Giant Osteosarcoma of the Mandible.

Osteosarcoma is a rare primary malignant bone tumor with considerable variations not only in clinical and histologic appearance, but also in the course and prognosis of the disease. It mainly occurs in the metaphyseal region of long bones. Jaw osteosarcomas are relatively rare as compared to those occurring in long bones and share similar histopathologic features, but biologically behave in a different manner. Early diagnosis and complete resection of the lesion are necessary for better prognosis. This report highlights an aggressive and fatal case of mandibular osteosarcoma in a 23-year male patient, which, if diagnosed earlier, would have added some valuable years to the patient's life.

Modified bisecting angle technique in eliminating zygomatic superimposition over apices of maxillary molars.

BACKGROUND: Image superimposition is a part and parcel of two-dimensional radiography. However, some overlappings are a result of radiographic technique itself. The technique induced superimposition of zygomatic buttress on apices of maxillary molars is common in bisecting angle technique (BAT), which affects the endodontic performance. Certain alterations were carried out in BAT to remove these undiagnostic shadows. The aim of this study was to compare two techniques of periapical radiography namely, BAT and modified BAT (MBAT) in preventing zygomatic superimposition over apices of maxillary molars. MATERIALS AND METHODS: A total of 62 patients requiring endodontic treatment for at least one maxillary molar were recruited in this cross-sectional study. One tooth from every patient was subjected for two periapical radiographs, one with each BAT and MBAT respectively giving a total of 124 radiographs. Each radiograph was recorded as acceptable or unacceptable, based on zygomatic superimposition and different technical aspects. Chi-square test was used for data analysis. The kappa statistic was used to test intra-observer reliability. RESULTS: With MBAT, the acceptability was 82.3% (n = 51) compared with 43.5% (n = 27) when BAT was employed. The statistically significant difference was found between these two techniques (P = 0.000). The level of agreement between two oral radiologists in their interpretation was high (kappa index = 0.897). CONCLUSION: Modified BAT was more accurate for periapical radiography of maxillary molars in preventing zygomatic superimposition and related technical errors than BAT.

Technetium-99m bone scan and panoramic radiography in detection of bone invasion by oral carcinoma.

OBJECTIVE: The correct extension of cancer in the bone usually remains undetected on static imaging which may lead to inadequate or over excision. The conventional radiography as well as other anatomical imaging modalities like computed tomography, magnetic resonance imaging often fails to detect functional changes in the bone. However, bone scinitigraphy is highly sensitive in detecting earlier changes in the bone but lack anatomical definition. The purpose of the study was to evaluate the accuracy of combining technetium-99m bone scan and panoramic radiography (Tc scan/PR) over using single diagnostic modality in detection of jaw bone invasion by oral carcinomas. The accuracy of these imaging modalities either alone or in combination were determined by comparing with the histopathological findings. MATERIALS AND METHODS: Twenty patients with biopsy-proven oral malignant tumors were randomly selected from Oral Medicine and Radiology department over a period of two years. All patients were investigated preoperatively by Tc scan and PR. Lewis - Jones's designed diagnostic criterion was applied on Tc scan/PR to evaluate bone involvement by cancer. To test the accuracy of Tc scan, PR and Tc scan/PR, their results were compared with the histopathological findings of resected specimen. RESULTS: Hybrid Tc scan/PR had higher specificity, accuracy and positive predictive value (83.3%, 94.7%, 92.8%) than Tc scan alone (50%, 84.2%, 81.2%) and higher sensitivity and negative predictive value (100%, 100%) than PR (69.2%, 55.5%). CONCLUSION: Combination of Tc scan and PR was more accurate in detecting jaw bone invasion by oral squamous cell carcinoma than Tc scan and PR alone.

Bone scintigraphy and panoramic radiography in deciding the extent of bone resection in benign jaw lesions.

OBJECTIVE: To find out the value of correlating radiographic and scintigraphic imaging for defining the extent and nature of benign jaw lesions (BJL). MATERIAL AND METHODS: Twenty patients with histologically proven benign lesions of the jaws were investigated pre-operatively by panoramic radiography (PR) and bone scintigraphy (BS). To test the efficacy of combination of these two imaging modalities, their results were compared with intra-operative and histopathological findings. RESULT: Most of the benign lesions presented radiographically as well-defined bone destructions with fine sclerotic rims. Such lesions were found to be silent on scintigraphs and the extent of radionuclide uptake was same as radiographically visible extent of bone involvement. However, aggressive lesions showed ill-defined bone destructions without sclerotic rims on radiographs and their scintigraphic uptake correctly exceeded the radiographic extent of the bone involvement. CONCLUSION: The efficacy of combination of both complementary imagings is rewarding in defining the extent of the BJL, especially when radiographic margins are not so well defined. So, that surgical excisions will be complete and the possibility recurrences is reduced.

Localization of a Peripheral Residual Cyst: Diagnostic Role of CT Scan.

The term residual cyst is used most often for retained radicular cyst from teeth that has been removed. Residual cysts are among most common cysts of the jaws. The location of all odontogenic cysts is usually intraosseous. The peripheral (extraosseous) presentations are rare. The peripheral presentation of residual cyst has never been reported in the literature. In this article, the role of CT in diagnosing an unusual peripheral presentation of a residual cyst is discussed.

Botryoid odontogenic cyst developing from lateral periodontal cyst: A rare case and review on pathogenesis.

Botryoid odontogenic cyst (BOC) is considered to be a polycystic variant of the lateral periodontal cyst (LPC) as the specimen resembled a cluster of grapes. It is a non-inflammatory odontogenic cyst. The BOCs can be unicystic or multicystic. These cysts have potential to extend in the bone and become multilocular and they have a high recurrence rate. Till now, only 73 cases of BOC have been reported. The pathogenesis of BOC is still debatable. We review different pathogenesis proposed for BOC and discuss a rare case of BOC developing from lining of an abnormally large LPC which showed aggressive behaviour in terms of growth and size.