerous)

Associated with the crown of an unerupted (or partially erupted) tooth. The cyst

cavity is lined by epithelial cells derived from the reduced enamel epithelium of

the tooth forming organ.

The most common location of dentigerous cysts are the mandibular 3rd molars

and the maxillary canines

M:F=2:1

more common in childhood

RTG: well demarcated, size up to 10 cm

Histology: multilayered epithelium , fibrous wall, nerly no inflammation

Odontogenic cyst

3. Eruption cyst

Eruption cyst is a benign cyst associated with a primary or permanent tooth in its

soft tissue phase after erupting through the bone.

Derived from epithelium of enamel organ

Superficially in the gingiva

Odontogenic cyst

4. Keratocyst

a rare and benign but locally aggressive developmental cystic neoplasm. It most

often affects the posterior mandible.

Multiple reccurences

Malignant transformation to squamous cell carcinoma may occur

Males 20- 30 years

Mandibula

RTG: multilocular cyst

Histology: squamous cell epithelium, keratinization,

Keratocyst

Keratocyst

Odontogenic cyst

5. Gingival

newborns, small nodule in gingiva – proliferation of epithelial remnants of

dental crest

Histology: thin squamous epithelium with keratinization,

6. Periodontal (paradental)

inflammatory odontogenic cyst typically related to crown or root of partially

erupted molar tooth.

Odontogenic tumor

Rare, from remnants od dental crest,

Classification:

• Epithelial

• Mesenchymal

• Mixed

Epithelial odontogenic tumors

Ameloblastoma (Adamantinoma)

• The most common

• Manifestation 20-40 yars

• Mandibula

• Cystic, ill.defined borders – destructive growts

• Histology: Histopathology will show cells that have the tendency to move the nucleus away from the basement membrane. This process is referred to as "Reverse Polarization". The follicular type will have outer arrangement of columnar or palisaded ameloblast like cells and inner zone of triangular shaped cells resembling stellate reticulum

• Commom reccurences

• May be malignant transformation

Ameloblastoma (adamantinoma)

Ameloblastoma (adamantinoma)

Ameloblastoma (adamantinoma)

Mesenchymal odontogenic tumors

Cementoblastoma

• Childhood

• Both jaws

• Cementoblastic proliferation around molars

Cementoblastoma

Mesenchymal odontogenic tumors

Odontogenic myxoma

• arising from embryonic connective tissue associated with tooth formation.

• consists mainly of spindle shaped cells and scattered collagen fibers distributed through a loose, mucoid material.

• young people

• Ill - defined borders

• bone resorption

• often reccurences

Mesenchymal odontogenic tumors Odontogenic myxoma

Mezenchymal odontogenic tumors

Odontogenic myxoma

Mesenchymal odontogenic tumors

Odontogenic fibroma 55% in mandible

45% in maxilla

• 2/3 of maxillary tumors found in the anterior segment

• 4-80 years

• Females 69%

• Recurrence rate is low

• Cellular tumor with minimal ground substance and droplets of calcified matrix representing bone or atubular dentin

• Small round nests and irregular clusters of epithelial cells

Mesenchymal odontogenic tumors

Odontogenic fibroma

Mixed odontogenic tumors

Ameloblastic fibroma

• Childhood, adolescence

• Ameloblastic fibromas are neoplasms of odontogenic epithelium and mesenchymal tissues

• 2% of odontogenic tumors

• Uni or multilocular cysts

Mixed odontogenic tumors Ameloblastic fibroma

Mixed odontogenic tumors

Odontoma • 66% of odontogenic tumors are odontomas • hamartoma • Between 10 and 20 years • More often in maxila • compound odontoma – three separate dental tissues (enamel, dentin and

cementum) no definitive demarcation of separate tissues between the individual "toothlets

• Complex odontoma – type is unrecognizable as dental tissues, usually presenting as a radioopaque area with varying densities.

Mixed odontogenic tumors Odontoma

Mixed odontogenic tumors Odontoma

Ameloblastic fibrosarcoma

• Rare malignant variant of ameloblastic fibroma

• Invazive and destructive growth, minimal metastases

Ameloblastic fibrosarcoma

Ameloblastic fibrosarcoma