Malignant transformation in odontogenic keratocysts. Case report.

Squamous cell carcinoma arising in the epithelial lining of an odontogenic keratocyst is a rare finding. Up to now, only 12 cases have been reported in the literature. The present work reports a new case diagnosed in a 70 year old man. The clinical, radiographic, and histopathological findings and the treatment are described.

Scientific presentations and publications on odontological research in Argentina.

The results of odontological research which are presented at the annual meetings of the Argentine Division of the International Association for Dental Research (A.D.I.A.D.R.) are proof of the scientific production of this country in this area. An analysis of the presentations allows for the quantitative evaluation of the activity of the area. A deeper appraisal of the reality of research, involves the analysis of quality and publication efficiency. A useful indicator is the relationship between the quantity of the presentations and subsequent publications (Publ./Pres. Ratio) in Journals with peer review. In 1990, the authorities of the Division presented an evaluation of the 10 previous years (Acta Odont. Latinoamer. 7(2):39-46, 1993). The current Board of Directors has considered timely to update that information. With this aim in mind the presentations at A.D.I.A.D.R. over the period 1990-1995 were considered. Employing the authors index of the A.D.I.A.D.R. meeting we searched for possible publications in Medline. The references were compared with the data from the presentations, disregarding those which had not been communicated previously in the Division. The data obtained were grouped according to Research Center and subject area. The Publ./Pres. Ratio was calculated. The time to publication and language of publication were considered. Of a total of 506 presentations, 61 were published, Ratio Publ./Pres. 1:8 (12%). Considering each Center individually the ratio was 1:6 for the University of Buenos Aires (UBA), 1:13 for the National University of Córdoba (UNC), 1:3 for the National University of La Plata (UNLP) and 1:2 for the National University of Rosario (UNR). There were no records of publications from the National Universities of Tucumán and of the North-East. The groups of investigation with greater quantity of presentations and better Publ./Pres. Ratio were Dental Mat./Restorative Dent./Endod. (ratio 1:8), Physiol./Pharmacol./Biochem. (Ratio 1:4) and Oral Pathol. (Ratio 1:4) of UBA, and Physiol./Pharmacol. (Ratio 1:1) of UNC. Most of the publications were in English (86%) and within 4 years of presentation. The current Publ./Pres. Ratios are similar to those communicated in 1990 in the area of the basic investigation and represent acceptable values. An increase in this proportion is expected in the future especially in the area of applied clinical research, since publication would imply prior peer review and thus qualitative evaluation of the work.

Impairment of molar tooth eruption caused by x-radiation.

The effect of x-radiation on erupting molars is presented. New born, 5 day old Wistar rats were locally irradiated in the molar area with doses of 20 Gy. They were killed in two groups, 30 and 60 days postirradiation respectively. Two other groups of non irradiated, age matched rats were killed at the given times. In addition a control group of 5 day old animals was also studied. Radiographic and histologic studies were performed. Odontoblastic atrophy, odontodysplasia, rootless formation, and ankylosis of tooth to bone by osteodentin formation with the resulting lack of tooth eruption were observed. The relation between the histologic alterations and tooth eruption is discussed.

Bone growth is impaired by uranium intoxication.

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2% and at 4%--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Bone growth is impaired by uranium intoxication.

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2

and at 4

--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Bone growth is impaired by uranium intoxication

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2

and at 4

--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Scientific presentations and their publication. Experience over a 10-year period in the Argentine Division of the I.A.D.R.

At present the "Impact Factor" developed by the Scientific Information Institute (Philadelphia), is an indicator of the quality of the journals in terms of the quality of the papers which are published. The results of odontological research which are presented and discussed at the annual meetings of the DAAIIO are proof of the quality and quantity of scientific production in this area in Argentina. Presentations are undoubtedly numerous. However, their diffusion and qualitative evaluation are of utmost importance. One way to estimate these parameters would be to monitor the ratio between number of presentations and their publication as full papers in journals with a system of referees (Ratio Publ./Pres.). With this aim in mind the presentations at DAAIIO over the 1980-1989 period were considered. Employing the author index of the DAAIIO meetings, we searched for possible publications in the Index Dental and the Index Medicus. The references were compared with the results presented to disregard publications which had not been previously presented at DAAIIO meetings. The data obtained were grouped according to subject area and Research Center. A total of 747 presentations led to 94 publications, the Publ./Pres. Ratio being 1/8 (12.5%). The ratio for each research center was the following: Univ. Buenos Aires 1/7; Natl. Univ. La Plata 1/8; Natl. Univ. Córdoba 1/15. The research groups with the highest publication ratios were Dent. Mat., Natl. Univ. La Plata 1/3; Clinical Pathol., Univ. Bs. As. 1/4; Oral Pathol., Univ. Bs. As. 1/4; Physiol. and Pharmacol., Univ. Bs. As. 1/4; Natl. Univ. Córdoba 1/7. The majority of the publications within 2 years of presentation were in English (69%). These results suggest that an acceptable number of presentations are published, particularly in the area of basic research. We should hope for an increase in the publication/presentation ratio in the future, particularly in the area of applied clinical research since publication would imply technical-scientific quality evaluation of the work by the experts who condition publication.

Scientific presentations and their publication. Experience over a 10-year period in the Argentine Division of the I.A.D.R.

At present the [quot ]Impact Factor[quot ] developed by the Scientific Information Institute (Philadelphia), is an indicator of the quality of the journals in terms of the quality of the papers which are published. The results of odontological research which are presented and discussed at the annual meetings of the DAAIIO are proof of the quality and quantity of scientific production in this area in Argentina. Presentations are undoubtedly numerous. However, their diffusion and qualitative evaluation are of utmost importance. One way to estimate these parameters would be to monitor the ratio between number of presentations and their publication as full papers in journals with a system of referees (Ratio Publ./Pres.). With this aim in mind the presentations at DAAIIO over the 1980-1989 period were considered. Employing the author index of the DAAIIO meetings, we searched for possible publications in the Index Dental and the Index Medicus. The references were compared with the results presented to disregard publications which had not been previously presented at DAAIIO meetings. The data obtained were grouped according to subject area and Research Center. A total of 747 presentations led to 94 publications, the Publ./Pres. Ratio being 1/8 (12.5

). The ratio for each research center was the following: Univ. Buenos Aires 1/7; Natl. Univ. La Plata 1/8; Natl. Univ. Córdoba 1/15. The research groups with the highest publication ratios were Dent. Mat., Natl. Univ. La Plata 1/3; Clinical Pathol., Univ. Bs. As. 1/4; Oral Pathol., Univ. Bs. As. 1/4; Physiol. and Pharmacol., Univ. Bs. As. 1/4; Natl. Univ. Córdoba 1/7. The majority of the publications within 2 years of presentation were in English (69

). These results suggest that an acceptable number of presentations are published, particularly in the area of basic research. We should hope for an increase in the publication/presentation ratio in the future, particularly in the area of applied clinical research since publication would imply technical-scientific quality evaluation of the work by the experts who condition publication.

Scientific presentations and their publication. Experience over a 10-year period in the Argentine Division of the I.A.D.R

At present the [quot ]Impact Factor[quot ] developed by the Scientific Information Institute (Philadelphia), is an indicator of the quality of the journals in terms of the quality of the papers which are published. The results of odontological research which are presented and discussed at the annual meetings of the DAAIIO are proof of the quality and quantity of scientific production in this area in Argentina. Presentations are undoubtedly numerous. However, their diffusion and qualitative evaluation are of utmost importance. One way to estimate these parameters would be to monitor the ratio between number of presentations and their publication as full papers in journals with a system of referees (Ratio Publ./Pres.). With this aim in mind the presentations at DAAIIO over the 1980-1989 period were considered. Employing the author index of the DAAIIO meetings, we searched for possible publications in the Index Dental and the Index Medicus. The references were compared with the results presented to disregard publications which had not been previously presented at DAAIIO meetings. The data obtained were grouped according to subject area and Research Center. A total of 747 presentations led to 94 publications, the Publ./Pres. Ratio being 1/8 (12.5

). The ratio for each research center was the following: Univ. Buenos Aires 1/7; Natl. Univ. La Plata 1/8; Natl. Univ. Córdoba 1/15. The research groups with the highest publication ratios were Dent. Mat., Natl. Univ. La Plata 1/3; Clinical Pathol., Univ. Bs. As. 1/4; Oral Pathol., Univ. Bs. As. 1/4; Physiol. and Pharmacol., Univ. Bs. As. 1/4; Natl. Univ. Córdoba 1/7. The majority of the publications within 2 years of presentation were in English (69

). These results suggest that an acceptable number of presentations are published, particularly in the area of basic research. We should hope for an increase in the publication/presentation ratio in the future, particularly in the area of applied clinical research since publication would imply technical-scientific quality evaluation of the work by the experts who condition publication.

Mandibular growth and tooth eruption after localized x-radiation.

The effect of localized x-radiation on the growth of mandibular bone and molar eruption was evaluated by morphometric methods. A dose of 20 Gy of x-radiation was given to the molar zone of growing rats. The animals were then killed in groups at 30 and 60 days postirradiation. Two groups of nonirradiated, age-matched rats were used as controls. Parameters related to molar eruption, mandibular length, and mandibular height were measured on lateral radiographs. The results obtained showed that the values of the biometric parameters were lower in experimental than in control animals. Odontoblastic atrophy, alveolodentary ankylosis, and meager or no root formation were the most conspicuous histologic findings. Osteodentin was found between canaliculary dentin and bone in cases of ankylosis. The morphometric data presented confirm the probability of alterations in mandibular growth and tooth eruption following x-radiation and suggest that this be considered in planning radiotherapy in children.