Tadahiko Kawai

Cemento-osseous dysplasia of the jaws in 54 Japanese patients: A radiographic study

OBJECTIVE The aim of this study was to describe the radiographic patterns of cemento-osseous dysplasia. STUDY DESIGN Fifty-four patients affected with benign fibro-osseous jaw lesions that showed periapical radiopacities and/or radiolucencies in a focal or a multiplex form were studied. The clinical, radiographic, and histopathologic features of the patients with cemento-osseous dysplasia were retrospectively studied. Radiographic features of the cemento-osseous dysplasia lesions were classified according to the appearance of calcified bodies. Radiographic visibility of periodontal ligament spaces of related teeth was assessed. RESULTS Forty-nine (91 %) of the 54 patients were women. The mean age of the total group was 50.8 years, and that of the male group was 64.6 years. The cemento-osseous dysplasia lesions could be classified into 6 types radiographically. Eighteen patients had at least 2 or more types of cemento-osseous dysplasia lesions. Of 147 related teeth, 142 had periodontal ligament spaces clearly visible. Six of 9 patients who had a total of 25 teeth with active hypercementosis showed concomitant occurrence of other types of cemento-osseous dysplasia lesions. Biopsy specimens showed various amounts of bonelike and cementumlike tissues. CONCLUSIONS It is likely that cemento-osseous dysplasia consists of 3 variations of a single entity, all with the same unknown cause. In one variation, the entity originates from the periodontium; in another, it is of medullary bone origin; and in the third it results from the simultaneous involvement of both tissues.

A unique case of desmoplastic ameloblastoma of the mandible: report of a case and brief review of the English language literature.

A unique case of desmoplastic ameloblastoma is reported from the clinical, radiographic, and histologic viewpoints. The patient was a 56-year-old man who complained of a painless swelling on the buccal aspect of the left mandible. Periapical and panoramic radiographs revealed a rounded, slightly radiolucent area with blurred osteosclerotic margins. Occlusal radiograph and computed tomography images disclosed buccal bone expansion outlined by thinned cortices. Computed tomography images exhibited an enhanced area in the anterior portion of the lesion. Interestingly, the coronal computed tomography images revealed a close relationship between the periodontal membrane of the left mandibular second premolar and the enhanced area. Biopsy specimens from the anterior portion of the lesion displayed typical histologic features of the desmoplastic variant of ameloblastoma. However, those from the posterior portion disclosed a large cystic formation. Oxytalan fibers were identified in the stromal tissue of the tumor, which suggested that the tumor arose from the epithelial rests of Malassez in the periodontal membrane of the related tooth. We also reviewed previously reported 41 cases. In 36 of 38 cases in which the location was specified, the tumor was found in the anterior to premolar region of the maxilla or mandible. A radiographic description was given in only 29 previous cases, 28 of which involved multilocular lesions. No cyst as large as the one in the present case was found among the previously reported desmoplastic ameloblastomas. Although the present case deviates from the usual desmoplastic variant of ameloblastoma in terms of locus, radiologic appearance, and cyst formation, it still meets the histologic criteria for this variant in both the stromal and epithelial components.

Diagnostic imaging for a case of maxillary myxoma with a review of the magnetic resonance images of myxoid lesions

The findings of conventional radiography, computed tomography, and magnetic resonance imaging are reported for an odontogenic myxoma arising in the left anterior maxilla of a 50-year-old man. The magnetic resonance imaging characteristics of an intraosseous myxoma are described for the first time. The initial conventional radiographic examination disclosed a unilocular radiolucency with poorly delineated margins as typically seen in malignant tumors. Subsequently, acquired computed tomography scans displayed bony expansion and thinning of cortices on the labial aspect of the lesion. Magnetic resonance imaging revealed a well-defined, well-enhanced mass lesion with homogeneous signal intensity on every pulse sequence. The lesion showed intermediate signal intensity on the T1- and T2-weighted images. Magnetic resonance imaging of the present maxillary myxoma revealed a higher signal intensity on T1-weighted and a lower signal intensity on T2-weighted images than for previously reported myxomas of the soft tissues. This discrepancy might be related to the viscosity of the mucoid substance or the protein density of the tumor.

Radiographic investigation ofidiopathic osteosclerosis of the jaws in Japanese dental outpatients

Panoramic radiographs of 1203 Japanese patients were examined to detect idiopathic radiopaque foci of dense bone. One hundred seventeen patients (9.7%) exhibited 134 such lesions. The majority (97%) of the opacities were found in the mandible, especially in the mandibular first premolar to second molar region (85.4%). The lesion was most prevalent in the first three decades of life.

Radiographic changes during bone healing after mandibular fractures

The study aimed to find out the best time to undertake radiological follow-up examinations and remove fixation materials after fractures of the mandible through a retrospective study of radiographs. Serial radiographs of 325 fracture sites in 231 patients over a 10-year period were examined. Outcome was measured by radiographic features of healing at less than 2, 2-3, 3-4, and 4 or more months. Osteogenic change (osteogenesis and union) was the best radiographic criterion for evaluating follow-up radiographs. This change started to predominate 1-2 months after injury in patients less than 18 years of age (21/31, 68%) and 2-3 months after injury in older patients (21/25, 84%). Overall, union was noted in 98 of 115 patients (85%) 3 months or more after the fracture. We recommend follow-up radiographic examination to confirm clinical judgement during the fifth week after a mandibular fracture in patients less than 18 years of age, and the ninth week for older patients. The fixation materials should be removed during the fifth month after injury.

Gigantic dense bone island of the jaw

The clinical and radiographic features of gigantic dense bone islands of the jaw were reviewed in 21 subjects to better determine the pathogenesis of this condition. Most of the islands were asymptomatic. They showed a striking predilection for occurrence in the premolar to molar region of the mandible. The greatest dimension of gigantic dense bone islands measured on panoramic radiographs ranged from 2.5 to 7.0 cm, and they were most commonly structureless radiopaque areas. None showed bony expansion buccolingually, nor did they displace adjacent teeth or bony anatomic structures. It is concluded that gigantic dense bone island is not a benign bone neoplasm and is perhaps merely a large counterpart of smaller dense bone islands or idiopathic osteosclerosis.

Radiographic investigation of mandibular periostitis ossificans in 55 cases

The radiographic and clinical features of periostitis ossificans in 55 patients with mandibular osteomyelitis were studied. On the basis of whether the original mandibular contour was preserved or not, the lesions could be classified radiographically into two major types, each with two subtypes. Type I lesions were of shorter duration than Type II. Type 1-2 and Type II-1 periostitis ossificans were characteristically observed in patients under 25 years of age. Extraction of the lower third molar with pericoronitis was the most frequent cause of periostitis ossificans. An unerupted third molar tooth bud was found in close proximity to the area of periostitis ossificans in six patients. With adequate treatment there can be complete resolution of periostitis ossificans in Type I cases; however, when there has been loss of mandibular contour (Type II cases), mandibular deformity remains even when normal bony architecture has been restored.

Radiologic appraisal of healing after iliac crest bone grafts

Radiographic changes were observed in 45 patients who had undergone iliac bone grafting with either metal or wire fixation after resection of the mandible. Changes were generally not observed during the first month after surgery. Bony resorption was seen during the second or third month. Osteogenesis commenced at any stage, but was usually radiographically evident by 3 to 6 months. Union was not radiographically evident in most cases until more than 6 months had elapsed after surgery. For follow up, plain film radiographs 4 to 6 months after surgery are recommended in patients who receive bone grafts.

Radiographic features of chronic osteomyelitis of the mandible

ConclusionAs shown in the present cases, osteomyehtis varies in its radiographic appearance depending greatly on the stage of the disease at which the radiograph is taken, as well as the resistance of the tissue and the virulence of the infection.Therefore, when we make a radiographic diagnosis of osteomyelitis, it would be also of utmost importance to understand what type and what stage in the radiographic transition of chronic osteomyelitis are shown in mature consideration of the present status, history of the disease, age of the patient and any other factors.As shown in the present cases, osteomyehtis varies in its radiographic appearance depending greatly on the stage of the disease at which the radiograph is taken, as well as the resistance of the tissue and the virulence of the infection. Therefore, when we make a radiographic diagnosis of osteomyelitis, it would be also of utmost importance to understand what type and what stage in the radiographic transition of chronic osteomyelitis are shown in mature consideration of the present status, history of the disease, age of the patient and any other factors.

A report on the follow-up of a case of cemento-osseous dysplasia (COD) of the mandible

We report herein on the follow-up case of a 44-year-old female patient with multiplex COD lesions of the jaws. The etiology of this entity remains controversial as to whether it is a reactive or a dysplastic processlL The radiographs taken of this patient revealed non-expansile, multifocal radiopaque and / or radiolucent lesions in close proximity to apical areas of the right and left mandibular first and second molars (Fig. 1 and 2). After a 9-year-period of follow-up observation, two new radiopaque lesions developed in the region of the alveolar crestal bone posterior to the mandibular right second molar (Fig. 1) and in the apical area of the left mandibular second molar (Fig. 2). These radiopque lesions gradually increased their radiodensities without changing their sizes. The other radiolucent lesion including radiopaque bodies in the region of the left mandibular first molar, increased their areas of radiopacity, without changing in size (of the overall lesion). (Fig. 2, arrowheads). This phenomenon did not indicate that COD lesions might grow from a small focus area. That is to say, a certain area might at first fall into a dysplastic process at one time which may or may not progress within the lesion. Considering that the COD patients are predilected just for over middle-aged women, COD might not be a reactive, but a dysplastic process.