Biomedical subjects

A Buchner

Publications and source records attributed to A Buchner.

At least 73 records · Page 4Linked to original sources

PubMed1994

Calcifying odontogenic cyst associated with odontoma: a possible separate entity (odontocalcifying odontogenic cyst).

The calcifying odontogenic cyst (COC) has been reported to be associated with odontoma in about 24% of cases. Separation of the cases of COC associated with odontoma (COCaO) may lead to a better understanding of the pathogenesis of this lesion. A screen of the literature revealed 52 cases of COCaO. The male to female ratio was 1:1.9, with a mean age of 16 years. The most common location was the maxilla (61.5%). The radiographic appearance of most cases (80.5%) was of a well-defined, mixed radiolucent-radiopaque lesion. Histologically, the lesions usually consisted of a single large cyst (which is similar to simple COC) with tooth-like structures that appear to be an integral part of the lesion, giving the impression of a single lesion. In addition to the unique histologic features, differences in gender and in distribution were found between the cases of COCaO and those of simple COC. COCaO may be regarded as a separate entity and classified as a benign, mixed odontogenic tumor. The term odontocalcifying odontogenic cyst is suggested.

Adolescent↗

PubMed1994

Peripheral osteoma of the mandible: a study of 10 new cases and analysis of the literature.

Ten new cases of peripheral osteoma of the mandible are described. These lesions are uncommon and only 15 other cases have been reported in the English language literature over the past 30 years. There is evidence to suggest that the peripheral osteoma of the mandible is a traumatically induced reactive lesion and that muscle traction plays a role in its initiation. In view of this possibility, the term "parosteal osseous hyperplasia" may be more appropriate for those lesions in which a positive history of trauma preceded the onset.

Adolescent↗

PubMed1994

Metastatic tumors to the jawbones: analysis of 390 cases.

A review of the English language literature revealed 390 well-documented cases of metastatic lesions to the jawbones. Most metastatic lesions were diagnosed in patients in their fifth to seventh decade. The primary site differed between the genders: for women, it was the breast followed by the adrenal, colo-rectum, female genital organs and thyroid; for men, it was the lung, followed by the prostate, kidney, bone and adrenal. The most common location of the metastatic tumors was the mandible, with the molar area the most frequent site involved. In about 30% of cases the oral lesion was the first sign of the malignant disease. The present data are compared with those of metastatic tumors to the oral mucosa and a view on the possible pathogenesis is presented.

Adolescent↗

PubMed1994

[Discrete dynamic systems: the effect of perceptual structuring on composition and transfer of knowledge about operating sequences].

This paper reports two experiments in which we explored the impact of perceptual grouping of elements on the organization and use of knowledge about how to operate a device. Experiment 1 explored the effects of different perceptual display regions on the creation of chunks when sequences of inputs had to be reproduced. The effects of regions were not homogeneous, but rather their influence depended on interactions between different modalities and learning conditions. Experiment 2 investigated the influence of grouping-induced composition of knowledge elements on the transfer of sequential knowledge. Two different learning criteria were used in the acquisition phase to manipulate the degree of composition of knowledge elements. In the transfer phase, subjects could transfer (1) the whole sequence of one region, (2) two partial sequences of adjacent regions, or (3) single components. It was found that regional invariance and immediate succession of components were both important for transfer performance. These results suggests that the temporal order of regions is important for the organization and use of sequential knowledge, and not the grouping of elements by itself.

Adult↗

PubMed1993

Radiologic features of desmoplastic variant of ameloblastoma.

Desmoplastic variant of ameloblastoma is a newly described variant characterized by unique histologic and radiographic features. This study reviews and analyzes the clinical and radiographic features of 15 cases of desmoplastic variant of ameloblastoma (14 cases from the literature and one case from our files). Desmoplastic variant of ameloblastoma shows a predilection for the maxilla and has a tendency to occur in the anterior region of the mandible and maxilla. Radiographically, almost all desmoplastic variant of ameloblastomas exhibit a mixed radiolucent-radiopaque appearance. Most show poorly defined or diffused borders and are mistakenly diagnosed as fibro-osseous lesions.

Adult↗

PubMed1993

Metastatic tumors to postextraction sites.

Review of the literature revealed 55 cases where tooth extraction preceded the discovery of metastases. The lung and breast were the most common sources of the metastasis, and the mandibular premolar area was the most common site. A soft tissue mass extruding from a recent extraction wound, and accompanied by pain, were the main symptoms in most patients. The mean time from discovery of the metastasis to death was 3.8 months. Tooth extraction appears to serve as a promoting factor in the metastatic process. A case of metastatic transitional cell carcinoma of the urinary bladder involving the area of a recently extracted mandibular third molar is reported.

Carcinoma, Transitional Cell↗

PubMed1993

Metastases to the oral mucosa: analysis of 157 cases.

A review of the English-language literature revealed 157 well-documented cases of metastatic lesions to the oral mucosa. Most (64%) were diagnosed in patients in their fifth to seventh decade. The frequency of the primary site differed between genders: for men it was the lung (35.5%) followed by the kidney (16%) and skin (15%); for women it was the breast (24%) followed by the genital organs (17%). The most common oral site was the gingiva and alveolar mucosa (54.8%) followed by the tongue (27.4%), and with much less frequency by the tonsil, palate, lip, buccal mucosa and floor of the mouth. Of the dentulous patients, 79% exhibited the metastatic tumor in the attached gingiva. The clinical appearance of the metastatic oral lesion in most cases resembled hyperplastic or reactive lesions.

Age Factors↗

PubMed1992

A desmoplastic granular cell tumour of the oral cavity: report of a case.

A case of granular cell tumour of the buccal mucosa demonstrating marked desmoplasia is presented. The bulk of the tumour is composed of dense collagenous stroma, which surrounds isolated nests of tumour cells. Since the histomorphologic appearance of this variant is different from that usually seen in this lesion, the diagnosis is supported by immunohistochemical demonstration of S-100 and Vimentin in the tumour cells. The authors believe that this case represents the first report of a desmoplastic granular cell tumour of the oral tissues.

Cell Nucleus↗

PubMed1991

Peripheral (extraosseous) calcifying odontogenic cyst. A review of forty-five cases.

The peripheral calcifying odontogenic cyst (PCOC) is a rare lesion. The number of well-documented cases reported in the English-language literature until now is 38. The purpose of the present study is twofold: (1) to report seven new cases of PCOC and (2) to review and analyze the clinical and histomorphologic features of the previously reported cases of PCOC together with those of the present study. Most of the lesions were located in the maxillary and mandibular gingiva or alveolar mucosa anterior to the region of the first molar. Histologically, 66% of the lesions were of the cystic variant and 34% of the solid (neoplastic) variant. The terminology of the lesion and its histogenesis are discussed.

Aged↗

PubMed1991

Physiologic pigmentation of the oral mucosa in Israeli children.

Physiologic melanin pigmentation (racial pigmentation) of the oral mucosa varies in prevalence among different races and ethnic groups. The purpose of this study was to investigate the prevalence of physiologic pigmentation in Israeli Jewish children of different ethnic origins. A total of 1,300 children, 6 to 10 years of age, was examined. Physiologic pigmentation was found in 13.5% of the population studied. Children of Eastern origin showed a significantly higher prevalence of pigmentation compared with Ashkenazi and Sephardic groups. Because melanin pigmentation can be enhanced by mechanical and chemical stimulation (smoking), this study may serve as a baseline for investigation of melanin pigmentation in various ethnic groups.

Child↗

PubMed1991

Adenomatoid hyperplasia of minor salivary glands.

Adenomatoid hyperplasia of minor salivary glands is an uncommon clinicopathologic entity. It comprises clinical swelling resembling a neoplasm with a histologic picture of aggregates of normal-appearing salivary gland tissue in excess of that anticipated for the anatomic site. The significance of this lesion is derived from its clinical resemblance to a neoplasm of salivary gland origin. This study adds 40 new cases to the literature and analyzes their clinical and histologic features. Most of the lesions were located on the hard and soft palates. The exact nature of the minor salivary gland hyperplasia is not clear. Some of the cases may represent a hamartoma or a reactive hyperplasia, but in most cases the nature of the hyperplasia is idiopathic.

Adolescent↗

PubMed1991

Anterior lingual mandibular salivary gland defect. Evaluation of twenty-four cases.

Lingual mandibular salivary gland defects in the posterior part of the mandible are not uncommon. Analogous defects in the anterior region, however, are rare, and the four new cases presented in this report bring the total number of reported cases up to 24. The purpose of the present study was to review and analyze the clinical, radiographic, and histologic features of the previously reported cases together with those of the present study. The majority of these defects were located in the cuspid and/or premolar area and were diagnosed in men in their fifth and sixth decades of life. Almost all defects contained normal salivary gland tissue. The differential diagnosis, treatment, and pathogenesis of these defects are discussed.

Adult↗

PubMed1991

Melanocytic hyperplasia of the oral mucosa.

Lesions that exhibit melanocytic hyperplasia are uncommon in the oral mucosa. They are even more rare than the various morphologic types of nevomelanocytic lesions. This article reports the clinicopathologic features of oral lesions diagnosed as lentigo simplex, junctional lentigo ("jentigo"), atypical melanocytic hyperplasia (melanoma in situ), and melanocanthoma. The proper terminology for these lesions is also discussed.

Adolescent↗

PubMed1991

The central (intraosseous) calcifying odontogenic cyst: an analysis of 215 cases.

This study reviews and analyzes the clinical, radiographic, and histomorphologic features of the 215 cases of central calcifying odontogenic cyst (CCOC) reported in the literature. Based on the present information, a clinicopathologic classification of calcifying odontogenic cyst is proposed. The CCOC is also compared with its peripheral counterpart and the differences discussed.

Adolescent↗

PubMed1990

Oral focal mucinosis.

Oral focal mucinosis (OFM) is an uncommon clinicopathological entity which is considered to be the oral counterpart of cutaneous focal mucinosis and/or cutaneous myxoid cyst. It is comprised of a clinically elevated mass with a histological picture of localized areas of myxomatous connective tissue. The present study adds 15 new cases of OFM to the literature and analyzes their clinical, histological and histochemical features. Most of the lesions were located in the gingiva and alveolar mucosa. The nature of the lesion is unclear and it is suggested that the mucinous accumulation is the result of fibroblastic overproduction of hyaluronic acid.

Adolescent↗

PubMed1990

Central (intraosseous) calcifying odontogenic cyst.

The central calcifying odontogenic cyst (CCOC) is an uncommon lesion. The present study reports 17 new cases of CCOC and analyses their clinical and histomorphologic features. The data revealed that CCOC were usually diagnosed in the second decade of life with an almost equal distribution between the maxilla and the mandible. Six of the 17 cases (35%) were associated with odontomas and 6 lesions (35%) were associated with unerupted teeth. Histologically, most of the lesions were unilocular cysts but at least one was multilocular and one was a mixed lesion - partially cystic and partially solid. Excision with long-term follow-up (up to 10 years) is the treatment of choice.

Adolescent↗

PubMed1990

Melanocytic nevi of the oral mucosa: a clinicopathologic study of 130 cases from northern California.

This paper presents analysis of data on 130 cases of oral melanocytic nevi from the files of the University of the Pacific, San Francisco and the University of California, San Francisco. This is the largest detailed series from one geographic location published to date. Nevi of the intramucosal type are the most common (63%) followed by the common blue nevus (19%). Compound nevi are uncommon (9%) and junctional nevi are rare (5%). Combined nevi are the rarest type (4%). The data are analyzed as to the location, presence of clinical pigmentation, configuration, and size of the nevi, as well as the patient's age, gender and race. Because the malignant potential of oral nevi is still uncertain and because preexisting macular pigmentation is present in about one third of all patients with oral melanoma, it is advisable to remove all pigmented lesions suspected to be melanocytic nevi.

Adolescent↗

PubMed1990

Oral intravascular papillary endothelial hyperplasia.

Intravascular papillary endothelial hyperplasia (IPEH) is usually a cutaneous lesion thought to represent a peculiar manifestation of an organizing thrombus. IPEH can be subdivided into a pure form that occurs within a dilated vascular space and a mixed form that appears as a focal change within a preexisting vascular lesion, such as hemangioma. The principle significance of the lesion lies in the fact that it may be mistaken for angiosarcoma. Oral lesions are uncommon and the present paper reports on 16 new cases of oral IPEH, analyzing their clinical and histomorphologic features. Histologically, 11 lesions appeared in a pure form and 5 lesions in a mixed form. Thrombi were detected in all but one case. The most common location was the lip, followed in decreasing frequency by the tongue and buccal mucosa. Local excision was the treatment of choice.

Adult↗