Odontogenic tumors - Classified and Treatment

Introduction:

The tooth structure and apparatus usually arise through the interaction between ectoderm (which gives rise to tooth enamel) and ectomesenchyme (which produces structures other than enamel) tissues. Odontogenic tumors arise from the tissues that are involved in tooth development. The tumors mainly affect jaws, such as the maxilla and mandible. These tumors are usually benign (non-cancerous). Usually, the person with the condition remains asymptomatic, and the condition can be accidentally discovered on routine radiographs. This article reviews the various tumors arising from the tissues that form teeth and their structures.

What Are Odontogenic Tumors?

The odontogenic tumor is an abnormal mass developed from the ectoderm or ectomesenchyme that gives rise to the teeth and surrounding structures. However, the exact cause of the odontogenic tumors is still a mystery. They are mostly benign (non-cancerous) and rarely spread to surrounding tissues (malignant). The condition ranges from asymptomatic lesions to symptomatic masses associated with pain and swelling.

What Is the Classification of Odontogenic Tumors?

The recent classification of benign odontogenic tumors by the World Health Organization (WHO) is listed below:

• Benign Epithelial Odontogenic Tumors:

  • Ameloblastoma: The tumor is non-cancerous and aggressive. It is derived from odontogenic epithelium. It can be unicystic or multicystic.

  • Clear Cell Odontogenic Tumor: The tumor is characterized by sheets of clear cells enriched with glycogen-rich cytoplasm.

  • Calcifying Epithelial Odontogenic Tumor: It is also called Pindborg tumor. The non-cancerous tumor consists of polygonal epithelial cells that form concentric rings called Liesegang rings.

  • Squamous Odontogenic Tumor: It is a rare type of benign epithelial odontogenic tumor. It is a tumor consisting of squamous epithelial cells arranged in the form of cords or nests.

  • Adenomatoid Odontogenic Tumor: It is a slow-growing tumor associated with the tooth that is embedded in the jaw bone (impacted tooth). The common feature is a duct-like structure.

  • Keratocystic Odontogenic Tumor: It is also called odontogenic keratocyst. The tumor is lined by stratified squamous epithelium.

  • Primordial Odontogenic Tumor: It is a rare type of tumor that is lined by odontogenic epithelium.

• Benign Odontogenic Mixed Tumors: The benign odontogenic tumor rarely spreads to surrounding tissues. The characteristic features include pain, rapid growth, and loss of sensation.

  • Ameloblastic Fibroma: It is a rare mixed type of tumor derived from odontogenic epithelium.

  • Odontoma: It is a non-cancerous type of tumor affecting the mandible. It is associated with unerupted teeth. It comprises the hard and soft tissues of the teeth.

• Malignant Odontogenic Tumors:

  • Ameloblastic Carcinoma: It is a rare type of cancerous lesion that develops within the jaw bone. Individuals over 45 years of age are usually affected, and on examination, abnormal voice, pain, swelling, and difficulty in jaw motions are observed.

  • Primary Intraosseous Carcinoma: The cancerous lesion develops within the jaw bone.

  • Clear Cell Odontogenic Carcinoma: It is a type of cancerous and aggressive tumor consisting of clear cells.

  • Ameloblastic Fibrosarcoma: This is a rare type of cancerous lesion characterized by swelling of the maxilla and mandible.

  • Sclerosing Odontogenic Carcinoma: It rarely occurs and is usually present in the molar region of the lower jaw, destroying the surrounding bone.

  • Odontogenic Sarcoma: The incidence is high in adults over 30 years of age. An expanding growth that causes pain and altered sensation in the lower jaw is usually reported.

• Others:

  • Odontogenic Myxoma: It consists of spindle-shaped cells with odontogenic epithelial islands.

  • Cementoblastoma: The non-cancerous tumor of cementum-producing cells attached to the roots of teeth.

  • Cemento-Ossifying Fibroma: It is a fibrous type of lesion with varying degrees of calcification. It is composed of osteoblasts, fibroblasts, and cementoblasts type of cells.

What Are the Clinical Features of Odontogenic Tumors?

The common signs and symptoms of odontogenic tumors are as follows:

• A noticeable swelling or mass is present in the jawbone or surrounding soft tissues. The swelling can be painless or associated with discomfort.

• The person may experience pain or discomfort if the tumor may impinge on surrounding nerves or vessels.

• When the tumor is present near the roots of the teeth or within the jawbone, it causes changes in the dentition, such as tooth displacement or mobility.

• Tumors arising from gingival tissues may cause ulceration.

• Bone expansion or destruction.

• Sometimes, there can be neurological symptoms, such as numbness, tingling, or weakness in the face or oral cavity.

How Are Odontogenic Tumors Diagnosed, and What Are the Radiological Findings of Odontogenic Tumors?

It is essential to understand specific terms before getting into their radiographic features.

• Unilocular: Single cavity or compartment.

• Multilocular: It consists of many cavities.

• Radiolucent: Areas that appear dark in the X-rays.

• Radiopaque: Refers to areas that appear dense (resist the passage of light) in X-rays.

• Ameloblastoma: The tumor presents as multilocular, and one of its types, known as unicystic ameloblastoma, shows a radiolucent margin covering the crown portion of an unerupted tooth.

• Squamous Odontogenic Tumor: A triangular-shaped radiolucency is visualized between the teeth and is unilocular.

• Adenomatoid Odontogenic Tumor: It presents small radiopaque areas within the single radiolucent mass.

• Calcifying Epithelial Odontogenic Tumor: Calcified areas are observed within the radiolucent mass. It varies from radiolucent to radiopaque areas around the unerupted tooth.

• Ameloblastic Fibroma: The radiolucent areas are visualized around the misplaced teeth.

• Odontomas: It is often diagnosed incidentally and shows calcified tooth-like structures surrounded by a radiolucent margin.

• Cementoblastoma: The margins of the tumor appear as a radiolucent rim covering a mass around the tooth root.

How Are Odontogenic Tumors Treated?

Odontogenic tumors are diagnosed with various imaging techniques like X-rays, computed tomography (CT), or magnetic resonance imaging (MRI) and through biopsy (a sample of tissue is surgically removed for examination). Then, the treatments are planned accordingly depending on the clinical and radiographic features.

• Enucleation: The whole tumor is surgically removed, leaving behind the surrounding tissues intact. It is done for benign tumors, and the recurrence is relatively high.

• Wide Excision: The tumor is surgically removed and the surrounding tissues to reduce its recurrence rate.

• Radiotherapy: High-frequency radiation is targeted on the tumor site to reduce its size and control its progression.

• Chemotherapy: Certain drugs are used to destroy the tumor cells. It is usually followed after surgical excision.

Conclusion:

The occurrence of odontogenic tumors is few and far between. The odontogenic tumors are usually asymptomatic, and the signs are usually discovered on accidental radiological examination. The prognosis depends on the type of tumor and the treatment provided. Generally, the recurrence is low in benign tumors after complete excision. It is advisable to consult a dental surgeon for any abnormal swelling and pain in the jaw to diagnose the condition and differentiate it from tumors.