Radiolucent Lesions Question And Answers

Radiolucent Lesions Essay Questions

Question 1. Discuss in detail the differential diagnosis of unilocular radiolucencies of the jaw.
Answer:

• Unilocular Radiolucencies of the Jaw:
  • Periapical radiolucencies
  • Fissural cysts
  • Odontogenic tumors.

Read And Learn More: Oral Medicine and Radiology Question And Answers

• Periapical Radiolucencies:
  • Periapical periodontitis
  • Periapical granuloma
  • Periapical abscess
  • Periapical cyst
  • Residual cyst
  • Periapical scar
  • Surgical defect.
• Periapical Periodontitis: Inflammation of periodontal ligament space is caused due to the exit of toxic products from the necrotic pulp at the root apex. It is seen as a widening of periodontal ligament space and loss of lamina dura at the root apex.
• Periapical Granuloma: A periapical granuloma is the formation of granulation tissue in the periapical region as a result of the host’s response to neutralize the toxic products from the root canal into periapical tissue. It is the frequently occurring periapical radiolucency presenting as a well-circumscribed radiolucency surrounded by a thin radiopaque border.
• Periapical Abscess: It is a localized accumulation of pus in the periapical region as a result of pulpal death. It is seen as an ill-defined periapical radiolucency with no peripheral certification.
• Periapical Cyst: It is an inflammatory odontogenic cyst resulting from the periapical granuloma. It is the second most common pulp-periapical infection and presents with a well-defined radiolucency measuring more than 2.5 cm in diameter and is usually surrounded by a thin radiopaque border.
• Residual Cyst: The cyst present after the removal of the infected tooth. It is seen as a well-defined radiolucency (ovoid or circular) surrounded by a thin radiopaque border
• Periapical Scar: A mass of fibrous tissue at the periapical region of a nonvital tooth which is root canal filled. Round, well-circumscribed radiolucency resembling periapical granuloma or cyst (smaller than both). The anterior region of the maxilla is the more common site.
• Surgical Defect: The surgical defect is seen as round radiolucency with a well-defined border. It is due to the defective healing process characterized by the absence of bone formation in an area following surgery.

Fissural Cysts:

• Globulomaxillary Cyst: It is a developmental non odontogenic cyst along the fusion line between the maxillary process and globular process of the frontonasal process in embryonic life. It is seen as an inverted pear-shaped or tear-shaped radiolu- cency between the roots of the lateral incisor and canine.

Nasopalatine Cyst: A fissural cyst originating from the nests of epithelium that remains after the disintegra¬tion of nasopalatine duct early epithelial fetal structure present within the incisive canal. It appears as a heart-shaped radiolucency with a radiopaque border between the maxillary central incisors.

Median Palatine Cyst: A developmental, non odontogenic cyst arising from the epithelium entrapped between the two shelves of the palatine bone. It appears as a well-defined radiolucency with a distinct border seen along the midline of the palate.

Median Mandibular Cyst: It is a true fissural cyst originating from epithelial trapping during the fusion process or from the merging of the paired mandibular process at the fourth week of embryonic life. A radiolucent line is seen in the symphyseal region.

Odontogenic Tumors:

• Unicystic ameloblastoma or mural ameloblastoma: It is an odontogenic tumor arising from the wall of the dentigerous cyst. The frequent site of occurrence is the mandibular third molar region. It presents as peri coronal radiolucency with a hyperostotic radiopaque border due to the localized thinning of the bone.

Question 2. Discuss in detail about multilocular radiolucencies.
Answer: Multilocular radiolucencies are produced by multiple adjacent pathological chambers partially separated by bony septa.

Multilocular radiolucencies Types:

1. Soap-bubble appearance—Radiolucency in which locules are larger.
2. Honeycomb appearance—Radiolucency in which smaller compartments resemble a honeycomb.
3. Tennis-racket appearance—Angular compartments resulting from the development of straight septa.

Anatomical Multilocular Radiolucencies:

• Maxillary sinus: Soap-bubble type radio-lucent appearance
• Bone marrow spaces and trabecular patterns: Especially in the mandible.

Multilocular Radiolucent Lesions:

• Tumors
  • Keratocystic odontogenic tumor
  • Ameloblastoma
  • Odontogenic fibro myxoma
  • Metastatic tumors to jaw.
• Reactive Lesions
  • Aneurysymal bone cyst
  • Central giant cell granuloma
  • Hyperparathyroidism
  • Central hemangioma
  • Cherubism.
• Keratocystic Odontogenic Tumor: WHO (2005) classified the odontogenic keratocystic lesion into unicystic and multi-cystic odontogenic tumors.
• Location: Posterior body of the mandible is the common site
  Periphery: Corticated, scalloped border.
• Internal structure: Internal septae within the radiolucency giving a soap-bubble pattern.
• Effects on surrounding structures:
  • Cortical expansion can be seen in occlusal radiograph
  • Associated teeth may show displacement, and in chronic cases, root resorption is present.
  • In the maxilla, it may invaginate the maxillary sinus.

Ameloblastoma: Benign aggressive tumor of odontogenic epithelium which is clinically persistent, and locally invasive. It is a slow-growing tumor, common in 20-50 years of age.

• Location: Mandible molar—ramus region is the common site
• Periphery: Well-defined, corticated border. Maxillary lesions are ill-defined.
• Internal structure: Curved internal septae within the radiolucency giving a soap-bubble or honeycomb pattern.
• Effects on surrounding structures:
  • The bicortical expansion is seen in the occlusal radiographs.
  • Associated teeth show displacement and root resorption.
  • The maxillary lesions may invaginate the paranasal sinus, orbit, and nasopharynx.

Odontogenic Fibromyxoma: Benign intraosseous neoplasm.

• Mandible premolar-molar regions are the frequent site of occurrence.
• Well defined.
• Straight thin internal septae give a tennis- racket or stepladder appearance.
  • A large tumor causes cortical expansion
  • Displacement and loosening of the associated teeth are common, but root resorption is rare.

Metastatic Tumors of Jaw: Multiple separated poorly defined radiolucencies is evident when several foci of malignant nests are present and growing separately.

Aneurysmal Bone Cyst: It arises due to the localized proliferative response of the vascular tissues in the bone.

• Mandible molar—Ramus region is the com-mon site. Located above the mandibular canal.
• Well-defined.
• Wispy ill-defined septa within the radiolucency giving a soap-bubble or honeycomb pattern.
• Associated teeth show displacement and root resorption.

Central Giant Cell Granuloma:

• It is a reactive lesion of the jaw.
• Mandible (anterior to the first molar) is affected twice as commonly as the maxilla (anterior to cuspid).
• Well-defined.
• Wispy ill-defined septa within the radiolucency give a soap-bubble or honeycomb pattern.
• Associated teeth show displacement and root resorption.

Hyperparathyroidism:

• Intraoral periapical radiographs reveal: Par¬tial or complete loss of lamina dura.
• The tapered appearance of roots due to loss of lamina dura.
  Ground glass appearance is given by the numerous, small, randomly arranged trabeculations.
• OPG features Osteitis fibrosa cystica (localized cystic cavities due to bone destruction as a result of excess osteoclastic activity).

Central Hemangioma: The abnormal tangle of vascular channels gives rise to a tumor-like mass.

• Mandible (molar ramus region) is twice as common as the maxilla
• Well defined
• Multilocular radiolucency with coarse, dense, well-defined trabeculations resembling soap-bubble or honeycomb pattern.
• Expanding lesions may show a sunray or sunburst appearance.
• Associated teeth show root resorption.
• Mandibular and mental foramen may be enlarged.

Pathological fractures occur in severe cases. Thinning of the cortical boundaries is present.

Cherubism:

• The bilateral angle of the mandible
• Well-defined by cortical border
• Wispy fine septa within the radiolucency giving a multilocular pattern
• Teeth are floating in cyst-like spaces.

Radiolucent Lesions Short Notes

Question 1. Radiographic features of metastatic carcinoma.
Answer: Malignant tumors that most commonly metastasize to the jaw bones are from the breast, adrenal gland, colorectal, genital, and thyroid in women and from the lung, prostate, kidney, bone, and adrenal gland in men. It accounts for about 1-3% of all metastasis.

Metastatic carcinoma Radiographic Features: There are multiple varied radiographic appearances in metastatic tumors to the jaw.

• Solitary well-Defined cysts like radiolucency—Slowly growing tumors or a tumor under successful treatment.
• Solitary poorly defined radiolucency— It is the common pattern of metastatic carcinoma appearance in the posterior mandible. In the initial stage, it may appear as a multilocular pattern but later they coalesce to a single radiolucent lesion.
• Multiple, separated, poorly defined radiolucencies is evident when several foci of malignant nests are present and growing separately.
• Multiple punched-out radiolucencies— Several nests of slowly growing tumor cells located close to each other in the bone.
• Radiopaque pattern with any of the preceding radiolucent appearance— Osteoblastic activity is induced by the tumor
• Salt and pepper appearance-widely disseminated tumor with malignant nests appearing as radiolucency (pepper) and sclerotic areas seen as radiopacities (salt)
• Dense solitary radiopaque area: Osteoblastic activity is more.

Question 2. Describe the radiographic features of hyperparathyroidism.
Answer: It is an endocrine abnormality characterized by excess secretion of the parathyroid hormone, which helps in calcium homeostasis.

• Primary hyperparathyroidism is caused due to the adenoma of the parathyroid gland.
• Secondary hyperparathyroidism is caused due to hypocalcemia in renal failure.
• Oral manifestations:
  • Hyperparathyroidism: It is a giant cell lesion due to the presence of multi-nucleated giant cells (osteoclasts). It causes:
  • Mobility and drifting of teeth
  • Osteitis fibrosa cystica (bone inflammation with cystic cavities due to bone destruction)
  • A brown tumor (granulation tissue over-growth in response to bone destruction, brown, color is due to hemolysis causing release of hemosiderin).

Hyperparathyroidism Radiographic Features:

• Intraoral periapical radiographs reveal: Partial or complete loss of lamina dura which may be generalized in severe cases.
  • The tapered appearance of roots is due to the loss of lamina dura.
  • Ground glass appearance is given by the numerous, small, randomly oriented trabecu- lations.
  • Orthopantomogram reveals osteitis fibrosa cystic as a localized cystic cavity as a result of bone destruction caused by excess osteoclastic activity.
  • Pathological fracture in severe cases.
  • Thinning of the cortical boundaries inferior border and mandibular canal in the mandible and cortical outlines of the maxillary sinus in the maxilla.

Question 3. Enumerate the radiographic appearance of jaw lesions.
Answer:

Question 4. Differential diagnosis of inter-radicular radiolucencies.
Answer: Radiolucencies are present between the roots.

Anatomic Interradicular Radiolucencies:

• Incisive foramen
• Intermaxillary suture
• Nutrient canals
• Radiolucent crypts of permanent teeth are seen between the roots of the primary molars
• Radiolucent shadow of maxillary sinus extending down between the molars and premolars
• Mental foramen.

Pathological Inter-radicular Radioloucencies

• Vertical bone loss: Inter-radicular radio- lucency closer to the involved tooth, contacting the mesial and distal aspects of the teeth.
• Horizontal bone loss: Bone loss occurs in a plane parallel to the cementoenamel junction of teeth.
• Furcation involvement: Bone destruction in the furcation area is seen as radiolucency.
• Globulomaxillary cyst: Developmental non odontogenic cyst along the fusion line between the maxillary process and the globular process of the frontonasal process in the embryonic life.
• Inverted pear or tear-shaped radiolucency between the roots of the lateral incisor and canine.
• Nasopalatine cyst: Fissural cyst originates from the nests of epithelium that remain after disintegration of the nasopalatine duct. Radiographically appears as a heart-shaped radiolucency between the roots of maxillary central incisors
• Lateral periodontal cyst: Unusual inflammatory odontogenic cyst occurs in the peri¬odontal ligament near the alveolar crest. It appears as inter-radicular radiolucency between the mandibular canine and the first premolar.
• Median mandibular cyst: True fissural cyst, originating from the epithelial inclusions during the fusion process or from the merging of a paired mandibular process at the fourth week of embryonic life. It is seen as a radiolucent line in the symphyseal region.

Question 5. Differential diagnosis of pericoronal radiolucencies.
Answer:

• Anatomic radiolucencies: Follicular space (soft tissue remnant of enamel organ) around the crown of erupting tooth which then merges with periodontal ligament space. Homogenous radiolucent halo with thin outer radiopaque border (compact bone becomes continuous with lamina dura).
• Dentigerous cyst: It is an odontogenic cyst around the crown of unerupted teeth seen as pericoronal radiolucency usually starting from the cementoenamel junction with the crown projecting into the radiolucency.
• Unicystic ameloblastoma or mural ameloblastoma: It is an odontogenic tumor arising from the wall of the dentigerous cyst and is commonly seen in the mandibular third molar region and is seen as peri coronal radiolucency with hyperostotic radiopaque border due to localized thin¬ning of bone.
• Adenomatoid odontogenic tumor or ade- ameloblastoma: It is an uncommon, benign, noninvasive odontogenic tumor that develops from the residual periodontal ligament and is usually associated with unerupted teeth (canine). The pericoronal radiolucency mimics a dentigerous cyst.
• Ameloblastic fibroma: Mixed odontogenic tumor is seen as unilocular or peri coronal radiolucency with a cortical expansion and root displacement.

Radiolucent Lesions Viva Voce

Question 1. What are the different multilocular radio-lucencies of the jaw?
Answer:

• Soap-bubble appearance
• Honeycomb appearance
• Tennis-racket appearance.

Question 2. Differential diagnosis of multiple sepa¬rate radiolucencies.
Answer:

• Multiple myeloma
• Basal cell nevus syndrome
• Hyperparathyroidism
• Metastatic carcinoma
• Langerhans cell histiocytosis.

Question 3. Conditions associated with Codman’s triangle.
Answer: This occurs when the periosteum is elevated and maintains its osteogenic potential but is breached in the center and it is a feature of:

• Osteosarcoma
• Ewing’s sarcoma
• Fibrosarcoma.

Question 4. Name the primary sites from which malignant tumors commonly metastasize to jaw bones.
Answer: From breast, adrenal gland, colorectal, genital, and thyroid in women and from lung, prostate, kidney, bone, and adrenal gland in men.

Question 5. Conditions associated with alveolar bone loss.
Answer:

• Periodontal diseases
• Diabetes
• Histiocytosis X
• Leukemia
• Malignant neoplasm.

Question 6. Name a few radiolucent lesions associated with the edentulous region.
Answer:

• Residual cyst
• Primordial cyst
• Static bone cyst
• Central giant cell granuloma.

Radiolucent Lesions Highlights

• Radiolucent refers to the portion of processed radiograph that appears dark or black. A dental image appears radiolucent where the tissues are less dense. Lack of density permits the passage of an X-ray beam with little or no resistance.
• Consequently, most of the beam energy reaches the receptor resulting in a dark or radiolucent area. A lesion that appears radiolucent permits the passage of an X-ray beam and represents the destruction of bone or space within the bone.
• Radiolucent jaw lesions are explained based on their appearance and location. Causes include inflammation, cysts, and odontogenic tumors.