Ömer Günhan

Bio: Ömer Günhan is an academic researcher from Military Medical Academy. The author has contributed to research in topics: Ameloblastoma & Carcinoma. The author has an hindex of 27, co-authored 225 publications receiving 3104 citations. Previous affiliations of Ömer Günhan include Ankara University.

Odontogenic tumours. A series of 409 cases

Abstract: Reports on the incidence of odontogenic tumours are infrequent with only a limited number of series having appeared in the literature. In this paper, the results of a multicentre retrospective study on the histologic types and relative frequencies of odontogenic tumours in Turkey are presented. The results indicated that the most frequent histologic type was ameloblastoma (36.5 per cent) and the area at greatest risk for the development of odontogenic tumours was the mandibular molar region. A Table showing the most likely type of tumour by location is also presented.

Jaw bone changes in rats after treatment with zoledronate and pamidronate

Abstract: Objective The aim of this study was to histopathologically evaluate the effects of pamidronate and zoledronate on the mandible in an animal model. Study design Sixty female Sprague-Dawley rats were used in this study. Animals were divided into 6 groups (10 per group): control-1 (C1), injected with saline solution for 6 weeks; zoledronate-1 (ZA1), injected with zoledronate for 6 weeks; pamidronate-1 (PA1), injected with pamidronate for 6 weeks; control-2 (C2), injected with saline solution for 8 weeks; zoledronate-2 (ZA2), injected with zoledronate for 8 weeks; and pamidronate-2 (PA2), injected with pamidronate for 8 weeks. No dental procedures were performed on the animals. Rats were killed 2 days after the end of drug therapy, and the posterior and anterior mandible and femur of each rat were evaluated histopathologically. Results Histological examination revealed inflammation limited to the posterior mandible of the ZA2 and PA2 groups; the anterior mandible and femur were not affected. Soft tissue necrosis was evident in one rat in the ZA2 group. Conclusion Specific, bisphosphonate-asociated inflammatory bony and soft tissue changes were observed in the mandible, suggesting that these drugs may set the stage for altered healing associated with the development of bisphosphonate-related osteonecrosis of the jaw.

Management of Helicobacter pylori infection—the Maastricht V/Florence Consensus Report

Abstract: Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Androgens and bone

Abstract: Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. Such androgen action on bone is mediated by the AR and ERalpha.